Video
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Contents Articles Video
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High-definition television
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Video compression
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H.264/MPEG-4 AVC
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MPEG-4
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Display resolution
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Pixel density
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Image resolution
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AVCHD
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High-definition video
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References Article Sources and Contributors
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Image Sources, Licenses and Contributors
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Article Licenses License
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Video
Video Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.
History Video technology was first developed for cathode ray tube (CRT) television systems, but several new technologies for video display devices have since been invented. Charles Ginsburg led an Ampex research team developing the first practical video tape recorder (VTR). In 1951 the first video tape recorder captured live images from television cameras by converting the camera's electrical impulses and saving the information onto magnetic video tape. This tape was sold for around $50,000 in 1956. Sony began selling videocassette recorder (VCR) tapes to the public in 1971. Later advances in computer technology have allowed computers to capture, store, edit and transmit video clips. After the invention of the DVD in 1997 and Blu-ray Disc in 2006, sales of video tape and tape equipment plummeted.
Description of video The term video ("video" meaning "I see", from the Latin verb "videre") commonly refers to several storage formats for moving pictures: digital video formats, including Blu-ray Disc, DVD, QuickTime (QT), and MPEG-4; and analog videotapes, including VHS and Betamax. Video can be recorded and transmitted in various physical media: in magnetic tape when recorded as PAL or NTSC electric signals by video cameras, or Analog video standards worldwide NTSC PAL or switching to PAL SECAM in MPEG-4 or DV digital media when No information recorded by digital cameras. Quality of video essentially depends on the capturing method and storage used. Digital television (DTV) is a relatively recent format with higher quality than earlier television formats and has become a standard for television video. (See List of digital television deployments by country.) 3D-video, digital video in three dimensions, premiered at the end of 20th century. Six or eight cameras with realtime depth measurement are typically used to capture 3D-video streams. The format of 3D-video is fixed in MPEG-4 Part 16 Animation Framework eXtension (AFX). In many countries, the term video is often used informally to refer to both Videocassette recorders and video cassettes; the meaning is normally clear from the context.
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Characteristics of video streams Number of frames per second Frame rate, the number of still pictures per unit of time of video, ranges from six or eight frames per second (frame/s) for old mechanical cameras to 120 or more frames per second for new professional cameras. PAL (Europe, Asia, Australia, etc.) and SECAM (France, Russia, parts of Africa etc.) standards specify 25 frame/s, while NTSC (USA, Canada, Japan, etc.) specifies 29.97 frame/s. Film is shot at the slower frame rate of 24photograms/s, which complicates slightly the process of transferring a cinematic motion picture to video. The minimum frame rate to achieve the illusion of a moving image is about fifteen frames per second.
Interlacing Video can be interlaced or progressive. Interlacing was invented as a way to achieve good visual quality within the limitations of a narrow bandwidth. The horizontal scan lines of each interlaced frame are numbered consecutively and partitioned into two fields: the odd field (upper field) consisting of the odd-numbered lines and the even field (lower field) consisting of the even-numbered lines. NTSC, PAL and SECAM are interlaced formats. Abbreviated video resolution specifications often include an i to indicate interlacing. For example, PAL video format is often specified as 576i50, where 576 indicates the vertical line resolution, i indicates interlacing, and 50 indicates 50 fields (half-frames) per second. In progressive scan systems, each refresh period updates all of the scan lines. The result is a higher spatial resolution and a lack of various artifacts that can make parts of a stationary picture appear to be moving or flashing. A procedure known as deinterlacing can be used for converting an interlaced stream, such as analog, DVD, or satellite, to be processed by progressive scan devices, such as Liquid crystal display television TFT LCD Television sets, projectors, and plasma panels. Deinterlacing cannot, however, produce a video quality that is equivalent to true progressive scan source material.
Display resolution The size of a video image is measured in pixels for digital video, or horizontal scan lines and vertical lines of resolution for analog video. In the digital domain (e.g. DVD) standard-definition television (SDTV) is specified as 720/704/640×480i60 for NTSC and 768/720×576i50 for PAL or SECAM resolution. However in the analog domain, the number of visible scanlines remains constant (486 NTSC/576 PAL) while the horizontal measurement varies with the quality of the signal: approximately 320 pixels per scanline for VCR quality, 400 pixels for TV broadcasts, and 720 pixels for DVD sources. Aspect ratio is preserved because of non-square "pixels". New high-definition televisions (HDTV) are capable of resolutions up to 1920×1080p60, i.e. 1920 pixels per scan line by 1080 scan lines, progressive, at 60 frames per second.
Common computer and TV display resolutions.
Video resolution for 3D-video is measured in voxels (volume picture element, representing a value in three dimensional space). For example 512×512×512 voxels resolution, now used for simple 3D-video, can be displayed even on some PDAs.
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Aspect ratio Aspect ratio describes the dimensions of video screens and video picture elements. All popular video formats are rectilinear, and so can be described by a ratio between width and height. The screen aspect ratio of a traditional television screen is 4:3, or about 1.33:1. High definition televisions use an aspect ratio of 16:9, or about 1.78:1. The aspect ratio of a full 35 mm film frame with soundtrack (also known as the Academy ratio) is 1.375:1.
Comparison of common cinematography and traditional television (green) aspect ratios.
Ratios where the height is taller than the width are uncommon in general everyday use, but do have application in computer systems where the screen may be better suited for a vertical layout. The most common tall aspect ratio of 3:4 is referred to as portrait mode and is created by physically rotating the display device 90 degrees from the normal position. Other tall aspect ratios such as 9:16 are technically possible but rarely used. (For a more detailed discussion of this topic please refer to the page orientation article.) Pixels on computer monitors are usually square, but pixels used in digital video often have non-square aspect ratios, such as those used in the PAL and NTSC variants of the CCIR 601 digital video standard, and the corresponding anamorphic widescreen formats. Therefore, an NTSC DV image which is 720 pixels by 480 pixels is displayed with the aspect ratio of 4:3 (which is the traditional television standard) if the pixels are thin and displayed with the aspect ratio of 16:9 (which is the anamorphic widescreen format) if the pixels are fat.
Color space and bits per pixel Color model name describes the video color representation. YIQ was used in NTSC television. It corresponds closely to the YUV scheme used in NTSC and PAL television and the YDbDr scheme used by SECAM television. The number of distinct colors that can be represented by a pixel depends on the number of bits per pixel (bpp). A common way to reduce the number of bits per pixel in digital video is by chroma subsampling (e.g. 4:4:4, 4:2:2, 4:2:0/4:1:1).
Video quality Video quality can be measured with formal metrics like PSNR or with subjective video quality using expert observation. The subjective video quality of a video processing system may be evaluated as follows: • • • • •
Example of U-V color plane, Y value=0.5
Choose the video sequences (the SRC) to use for testing. Choose the settings of the system to evaluate (the HRC). Choose a test method for how to present video sequences to experts and to collect their ratings. Invite a sufficient number of experts, preferably not fewer than 15. Carry out testing.
• Calculate the average marks for each HRC based on the experts' ratings.
Video Many subjective video quality methods are described in the ITU-T recommendation BT.500. One of the standardized method is the Double Stimulus Impairment Scale (DSIS). In DSIS, each expert views an unimpaired reference video followed by an impaired version of the same video. The expert then rates the impaired video using a scale ranging from "impairments are imperceptible" to "impairments are very annoying".
Video compression method (digital only) A wide variety of methods are used to compress video streams. Video data contains spatial and temporal redundancy, making uncompressed video streams extremely inefficient. Broadly speaking, spatial redundancy is reduced by registering differences between parts of a single frame; this task is known as intraframe compression and is closely related to image compression. Likewise, temporal redundancy can be reduced by registering differences between frames; this task is known as interframe compression, including motion compensation and other techniques. The most common modern standards are MPEG-2, used for DVD, Blu-ray and satellite television, and MPEG-4, used for AVCHD, Mobile phones (3GP) and Internet.
Bit rate (digital only) Bit rate is a measure of the rate of information content in a video stream. It is quantified using the bit per second (bit/s or bps) unit or Megabits per second (Mbit/s). A higher bit rate allows better video quality. For example VideoCD, with a bit rate of about 1 Mbit/s, is lower quality than DVD, with maximum bit rate of 10.08 Mbit/s for video. HD (High Definition Digital Video and TV) has a still higher quality, with a bit rate of about 20 Mbit/s. Variable bit rate (VBR) is a strategy to maximize the visual video quality and minimize the bit rate. On fast motion scenes, a variable bit rate uses more bits than it does on slow motion scenes of similar duration yet achieves a consistent visual quality. For real-time and non-buffered video streaming when the available bandwidth is fixed, e.g. in videoconferencing delivered on channels of fixed bandwidth, a constant bit rate (CBR) must be used.
Stereoscopic Stereoscopic video can be created using several different methods: • two channels — a right channel for the right eye and a left channel for the left eye. Both channels may be viewed simultaneously by using light-polarizing filters 90 degrees off-axis from each other on two video projectors. These separately polarized channels are viewed wearing eyeglasses with matching polarization filters. • one channel with two overlaid color coded layers. This left and right layer technique is occasionally used for network broadcast, or recent "anaglyph" releases of 3D movies on DVD. Simple Red/Cyan plastic glasses provide the means to view the images discretely to form a stereoscopic view of the content. • One channel with alternating left/right frames for each eye, using LCD shutter glasses which read the frame sync from the VGA Display Data Channel to alternately cover each eye, so the appropriate eye sees the correct frame. This method is most common in computer virtual reality applications such as in a Cave Automatic Virtual Environment, but reduces the effective video framerate to one-half of normal (for example, from 120 Hz to 60 Hz). Blu-ray Discs greatly improve the sharpness and detail of the two-color 3D effect in color coded stereo programs. See articles Stereoscopy and 3-D film.
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Video formats There are different layers of video transmission and storage, each with its own set of formats to choose from. For transmission, there is a physical connector and signal protocol ("video connection standard" below). A given physical link can carry certain "display standards" which specify a particular refresh rate, display resolution, and color space. Many analog and digital recording formats are in use, and digital video clips can also be stored on a computer file system as files which have their own formats. In addition to the physical format used by the data storage device or transmission medium, the stream of ones and zeros that is sent must be in a particular digital "video encoding", of which a number are available.
Video connectors, cables, and signal standards • See List of video connectors for information about physical connectors and related signal standards.
Video display standards Further information: Display technology Digital television Further information: Broadcast television systems New formats for digital television broadcasts use the MPEG-2 video codec and include: • ATSC - USA, Canada, Korea • Digital Video Broadcasting (DVB) - Europe • ISDB - Japan • ISDB-Tb - Uses the MPEG-4 video codec. Brazil, Peru • Digital Multimedia Broadcasting (DMB) - Korea Analog television Further information: Broadcast television systems Analog television broadcast standards include: • • • • •
FCS - USA, Russia; obsolete MAC - Europe; obsolete MUSE - Japan NTSC - USA, Canada, Japan PAL - Europe, Asia, Oceania
• PAL-M - PAL variation. Brazil • PALplus - PAL extension, Europe • RS-343 (military) • SECAM - France, Former Soviet Union, Central Africa An analog video format consists of more information than the visible content of the frame. Preceding and following the image are lines and pixels containing synchronization information or a time delay. This surrounding margin is known as a blanking interval or blanking region; the horizontal and vertical front porch and back porch are the building blocks of the blanking interval. Many countries are planning a digital switchover soon.
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Computer displays See Computer display standard for a list of standards used for computer monitors and comparison with those used for television.
Recording formats before video tape • Phonovision • Kinescope
Analog tape formats • • • • • • • •
1" Type B video tape (Robert Bosch GmbH]) 1" Type C videotape (Ampex and Sony) 2" Quadruplex videotape (Ampex) Betacam (Sony) Betacam SP (Sony) Betamax (Sony) S-VHS (JVC) (1987) W-VHS (JVC) (1994)
• • • • • •
U-matic 3/4" (Sony) VCR, VCR-LP, SVR VERA (BBC experimental format ca. 1958) VHS (JVC) VHS-C (JVC) Video 2000 (Philips)
(See List of video recording formats.)
Digital tape formats • • • • • • • • • • • • • • •
Betacam IMX (Sony) D-VHS (JVC) D-Theater D1 (Sony) D2 (Sony) D3 D5 HD Digital-S D9 (JVC) Digital Betacam (Sony) Digital8 (Sony) DV HDV ProHD (JVC) MicroMV MiniDV
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Optical disc storage formats • • • • •
Blu-ray Disc (Sony) China Blue High-definition Disc (CBHD) DVD (was Super Density Disc, DVD Forum) Professional Disc Universal Media Disc (UMD) (Sony)
Discontinued • • • •
Enhanced Versatile Disc (EVD, Chinese government-sponsored) HD DVD (NEC and Toshiba) HD-VMD Laserdisc (old, MCA and Philips)
Digital encoding formats • CCIR 601 (ITU-T) • H.261 (ITU-T) • H.263 (ITU-T) • • • • • • •
H.264/MPEG-4 AVC (ITU-T + ISO) M-JPEG (ISO) MPEG-1 (ISO) MPEG-2 (ITU-T + ISO) MPEG-4 (ISO) Ogg-Theora VC-1 (SMPTE)
Standards • System M • System B
Display devices Display devices for showing videos are generally full-area (rather than segmented display), sometimes simply called video displays.
References External links • Video as Arts (http://www.dmoz.org/Arts/Video//) at the Open Directory Project • Video as Media Production (http://www.dmoz.org/Business/Arts_and_Entertainment/Media_Production/ Video//) at the Open Directory Project • Programmer's Guide to Video Systems: in-depth technical info on 480i, 576i, 1080i, 720p, etc. (http://lurkertech. com/lg/video-systems)
High-definition television
High-definition television High-definition television (or HDTV) is video that has resolution substantially higher than that of traditional television systems (standard-definition TV, or SDTV, or SD). HDTV has one or two million pixels per frame, roughly five times that of SD. Early HDTV broadcasting used analog techniques, but today HDTV is digitally broadcast using video compression. Some personal video recorders (PVRs) with hard disk storage but without high-definition tuners are described as "HD", for "Hard Disk", which can be a cause of confusion.
History of high-definition television Further information: Analog high-definition television system and History of television On 2 November 1936 the BBC began transmitting the world's first public regular high-definition service from the Victorian Alexandra Palace in north London.[1] It therefore claims to be the birthplace of television broadcasting as we know it today. The term high definition once described a series of television systems originating from the late 1930s; however, these systems were only high definition when compared to earlier systems that were based on mechanical systems as few as 30 lines of resolution. The British high definition TV service started trials in August 1936 and a regular service in November 1936 using both the (mechanical) Baird 240 line and (electronic) Marconi-EMI 405 line (377i) systems. The Baird system was discontinued in February 1937. In 1938 France followed with their own 441 line system, variants of which were also used by a number of other countries. The US NTSC system joined in 1941. In 1949 France introduced an even higher resolution standard at 819 lines (768i), a system that would be high definition even by today's standards, but it was monochrome only. All of these systems used interlacing and a 4:3 aspect ratio except the 240 line system which was progressive (actually described at the time by the technically correct term "sequential") and the 405 line system which started as 5:4 and later changed to 4:3. The 405 line system adopted the (at that time) revolutionary idea of interlaced scanning to overcome the flicker problem of the 240 line with its 25 Hz frame rate. The 240 line system could have doubled its frame rate but this would have meant that the transmitted signal would have doubled in bandwidth, an unacceptable option. Color broadcasts started at similarly higher resolutions, first with the US NTSC color system in 1953, which was compatible with the earlier B&W systems and therefore had the same 525 lines (480i) of resolution. European standards did not follow until the 1960s, when the PAL and SECAM colour systems were added to the monochrome 625 line (576i) broadcasts. Since the formal adoption of Digital Video Broadcasting's (DVB) widescreen HDTV transmission modes in the early 2000s the 525-line NTSC (and PAL-M) systems as well as the European 625-line PAL and SECAM systems are now regarded as standard definition television systems. In Australia, the 625-line digital progressive system (with 576 active lines) is officially recognized as high definition.[2]
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Analog systems In 1949, France started its transmissions with an 819 lines system (768i). It was monochrome only, it was used only on VHF for the first French TV channel, and it was discontinued in 1985. In 1958, the Soviet Union developed Тransformator (Russian: Трансформатор, Transformer), the first high-resolution (definition) television system capable of producing an image composed of 1,125 lines of resolution aimed at providing teleconferencing for military command. It was a research project and the system was never deployed in the military or broadcasting.[3] In 1979, the Japanese state broadcaster NHK first developed consumer high-definition television with a 5:3 display aspect ratio.[4] The system, known as Hi-Vision or MUSE after its Multiple sub-Nyquist sampling encoding for encoding the signal, required about twice the bandwidth of the existing NTSC system but provided about four times the resolution (1080i/1125 lines). Satellite test broadcasts started in 1989, with regular testing starting in 1991 and regular broadcasting of BS-9ch commenced on 25 November 1994, which featured commercial and NHK programming. In 1981, the MUSE system was demonstrated for the first time in the United States, using the same 5:3 aspect ratio as the Japanese system.[5] Upon visiting a demonstration of MUSE in Washington, US President Ronald Reagan was most impressed and officially declared it "a matter of national interest" to introduce HDTV to the USA.[6] Several systems were proposed as the new standard for the USA, including the Japanese MUSE system, but all were rejected by the FCC because of their higher bandwidth requirements. At this time, the number of television channels was growing rapidly and bandwidth was already a problem. A new standard had to be more efficient, needing less bandwidth for HDTV than the existing NTSC.
Demise of analog HD systems The limited standardization of analogue HDTV in the 1990s did not lead to global HDTV adoption as technical and economic reasons at the time did not permit HDTV to use bandwidths greater than normal television. Early HDTV commercial experiments such as NHK's MUSE required over four times the bandwidth of a standard-definition broadcast—and HD-MAC was not much better. Despite efforts made to reduce analog HDTV to about 2x the bandwidth of SDTV these television formats were still only distributable by satellite. In addition, recording and reproducing an HDTV signal was a significant technical challenge in the early years of HDTV (Sony HDVS). Japan remained the only country with successful public broadcasting analog HDTV, with seven broadcasters sharing a single channel. Digital HDTV broadcasting started in 2000 in Japan, and the analog service ended in the early hours of 1 October 2007.
Rise of digital compression Since 1972, International Telecommunication Union's radio telecommunications sector (ITU-R) has been working on creating a global recommendation for Analogue HDTV. These recommendations however did not fit in the broadcasting bands which could reach home users. The standardization of MPEG-1 in 1993 also led to the acceptance of recommendations ITU-R BT.709.[7] In anticipation of these standards the Digital Video Broadcasting (DVB) organisation was formed, an alliance of broadcasters, consumer electronics manufacturers and regulatory bodies. The DVB develops and agrees on specifications which are formally standardised by ETSI.[8] DVB created first the standard for DVB-S digital satellite TV, DVB-C digital cable TV and DVB-T digital terrestrial TV. These broadcasting systems can be used for both SDTV and HDTV. In the USA the Grand Alliance proposed ATSC as the new standard for SDTV and HDTV. Both ATSC and DVB were based on the MPEG-2 standard. The DVB-S2 standard is based on the newer and more efficient H.264/MPEG-4 AVC compression standards. Common for all DVB standards is the use of highly efficient modulation techniques for further reducing bandwidth, and foremost for reducing receiver-hardware and antenna requirements.
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High-definition television In 1983, the International Telecommunication Union's radio telecommunications sector (ITU-R) set up a working party (IWP11/6) with the aim of setting a single international HDTV standard. One of the thornier issues concerned a suitable frame/field refresh rate, the world already having split into two camps, 25/50 Hz and 30/60 Hz, related by reasons of picture stability to the frequency of their main electrical supplies. The IWP11/6 working party considered many views and through the 1980s served to encourage development in a number of video digital processing areas, not least conversion between the two main frame/field rates using motion vectors, which led to further developments in other areas. While a comprehensive HDTV standard was not in the end established, agreement on the aspect ratio was achieved. Initially the existing 5:3 aspect ratio had been the main candidate but, due to the influence of widescreen cinema, the aspect ratio 16:9 (1.78) eventually emerged as being a reasonable compromise between 5:3 (1.67) and the common 1.85 widescreen cinema format. (Bob Morris explained that the 16:9 ratio was chosen as being the geometric mean of 4:3, Academy ratio, and 2.4:1, the widest cinema format in common use, in order to minimize wasted screen space when displaying content with a variety of aspect ratios.[9] ) An aspect ratio of 16:9 was duly agreed at the first meeting of the IWP11/6 working party at the BBC's Research and Development establishment in Kingswood Warren. The resulting ITU-R Recommendation ITU-R BT.709-2 ("Rec. 709") includes the 16:9 aspect ratio, a specified colorimetry, and the scan modes 1080i (1,080 actively interlaced lines of resolution) and 1080p (1,080 progressively scanned lines). The British Freeview HD trials used MBAFF, which contains both progressive and interlaced content in the same encoding. It also includes the alternative 1440×1152 HDMAC scan format. (According to some reports, a mooted 750-line (720p) format (720 progressively scanned lines) was viewed by some at the ITU as an enhanced television format rather than a true HDTV format,[10] and so was not included, although 1920×1080i and 1280×720p systems for a range of frame and field rates were defined by several US SMPTE standards.)
Inaugural HDTV broadcast in the United States HDTV technology was introduced in the United States in the 1990s by the Digital HDTV Grand Alliance, a group of television, electronic equipment, communications companies and the Massachusetts Institute of Technology.[11] [12] Field testing of HDTV at 199 sites in the United States was completed August 14, 1994.[13] The first public HDTV broadcast in the United States occurred on July 23, 1996 when the Raleigh, North Carolina television station WRAL-HD began broadcasting from the existing tower of WRAL-TV south-east of Raleigh, winning a race to be first with the HD Model Station in Washington, D.C., which began broadcasting July 31, 1996 with the callsign WHD-TV, based out of the facilities of NBC owned and operated station WRC-TV.[14] [15] [16] The American Advanced Television Systems Committee (ATSC) HDTV system had its public launch on October 29, 1998, during the live coverage of astronaut John Glenn's return mission to space on board the Space Shuttle Discovery.[17] The signal was transmitted coast-to-coast, and was seen by the public in science centers, and other public theaters specially equipped to receive and display the broadcast.[17] [18]
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European HDTV broadcasts Although HDTV broadcasts had been demonstrated in Europe since the early 1990s, the first regular broadcasts started on January 1, 2004 when the Belgian company Euro1080 launched the HD1 channel with the traditional Vienna New Year's Concert. Test transmissions had been active since the IBC exhibition in September 2003, but the New Year's Day broadcast marked the official start of the HD1 channel, and the start of HDTV in Europe.[19] Euro1080, a division of the Belgian TV services company Alfacam, broadcast HDTV channels to break the pan-European stalemate of "no HD broadcasts mean no HD TVs bought means no HD broadcasts..." and kick-start HDTV interest in Europe.[20] The HD1 channel was initially free-to-air and mainly comprised sporting, dramatic, musical and other cultural events broadcast with a multi-lingual soundtrack on a rolling schedule of 4 or 5 hours per day. These first European HDTV broadcasts used the 1080i format with MPEG-2 compression on a DVB-S signal from SES Astra's 1H satellite. Euro1080 transmissions later changed to MPEG-4/AVC compression on a DVB-S2 signal in line with subsequent broadcast channels in Europe. The number of European HD channels and viewers has risen steadily since the first HDTV broadcasts, with SES Astra's annual Satellite Monitor market survey for 2010 reporting more than 200 commercial channels broadcasting in HD from Astra satellites, 185 million HD-Ready TVs sold in Europe (£60 million in 2010 alone), and 20 million households (27% of all European digital satellite TV homes) watching HD satellite broadcasts (16 million via Astra satellites).[21] In December 2009 the United Kingdom became the first European country to deploy high definition content on digital terrestrial television (branded as Freeview) using the new DVB-T2 transmission standard as specified in the Digital TV Group (DTG) D-book. The Freeview HD service currently contains 4 HD channels and is now rolling out region by region across the UK in accordance with the digital switchover process. Some transmitters such as the Crystal Palace and Emley Moor transmitters are broadcasting the Freeview HD service ahead of the digital switchover by means of a temporary, low-power pre-DSO multiplex.
Notation HDTV broadcast systems are identified with three major parameters: • Frame size in pixels is defined as number of horizontal pixels × number of vertical pixels, for example 1280 × 720 or 1920 × 1080. Often the number of horizontal pixels is implied from context and is omitted, as in the case of 720p and 1080p. • Scanning system is identified with the letter p for progressive scanning or i for interlaced scanning. • Frame rate is identified as number of video frames per second. For interlaced systems an alternative form of specifying number of fields per second is often used. If all three parameters are used, they are specified in the following form: [frame size][scanning system][frame or field rate] or [frame size]/[frame or field rate][scanning system]. Often, frame size or frame rate can be dropped if its value is implied from context. In this case the remaining numeric parameter is specified first, followed by the scanning system. For example, 1920×1080p25 identifies progressive scanning format with 25 frames per second, each frame being 1,920 pixels wide and 1,080 pixels high. The 1080i25 or 1080i50 notation identifies interlaced scanning format with 25 frames (50 fields) per second, each frame being 1,920 pixels wide and 1,080 pixels high. The 1080i30 or 1080i60 notation identifies interlaced scanning format with 30 frames (60 fields) per second, each frame being 1,920 pixels wide and 1,080 pixels high. The 720p60 notation identifies progressive scanning format with 60 frames per second, each frame being 720 pixels high; 1,280 pixels horizontally are implied. 50 Hz systems support three scanning rates: 25i, 25p and 50p. 60 Hz systems support a much wider set of frame rates: 23.976p, 24p, 29.97i/59.94i, 29.97p, 30p, 59.94p and 60p. In the days of standard definition television, the
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fractional rates were often rounded up to whole numbers, e.g. 23.976p was often called 24p, or 59.94i was often called 60i. 60 Hz high definition television supports both fractional and slightly different integer rates, therefore strict usage of notation is required to avoid ambiguity. Nevertheless, 29.97i/59.94i is almost universally called 60i, likewise 23.976p is called 24p. For commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames per second.[22] There is no standard for HDTV color support. Until recently the color of each pixel was regulated by three 8-bit color values, each representing the level of red, blue, and green which defined a pixel color. Together the 24 total bits defining color yielded just under 17 million possible pixel colors. Recently some manufacturers have produced systems that can employ 10 bits for each color (30 bits total) which provides for a palette of 1 billion colors, saying that this provides a much richer picture, but there is no agreed way to specify that a piece of equipment supports this feature. Human vision can only discern approximately 1 million colors so an expanded color palette is of questionable benefit to consumers. Most HDTV systems support resolutions and frame rates defined either in the ATSC table 3, or in EBU specification. The most common are noted below.
High-definition display resolutions Video format Native supported [image resolution resolution] [inherent resolution] (W×H)
Pixels
720p 1280×720
1024×768 XGA
786,432
0.8
4:3
4:3
Typically a PC resolution (XGA); also a native resolution on many entry-level plasma displays with non-square pixels.
1280×720
921,600
0.9
16:9
1:1
Standard HDTV resolution and a typical PC resolution (WXGA), frequently used by high-end video projectors; also used for 750-line video, as defined in SMPTE 296M, ATSC A/53, ITU-R BT.1543.
1366×768 WXGA
1,049,088 1.0
683:384 (approx. 16:9)
1:1
A typical PC resolution (WXGA); also used by many HD ready TV displays based on LCD technology.
1920×1080
2,073,600 2.1
16:9
1:1
Standard HDTV resolution, used by Full HD and HD ready 1080p TV displays such as high-end LCD, Plasma and rear projection TVs, and a typical PC resolution (lower than WUXGA); also used for 1125-line video, as defined in SMPTE 274M, ATSC A/53, ITU-R BT.709;
1080p/1080i 1920×1080
Actual
Aspect ratio (W:H) Advertised (Mpixel)
Image
Description
Pixel
High-definition television
Video format supported
Screen resolution (W×H)
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Pixels
Actual
Aspect ratio (W:H) Advertised (Mpixel)
Image
Description
Pixel
720p 1780×956
1780×956 Clean Aperture
876,096
0.9
16:9
1:1
Used for 750-line video with faster artifact/overscan compensation, as defined in SMPTE 296M.
1080p 1920×1080
1888×1062 Clean aperture
2,005,056 2.0
16:9
1:1
Used for 1125-line video with faster artifact/overscan compensation, as defined in SMPTE 274M.
1080i 1920×1080
1440×1080 HDCAM/HDV
1,555,200 1.6
16:9
4:3
Used for anamorphic 1125-line video in the HDCAM and HDV formats introduced by Sony and defined (also as a luminance subsampling matrix) in SMPTE D11.
Standard frame or field rates • • • • • • • •
23.976 Hz (film-looking frame rate compatible with NTSC clock speed standards) 24 Hz (international film and ATSC high definition material) 25 Hz (PAL, SECAM film, standard definition, and high definition material) 29.97 Hz (NTSC standard definition material) 50 Hz (PAL & SECAM high definition material) 59.94 Hz (ATSC high definition material) 60 Hz (ATSC high definition material) 120 Hz (ATSC high definition material)
At a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or anamorphic stretching, thus increasing the effective image resolution. The optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. The field and frame rate should match the source and the resolution. A very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed source. There is widespread confusion in the use of the terms PAL, SECAM and NTSC when referring to HD material. These terms apply only to standard definition television, not HD. The only technical reason for keeping 25 Hz as the HD frame rate in a former PAL country is to maintain compatibility between HD and standard definition television systems.
Types of media Standard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate of 25 frame/s, causing a speedup of 4.1 percent, which is generally considered acceptable. In NTSC-system countries, the TV scan rate of 30 frame/s would cause a perceptible speedup if the same were attempted, and the necessary correction is performed by a technique called 3:2 Pulldown: Over each successive pair of film frames, one is held for three video fields (1/20 of a second) and the next is held for two video fields (1/30 of a second), giving a total time for the two frames of 1/12 of a second and thus achieving the correct average film frame rate.
High-definition television Non-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode. 720p also imposes less strenuous storage and decoding requirements compared to both 1080i and 1080p. 1080p-24 frame/s and 1080i-30 frame/s is most often used on Blu-ray Disc; as of 2011, there is still no disc that can support full 1080p-60 frame/s.
Contemporary systems Besides an HD-ready television set, other equipment may be needed to view HD television. In the US, Cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD.[23] High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV, the high definition Blu-ray video disc (BD), internet downloads. Sony's Playstation 3 has extensive HD compatibility because of the Blu-ray platform, so does Microsoft's Xbox 360 with the addition of Netflix streaming capabilities, and the Zune marketplace where users can rent or purchase digital HD content.[24] The HD capabilities of the consoles has influenced some developers to port games from past consoles onto the PS3 and 360, often with remastered graphics.
Recording and compression HDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD recorders), or an HDTV-ready HTPC. Some cable boxes are capable of receiving or recording two or more broadcasts at a time in HDTV format, and HDTV programming, some free, some for a fee, can be played back with the cable company's on-demand feature. The massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available in the consumer market until recently. In 2008 the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component video inputs and stores the content in an uncompressed MPEG transport stream (.ts) file or Blu-ray format .m2ts file on the hard drive or DVD burner of a computer connected to the PVR through a USB 2.0 interface. Realtime MPEG-2 compression of an uncompressed digital HDTV signal is prohibitively expensive for the consumer market at this time, but should become inexpensive within several years (although this is more relevant for consumer HD camcorders than recording HDTV). Analog tape recorders with bandwidth capable of recording analog HD signals such as W-VHS recorders are no longer produced for the consumer market and are both expensive and scarce in the secondary market. In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" Firewire (IEEE 1394) upon request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes, but some cable TV companies have. As of July 2004, boxes are not included in the FCC mandate. This content is protected by encryption known as 5C.[25] This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all fair use of the content.
14
High-definition television
Notes [1] "Teletronic – The Television History Site" (http:/ / www. teletronic. co. uk/ tvera. htm). Teletronic.co.uk. . Retrieved 2011-08-30. [2] "SBS jubilant with its 576p HD broadcasts" (http:/ / www. broadcastandmedia. com/ articles/ ff/ 0c0276ff. asp). . [3] "HDTV in the Russian Federation: problems and prospects of implementation (in Russian)" (http:/ / rus. 625-net. ru/ 625/ 2007/ 01/ tvch. htm). . [4] "Researchers Craft HDTV's Successor" (http:/ / www. pcworld. com/ article/ id,132289-c,hdtv/ article. html). . [5] "Digital TV Tech Notes, Issue #2" (http:/ / www. tech-notes. tv/ Archive/ tech_notes_002. htm). . [6] James Sudalnik and Victoria Kuhl, "High definition television" [7] "High definition television comes of age thanks to ITU" (http:/ / www. itu. int/ ITU-R/ index. asp?category=information& link=hdtv-25& lang=en). . [8] "History of the DVB Project" (http:/ / www. dvb. org/ about_dvb/ history/ ). . [9] Bob Morris (2003-07-13). "[news:morris.1058102022@albireo.sce.carleton.ca The true origins of the 16:9 HDTV aspect ratio!]". [news:rec.arts.movies.tech rec.arts.movies.tech]. (Web link) (http:/ / groups. google. com/ group/ rec. arts. movies. tech/ msg/ 9e7d2e0a5971a988). Retrieved 2010-01-16. [10] "Digital TV Tech Notes, Issue #41" (http:/ / www. tech-notes. tv/ Archive/ tech_notes_041. htm). . [11] The Grand Alliance includes AT&T Bell Labs, General Instrument, MIT, Philips, Sarnoff, Thomson, and Zenith) [12] Carlo Basile et al. (1995). "The U.S. HDTV standard: the Grand Alliance". IEEE Spectrum 32 (4): 36–45. [13] "HDTV field testing wraps up" (http:/ / www. allbusiness. com/ electronics/ consumer-household-electronics-high/ 7686036-1. html). Allbusiness.com. . Retrieved 2010-10-02. [14] "History of WRAL Digital" (http:/ / www. wral. com/ wral-tv/ story/ 1069461/ ). Wral.com. 2006-11-22. . Retrieved 2010-10-02. [15] "WRAL-HD begins broadcasting HDTV" (http:/ / www. allbusiness. com/ electronics/ consumer-household-electronics-high/ 7691754-1. html). Allbusiness.com. . Retrieved 2010-10-02. [16] "Comark transmitter first in at Model Station" (http:/ / www. allbusiness. com/ electronics/ computer-electronics-manufacturing/ 7691367-1. html). Allbusiness.com. . Retrieved 2010-10-02. [17] Albiniak, Paige (1998-11-02). "HDTV: Launched and Counting." (http:/ / findarticles. com/ p/ articles/ mi_hb5053/ is_199811/ ai_n18386452?tag=content;col1). Broadcasting and cable (BNET). . Retrieved 2008-10-24. [18] "Space Shuttle Discovery: John Glenn Launch" (http:/ / www. imdb. com/ title/ tt0384554/ ). Internet Movie Database. 1998. . Retrieved 2008-10-25. [19] SES ASTRA (October 23, 2003). "SES ASTRA and Euro1080 to pioneer HDTV in Europe" (http:/ / www. ses-astra. com/ business/ en/ news-events/ press-archive/ 2003/ 23-10-03/ index. php). Press release. . [20] Bains, Geoff. "Take The High Road" What Video & Widescreen TV (April, 2004) 22-24 [21] ASTRA Satellite Monitor research (http:/ / www. ses-astra. com/ business/ en/ support/ market-research/ index. php). [22] "Scanning Methods (p, i, PsF)" (http:/ / www. arridigital. com/ creative/ camerabasics/ 7). ARRI Digital. . Retrieved 2011-08-30. [23] "HDTV information" (http:/ / www. hidefster. com/ HDTV_blog/ ?cat=9). . [24] Nelson, Randy. "Microsoft unveils Zune HD, Zune marketplace headed to Xbox 360" (http:/ / www. joystiq. com/ 2009/ 05/ 26/ microsoft-unveils-zune-hd-zune-marketplace-headed-to-360/ ). www.Joystiq.com. . [25] "5C Digital Transmission Content Protection White Paper" (http:/ / web. archive. org/ web/ 20060616075812/ http:/ / dtcp. com/ data/ wp_spec. pdf) (PDF). 1998-07-14. Archived from the original (http:/ / www. dtcp. com/ data/ wp_spec. pdf) on 2006-06-16. . Retrieved 2006-06-20.
External links • Technology, Television, and Competition (http://www.cambridge.org/uk/catalogue/catalogue. asp?isbn=0521826241) (New York: Cambridge University Press, 2004) • (http://www.bolumfragmani.gen.tr) HDTV Primer • HD Quality TV (http://www.filminiizle.com) • Film indir (http://www.trfilmindir.net) • Sony HD TV (http://www.sony.co.uk/hub/bravia-hd-tv) • (http://www.gazetedunyasi.com) gazeteler • Images formats for HDTV (http://tech.ebu.ch/docs/techreview/trev_299-ive.pdf), article from the EBU Technical Review. • High Definition for Europe - a progressive approach (http://tech.ebu.ch/docs/techreview/trev_300-wood. pdf), article from the EBU Technical Review. • High Definition (HD) Image Formats for Television Production (http://tech.ebu.ch/docs/tech/tech3299.pdf), technical report from the EBU
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High-definition television • HDTV in Germany: Lack of Innovation Management Leads to Market Failure (http://www.diw.de/documents/ publikationen/73/diw_01.c.360950.de/diw_wr_2010-28.pdf), diffusion of HDTV in Germany from the DIW Berlin
Video compression Video compression refers to reducing the quantity of data used to represent digital video images, and is a combination of spatial image compression and temporal motion compensation. Video compression is an example of the concept of source coding in Information theory. This article deals with its applications: compressed video can effectively reduce the bandwidth required to transmit video via terrestrial broadcast, via cable TV, or via satellite TV services.
Video quality Most video compression is lossy — it operates on the premise that much of the data present before compression is not necessary for achieving good perceptual quality. For example, DVDs use a video coding standard called MPEG-2 that can compress video data by 15 to 30 times, while still producing a picture quality that is generally considered high-quality for standard-definition video. Video compression is a tradeoff between disk space, video quality, and the cost of hardware required to decompress the video in a reasonable time. However, if the video is overcompressed in a lossy manner, visible (and sometimes distracting) artifacts can appear. Video compression typically operates on square-shaped groups of neighboring pixels, often called macroblocks. These pixel groups or blocks of pixels are compared from one frame to the next and the video compression codec (encode/decode scheme) sends only the differences within those blocks. This works extremely well if the video has no motion. A still frame of text, for example, can be repeated with very little transmitted data. In areas of video with more motion, more pixels change from one frame to the next. When more pixels change, the video compression scheme must send more data to keep up with the larger number of pixels that are changing. If the video content includes an explosion, flames, a flock of thousands of birds, or any other image with a great deal of high-frequency detail, the quality will decrease, or the variable bitrate must be increased to render this added information with the same level of detail. The programming provider has control over the amount of video compression applied to their video programming before it is sent to their distribution system. DVDs, Blu-ray discs, and HD DVDs have video compression applied during their mastering process, though Blu-ray and HD DVD have enough disc capacity that most compression applied in these formats is light, when compared to such examples as most video streamed on the internet, or taken on a cellphone. Software used for storing video on hard drives or various optical disc formats will often have a lower image quality. High-bitrate video codecs with little or no compression exist for video post-production work, but create very large files and are thus almost never used for the distribution of finished videos. Once excessive lossy video compression compromises image quality, it is impossible to restore the image to its original quality.
16
Video compression
Theory Video is basically a three-dimensional array of color pixels. Two dimensions serve as spatial (horizontal and vertical) directions of the moving pictures, and one dimension represents the time domain. A data frame is a set of all pixels that correspond to a single time moment. Basically, a frame is the same as a still picture. Video data contains spatial and temporal redundancy. Similarities can thus be encoded by merely registering differences within a frame (spatial), and/or between frames (temporal). Spatial encoding is performed by taking advantage of the fact that the human eye is unable to distinguish small differences in color as easily as it can perceive changes in brightness, so that very similar areas of color can be "averaged out" in a similar way to jpeg images (JPEG image compression FAQ, part 1/2) [1]. With temporal compression only the changes from one frame to the next are encoded as often a large number of the pixels will be the same on a series of frames.
Lossless compression Some forms of data compression are lossless. This means that when the data is decompressed, the result is a bit-for-bit perfect match with the original. While lossless compression of video is possible, it is rarely used, as lossy compression results in far higher compression ratios at an acceptable level of quality.
Intraframe versus interframe compression One of the most powerful techniques for compressing video is interframe compression. Interframe compression uses one or more earlier or later frames in a sequence to compress the current frame, while intraframe compression uses only the current frame, which is effectively image compression. The most commonly used method works by comparing each frame in the video with the previous one. If the frame contains areas where nothing has moved, the system simply issues a short command that copies that part of the previous frame, bit-for-bit, into the next one. If sections of the frame move in a simple manner, the compressor emits a (slightly longer) command that tells the decompresser to shift, rotate, lighten, or darken the copy — a longer command, but still much shorter than intraframe compression. Interframe compression works well for programs that will simply be played back by the viewer, but can cause problems if the video sequence needs to be edited. Since interframe compression copies data from one frame to another, if the original frame is simply cut out (or lost in transmission), the following frames cannot be reconstructed properly. Some video formats, such as DV, compress each frame independently using intraframe compression. Making 'cuts' in intraframe-compressed video is almost as easy as editing uncompressed video — one finds the beginning and ending of each frame, and simply copies bit-for-bit each frame that one wants to keep, and discards the frames one doesn't want. Another difference between intraframe and interframe compression is that with intraframe systems, each frame uses a similar amount of data. In most interframe systems, certain frames (such as "I frames" in MPEG-2) aren't allowed to copy data from other frames, and so require much more data than other frames nearby. It is possible to build a computer-based video editor that spots problems caused when I frames are edited out while other frames need them. This has allowed newer formats like HDV to be used for editing. However, this process demands a lot more computing power than editing intraframe compressed video with the same picture quality.
Current forms Today, nearly all commonly used video compression methods (e.g., those in standards approved by the ITU-T or ISO) apply a discrete cosine transform (DCT) for spatial redundancy reduction. Other methods, such as fractal compression, matching pursuit and the use of a discrete wavelet transform (DWT) have been the subject of some research, but are typically not used in practical products (except for the use of wavelet coding as still-image coders without motion compensation). Interest in fractal compression seems to be waning, due to recent theoretical analysis
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Video compression
18
showing a comparative lack of effectiveness to such methods.
Timeline The following table is a partial history of international video compression standards.
History of Video Compression Standards Year
Standard
Publisher
1984
H.120
ITU-T
1990
H.261
ITU-T
Videoconferencing, Videotelephony
1993
MPEG-1 Part 2
ISO, IEC
Video-CD
1995
H.262/MPEG-2 Part 2 ISO, IEC, ITU-T
Popular Implementations
DVD Video, Blu-ray, Digital Video Broadcasting, SVCD
1996
H.263
ITU-T
Videoconferencing, Videotelephony, Video on Mobile Phones (3GP)
1999
MPEG-4 Part 2
ISO, IEC
Video on Internet (DivX, Xvid ...)
2003 2008
H.264/MPEG-4 AVC ISO, IEC, ITU-T VC-2 (Dirac)
ISO, BBC
Blu-ray, Digital Video Broadcasting, iPod Video, HD DVD Video on Internet, HDTV broadcast, UHDTV
References [1] http:/ / www. faqs. org/ faqs/ jpeg-faq/ part1/
External links • Videsignline - Intro to Video Compression (http://www.videsignline.com/howto/showArticle. jhtml?articleID=185301351) • TestVid - 2,000+ HD and other uncompressed source video clips for compression testing (http://www.testvid. com/index.html) • Data Compression Basics (Video) (http://dvd-hq.info/data_compression_3.php) • MPEG 1&2 video compression intro (pdf format) (http://web.archive.org/web/20070928023157/http://mia. ece.uic.edu/~papers/WWW/MultimediaStandards/chapter7.pdf) • HD Greetings - 1080p Uncompressed source material for compression testing and research (http://www. hdgreetings.com/ecard/video-1080p.aspx) • Wiley - Introduction to Compression Theory (http://media.wiley.com/product_data/excerpt/99/04705184/ 0470518499.pdf) • Video compression 4:2:2 10-bit and its benefits (http://extranet.ateme.com/download.php?file=1114) • Why does 10-bit save bandwidth (even when content is 8-bit)? (http://extranet.ateme.com/download. php?file=1194) • Which compression technology should be used (http://extranet.ateme.com/download.php?file=1196)
H.264/MPEG-4 AVC
H.264/MPEG-4 AVC H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video. The final drafting work on the first version of the standard was completed in May 2003. H.264/MPEG-4 AVC is a block-oriented motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) together with the International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) Moving Picture Experts Group (MPEG). It was the product of a partnership effort known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 AVC standard (formally, ISO/IEC 14496-10 – MPEG-4 Part 10, Advanced Video Coding) are jointly maintained so that they have identical technical content. H.264 is perhaps best known as being one of the codec standards for Blu-ray Discs; all Blu-ray Disc players must be able to decode H.264. It is also widely used by streaming internet sources, such as videos from Vimeo, YouTube, and the iTunes Store, web software such as the Adobe Flash Player and Microsoft Silverlight, broadcast services for DVB and SBTVD, direct-broadcast satellite television services, cable television services, and real-time videoconferencing.
Overview The intent of the H.264/AVC project was to create a standard capable of providing good video quality at substantially lower bit rates than previous standards (i.e., half or less the bit rate of MPEG-2, H.263, or MPEG-4 Part 2), without increasing the complexity of design so much that it would be impractical or excessively expensive to implement. An additional goal was to provide enough flexibility to allow the standard to be applied to a wide variety of applications on a wide variety of networks and systems, including low and high bit rates, low and high resolution video, broadcast, DVD storage, RTP/IP packet networks, and ITU-T multimedia telephony systems. The H.264 standard can be viewed as a "family of standards", the members of which are the profiles described below. A specific decoder decodes at least one, but not necessarily all profiles. The decoder specification describes which of the profiles can be decoded. The H.264 name follows the ITU-T naming convention, where the standard is a member of the H.26x line of VCEG video coding standards; the MPEG-4 AVC name relates to the naming convention in ISO/IEC MPEG, where the standard is part 10 of ISO/IEC 14496, which is the suite of standards known as MPEG-4. The standard was developed jointly in a partnership of VCEG and MPEG, after earlier development work in the ITU-T as a VCEG project called H.26L. It is thus common to refer to the standard with names such as H.264/AVC, AVC/H.264, H.264/MPEG-4 AVC, or MPEG-4/H.264 AVC, to emphasize the common heritage. Occasionally, it is also referred to as "the JVT codec", in reference to the Joint Video Team (JVT) organization that developed it. (Such partnership and multiple naming is not uncommon. For example, the video codec standard known as MPEG-2 also arose from the partnership between MPEG and the ITU-T, where MPEG-2 video is known to the ITU-T community as H.262.[1] ) Some software programs (such as VLC media player) internally identify this standard as AVC1. The standardization of the first version of H.264/AVC was completed in May 2003. In the first project to extend the original standard, the JVT then developed what was called the Fidelity Range Extensions (FRExt). These extensions enabled higher quality video coding by supporting increased sample bit depth precision and higher-resolution color information, including sampling structures known as Y'CbCr 4:2:2 (=YUV 4:2:2) and Y'CbCr 4:4:4. Several other features were also included in the Fidelity Range Extensions project, such as adaptive switching between 4×4 and 8×8 integer transforms, encoder-specified perceptual-based quantization weighting matrices, efficient inter-picture lossless coding, and support of additional color spaces. The design work on the Fidelity Range Extensions was completed in July 2004, and the drafting work on them was completed in September 2004.
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H.264/MPEG-4 AVC Further recent extensions of the standard then included adding five other new profiles intended primarily for professional applications, adding extended-gamut color space support, defining additional aspect ratio indicators, defining two additional types of "supplemental enhancement information" (post-filter hint and tone mapping), and deprecating one of the prior FRExt profiles that industry feedback indicated should have been designed differently. The next major feature added to the standard was Scalable Video Coding (SVC). Specified in Annex G of H.264/AVC, SVC allows the construction of bitstreams that contain sub-bitstreams that also conform to the standard, including one such bitstream known as the "base layer" that can be decoded by an H.264/AVC that does not support SVC. For temporal bitstream scalability, i.e., the presence of a sub-bitstream with a smaller temporal sampling rate than the bitstream, complete access units are removed from the bitstream when deriving the sub-bitstream. In this case, high-level syntax and inter prediction reference pictures in the bitstream are constructed accordingly. For spatial and quality bitstream scalability, i.e. the presence of a sub-bitstream with lower spatial resolution or quality than the bitstream, NAL (Network Abstraction Layer) removed from the bitstream when deriving the sub-bitstream. In this case, inter-layer prediction, i.e., the prediction of the higher spatial resolution or quality signal by data of the lower spatial resolution or quality signal, is typically used for efficient coding. The Scalable Video Coding extensions were completed in November 2007. The next major feature added to the standard was Multiview Video Coding (MVC). Specified in Annex H of H.264/AVC, MVC enables the construction of bitstreams that represent more than one view of a video scene. An important example of this functionality is stereoscopic 3D video coding. Two profiles were developed in the MVC work: Multiview High Profile supports an arbitrary number of views, and Stereo High Profile is designed specifically for two-view stereoscopic video. The Multiview Video Coding extensions were completed in November 2009.
Standardization committee and history In early 1998, the Video Coding Experts Group (VCEG – ITU-T SG16 Q.6) issued a call for proposals on a project called H.26L, with the target to double the coding efficiency (which means halving the bit rate necessary for a given level of fidelity) in comparison to any other existing video coding standards for a broad variety of applications. VCEG was chaired by Gary Sullivan (Microsoft, formerly PictureTel, USA). The first draft design for that new standard was adopted in August 1999. In 2000, Thomas Wiegand (Heinrich Hertz Institute, Germany) became VCEG co-chair. In December 2001, VCEG and the Moving Picture Experts Group (MPEG – ISO/IEC JTC 1/SC 29/WG 11) formed a Joint Video Team (JVT), with the charter to finalize the video coding standard. Formal approval of the specification came in March 2003. The JVT was (is) chaired by Gary Sullivan, Thomas Wiegand, and Ajay Luthra (Motorola, USA). In June 2004, the Fidelity range extensions (FRExt) project was finalized. From January 2005 to November 2007, the JVT was working on an extension of H.264/AVC towards scalability by an Annex (G) called Scalable Video Coding (SVC). The JVT management team was extended by Jens-Rainer Ohm (Aachen University, Germany). From July 2006 to November 2009, the JVT worked on Multiview Video Coding (MVC), an extension of H.264/AVC towards free viewpoint television and 3D television. That work included the development of two new profiles of the standard: the Multiview High Profile and the Stereo High Profile.
Applications Further information: List of video services using H.264/MPEG-4 AVC The H.264 video format has a very broad application range that covers all forms of digital compressed video from low bit-rate Internet streaming applications to HDTV broadcast and Digital Cinema applications with nearly lossless coding. With the use of H.264, bit rate savings of 50%[2] or more are reported. For example, H.264 has been reported to give the same Digital Satellite TV quality as current MPEG-2 implementations with less than half the bitrate, with current MPEG-2 implementations working at around 3.5 Mbit/s and H.264 at only 1.5 Mbit/s.[3] To ensure compatibility and problem-free adoption of H.264/AVC, many standards bodies have amended or added to their
20
H.264/MPEG-4 AVC video-related standards so that users of these standards can employ H.264/AVC. Both the Blu-ray Disc format and the now-discontinued HD DVD format include the H.264/AVC High Profile as one of 3 mandatory video compression formats. The Digital Video Broadcast project (DVB) approved the use of H.264/AVC for broadcast television in late 2004. The Advanced Television Systems Committee (ATSC) standards body in the United States approved the use of H.264/AVC for broadcast television in July 2008, although the standard is not yet used for fixed ATSC broadcasts within the United States.[4] [5] It has also been approved for use with the more recent ATSC-M/H (Mobile/Handheld) standard, using the AVC and SVC portions of H.264.[6] AVCHD is a high-definition recording format designed by Sony and Panasonic that uses H.264 (conforming to H.264 while adding additional application-specific features and constraints). AVC-Intra is an intraframe-only compression format, developed by Panasonic. The CCTV (Closed Circuit TV) and Video Surveillance markets have included the technology in many products. The Canon DSLRs use the H.264 QuickTime MOV as the native recording.
Patent licensing In countries where patents on software algorithms are upheld, vendors and commercial users of products that use H.264/AVC are expected to pay patent licensing royalties for the patented technology[7] that their products use. This applies to the Baseline Profile as well.[8] A private organization known as MPEG LA, which is not affiliated in any way with the MPEG standardization organization, administers the licenses for patents applying to this standard, as well as the patent pools for MPEG-2 Part 1 Systems, MPEG-2 Part 2 Video, MPEG-4 Part 2 Video, and other technologies. The MPEG-LA patents in the US last at least until 2027.[9] On August 26, 2010 MPEG LA announced that H.264 encoded internet video that is free to end users will never be charged for royalties.[10] All other royalties will remain in place such as the royalties for products that decode and encode H.264 video.[11] The license terms are updated in 5-year blocks.[12] In 2005, Qualcomm, which was the assignee of U.S. Patent 5,452,104 [13] and U.S. Patent 5,576,767 [14] sued Broadcom in US District Court, alleging that Broadcom infringed the two patents by making products that were compliant with the H.264 video compression standard.[15] In 2007, the District Court found that the patents were unenforceable because Qualcomm had failed to disclose them to the JVT prior to the release of the H.264 standard in May 2003.[15] In December 2008, the US Court of Appeals for the Federal Circuit affirmed the District Court's order that the patents be unenforceable but remanded to the District Court with instructions to limit the scope of unenforceability to H.264 compliant products.[15]
Controversies Controversies surrounding the H.264 video compression standard stem primarily from its use within the HTML5 Internet standard. HTML5 adds two new tags to the HTML standard: <video> and <audio> for direct embedding of video and audio content to a web page. HTML5 is being developed by the HTML5 working group as an open standard to be adopted by all web browser developers. In 2009, the HTML5 working group was split between supporters of Ogg Theora, a free video format that its developers believe is unencumbered by patents, and H.264 which contains patented technology. As late as July 2009, Google and Apple were said to support H.264, while Mozilla and Opera support Ogg Theora.[16] Microsoft, with the release of Internet Explorer 9, has added support for both HTML 5 and H.264. Microsoft CEO Steve Ballmer at the Gartner Symposium/ITXpo in November, 2010, in answer to the question, "HTML 5 or Silverlight?" said, "If you want to do something that is universal, there is no question the world is going HTML5."[17] In January 2011, Google announced that they were pulling support for H.264 from their Chrome browser and supporting both Theora and WebM/VP8.[18]
21
H.264/MPEG-4 AVC
Features H.264/AVC/MPEG-4 Part 10 contains a number of new features that allow it to compress video much more effectively than older standards and to provide more flexibility for application to a wide variety of network environments. In particular, some such key features include: • Multi-picture inter-picture prediction including the following features: • Using previously-encoded pictures as references in a much more flexible way than in past standards, allowing up to 16 reference frames (or 32 reference fields, in the case of interlaced encoding) to be used in some cases. This is in contrast to prior standards, where the limit was typically one; or, in the case of conventional "B pictures", two. This particular feature usually allows modest improvements in bit rate and quality in most scenes. But in certain types of scenes, such as those with repetitive motion or back-and-forth scene cuts or uncovered background areas, it allows a significant reduction in bit rate while maintaining clarity. • Variable block-size motion compensation (VBSMC) with block sizes as large as 16×16 and as small as 4×4, enabling precise segmentation of moving regions. The supported luma prediction block sizes include 16×16, 16×8, 8×16, 8×8, 8×4, 4×8, and 4×4, many of which can be used together in a single macroblock. Chroma prediction block sizes are correspondingly smaller according to the chroma subsampling in use. • The ability to use multiple motion vectors per macroblock (one or two per partition) with a maximum of 32 in the case of a B macroblock constructed of 16 4×4 partitions. The motion vectors for each 8×8 or larger partition region can point to different reference pictures. • The ability to use any macroblock type in B-frames, including I-macroblocks, resulting in much more efficient encoding when using B-frames. This feature was notably left out from MPEG-4 ASP. • Six-tap filtering for derivation of half-pel luma sample predictions, for sharper subpixel motion-compensation. Quarter-pixel motion is derived by linear interpolation of the halfpel values, to save processing power. • Quarter-pixel precision for motion compensation, enabling precise description of the displacements of moving areas. For chroma the resolution is typically halved both vertically and horizontally (see 4:2:0) therefore the motion compensation of chroma uses one-eighth chroma pixel grid units. • Weighted prediction, allowing an encoder to specify the use of a scaling and offset when performing motion compensation, and providing a significant benefit in performance in special cases—such as fade-to-black, fade-in, and cross-fade transitions. This includes implicit weighted prediction for B-frames, and explicit weighted prediction for P-frames. • Spatial prediction from the edges of neighboring blocks for "intra" coding, rather than the "DC"-only prediction found in MPEG-2 Part 2 and the transform coefficient prediction found in H.263v2 and MPEG-4 Part 2. This includes luma prediction block sizes of 16×16, 8×8, and 4×4 (of which only one type can be used within each macroblock). • Lossless macroblock coding features including: • A lossless "PCM macroblock" representation mode in which video data samples are represented directly,[19] allowing perfect representation of specific regions and allowing a strict limit to be placed on the quantity of coded data for each macroblock. • An enhanced lossless macroblock representation mode allowing perfect representation of specific regions while ordinarily using substantially fewer bits than the PCM mode. • Flexible interlaced-scan video coding features, including: • Macroblock-adaptive frame-field (MBAFF) coding, using a macroblock pair structure for pictures coded as frames, allowing 16×16 macroblocks in field mode (compared with MPEG-2, where field mode processing in a picture that is coded as a frame results in the processing of 16×8 half-macroblocks). • Picture-adaptive frame-field coding (PAFF or PicAFF) allowing a freely-selected mixture of pictures coded either as complete frames where both fields are combined together for encoding or as individual single fields. • New transform design features, including:
22
H.264/MPEG-4 AVC • An exact-match integer 4×4 spatial block transform, allowing precise placement of residual signals with little of the "ringing" often found with prior codec designs. This is conceptually similar to the well-known DCT design, but simplified and made to provide exactly-specified decoding. • An exact-match integer 8×8 spatial block transform, allowing highly correlated regions to be compressed more efficiently than with the 4×4 transform. This is conceptually similar to the well-known DCT design, but simplified and made to provide exactly-specified decoding. • Adaptive encoder selection between the 4×4 and 8×8 transform block sizes for the integer transform operation. • A secondary Hadamard transform performed on "DC" coefficients of the primary spatial transform applied to chroma DC coefficients (and also luma in one special case) to obtain even more compression in smooth regions. • A quantization design including: • Logarithmic step size control for easier bit rate management by encoders and simplified inverse-quantization scaling • Frequency-customized quantization scaling matrices selected by the encoder for perceptual-based quantization optimization • An in-loop deblocking filter that helps prevent the blocking artifacts common to other DCT-based image compression techniques, resulting in better visual appearance and compression efficiency • An entropy coding design including: • Context-adaptive binary arithmetic coding (CABAC), an algorithm to losslessly compress syntax elements in the video stream knowing the probabilities of syntax elements in a given context. CABAC compresses data more efficiently than CAVLC but requires considerably more processing to decode. • Context-adaptive variable-length coding (CAVLC), which is a lower-complexity alternative to CABAC for the coding of quantized transform coefficient values. Although lower complexity than CABAC, CAVLC is more elaborate and more efficient than the methods typically used to code coefficients in other prior designs. • A common simple and highly structured variable length coding (VLC) technique for many of the syntax elements not coded by CABAC or CAVLC, referred to as Exponential-Golomb coding (or Exp-Golomb). • Loss resilience features including: • A Network Abstraction Layer (NAL) definition allowing the same video syntax to be used in many network environments. One very fundamental design concept of H.264 is to generate self contained packets, to remove the header duplication as in MPEG-4's Header Extension Code (HEC).[20] This was achieved by decoupling information relevant to more than one slice from the media stream. The combination of the higher-level parameters is called a parameter set.[20] The H.264 specification includes two types of parameter sets: Sequence Parameter Set (SPS) and Picture Parameter Set (PPS). An active sequence parameter set remains unchanged throughout a coded video sequence, and an active picture parameter set remains unchanged within a coded picture. The sequence and picture parameter set structures contain information such as picture size, optional coding modes employed, and macroblock to slice group map.[20] • Flexible macroblock ordering (FMO), also known as slice groups, and arbitrary slice ordering (ASO), which are techniques for restructuring the ordering of the representation of the fundamental regions (macroblocks) in pictures. Typically considered an error/loss robustness feature, FMO and ASO can also be used for other purposes. • Data partitioning (DP), a feature providing the ability to separate more important and less important syntax elements into different packets of data, enabling the application of unequal error protection (UEP) and other types of improvement of error/loss robustness. • Redundant slices (RS), an error/loss robustness feature allowing an encoder to send an extra representation of a picture region (typically at lower fidelity) that can be used if the primary representation is corrupted or lost. • Frame numbering, a feature that allows the creation of "sub-sequences", enabling temporal scalability by optional inclusion of extra pictures between other pictures, and the detection and concealment of losses of
23
H.264/MPEG-4 AVC
•
•
• • • • •
entire pictures, which can occur due to network packet losses or channel errors. Switching slices, called SP and SI slices, allowing an encoder to direct a decoder to jump into an ongoing video stream for such purposes as video streaming bit rate switching and "trick mode" operation. When a decoder jumps into the middle of a video stream using the SP/SI feature, it can get an exact match to the decoded pictures at that location in the video stream despite using different pictures, or no pictures at all, as references prior to the switch. A simple automatic process for preventing the accidental emulation of start codes, which are special sequences of bits in the coded data that allow random access into the bitstream and recovery of byte alignment in systems that can lose byte synchronization. Supplemental enhancement information (SEI) and video usability information (VUI), which are extra information that can be inserted into the bitstream to enhance the use of the video for a wide variety of purposes. Auxiliary pictures, which can be used for such purposes as alpha compositing. Support of monochrome, 4:2:0, 4:2:2, and 4:4:4 chroma subsampling (depending on the selected profile). Support of sample bit depth precision ranging from 8 to 14 bits per sample (depending on the selected profile). The ability to encode individual color planes as distinct pictures with their own slice structures, macroblock modes, motion vectors, etc., allowing encoders to be designed with a simple parallelization structure (supported only in the three 4:4:4-capable profiles).
• Picture order count, a feature that serves to keep the ordering of the pictures and the values of samples in the decoded pictures isolated from timing information, allowing timing information to be carried and controlled/changed separately by a system without affecting decoded picture content. These techniques, along with several others, help H.264 to perform significantly better than any prior standard under a wide variety of circumstances in a wide variety of application environments. H.264 can often perform radically better than MPEG-2 video—typically obtaining the same quality at half of the bit rate or less, especially on high bit rate and high resolution situations.[21] Like other ISO/IEC MPEG video standards, H.264/AVC has a reference software implementation that can be freely downloaded.[22] Its main purpose is to give examples of H.264/AVC features, rather than being a useful application per se. Some reference hardware design work is also under way in the Moving Picture Experts Group. The above mentioned are complete features of H.264/AVC covering all profiles of H.264. A profile for a codec is a set of features of that codec identified to meet a certain set of specifications of intended applications. This means that many of the features listed are not supported in some profiles. Various profiles of H.264/AVC are discussed in next section.
Profiles The standard defines 17 sets of capabilities, which are referred to as profiles, targeting specific classes of applications. Profiles for non-scalable 2D video applications include the following: Constrained Baseline Profile (CBP) Primarily for low-cost applications, this profile is most typically used in videoconferencing and mobile applications. It corresponds to the subset of features that are in common between the Baseline, Main, and High Profiles described below. Baseline Profile (BP) Primarily for low-cost applications that require additional data loss robustness, this profile is used in some videoconferencing and mobile applications. This profile includes all features that are supported in the Constrained Baseline Profile, plus three additional features that can be used for loss robustness (or for other purposes such as low-delay multi-point video stream compositing). The importance of this profile has faded somewhat since the definition of the Constrained Baseline Profile in 2009. All Constrained Baseline Profile
24
H.264/MPEG-4 AVC bitstreams are also considered to be Baseline Profile bitstreams, as these two profiles share the same profile identifier code value. Main Profile (MP) This profile is used for standard-definition digital TV broadcasts that use the MPEG-4 format as defined in the DVB standard.[23] It is not, however, used for high-definition television broadcasts, as the importance of this profile faded when the High Profile was developed in 2004 for that application. Extended Profile (XP) Intended as the streaming video profile, this profile has relatively high compression capability and some extra tricks for robustness to data losses and server stream switching. High Profile (HiP) The primary profile for broadcast and disc storage applications, particularly for high-definition television applications (for example, this is the profile adopted by the Blu-ray Disc storage format and the DVB HDTV broadcast service). High 10 Profile (Hi10P) Going beyond typical mainstream consumer product capabilities, this profile builds on top of the High Profile, adding support for up to 10 bits per sample of decoded picture precision. High 4:2:2 Profile (Hi422P) Primarily targeting professional applications that use interlaced video, this profile builds on top of the High 10 Profile, adding support for the 4:2:2 chroma subsampling format while using up to 10 bits per sample of decoded picture precision. High 4:4:4 Predictive Profile (Hi444PP) This profile builds on top of the High 4:2:2 Profile, supporting up to 4:4:4 chroma sampling, up to 14 bits per sample, and additionally supporting efficient lossless region coding and the coding of each picture as three separate color planes. For camcorders, editing, and professional applications, the standard contains four additional all-Intra profiles, which are defined as simple subsets of other corresponding profiles. These are mostly for professional (e.g., camera and editing system) applications: High 10 Intra Profile The High 10 Profile constrained to all-Intra use. High 4:2:2 Intra Profile The High 4:2:2 Profile constrained to all-Intra use. High 4:4:4 Intra Profile The High 4:4:4 Profile constrained to all-Intra use. CAVLC 4:4:4 Intra Profile The High 4:4:4 Profile constrained to all-Intra use and to CAVLC entropy coding (i.e., not supporting CABAC). As a result of the Scalable Video Coding (SVC) extension, the standard contains three additional scalable profiles, which are defined as a combination of a H.264/AVC profile for the base layer (identified by the second word in the scalable profile name) and tools that achieve the scalable extension: Scalable Baseline Profile Primarily targeting video conferencing, mobile, and surveillance applications, this profile builds on top of a constrained version of the H.264/AVC Baseline profile to which the base layer (a subset of the bitstream) must
25
H.264/MPEG-4 AVC
26
conform. For the scalability tools, a subset of the available tools is enabled. Scalable High Profile Primarily targeting broadcast and streaming applications, this profile builds on top of the H.264/AVC High Profile to which the base layer must conform. Scalable High Intra Profile Primarily targeting production applications, this profile is the Scalable High Profile constrained to all-Intra use. As a result of the Multiview Video Coding (MVC) extension, the standard contains two multiview profiles: Stereo High Profile This profile targets two-view stereoscopic 3D video and combines the tools of the High profile with the inter-view prediction capabilities of the MVC extension. Multiview High Profile This profile supports two or more views using both inter-picture (temporal) and MVC inter-view prediction, but does not support field pictures and macroblock-adaptive frame-field coding.
Feature support in particular profiles Feature Chroma formats
CBP 4:2:0
BP
XP
MP
HiP
4:2:0 4:2:0 4:2:0 4:2:0
Hi10P 4:2:0
Hi422P
Hi444PP
4:2:0/4:2:2 4:2:0/4:2:2/4:4:4
Sample depths (bits)
8
8
8
8
8
8 to 10
8 to 10
8 to 14
Flexible macroblock ordering (FMO)
No
Yes
Yes
No
No
No
No
No
Arbitrary slice ordering (ASO)
No
Yes
Yes
No
No
No
No
No
Redundant slices (RS)
No
Yes
Yes
No
No
No
No
No
Data Partitioning
No
No
Yes
No
No
No
No
No
SI and SP slices
No
No
Yes
No
No
No
No
No
B slices
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Interlaced coding (PicAFF, MBAFF)
No
No
Yes
Yes
Yes
Yes
Yes
Yes
CABAC entropy coding
No
No
No
Yes
Yes
Yes
Yes
Yes
8×8 vs. 4×4 transform adaptivity
No
No
No
No
Yes
Yes
Yes
Yes
Quantization scaling matrices
No
No
No
No
Yes
Yes
Yes
Yes
Separate Cb and Cr QP control
No
No
No
No
Yes
Yes
Yes
Yes
Monochrome (4:0:0)
No
No
No
No
Yes
Yes
Yes
Yes
Separate color plane coding
No
No
No
No
No
No
No
Yes
Predictive lossless coding
No
No
No
No
No
No
No
Yes
H.264/MPEG-4 AVC
27
Levels As the term is used in the standard, a "level" is a specified set of constraints indicating a degree of required decoder performance for a profile. For example, a level of support within a profile will specify the maximum picture resolution, frame rate, and bit rate that a decoder may be capable of using. A decoder that conforms to a given level is required to be capable of decoding all bitstreams that are encoded for that level and for all lower levels.
Levels with maximum property values Level
Max macroblocks
Max video bit rate (video coding layer – VCL) BP, XP, HiP Hi10P MP (kbit/s) (kbit/s) (kbit/s)
Hi422P, Hi444PP (kbit/s)
Examples for high resolution @ frame rate (max stored frames)
per second
per frame
1
1,485
99
64
80
192
256
128×96@30.9 (8) 176×144@15.0 (4)
1b
1,485
99
128
160
384
512
128×96@30.9 (8) 176×144@15.0 (4)
1.1
3,000
396
192
240
576
768
176×144@30.3 (9) 320×240@10.0 (3) 352×288@7.5 (2)
1.2
6,000
396
384
480
1,152
1,536
320×240@20.0 (7) 352×288@15.2 (6)
1.3
11,880
396
768
960
2,304
3,072
320×240@36.0 (7) 352×288@30.0 (6)
2
11,880
396
2,000
2,500
6,000
8,000
320×240@36.0 (7) 352×288@30.0 (6)
2.1
19,800
792
4,000
5,000
12,000
16,000
352×480@30.0 (7) 352×576@25.0 (6)
2.2
20,250
1,620
4,000
5,000
12,000
16,000
352×480@30.7(10) 352×576@25.6 (7) 720×480@15.0 (6) 720×576@12.5 (5)
3
40,500
1,620
10,000
12,500
30,000
40,000
352×480@61.4 (12) 352×576@51.1 (10) 720×480@30.0 (6) 720×576@25.0 (5)
3.1
108,000
3,600
14,000
17,500
42,000
56,000
720×480@80.0 (13) 720×576@66.7 (11) 1280×720@30.0 (5)
3.2
216,000
5,120
20,000
25,000
60,000
80,000
1,280×720@60.0 (5) 1,280×1,024@42.2 (4)
4
245,760
8,192
20,000
25,000
60,000
80,000
1,280×720@68.3 (9) 1,920×1,080@30.1 (4) 2,048×1,024@30.0 (4)
4.1
245,760
8,192
50,000
62,500 150,000
200,000
1,280×720@68.3 (9) 1,920×1,080@30.1 (4) 2,048×1,024@30.0 (4)
4.2
522,240
8,704
50,000
62,500 150,000
200,000
1,920×1,080@64.0 (4) 2,048×1,080@60.0 (4)
H.264/MPEG-4 AVC
28
5
589,824
22,080
135,000 168,750 405,000
540,000
1,920×1,080@72.3 (13) 2,048×1,024@72.0 (13) 2,048×1,080@67.8 (12) 2,560×1,920@30.7 (5) 3,680×1,536@26.7 (5)
5.1
983,040
36,864
240,000 300,000 720,000
960,000
1,920×1,080@120.5 (16) 4,096×2,048@30.0 (5) 4,096×2,304@26.7 (5)
Decoded picture buffering Previously-encoded pictures are used by H.264/AVC encoders to provide predictions of the values of samples in other pictures. This allows the encoder to make efficient decisions on the best way to encode a given picture. At the decoder, such pictures are stored in a virtual decoded picture buffer (DPB). The maximum capacity of the DPB is in units of frames (or pairs of fields), as shown in parentheses in the right column of the table above, can be computed as follows: Standard equation
Min(Floor(MaxDpbMbs / (PicWidthInMbs * FrameHeightInMbs)), 16)
Excel-compatible formula =MIN(FLOOR(MaxDpbMbs / (PicWidthInMbs * FrameHeightInMbs); 1); 16)
Where MaxDpbMbs is a constant value provided in the table below as a function of level number, and PicWidthInMbs and FrameHeightInMbs are the picture width and frame height for the coded video data, expressed in units of macroblocks (rounded up to integer values and accounting for cropping and macroblock pairing when applicable). This formula is specified in sections A.3.1.h and A.3.2.f of the 2009 edition of the standard. Level
1
1b
1.1
1.2
1.3
2
2.1
2.2
3
3.1
3.2
4
4.1
4.2
5
5.1
MaxDpbMbs 396 396 900 2,376 2,376 2,376 4,752 8,100 8,100 18,000 20,480 32,768 32,768 34,816 110,400 184,320
For example, for an HDTV picture that is 1920 samples wide (PicWidthInMbs = 120) and 1080 samples high (FrameHeightInMbs = 68), a Level 4 decoder has a maximum DPB storage capacity of Floor(32768/(120*68)) = 4 frames (or 8 fields) when encoded with minimal cropping parameter values. Thus, the value 4 is shown in parentheses in the table above in the right column of the row for Level 4 with the frame size 1920×1080. It is important to note that the current picture being decoded is not included in the computation of DPB fullness (unless the encoder has indicated for it to be stored for use as a reference for decoding other pictures or for delayed output timing). Thus, a decoder needs to actually have sufficient memory to handle (at least) one frame more than the maximum capacity of the DPB as calculated above.
Versions Versions of the H.264/AVC standard include the following completed revisions, corrigenda, and amendments (dates are final approval dates in ITU-T, while final "International Standard" approval dates in ISO/IEC are somewhat different and slightly later in most cases). Each version represents changes relative to the next lower version that is integrated into the text. Bold faced versions are published (or planned to be published). • Version 1: (May 2003) First approved version of H.264/AVC containing Baseline, Extended, and Main profiles. • Version 2: (May 2004) Corrigendum containing various minor corrections. • Version 3: (March 2005) Major addition to H.264/AVC containing the first amendment providing Fidelity Range Extensions (FRExt) containing High, High 10, High 4:2:2, and High 4:4:4 profiles.
H.264/MPEG-4 AVC
29
• Version 4: (September 2005) Corrigendum containing various minor corrections and adding three aspect ratio indicators. • Version 5: (June 2006) Amendment consisting of removal of prior High 4:4:4 profile (processed as a corrigendum in ISO/IEC). • Version 6: (June 2006) Amendment consisting of minor extensions like extended-gamut color space support (bundled with above-mentioned aspect ratio indicators in ISO/IEC). • Version 7: (April 2007) Amendment containing the addition of High 4:4:4 Predictive and four Intra-only profiles (High 10 Intra, High 4:2:2 Intra, High 4:4:4 Intra, and CAVLC 4:4:4 Intra) • Version 8: (November 2007) Major addition to H.264/AVC containing the amendment for Scalable Video Coding (SVC) containing Scalable Baseline, Scalable High, and Scalable High Intra profiles. • Version 9: (January 2009) Corrigendum containing minor corrections. • Version 10: (March 2009) Amendment containing definition of a new profile (the Constrained Baseline profile) with only the common subset of capabilities supported in various previously-specified profiles. • Version 11: (March 2009) Major addition to H.264/AVC containing the amendment for Multiview Video Coding (MVC) extension, including the Multiview High profile. • Version 12: (March 2010) Amendment containing definition of a new MVC profile (the Stereo High profile) for two-view video coding with support of interlaced coding tools and specifying an additional SEI message (the frame packing arrangement SEI message). • Version 13: (March 2010) Corrigendum containing minor corrections.
Software encoder feature comparison AVC software implementations Feature
QT
B slices
Yes
SI and SP slices
No
Multiple reference frames
Yes
Flexible Macroblock Ordering (FMO)
No
Arbitrary slice ordering (ASO)
No
Redundant slices (RS)
No
Data partitioning
No
Interlaced coding (PicAFF, MBAFF)
Nero
LEAD
x264
VSofts
ProCoder
Avivo
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
MBAFF
Yes
Yes
No
MBAFF
Yes
No MBAFF MBAFF
CABAC entropy coding
Yes
8×8 vs. 4×4 transform adaptivity
No
Quantization scaling matrices
No
MainConcept Elecard TSE
MBAFF
Elemental IPP
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
Yes
No
No
Yes
No
No
No
Yes
No
Yes
No
No
No
No
No
Yes
Yes
No
H.264/MPEG-4 AVC
30
Separate Cb and Cr QP control
No
Monochrome (4:0:0)
No
Chroma formats (4:2:x) Largest sample depth (bit)
No
No
No
Yes
Yes
Yes
No
Yes
No
No
No
No
No
No
No
No
No
Yes
No
No
No
0
0
0
0, 4:4:4 [24]
0, 2
0
0, 2
0, 2, 4:4:4
0
0
0
0
8
8
8
10
10
8
8
10
8
8
8
12
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
Separate color plane coding
No
Predictive lossless coding
No
Film grain modeling
No
No
No
No
No
Fully supported profiles Profile
QT
Constrained baseline
Yes
Baseline
No
Extended
No
Nero
LEAD x264 MainConcept Elecard TSE VSofts ProCoder Avivo Elemental IPP
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes/No
Yes
No
Yes
No
Yes
No
No
No
No
No
No
No
Main
No Yes/No Yes/No
High
No
No
No
Yes/No
No
Yes
No
No
No
No
Hardware-based encoding and decoding Because H.264 encoding and decoding requires significant computing power in specific types of arithmetic operations, software implementations that run on general-purpose CPUs are typically less power efficient. To improve the power efficiency and reduce hardware form-factor, special-purpose hardware may be employed, either for the complete encoding or decoding process, or for acceleration assistance within a CPU-controlled environment. CPU based solution is known to be much more flexible, particularly when encoding must be done concurrently in multiple formats, multiple bit rates and resolutions (multi-screen), and possibly with additional features on container format support, advanced integrated advertising features, etc. CPU based software solution generally makes it much easier to load balance multiple concurrent encoding sessions within the same CPU. The 2nd generation Intel Core i processors i3/i5/i7 (code named "Sandy Bridge") introduced at the January 2011 CES (Consumer Electronics Show) offer an on-chip hardware full HD H.264 encoder.[25] The Intel marketing name for the on-chip H.264 encoder feature is "Intel Quick Sync Video".[26] A hardware H.264 encoder can be an ASIC or an FPGA. An FPGA is a general programmable chip. To use an FPGA as a hardware encoder, an H.264 encoder design is required to customize the chip for the application. A full HD H.264 encoder could run on a single low cost FPGA chip by 2009 (High profile, level 4.1, 1080p, 30fps).
H.264/MPEG-4 AVC ASIC encoders with H.264 encoder functionality are available from many different semiconductor companies, but the core design used in the ASIC is typically licensed from one of a few companies such as Chips&Media, On2 (formally, Hantro. Now merged to Google), Imagination. Some companies have both FPGA and ASIC product offerings.[27] Texas Instruments manufactures a line of ARM + DSP cores that perform DSP H264 BP encoding 1080p at 30fps.[28] This permits flexibility with respect to codecs (which are implemented as highly optimized DSP code) while being more efficient than software on a generic CPU.
References [1] "H.262 : Information technology — Generic coding of moving pictures and associated audio information: Video" (http:/ / itu. int/ rec/ T-REC-H. 262). . Retrieved 2007-04-15. [2] "H.264 Joint Video Surveillance Group Compression Research Data: 2008" (http:/ / www. jvsg. com/ ). Jvsg.com. . Retrieved 2010-05-17. [3] Wenger, et al.. RFC 3984 : RTP Payload Format for H.264 Video (http:/ / tools. ietf. org/ html/ rfc3984#page-2). p. 2. . [4] "ATSC Standard A/72 Part 1: Video System Characteristics of AVC in the ATSC Digital Television System" (http:/ / www. atsc. org/ cms/ standards/ a_72_part_1. pdf) (PDF). . Retrieved 2011-07-30. [5] "ATSC Standard A/72 Part 2: AVC Video Transport Subsystem Characteristics" (http:/ / www. atsc. org/ cms/ standards/ a_72_part_2. pdf) (PDF). . Retrieved 2011-07-30. [6] "ATSC Standard A/153 Part 7: AVC and SVC Video System Characteristics" (http:/ / atsc. org/ cms/ standards/ a153/ a_153-Part-7-2009. pdf) (PDF). . Retrieved 2011-07-30. [7] "Summary of AVC/H.264 License Terms" (http:/ / www. mpegla. com/ main/ programs/ AVC/ Documents/ AVC_TermsSummary. pdf). . Retrieved 2010-03-25. [8] "OMS Video, A Project of Sun's Open Media Commons Initiative" (http:/ / blogs. sun. com/ openmediacommons/ entry/ oms_video_a_project_of). . Retrieved 2008-08-26. [9] http:/ / www. osnews. com/ story/ 24954/ US_Patent_Expiration_for_MP3_MPEG-2_H_264 has a MPEG-LA patent US 7826532 that was filed in Sep. 5, 2003 and has a 1546 day term extension. http:/ / patft1. uspto. gov/ netacgi/ nph-Parser?patentnumber=7826532 http:/ / www. google. com/ patents/ about?id=2onYAAAAEBAJ [10] "MPEG LA’s AVC License Will Not Charge Royalties for Internet Video that is Free to End Users through Life of License" (http:/ / www. mpegla. com/ Lists/ MPEG LA News List/ Attachments/ 231/ n-10-08-26. pdf). MPEG LA. 2010-08-26. . Retrieved 2010-08-26. [11] "MPEG LA Cuts Royalties from Free Web Video, Forever" (http:/ / www. pcmag. com/ article2/ 0,2817,2368359,00. asp). pcmag.com. 2010-08-26. . Retrieved 2010-08-26. [12] "AVC FAQ" (http:/ / www. mpegla. com/ main/ programs/ AVC/ Pages/ FAQ. aspx). Mpeg La. 2002-08-01. . Retrieved 2010-05-17. [13] http:/ / www. google. com/ patents?vid=5,452,104 [14] http:/ / www. google. com/ patents?vid=5,576,767 [15] See Qualcomm Inc. v. Broadcom Corp. (http:/ / caselaw. lp. findlaw. com/ data2/ circs/ fed/ 071545p. pdf), No. 2007-1545, 2008-1162 (Fed. Cir. Dec. 1, 2008). For articles in the popular press, see signonsandiego.com, "Qualcomm loses its patent-rights case" (http:/ / www. signonsandiego. com/ news/ business/ 20070127-9999-1b27verdict. html) and "Qualcomm's patent case goes to jury" (http:/ / www. signonsandiego. com/ news/ business/ 20070126-9999-1b26qualcomm. html); and bloomberg.com "Broadcom Wins First Trial in Qualcomm Patent Dispute" (http:/ / www. bloomberg. com/ apps/ news?pid=20601204& sid=aLX_DFMCEYWU& refer=technology) [16] "Decoding the HTML 5 video codec debate" (http:/ / arstechnica. com/ open-source/ news/ 2009/ 07/ decoding-the-html-5-video-codec-debate. ars). Ars Technica. 2009-07-06. . Retrieved 2011-01-12. [17] "Steve Ballmer, CEO Microsoft, interviewed at Gartner Symposium/ITxpo Orlando 2010" (http:/ / www. youtube. com/ watch?v=iI47b3a9cEI). Gartnervideo. 2010-11. . Retrieved 2011-01-12. [18] "HTML Video Codec Support in Chrome" (http:/ / blog. chromium. org/ 2011/ 01/ html-video-codec-support-in-chrome. html). 2011-01-11. . Retrieved 2011-01-12. [19] "The H.264/AVC Advanced Video Coding Standard: Overview and Introduction to the Fidelity Range Extensions" (http:/ / www. fastvdo. com/ spie04/ spie04-h264OverviewPaper. pdf) (PDF). . Retrieved 2011-07-30. [20] RFC 3984, p.3 [21] Apple Inc. (1999-03-26). "H.264 FAQ" (http:/ / www. apple. com/ quicktime/ technologies/ h264/ faq. html). Apple. . Retrieved 2010-05-17. [22] Karsten Suehring. "H.264/AVC JM Reference Software Download" (http:/ / iphome. hhi. de/ suehring/ tml/ download/ ). Iphome.hhi.de. . Retrieved 2010-05-17. [23] "TS 101 154 – V1.9.1 – Digital Video Broadcasting (DVB); Specification for the use of Video and Audio Coding in Broadcasting Applications based on the MPEG-2 Transport Stream" (http:/ / www. etsi. org/ deliver/ etsi_ts/ 101100_101199/ 101154/ 01. 09. 01_60/ ts_101154v010901p. pdf) (PDF). . Retrieved 2010-05-17. [24] x264 4:4:4 encoding support (http:/ / git. videolan. org/ ?p=x264. git;a=commit;h=c07df2f77dacfec444785bf60229f804dc43c10b), 2011-06-22
31
H.264/MPEG-4 AVC [25] "Quick Reference Guide to generation Intel® Core™ Processor Built-in Visuals – Intel® Software Network" (http:/ / software. intel. com/ en-us/ articles/ quick-reference-guide-to-intel-integrated-graphics/ ). software.intel.com. 2010-10-01. . Retrieved 2011-01-19. [26] "Intel® Quick Sync Video" (http:/ / www. intel. com/ technology/ quicksynch/ index. htm). www.intel.com. 2010-10-01. . Retrieved 2011-01-19. [27] "Design-reuse.com" (http:/ / www. design-reuse. com/ sip/ ?q=H. 264+ encoder). Design-reuse.com. 1990-01-01. . Retrieved 2010-05-17. [28] "Category:DM6467 - Texas Instruments Embedded Processors Wiki" (http:/ / processors. wiki. ti. com/ index. php/ Category:DM6467). Processors.wiki.ti.com. 2011-07-12. . Retrieved 2011-07-30.
Further reading • Wiegand, Thomas; Sullivan, Gary J.; Bjøntegaard, Gisle; Luthra, Ajay (July 2003). "Overview of the H.264/AVC Video Coding Standard" (http://ip.hhi.de/imagecom_G1/assets/pdfs/csvt_overview_0305.pdf) (PDF). IEEE Transactions on Circuits and Systems for Video Technology 13 (7). Retrieved 31 January 2011. • Topiwala, Pankaj; Sullivan, Gary J.; Luthra, Ajay (August 2004). "Overview and Introduction to the Fidelity Range Extensions" (http://www.fastvdo.com/spie04/spie04-h264OverviewPaper.pdf) (PDF). SPIE Applications of Digital Image Processing XXVII. Retrieved 31 January 2011. • Ostermann, J.; Bormans, J.; List, P.; Marpe, D.; Narroschke, M.; Pereira, F.; Stockhammer, T.; Wedi, T. (First Quarter 2004). "Video coding with H.264/AVC: Tools, Performance, and Complexity" (ftp://ftp.tnt. uni-hannover.de/pub/papers/2004/CASM_2004_MN.pdf) (PDF). IEEE Circuits and Systems Magazine 4 (1). Retrieved 31 January 2011. • Sullivan, Gary J.; Wiegand, Thomas (January 2005). "Video Compression—From Concepts to the H.264/AVC Standard" (http://ip.hhi.de/imagecom_G1/assets/pdfs/pieee_sullivan_wiegand_2005.pdf) (PDF). Proceedings of the IEEE 93 (1). Retrieved 31 January 2011. • Richardson, Iain E. G. (2011 January). "Learn about video compression and H.264" (http://www.vcodex.com/ h264.html). VCODEX. Vcodex Limited. Retrieved 31 January 2011.
External links • ITU-T publication page: H.264: Advanced video coding for generic audiovisual services (http://www.itu.int/ rec/T-REC-H.264) • MPEG-4 AVC/H.264 Information (http://forum.doom9.org/showthread.php?t=96059) Doom9's Forum • "Part 10: Advanced Video Coding" (http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail. htm?csnumber=43058). ISO publication page: ISO/IEC 14496-10:2005 – Information technology — Coding of audio-visual objects. • "H.264/AVC JM Reference Software" (http://iphome.hhi.de/suehring/tml/). IP Homepage. Retrieved 2007-04-15. • "JVT document archive site" (http://ftp3.itu.ch/av-arch/jvt-site). Retrieved 2007-05-06. • "Publications" (http://iphome.hhi.de/wiegand/pubs.htm). Thomas Wiegand. Retrieved 2007-06-23. • "Publications" (http://iphome.hhi.de/marpe/pub.htm). Detlev Marpe. Retrieved 2007-04-15. • "Fourth Annual H.264 video codecs comparison" (http://www.compression.ru/video/codec_comparison/ mpeg-4_avc_h264_2007_en.html). Moscow State University. (dated December 2007) • "Discussion on H.264 with respect to IP cameras in use within the security and surveillance industries" (http:// www.networkwebcams.com/ip-camera-learning-center/2009/04/03/ using-h264-video-compression-in-ip-video-surveillance-systems/). (dated April 2009) • "Diary Of An x264 Developer: Why so many H.264 encoders are bad" (http://x264dev.multimedia.cx/ ?p=164). 10/04/2009, – practical implementation issues of H.264 • "Sixth Annual H.264 video codecs comparison" (http://compression.ru/video/codec_comparison/h264_2010/ ). Moscow State University. (dated May 2010)
32
MPEG-4
MPEG-4 MPEG-4 is method of defining compression of audio and visual (AV) digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) (ISO/IEC JTC1/SC29/WG11) under the formal standard ISO/IEC 14496 – Coding of audio-visual objects. Uses of MPEG-4 include compression of AV data for web (streaming media) and CD distribution, voice (telephone, videophone) and broadcast television applications.
Background MPEG-4 absorbs many of the features of MPEG-1 and MPEG-2 and other related standards, adding new features such as (extended) VRML support for 3D rendering, object-oriented composite files (including audio, video and VRML objects), support for externally-specified Digital Rights Management and various types of interactivity. AAC (Advanced Audio Coding) was standardized as an adjunct to MPEG-2 (as Part 7) before MPEG-4 was issued. MPEG-4 is still a developing standard and is divided into a number of parts. Companies promoting MPEG-4 compatibility do not always clearly state which "part" level compatibility they are referring to. The key parts to be aware of are MPEG-4 part 2 (including Advanced Simple Profile, used by codecs such as DivX, Xvid, Nero Digital and 3ivx and by Quicktime 6) and MPEG-4 part 10 (MPEG-4 AVC/H.264 or Advanced Video Coding, used by the x264 encoder, by Nero Digital AVC, by Quicktime 7, and by high-definition video media like Blu-ray Disc). Most of the features included in MPEG-4 are left to individual developers to decide whether to implement them. This means that there are probably no complete implementations of the entire MPEG-4 set of standards. To deal with this, the standard includes the concept of "profiles" and "levels", allowing a specific set of capabilities to be defined in a manner appropriate for a subset of applications. Initially, MPEG-4 was aimed primarily at low bit-rate video communications; however, its scope as a multimedia coding standard was later expanded. MPEG-4 is efficient across a variety of bit-rates ranging from a few kilobits per second to tens of megabits per second. MPEG-4 provides the following functions: • • • •
Improved coding efficiency over MPEG-2 Ability to encode mixed media data (video, audio, speech) Error resilience to enable robust transmission Ability to interact with the audio-visual scene generated at the receiver
Overview MPEG-4 provides a series of technologies for developers, for various service-providers and for end users: • MPEG-4 enables different software and hardware developers to create multimedia objects possessing better abilities of adaptability and flexibility to improve the quality of such services and technologies as digital television, animation graphics, the World Wide Web and their extensions. • Data network providers can use MPEG-4 for data transparency. With the help of standard procedures, MPEG-4 data can be interpreted and transformed into other signal types compatible with any available network. • The MPEG-4 format provides end users with a wide range of interaction with various animated objects. • Standardized Digital Rights Management signaling, otherwise known in the MPEG community as Intellectual Property Management and Protection (IPMP). The MPEG-4 format can perform various functions, among which might be the following: • Multiplexes and synchronizes data, associated with media objects, in such a way that they can be efficiently transported further via network channels. • Interaction with the audio-visual scene, which is formed on the side of the receiver.
33
MPEG-4
34
Profiles and Levels MPEG-4 provides a large and rich set of tools for encoding. Subsets of the MPEG-4 tool sets have been provided for use in specific applications. These subsets, called 'Profiles', limit the size of the tool set a decoder is required to implement.[1] In order to restrict computational complexity, one or more 'Levels' are set for each Profile.[1] A Profile and Level combination allows:[1] • A codec builder to implement only the subset of the standard needed, while maintaining interworking with other MPEG-4 devices that implement the same combination.[1] • Checking whether MPEG-4 devices comply with the standard, referred to as conformance testing.[1]
MPEG-4 parts MPEG-4 consists of several standards—termed "parts"—including the following (each part covers a certain aspect of the whole specification):
MPEG-4 parts[2] [3] Number Part
First public release date (first edition)
Latest public release date (last edition) [5]
Part 1
ISO/IEC 14496-1 [4]
1999
2010
Part 2
ISO/IEC 14496-2 [12]
1999
2004
Part 3
ISO/IEC 14496-3 [14]
1999
2009
Part 4
ISO/IEC 14496-4 [18]
2000
2004
Part 5
ISO/IEC 14496-5 [20]
2000
2001
Part 6
ISO/IEC 14496-6 [22]
1999
2000
Latest amendment
[6]
Title
Description
2010
Systems
Describes synchronization and multiplexing of video and audio. For example the MPEG-4 file format version 1 (obsoleted by version 2 defined in MPEG-4 Part 14). The functionality of a transport protocol stack for transmitting and/or storing content complying with ISO/IEC 14496 is not within the scope of 14496-1 and only the interface to this layer is considered (DMIF). Information about transport of MPEG-4 content is defined e.g. in MPEG-2 Transport Stream, RTP Audio Video [7] [8] [9] [10] [11] Profiles and others.
2009
Visual
A compression codec for visual data (video, still textures, synthetic images, etc.). One of the many "profiles" in Part 2 is the Advanced Simple Profile (ASP).
2010 [17]
Audio
A set of compression codecs for perceptual coding of audio signals, including some variations of Advanced Audio Coding (AAC) as well as other audio/speech coding formats and tools (such as Audio Lossless Coding (ALS), Scalable Lossless Coding (SLS), Structured Audio, Text-To-Speech Interface (TTSI), HVXC, CELP and others)
[19]
2010 (2011)
Conformance testing
Describes procedures for testing conformance to other parts of the standard.
[21]
2010 (2011)
Reference software
Provides reference software for demonstrating and clarifying the other parts of the standard.
[13]
[15]
[23]
[16]
Delivery Multimedia Integration Framework (DMIF)
MPEG-4
35
ISO/IEC TR 14496-9 [28]
2004
2009
Part 10
ISO/IEC 14496-10 [30]
2003
2009
Part 11
ISO/IEC 14496-11 [33]
2005
2005
Part 12
ISO/IEC 14496-12 [36]
2004
2008
Part 13
ISO/IEC 14496-13 [39]
2004
2004
Part 14
ISO/IEC 14496-14 [50]
2003
2003
Part 15
ISO/IEC 14496-15 [53]
2004
2004
A codec for video signals which is technically identical to the ITU-T H.264 standard.
Part 9
Advanced Video Coding (AVC)
2004
Provides hardware designs for demonstrating how to implement the other parts of the standard.
2004
Reference hardware description
ISO/IEC 14496-8 [26]
[29]
Part 8
Carriage of ISO/IEC Specifies a method to carry MPEG-4 content on IP networks. It 14496 contents over also includes guidelines to design RTP payload formats, usage IP networks rules of SDP to transport ISO/IEC 14496-1-related information, MIME type definitions, analysis on RTP security and multicasting.
2004
[27]
2002
Optimized reference Provides examples of how to make improved implementations software for coding (e.g., in relation to Part 5). of audio-visual objects
ISO/IEC TR 14496-7 [24]
[25]
Part 7
[31]
[32]
(2010
)
[34]
2009
Scene description and application engine
Can be used for rich, interactive content with multiple profiles, including 2D and 3D versions. MPEG-4 Part 11 revised MPEG-4 Part 1 – ISO/IEC 14496-1:2001 and two amendments to MPEG-4 Part 1. It describes a system level description of an application engine (delivery, lifecycle, format and behaviour of downloadable Java byte code applications) and the Binary Format for Scene (BIFS) and the Extensible MPEG-4 Textual (XMT) format – a textual representation of the MPEG-4 [34] multimedia content using XML, etc. (It is also known as [35] BIFS, XMT, MPEG-J. MPEG-J was defined in MPEG-4 Part 21)
[37]
[38] 2009 [2] (2010 )
ISO base media file format
A file format for storing time-based media content. It is a general format forming the basis for a number of other more specific file formats (e.g. 3GP, Motion JPEG 2000, MPEG-4 Part 14). It is technically identical to ISO/IEC 15444-12 (JPEG 2000 image coding system – Part 12).
Intellectual Property Management and Protection (IPMP) Extensions
MPEG-4 Part 13 revised an amendment to MPEG-4 Part 1 – ISO/IEC 14496-1:2001/Amd 3:2004. It specifies common Intellectual Property Management and Protection (IPMP) processing, syntax and semantics for the carriage of IPMP tools in the bit stream, IPMP information carriage, mutual authentication for IPMP tools, a list of registration authorities required for the support of the amended specifications (e.g. CISAC), etc. It was defined due to the lack of interoperability of different protection mechanisms (different DRM systems) for protecting and distributing copyrighted digital content such as [41] [42] [43] [44] [45] [46] [47] [48] [49] music or video.
MP4 file format
It is also known as "MPEG-4 file format version 2". The designated container file format for MPEG-4 content, which is based on Part 12. It revises and completely replaces Clause 13 of ISO/IEC 14496-1 (MPEG-4 Part 1: Systems), in which the MPEG-4 file format was previously specified.
Advanced Video Coding (AVC) file format
For storage of Part 10 video. File format is based on Part 12, but also allows storage in other file formats.
[40]
[51]
[54]
[52]
(2010
)
2008 [55] (2010 )
MPEG-4
36 [57]
Part 16
ISO/IEC 14496-16 [56]
2004
2009
Part 17
ISO/IEC 14496-17 [59]
2006
2006
Part 18
ISO/IEC 14496-18 [61]
2004
2004
Part 19
ISO/IEC 14496-19 [63]
2004
2004
Part 20
ISO/IEC 14496-20 [65]
2006
2008
Part 21
ISO/IEC 14496-21 [68]
2006
2006
Part 22
ISO/IEC 14496-22 [72]
2007
2009
Part 23
ISO/IEC 14496-23 [76]
2008
2008
Part 24
ISO/IEC TR 14496-24 [78]
2008
2008
Part 25
ISO/IEC 14496-25 [80]
2009
2009
Part 26
ISO/IEC 14496-26 [82]
2010
2010
Part 27
ISO/IEC 14496-27 [84]
2009
Animation Framework eXtension (AFX)
It specifies MPEG-4 Animation Framework eXtension (AFX) model for representing 3D Graphics content. MPEG-4 is extended with higher-level synthetic objects for specifying geometry, texture, animation and dedicated compression algorithms.
[60]
Streaming text format
Timed Text subtitle format
[62]
Font compression and streaming
For Open Font Format defined in Part 22.
[64]
Synthesized texture stream
Synthesized texture streams are used for creation of very low bitrate synthetic video clips.
Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)
LASeR requirements (compression efficiency, code and memory footprint) are fulfilled by building upon the existing the Scalable Vector Graphics (SVG) format defined by the World [67] Wide Web Consortium.
[69]
MPEG-J Graphics Framework eXtensions (GFX)
Describes a lightweight programmatic environment for advanced interactive multimedia applications â&#x20AC;&#x201C; a framework that marries a subset of the MPEG standard Java application [35] [69] [70] [71] environment (MPEG-J) with a Java API. (at "FCD" stage in July 2005, FDIS January 2006, published as ISO standard on 2006-11-22).
[73]
Open Font Format
OFFS is based on the OpenType version 1.4 font format specification, and is technically equivalent to that [74] [75] specification. Reached "CD" stage in July 2005, published as ISO standard in 2007
[77]
Symbolic Music Representation (SMR)
Reached "FCD" stage in October 2006, published as ISO standard in 2008-01-28
[79]
Audio and systems interaction
Describes the desired joint behavior of MPEG-4 File Format and MPEG-4 Audio.
[81]
3D Graphics Defines a model for connecting 3D Graphics Compression tools Compression Model defined in MPEG-4 standards to graphics primitives defined in any other standard or specification.
[83]
Audio Conformance
[66]
[85]
[58]
(2010
)
2009
[86]
(2010
)
3D Graphics conformance
3D Graphics Conformance summarizes the requirements, cross references them to characteristics, and defines how conformance with them can be tested. Guidelines are given on constructing tests to verify decoder conformance.
MPEG-4
Part 28
37 [88]
Composite font representation
ISO/IEC CD 14496-28 [87]
Under development
Profiles are also defined within the individual "parts", so an implementation of a part is ordinarily not an implementation of an entire part. MPEG-1, MPEG-2, MPEG-7 and MPEG-21 are other suites of MPEG standards.
MPEG4 Levels Profile, Level
SP, L0
SP, L0b
SP, L1
SP, L2
SP, L3
ASP, L0
ASP, L1
ASP, L2
ASP, L3
ASP, L3b
ASP, L4
ASP, L5
Max. bitrate (kbit/s)
64
128
64
128
384
128
128
384
768
1500
3000
8000
Max. buffer (kbit)
160
320
160
640
640
160
160
640
640
1040
1280
1792
Max. delay @ max. bitrate (sec)
2.5
2.5
2.5
5
1.66
1.25
1.25
1.66
0.86
0.69
0.43
0.22
2048
2048
2048
4096
8192
2048
2048
4096
4096
4096
8192
16384
99
99
99
396
396
99
99
396
396
396
792
1620
1485
1485
5940
2970
5940
23760
48600
256×192
Max. VP size (bit) Max. VOP size (MB)
Max. 1485 decoder rate (MB/s) Max. framesize @ 30Hz
-
-
128×96
Max. framesize @ 25Hz
-
-
Max. framesize @ 24Hz
-
-
11880 2970
CIF
QCIF QCIF
144×96 304×192288×208
CIF
160×96
304×208
256×192
11880 11880
CIF
CIF
352×576704×288 720×576
QCIF QCIF 304×192288×208
CIF
CIF
352×576704×288 720×576
CIF
QCIF QCIF
304×208
CIF
CIF
352×576704×288 720×576
Max. framesize @ 15Hz
QCIF QCIF
QCIF
CIF
CIF
QCIF QCIF
CIF
CIF
CIF
352×576704×288 720×576
Max. framesize @ 12.5Hz
QCIF QCIF
QCIF
CIF
CIF
QCIF QCIF
CIF
CIF
CIF
352×576704×288 720×576
MPEG-4
Licensing MPEG-4 contains patented technologies that require licensing in countries that acknowledge software algorithm patents. Patents covering MPEG-4 are claimed by over two dozen companies. The MPEG Licensing Authority[89] licenses patents required for MPEG-4 Part 2 Visual from a wide range of companies (audio is licensed separately) and lists all of its licensors and licensees on the site. New licenses for MPEG-4 System patents are under development[90] and no new licenses are being offered while holders of its old MPEG-4 Systems license are still covered under the terms of that license for the patents listed (MPEG LA – Patent List [91]). AT&T is trying to sue companies such as Apple Inc. over alleged MPEG-4 patent infringement.[92] The terms of Apple's Quicktime 7 license for users[93] describes in paragraph 14 the terms under Apple's existing MPEG-4 System Patent Portfolio license from MPEGLA.
References [1] RFC 3640 (http:/ / tools. ietf. org/ html/ rfc3640#page-31), IETF, p. 31, . [2] MPEG. "MPEG standards – Full list of standards developed or under development" (http:/ / mpeg. chiariglione. org/ standards. htm). Chiariglione. . Retrieved 2010-02-09. [3] ISO/IEC JTC 1/SC 29 (2009-11-09). "Programme of Work – MPEG-4 (Coding of audio-visual objects)" (http:/ / www. itscj. ipsj. or. jp/ sc29/ 29w42911. htm#MPEG-4). . Retrieved 2009-11-10. [4] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=24462 [5] "ISO/IEC 14496-1:2010 – Information technology — Coding of audio-visual objects — Part 1: Systems" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=55688). . Retrieved 2011-01-28. [6] ISO. "ISO/IEC 14496-1:2010/Amd 1:2010 – Usage of LASeR in MPEG-4 systems and Registration Authority for MPEG-4 descriptors" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=55689). . Retrieved 2011-01-28. [7] ISO/IEC (2004-11-15) (PDF), ISO/IEC 14496-1:2004 – Third edition 2004-11-15 – Information technology — Coding of audio-visual objects — Part 1: Systems (http:/ / webstore. iec. ch/ preview/ info_isoiec14496-1{ed3. 0}en. pdf), , retrieved 2010-04-11 [8] WG11 (MPEG) (2002-03). "Overview of the MPEG-4 Standard" (http:/ / mpeg. chiariglione. org/ standards/ mpeg-4/ mpeg-4. htm). . Retrieved 2010-04-11. [9] WG11 (1997-11-21) (MS Word .doc), Text for CD 14496-1 Systems (http:/ / www. ece. cmu. edu/ ~ece796/ documents/ MPEG4_Systems_CD_w1901. doc), , retrieved 2010-04-11 [10] "MPEG-4 Systems Elementary Stream Management (ESM)" (http:/ / mpeg. chiariglione. org/ faq/ mp4-sys/ sys-faq-esm. htm). 2001-07. . Retrieved 2010-04-11. [11] "MPEG Systems (1-2-4-7) FAQ, Version 17.0" (http:/ / mpeg. chiariglione. org/ faq/ mp4-sys/ mp4-sys. htm). 2001-07. . Retrieved 2010-04-11. [12] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=25034 [13] "ISO/IEC 14496-2:2004 – Information technology — Coding of audio-visual objects — Part 2: Visual" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=39259). ISO. . Retrieved 2009-10-30. [14] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=25035 [15] "ISO/IEC 14496-3:2009 – Information technology — Coding of audio-visual objects — Part 3: Audio" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53943). ISO. . Retrieved 2009-10-30. [16] ISO (2009). "ISO/IEC 14496-3:2009/FPDAmd 2, ALS simple profile and transport of SAOC" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=54838). ISO. . Retrieved 2009-10-13. [17] "ISO/IEC 14496-3:2009/Amd 1:2009 – HD-AAC profile and MPEG Surround signaling" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53944). ISO. 2009-09-11. . Retrieved 2009-10-15. [18] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=25036 [19] "ISO/IEC 14496-4:2004 – Information technology — Coding of audio-visual objects — Part 4: Conformance testing" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=36084). ISO. . Retrieved 2009-10-30. [20] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=30554 [21] "ISO/IEC 14496-5:2001 – Information technology — Coding of audio-visual objects — Part 5: Reference software" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=36086). ISO. . Retrieved 2009-10-30. [22] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=30556 [23] "ISO/IEC 14496-6:2000 – Information technology — Coding of audio-visual objects — Part 6: Delivery Multimedia Integration Framework (DMIF)" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=34418). ISO. . Retrieved 2009-10-30. [24] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=35368 [25] "ISO/IEC TR 14496-7:2004 – Information technology — Coding of audio-visual objects — Part 7: Optimized reference software for coding of audio-visual objects" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=40728). ISO. .
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MPEG-4 Retrieved 2009-10-30. [26] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=36066 [27] "ISO/IEC 14496-8:2004 – Information technology — Coding of audio-visual objects — Part 8: Carriage of ISO/IEC 14496 contents over IP networks" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=36066). ISO. . Retrieved 2009-10-30. [28] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=38147 [29] "ISO/IEC TR 14496-9:2009 – Information technology — Coding of audio-visual objects — Part 9: Reference hardware description" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=52073). ISO. . Retrieved 2009-10-30. [30] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=37729 [31] "ISO/IEC 14496-10:2009 – Information technology — Coding of audio-visual objects — Part 10: Advanced Video Coding" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=52974). ISO. . Retrieved 2009-10-30. [32] "ISO/IEC 14496-10:2009/FPDAmd 1 – Constrained baseline profile, stereo high profile and frame packing arrangement SEI message" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=52975). ISO. . Retrieved 2009-12-29. [33] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=38560 [34] "ISO/IEC 14496-11:2005 – Information technology — Coding of audio-visual objects — Part 11: Scene description and application engine" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=38560). ISO. . Retrieved 2009-10-30. [35] "MPEG-J White Paper" (http:/ / mpeg. chiariglione. org/ technologies/ mpeg-4/ mp04-j/ ). 2005-07. . Retrieved 2010-04-11. [36] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=38539 [37] "ISO/IEC 14496-12:2008 – Information technology — Coding of audio-visual objects — Part 12: ISO base media file format" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=51533). ISO. . Retrieved 2009-10-30. [38] ISO. "ISO/IEC 14496-12:2008/Amd 1:2009 – General improvements including hint tracks, metadata support and sample groups" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=52356). . Retrieved 2009-12-30. [39] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=39110 [40] "ISO/IEC 14496-13:2004 – Information technology — Coding of audio-visual objects — Part 13: Intellectual Property Management and Protection (IPMP) extensions" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=39110). ISO. . Retrieved 2009-10-30. [41] MPEG (March 2002) (MS Word .doc), FPDAM ISO/IEC 14496-1:2001 / AMD3 (Final Proposed Draft Amendment) (http:/ / www. itscj. ipsj. or. jp/ sc29/ open/ 29view/ 29n4689t. doc), , retrieved 2010-08-01 [42] "MPEG-4 IPMPX white paper" (http:/ / mpeg. chiariglione. org/ technologies/ mpeg-4/ mp04-ipx/ ). MPEG. July 2005. . Retrieved 2010-08-01. [43] "MPEG Intellectual Property Management and Protection" (http:/ / mpeg. chiariglione. org/ technologies/ general/ mp-drm/ ). MPEG. April 2009. . Retrieved 2010-08-01. [44] (PDF) MPEG-4 IPMP Extension – For Interoperable Protection of Multimedia Content (http:/ / www. cs. missouri. edu/ ~zengw/ MPEG-4_IPMP_final_manuscript. pdf), 2004, , retrieved 2010-08-01 [45] "MPEG Registration Authority – IPMP" (http:/ / www. mpegra. org/ aspx/ Login. aspx?Type=IPMP). MPEG RA International Agency (CISAC). . Retrieved 2010-08-01. [46] "MPEG RA – FAQ IPMP" (http:/ / www. mpegra. org/ aspx/ FAQ. aspx). MPEG RA International Agency (CISAC). . Retrieved 2010-08-01. [47] "Intellectual Property Management and Protection Registration Authority" (http:/ / web. archive. org/ web/ 20041205233806/ www. ipmp-ra. org/ ipmp/ ipmpweb. nsf/ home1). CISAC. 2004-12-05. Archived from the original (http:/ / www. ipmp-ra. org/ ipmp/ ipmpweb. nsf/ home1) on 2004-12-05. . Retrieved 2010-08-01. [48] Chiariglione, Leonardo (2003), Digital media: Can content, business and users coexist? (http:/ / leonardo. chiariglione. org/ publications/ nab03/ nab2003_2. htm), Torino, IT: Telecom Italia Lab, , retrieved 2010-08-01 [49] (PPT) IPMP in MPEG – W3C DRM workshop 22/23 January 2001 (http:/ / www. w3. org/ 2000/ 12/ drm-ws/ pp/ mpeg-koenen. ppt), , retrieved 2010-08-01 [50] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=38538 [51] ISO. "ISO/IEC 14496-14:2003 – Information technology — Coding of audio-visual objects — Part 14: MP4 file format" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=38538). . Retrieved 2009-10-30. [52] "ISO/IEC 14496-14:2003/FPDAmd 1 – Handling of MPEG-4 audio enhancement layers" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53749). ISO. . Retrieved 2009-12-29. [53] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=38573 [54] "ISO/IEC 14496-15:2004 – Information technology — Coding of audio-visual objects — Part 15: Advanced Video Coding (AVC) file format" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=38573). ISO. . Retrieved 2009-10-30. [55] "ISO/IEC 14496-15:2004/FDAmd 3 – File format support for Multiview Video Coding" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=52885). ISO. . Retrieved 2009-12-29. [56] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=38569 [57] "ISO/IEC 14496-16:2009 – Information technology — Coding of audio-visual objects — Part 16: Animation Framework eXtension (AFX)" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=54596). ISO. . Retrieved 2009-12-29. [58] "ISO/IEC 14496-16:2009/FPDAmd 1 – Scalable complexity 3D mesh coding" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=54603). . Retrieved 2009-12-29.
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MPEG-4 [59] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=39478 [60] "ISO/IEC 14496-17:2006 – Information technology — Coding of audio-visual objects — Part 17: Streaming text format" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=39478). ISO. . Retrieved 2009-10-30. [61] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=40151 [62] "ISO/IEC 14496-18:2004 – Information technology — Coding of audio-visual objects — Part 18: Font compression and streaming" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=40151). ISO. . Retrieved 2009-10-30. [63] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=40152 [64] "ISO/IEC 14496-19:2004 – Information technology – Coding of audio-visual objects — Part 19: Synthesized texture stream" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=40152). ISO. . Retrieved 2009-10-30. [65] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=41650 [66] "ISO/IEC 14496-20:2008 – Information technology — Coding of audio-visual objects — Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=52454). ISO. . Retrieved 2009-10-30. [67] "MPEG-4 LASeR white paper" (http:/ / mpeg. chiariglione. org/ technologies/ mpeg-4/ mp04-lsr/ ). 2005-07. . Retrieved 2010-04-11. [68] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=41733 [69] "ISO/IEC 14496-21:2006 – Information technology — Coding of audio-visual objects — Part 21: MPEG-J Graphics Framework eXtensions (GFX)" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=41733). ISO. . Retrieved 2009-10-30. [70] "MPEG-4 Systems MPEG-J" (http:/ / mpeg. chiariglione. org/ faq/ mp4-sys/ sys-faq-mpegj. htm). 2001-07. . Retrieved 2010-04-11. [71] "MPEG-J GFX white paper" (http:/ / mpeg. chiariglione. org/ technologies/ mpeg-4/ mpj-gfx/ ). 2005-07. . Retrieved 2010-04-11. [72] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ts/ catalogue_detail. htm?csnumber=43466 [73] "ISO/IEC 14496-22:2009 – Information technology — Coding of audio-visual objects — Part 22: Open Font Format" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_ics/ catalogue_detail_ics. htm?csnumber=52136). ISO. . Retrieved 2009-10-30. [74] ISO/IEC JTC 1/SC 29/WG 11 (2008-07). "ISO/IEC 14496-22 "Open Font Format"" (http:/ / mpeg. chiariglione. org/ technologies/ mpeg-4/ mp04-off/ ). Chiariglione. . Retrieved 2010-02-09. [75] "ISO/IEC 14496-22 Information technology — Coding of audio-visual objects — Part 22: Open Font Format" (http:/ / standards. iso. org/ ittf/ PubliclyAvailableStandards/ c043466_ISO_IEC_14496-22_2007(E). zip) (Zip). 2007-03-15. . Retrieved 2010-01-28. [76] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=45531 [77] "ISO/IEC 14496-23:2008 – Information technology — Coding of audio-visual objects — Part 23: Symbolic Music Representation" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=45531). ISO. . Retrieved 2009-10-30. [78] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=46461 [79] "ISO/IEC TR 14496-24:2008 – Information technology — Coding of audio-visual objects — Part 24: Audio and systems interaction" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=46461). ISO. . Retrieved 2009-10-30. [80] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=50552 [81] "ISO/IEC 14496-25:2009 – Information technology — Coding of audio-visual objects — Part 25: 3D Graphics Compression Model" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=50552). ISO. . Retrieved 2009-10-30. [82] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53750 [83] "ISO/IEC 14496-26:2010 – Information technology — Coding of audio-visual objects — Part 26: Audio conformance" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53750). ISO. . Retrieved 2010-05-16. [84] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53751 [85] "ISO/IEC 14496-27:2009 – Information technology — Coding of audio-visual objects — Part 27: 3D Graphics conformance" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53751). ISO. . Retrieved 2009-12-29. [86] ISO. "ISO/IEC 14496-27:2009/FPDAmd 2 – Handling of MPEG-4 audio enhancement layers" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=53752). . Retrieved 2009-12-29. [87] http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=59240 [88] "ISO/IEC CD 14496-28 – Information technology — Coding of audio-visual objects — Part 28: Composite font representation" (http:/ / www. iso. org/ iso/ iso_catalogue/ catalogue_tc/ catalogue_detail. htm?csnumber=59240). ISO. . Retrieved 2011-04-06. [89] MPEG Licensing Authority – MPEG-4 Visual: Introduction (http:/ / www. mpegla. com/ main/ programs/ M4V/ Pages/ Intro. aspx) [90] MPEG Licensing Authority – MPEG-4 Systems: Introduction (http:/ / www. mpegla. com/ main/ programs/ M4S/ Pages/ Intro. aspx) [91] http:/ / www. mpegla. com/ main/ programs/ M4S/ Pages/ PatentList. aspx [92] "AT&T Warns Apple, Others, Of Patent Infringement" (http:/ / www. pcmag. com/ article2/ 0,1895,1923218,00. asp). PC Magazine. February 9, 2006. . Retrieved 2007-08-10. [93] Apple Quicktime 7 Software License (PDF) (http:/ / images. apple. com/ legal/ sla/ docs/ quicktime7. pdf)
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MPEG-4
External links • Overview of the MPEG-4 Standard (http://mpeg.chiariglione.org/standards/mpeg-4/mpeg-4.htm) at the MPEG Official Website • MPEG-4: The container for digital media (http://www.apple.com/br/quicktime/technologies/mpeg4/) • AAC at core of MPEG-4, 3GPP and 3GPP2 specifications (http://www.apple.com/quicktime/technologies/ aac/) • MPEG Industry Forum (MPEGIF) MPEG-4 page (http://www.m4if.org/mpeg4/) • MPEG Industry Forum (MPEGIF) MPEG-4 White Paper (http://www.m4if.org/public/documents/vault/ MPEG4WhitePaperV2a.zip) • JM MPEG-4 AVC /H.264 Reference Code (http://iphome.hhi.de/suehring/tml/) • OpenIPMP: Open Source DRM Project for MPEG-4 (http://sourceforge.net/projects/openipmp/)
Display resolution The display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube (CRT) and flat panel or projection displays using fixed picture-element (pixel) arrays. It is usually quoted as width × height, with the units in pixels: for example, "1024x768" means the width is 1024 pixels and the height is 768 pixels. One use of the term “display resolution” applies to fixed-pixel-array This chart shows the most common display resolutions, with the color of each resolution displays such as plasma display panels type indicating the display ratio (e.g., orange indicates a 4:3 ratio) (PDPs), liquid crystal displays (LCDs), digital light processing (DLP) projectors, or similar technologies, and is simply the physical number of columns and rows of pixels creating the display (e.g., 1920×1080). A consequence of having a fixed grid display is that, for multi-format video inputs, all displays need a "scaling engine" (a digital video processor that includes a memory array) to match the incoming picture format to the display. Note that the use of the word resolution here is a misnomer, though common. The term “display resolution” is usually used to mean pixel dimensions, the number of pixels in each dimension (e.g., 1920×1080), which does not tell anything about the resolution of the display on which the image is actually formed: resolution properly refers to the pixel density, the number of pixels per unit distance or area, not total number of pixels. In digital measurement, the display resolution would be given in pixels per inch. In analog measurement, if the screen is 10 inches high, then the horizontal resolution is measured across a square 10 inches wide. This is typically stated as "lines horizontal resolution, per picture height;" for example, analog NTSC TVs can typically display 486 lines of "per picture height" horizontal resolution, which is equivalent to 648 total lines of actual picture information from left edge to right edge. Which would give NTSC TV a display resolution of 648×486 in actual lines/picture information, but in "per picture
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height" a display resolution of 486×486.
Considerations Some commentators also use this term to indicate a range of input formats that the display's input electronics will accept and often include formats greater than the screen's native grid size even though they have to be down-scaled to match the screen's parameters (e.g., accepting a 1920×1080 input on a display with a native 1366×768 pixel array). In the case of television inputs, many manufacturers will take the input and zoom it out to "overscan" the display by as much as 5% so input resolution is not necessarily display resolution.
1080p progressive scan HDTV, which uses a 16:9 ratio.
The eye's perception of "display resolution" can be affected by a number of factors—see Image resolution and Optical resolution. One factor is the display screen's rectangular shape, which is expressed as the ratio of the physical picture width to the picture height. This is known as the aspect ratio. A screen's physical aspect ratio and the individual pixels' aspect ratio may not necessarily be the same. An array of 1280×720 on a 16:9 display has square pixels. An array of 1024×768 on a 16:9 display has rectangular pixels. An example of pixel shape affecting "resolution" or perceived sharpness: displaying more information in a smaller area using a higher resolution makes the image much clearer. However, newer LCD screens and such are fixed at a certain resolution; making the resolution lower on these kinds of screens will greatly decrease sharpness, as an interpolation process is used to "fix" the non-native resolution input into the display's native resolution output. While some CRT-based displays may use digital video processing that involves image scaling using memory arrays, ultimately "display resolution" in CRT-type displays is affected by different parameters such as spot size and focus, astigmatic effects in the display corners, the color phosphor pitch shadow mask (such as Trinitron) in color displays, and the video bandwidth.
Overview Analog television systems use interlaced video scanning with two sequential scans called fields (50 PAL or 60 NTSC fields per second), one with the odd numbered scan lines, the other with the even numbered scan lines to give a complete picture or frame (25 or 30 frames per second). This is done to save transmission bandwidth but a consequence is that in picture tube (CRT) displays, the full vertical resolution cannot be realized. For example, the maximum detail in the vertical direction would be for adjacent lines to be alternately black then white. This is not as great a problem in a progressive video display but an interlace display will have an unacceptable flicker at the slower frame rate. This is why interlace is unacceptable for fine detail such as computer word processing or spreadsheets. For television it means that if the picture is intended for interlace displays the picture must be vertically filtered to remove this objectionable flicker with a reduction of vertical resolution. According to the Kell factor the reduction is to about 85%, so a 576 line PAL interlace display only has
A 16:9-ratio television from the early 2000s.
Display resolution about 480 lines vertical resolution, and a 486 line NTSC interlace display has a resolution of approximately 410 lines vertical. Similarly, 1080i digital interlaced video would need to be filtered to about 910 lines for an interlaced display, although a fixed pixel display (such as LCD television) eliminates the inaccuracies of scanning, and thus can achieve Kell factors as high as 95% or 1020 lines. It should be noted that the Kell Factor equally applies to progressive scan. Using a Kell factor of 0.9, a 1080p HDTV video system using a CCD camera and an LCD or plasma display will only have 1728×972 lines of resolution. Fixed pixel array displays such as LCDs, plasmas, DLPs, LCoS, etc. need a "video scaling" processor with frame memory, which, depending on the processing system, effectively converts an incoming interlaced video signal into a progressive video signal. A similar process occurs in a PC and its display with interlaced video (e.g., from a TV tuner card). The downside is that interlace motion artifacts are almost impossible to remove resulting in horizontal "toothed" edges on moving objects. In analog connected picture displays such as CRT TV sets, the horizontal scanlines are not divided into pixels, but by the sampling theorem, the bandwidth of the luma and chroma signals implies a horizontal resolution. For television, the analog bandwidth for luminance in standard definition can vary from 3 MHz (approximately 330 lines edge-to-edge; VHS) to 4.2 MHz (440 lines; live analog) up to 7 MHz (660 lines; DVD). In high definition the bandwidth is 37 MHz (720p/1080i) or 74 MHz (1080p/60).
Current standards Further information: List of common resolutions
Televisions Televisions are of the following resolutions: • Standard-definition television (SDTV): • 480i (NTSC uses an analog system of 486i split into two interlaced fields of 243 lines) • 576i (PAL, 720×576 split into two interlaced fields of 288 lines) • Enhanced-definition television (EDTV): • 480p (720×480 progressive scan) • 576p (720×576 progressive scan) • High-definition television (HDTV): • 720p (1280×720 progressive scan) • 1080i (1920×1080 split into two interlaced fields of 540 lines) • 1080p (1920×1080 progressive scan)
Computer Monitors Further information: Computer display standard Computer monitors have higher resolutions than most televisions. As of July 2002, 1024×768 eXtended Graphics Array was the most common display resolution.[1] [2] Many web sites and multimedia products were re-designed from the previous 800×600 format to the higher 1024×768-optimized layout. The availability of inexpensive LCD monitors has made the 5:4 aspect ratio resolution of 1280×1024 more popular for desktop usage. Many computer users including CAD users, graphic artists and video game players run their computers at 1600×1200 resolution (UXGA, Ultra-eXtended) or higher if they have the necessary equipment. Other recently available resolutions include oversize aspects like 1400×1050 SXGA+ and wide aspects like 1280×800 WXGA, 1440x900 WXGA+, 1680×1050 WSXGA+, and 1920×1200 WUXGA. A new more-than-HD resolution of 2560×1600 WQXGA was released in 30" LCD monitors in 2007. In 2010, 27" LCD monitors with the resolution 2560×1440 were released by multiple manufacturers including Apple.[3] Special monitors for medical diagnostic
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Display resolution
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work support a resolution of up to 4096×2160,[4] which is as of May 2011 the maximum resolution available in a single monitor. The most common computer display resolutions are as follows:[5] Resolution Higher than 1024×768
% of Internet Users 85.1%
Less than or equal to 1280×1024 77.7+% 1280×1024
14.8%
1024×768
13.8%
800×600
0.6%
Lower than 800×600
0%
Unknown
0.5%
Note: These statistics were gathered from visitors to a website dedicated to web technologies, so there may be an over-representation of both higher-resolution monitors and lower-resolution handheld devices. Updated to January 2011 results. These are the results of Steam hardware survey of July 2011 (note that these figures reflect video-gaming enthusiasts only):[6] Code
Name
Aspect ratio
Width
Height
% of Steam users
XGA
eXtended Graphics Array
4:3
1024
768
5.12%
XGA+
eXtended Graphics Array Plus
4:3
1152
864
1.04%
WXGA
Widescreen eXtended Graphics Array
16:9
1280
720
0.69%
WXGA
Widescreen eXtended Graphics Array
16:10
1280
800
5.28%
SXGA (UVGA) Super eXtended Graphics Array
4:3
1280
960
0.95%
SXGA
Super eXtended Graphics Array
5:4
1280
1024
11.80%
HD
High Definition
16:9
1360
768
1.42%
HD
High Definition
16:9
1366
768
6.50%
WXGA+
Widescreen eXtended Graphics Array Plus
16:10
1440
900
9.20%
HD+
High Definition Plus
16:9
1600
900
4.05%
UXGA
Ultra eXtended Graphics Array
4:3
1600
1200
0.81%
WSXGA+
Widescreen Super eXtended Graphics Array Plus 16:10
1680
1050
18.01%
FHD (Full HD)
Full High Definition
16:9
1920
1080
21.78%
WUXGA
Widescreen Ultra eXtended Graphics Array
16:10
1920
1200
7.80%
QFHD
Quad Full High Definition
16:9
2560
1440
0.65%
Other
4.92%
When a computer display resolution is set higher than the physical screen resolution (native resolution) , some video drivers make the virtual screen scrollable over the physical screen thus realizing a two dimensional virtual desktop with its viewport. Most LCD manufacturers do make note of the panel's native resolution as working in a non-native resolution on LCDs will result in a poorer image, due to dropping of pixels to make the image fit (when using DVI) or insufficient sampling of the analog signal (when using VGA connector). Few CRT manufacturers will quote the true native resolution since CRTs are analog in nature and can vary their display from as low as 320×200 (emulation of older computers or game consoles) to as high as the internal board will allow, or the image becomes too detailed for the vacuum tube to recreate (i.e. analog blur). Thus CRTs provide a variability in resolution that LCDs can not
Display resolution
45
provide (LCDs have fixed resolution). In recent years the popularity of 16:9 aspect ratios has resulted in more notebook display resolutions adhering to this aspect ratio. 1366×768 (HD) has become popular for most notebook sizes, while 1600×900 (HD+) and 1920x1080 (FHD) are available for larger notebooks. As far as digital cinematography is concerned, video resolution standards depend first on the frames' aspect ratio in the film stock (which is usually scanned for digital intermediate post-production) and then on the actual points' count. Although there is not a unique set of standardized sizes, it is commonplace within the motion picture industry to refer to "nK" image "quality", where is a (small, usually even) integer number which translates into a set of actual resolutions, depending on the film format. As a reference consider that, for a 4:3 (around 1.33:1) aspect ratio which a film frame (no matter what is its format) is expected to horizontally fit in, is the multiplier of 1024 such that the horizontal resolution is exactly points. For example, 2K reference resolution is 2048×1536 pixels, whereas 4K reference resolution is 4096×3072 pixels. Nevertheless, 2K may also refer to resolutions like 2048×1556 (full-aperture), 2048×1152 (HDTV, 16:9 aspect ratio) or 2048×872 pixels (Cinemascope, 2.35:1 aspect ratio). It is also worth noting that while a frame resolution may be, for example, 3:2 (720×480 NTSC), that is not what you will see on-screen (i.e. 4:3 or 16:9 depending on the orientation of the rectangular pixels). Videos on resolution 1280x1024 are with incorrect aspect ratio and videogames graphics is correct on 1280x1024 resolution. It's because this resolution have physical display aspect ratio 4:3 and resolution aspect ratio 1280:1024=5:4. So such monitors are good only for videogames and 3D graphics and not for watching videos and pictures. It can be not true for all LCD monitors, but is true for all CRT monitors, in this (CRT) case need to choose resolution 1280:960=4:3. Evolution of standards Many personal computers introduced in the late 1970s and the 1980s were designed to use television sets as their display devices, making the resolutions dependent on the television standards in use, including PAL and NTSC. Picture sizes were usually limited to ensure the visibility of all the pixels in the major television standards and the broad range of television sets with varying amounts of overscan. The actual drawable picture area was therefore somewhat smaller than the whole screen, and was usually surrounded by a static-colored border (see image to right). Also, the interlace scanning was usually omitted in order to provide more stability to the picture, effectively halving the vertical resolution in progress. 160×200, 320×200 and 640×200 on NTSC were relatively common resolutions in the era (224, 240 or 256 scanlines were also common). In the IBM PC world, these resolutions came to be used by 16-color EGA video cards.
The blue borders in the overscan region would have been barely visible.
One of the drawbacks of using a classic television is 640×200 – monitor vs. television that the computer display resolution is higher than the TV could decode. Chroma resolution for NTSC/PAL televisions are bandwidth-limited to a maximum 1.5 megahertz, or approximately 160 pixels wide, which led to blurring of the color for 320- or 640-wide signals, and made text difficult to read (see second image to right). Many users upgraded to higher-quality televisions with S-Video or RGBI inputs that helped eliminate chroma blur and
Display resolution
46
produce more legible displays. The earliest, lowest cost solution to the chroma problem was offered in the Atari 2600 Video Computer System and the Apple II+, both of which offered the option to disable the color and view a legacy black-and-white signal. On the Commodore 64, the GEOS mirrored the Mac OS method of using black-and-white to improve readability. The 640×400i resolution (720×480i with borders disabled) was first introduced by home computers such as the Commodore Amiga and (later) Atari Falcon. These computers used interlace to boost the maximum vertical resolution. These modes were only suited to graphics or gaming, as the flickering interlace made reading text in word processor, database, or spreadsheet software difficult. (Modern game consoles solve this problem by pre-filtering the 480i video to a lower resolution. For example, Final Fantasy XII suffers from flicker when the filter is turned off, but stabilizes once filtering is restored. The computers of the 1980s lacked sufficient power to run similar filtering software.)
A 4096 color interlaced image on an Amiga from 1989.
The advantage of a 720×480i overscanned computer was an easy interface with interlaced TV production, leading to the development of Newtek's Video Toaster. This device allowed Amigas to be used for CGI creation in various news departments (example: weather overlays), drama programs such as NBC's seaQuest, WB's Babylon 5, and early computer-generated animation by Disney for the Little Mermaid, Beauty and the Beast, and Aladdin. In the PC world, the IBM PS/2 VGA and MCGA (multi-color) on-board graphics chips used a non-interlaced (progressive) 640×480×16 color resolution that was easier to read and thus more-useful for office work. It was the standard resolution from 1990 to around 1996. The standard resolution was 800×600 until around 2000. Microsoft Windows XP, 16-color (top) and 256-color (bottom) progressive from 1980s VGA released in 2001, was designed to run at 800×600 card. Dithering is used to overcome color limitations. minimum although it is possible to select the original 640×480 in the Advanced Settings window. Linux, FreeBSD, and most Unix variants use the X Window System and can run at any desired resolution as long as the display and video card support it, and tend to go a long way towards being usable even on small screens, though not all applications may support very low display resolutions. Programs designed to mimic older hardware such as Atari, Sega, or Nintendo game consoles (emulators) when attached to multiscan CRTs, routinely use much lower resolutions such as 160×200 or 320×400 for greater authenticity.
Display resolution Commonly used The list of common display resolutions article lists the most commonly used display resolutions for computer graphics, television, films, and video conferencing.
Overscan and underscan Most television display manufacturers "overscan" the pictures on their displays (CRTs and PDPs, LCDs etc.), so that the effective on-screen picture may be reduced from 720×576(480) to 680×550(450), for example. The size of the invisible area somewhat depends on the display device. HD televisions do this as well, to a similar extent. Computer displays including projectors generally do not overscan although many models (particularly CRT displays) allow it. CRT displays tend to be underscanned in stock configurations, to compensate the increasing distortions at the corners.
References [1] "Higher screen resolutions more popular for exploring the Internet according to OneStat.com" (http:/ / www. onestat. com/ html/ aboutus_pressbox8. html), July 24, 2002. [2] "Screen resolution 800×600 significantly decreased for exploring the Internet according to OneStat.com" (http:/ / www. onestat. com/ html/ aboutus_pressbox51_screen_resolutions_internet. html), April 18, 2007. [3] [4] [5] [6]
Apple Releases New Cinema Display: 27 inches, 2560x1440 Resolution (http:/ / www. desktopreview. com/ default. asp?newsID=1158) EYE-LCD 6400-4K (http:/ / www. eyevis. de/ index. php?article_id=51& clang=1) "Browser Display Statistics" (http:/ / www. w3schools. com/ browsers/ browsers_display. asp) — Statistics from W3Schools' web logs. "Primary Display Resolution", The Steam hardware survey." (http:/ / store. steampowered. com/ hwsurvey/ )
• Sony SXRD 4K Projector (SRXR110) resolution retrieved from (http://bssc.sel.sony.com/ BroadcastandBusiness/DisplayModel?id=79210)
External links • How many dots has it got? (http://www.fourmilab.ch/documents/howmanydots/) — Fourmilab • ScreenResolution.org (http://www.screenresolution.org/) — Free online browser screen tester; shows the screen resolution of your current monitor; realtime statistics on Internet users’ screen resolution • Video Format Resolutions (http://www.videotechnology.com/0904/formats.html) — Video Technology Magazine • Browser Display Statistics (http://www.w3schools.com/browsers/browsers_display.asp) — W3Schools • Standard resolutions used for computer graphics equipment, TV and video applications and mobile devices. (http://www.equasys.de/standardresolution.html) • Screen resolution simulator (http://www.infobyip.com/testwebsiteresolution.php)
47
Pixel density
48
Pixel density Pixels per inch (PPI) or pixel density is a measurement of the resolution of devices in various contexts; typically computer displays, image scanners, and digital camera image sensors. PPI can also describe the resolution, in pixels, of an image to be printed within a specified space. For instance, a 100 x 100 pixel image that is printed in a 1-inch square could be said to have 100 dots per inch (DPI). Used in this way, the measurement is meaningful when printing an image. Good quality photographs usually require 300 dots per inch when printed.
Computer displays The PPI of a computer display is related to the size of the display in inches and the total number of pixels in the horizontal and vertical directions. This measurement is often referred to as dots per inch, though that measurement more accurately refers to the resolution of a computer printer. For example, a 15 inch (38 cm) display whose dimensions work out to 12 inches (30.48 cm) wide by 9 inches (22.86 cm) high, capable of a maximum 1024 × 768 (or XGA) pixel resolution, can display around 85 PPI in both the horizontal and vertical directions. This figure is determined by dividing the width (or height) of the display area in pixels by the width (or height) of the display area in inches. It is possible for a display’s horizontal and vertical PPI measurements to be different (e.g., a typical 4:3 ratio CRT monitor showing a 1280×1024 mode computer display at maximum size, which is a 5:4 ratio, not quite the same as 4:3). The apparent PPI of a monitor depends upon the screen resolution (that is, the number of pixels) and the size of the screen in use; a monitor in 800×600 mode has a lower PPI than does the same monitor in a 1024×768 or 1280×960 mode.
The square shown above is 200 pixels by 200 pixels. To determine a monitor's PPI, measure the width and height, in inches, of the square as displayed on a given monitor. Dividing 200 by the measured width or height gives the monitor's horizontal or vertical PPI, respectively, at the current screen resolution. Note: May not apply on mobile devices.
The dot pitch of a computer display determines the absolute limit of possible pixel density. Typical circa-2000 cathode ray tube or LCD computer displays range from 67–130 PPI. The IBM T220/T221 LCD monitors marketed from 2001–2005 reached 204 PPI. The Toshiba Portégé G900 Windows Mobile 6 Professional phone, launched in mid 2007, came with a 3″ WVGA LCD having “print-quality” pixel density of 313 PPI.[1] In April 2007, Sony released the Cyber-shot DSC-G1 digital camera with a 3.5″ LCD dubbed “Xtra Fine”; with 921K pixels displayed, making it a 395 PPI display, with each pixel approximately 64.2 μm.[2] In January 2008, Kopin Corp. announced a 0.44″ (1.12 cm) SVGA LCD with an astonishing pixel density of 2272 PPI (each pixel only 11¼ μm).[3] [4] According to the manufacturer, the LCD was designed to be optically magnified to yield a vivid image and therefore expected to find use in high-resolution eye-wear devices. In June 2010, Apple Inc. announced and launched the iPhone 4, with its “Retina Display” LCD boasting 326 PPI (960×640, 3½″ diagonal, each pixel only 78 μm).[5] [6] It has been observed that the unaided human eye can generally not differentiate detail beyond 300 PPI; however, this figure depends both on the distance between viewer and image, and the viewer’s visual acuity. Modern displays having upwards of 300 PPI pixel densities, combined with their non-reflective, bright, evenly lit and interactive display areas, may have vastly more appeal to users than the best prints available on paper. Such high pixel density
Pixel density display technologies would make supersampled antialiasing obsolete, enable true WYSIWYG graphics and, further, pave the way towards the elusive “paperless office” era.[7] For perspective, such a device at 15″ (38 cm) screen size would have to display more than four Full HD screens (or WQUXGA resolution). The PPI pixel density specification of a display is also useful for calibrating a monitor with a printer. Software can use the PPI measurement to display a document at “actual size” on the screen.
Calculation of monitor PPI Theoretically, PPI can be calculated from knowing the diagonal size of the screen in inches and the resolution in pixels (width and height). This can be done in two steps: 1. Calculate diagonal resolution in pixels using the Pythagorean theorem:
2. Calculate PPI:
where • •
is diagonal resolution in pixels, is width resolution in pixels,
• •
is height resolution in pixels and is diagonal size in inches. (This is the number advertised as the size of the display.)
For example, for a 20″ (50.8 cm) screen with a 1680x1050 resolution, we get 99.06 PPI; for a typical 10.1″ netbook screen with a 1024x600 resolution, we get 118 PPI. Note that these calculations are not very precise. Frequently, screens advertised as “X inch screen” can have their real physical dimensions of viewable area differ, for example: • HP LP2065 20″ (50.8 cm) monitor — 20.1″ (51 cm) viewable area[8]
Scanners and cameras "PPI" or "pixel density" may also be used to describe the resolution of an image scanner. In this context, PPI is synonymous with samples per inch. In digital photography, pixel density is the number of pixels divided by the area of the sensor. A typical DSLR circa 2011 will have 1-4,5 MP/cm2; a typical compact will have 20-60 MP/cm2. For example Sony Alpha 55 has 16.2 megapixels on an APS-C sensor having 4,5 MP/cm2 since a compact camera like Sony Cybershot DSC-H70 has 16.2 megapixels on an 1/2.3" sensor having 60 MP/cm2. Interestingly, as can be seen here, the professional camera has a lower PPI than does a compact, because it has larger photodiodes due to having far larger sensors.
49
Pixel density
50
Metrication The digital publishing industry often uses "pixels per centimeter" instead of "pixels per inch".[9] because all countries in the world except three use the metric system.
[10] [11]
This is
References [1] "Toshiba Portégé G900 Official Page" (http:/ / www. toshiba-europe. com/ mobile/ Mobile2Live. aspx?WCI=PageNavigate& WCE=& WCU=;LANG=1;PID=165;TYP=18;PNT=0;SEC=2). Toshiba Portege G900 Review (http:/ / www. phonearena. com/ htmls/ Toshiba-Portege-G900-Review-review-r_1787. html). 2007-07-27. . Retrieved 2008-05-01. [2] DSC-G1 | Cyber-shot® Digital Camera DSC-G1 | Sony | SonyStyle USA (http:/ / www. sonystyle. com/ webapp/ wcs/ stores/ servlet/ ProductDisplay?catalogId=10551& storeId=10151& langId=-1& productId=6148914691253945336#specifications) (SonyStyle USA official website) [3] "Kopin unveils smallest color SVGA display" (http:/ / optics. org/ cws/ article/ industry/ 32411). optics.org (http:/ / optics. org/ cws/ contact-us). 2008-01-11. . Retrieved 2008-06-06. [4] "Company Debuts World’s Smallest Color SVGA Display" (http:/ / www. kopin. com/ data/ Mar 08 Med Products Manu. pdf). SID, Information Display magazine May 2008 Vol. 24, No. 05 (http:/ / www. informationdisplay. org/ article. cfm?year=2008& issue=05& file=art8). 2008-05-31. . Retrieved 2008-06-06. [5] "Apple - iPhone 4 - Learn about the high-resolution Retina display" (http:/ / www. apple. com/ iphone/ features/ retina-display. html). (http:/ / apple. com/ ). 2010-06-07. . Retrieved 2010-06-08. [6] "iPhone 4 Technical Specifications" (http:/ / www. apple. com/ iphone/ specs. html). (http:/ / apple. com/ ). 2010-06-09. . Retrieved 2010-06-09. [7] "Electronic displays for information technology" (http:/ / www. research. ibm. com/ journal/ rd/ 443/ wisnieff. html). IBM Journal of Research and Development Volume 44, Number 3, 2000 (http:/ / www. research. ibm. com/ journal/ ). 1999-11-10. . Retrieved 2008-06-06. [8] HP LP2065 20-inch (50.8 cm) LCD Monitor - Specifications and Warranty (http:/ / h10010. www1. hp. com/ wwpc/ us/ en/ sm/ WF06a/ 382087-382087-64283-72270-444767-1815933. html) (Hewlett-Packard Company official website) [9] "Web Graphics Basics" (http:/ / www. washington. edu/ accessit/ webdesign/ student/ unit4/ module2/ web_graphics_basics. htm). . [10] "Utads.com Glossary of Terms" (http:/ / www. utads. com/ ad_specs/ glossary. html). . [11] "Resolution, dpi and ppi" (http:/ / www. monarda. se/ extra/ ppi-test/ ppitest_english. htm). .
External links • A very nice graphical PPI ruler - works even if you have just a piece of office paper (http://pediddle.net/ dpi-ruler.html) • Easy to use monitor DPI/PPI calculator, includes dot pitch (http://members.ping.de/~sven/dpi.html) • All About Photo Printing - The Differences between DPI and PPI (http://www.printrates.com/ resources_DPI_PPI.php) • Free on screen pixel ruler for Windows (http://www.arulerforwindows.com) • A ruler-based graphical pixel size/density measurement tool (http://concentriclivers.com/screen_density.html) • Nice looking online monitor DPI (or PPI or pixel-density) calculator with automatic resolution detection (http:// www.pxcalc.com)
Image resolution
Image resolution Image resolution describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail. Image resolution can be measured in various ways. Basically, resolution quantifies how close lines can be to each other and still be visibly resolved. Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to the overall size of a picture (lines per picture height, also known simply as lines, or TV lines), or to angular subtenant. Line pairs are often used instead of lines; a line pair comprises a dark line and an adjacent light line. A Line (or TV line, TVL) is either a dark line or a light line. A resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter (5 LP/mm). Photographic lens and film resolution are most often quoted in line pairs per millimeter.
Resolution of digital images The resolution of digital images can be described in many different ways.
Pixel resolution The term resolution is often used for a pixel count in digital imaging, even though American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field.[1] [2] An image of N pixels high by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when the pixel counts are referred to as resolution, the convention is to describe the pixel resolution with the set of two positive integer numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as 640 by 480. Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of megapixels, which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as pixels per inch or per square inch. None of these pixel resolutions are true resolutions, but they are widely referred to as such; they serve as upper bounds on image resolution. According to the same standards, the number of effective pixels that an image sensor or digital camera has is the count of elementary pixel sensors that contribute to the final image, as opposed to the number of total pixels, which includes unused or light-shielded pixels around the edges. Below is an illustration of how the same image might appear at different pixel resolutions, if the pixels were poorly rendered as sharp squares (normally, a smooth image reconstruction from pixels would be preferred, but for illustration of pixels, the sharp squares make the point better).
An image that is 2048 pixels in width and 1536 pixels in height has a total of 2048Ă&#x2014;1536 = 3,145,728 pixels or 3.1 megapixels. One could refer to it as 2048 by 1536 or a 3.1-megapixel image. Unfortunately, the count of pixels isn't a real measure of the resolution of digital camera images, because color image sensors are typically set up to alternate color filter types over the light sensitive individual pixel sensors. Digital images ultimately require a red, green, and blue value for each pixel to be displayed or printed, but one individual pixel in the image sensor will only supply one of those three pieces of information. The image has to be interpolated or demosaiced to produce all three colors for each output pixel.
51
Image resolution
52
Spatial resolution
The 1951 USAF resolution test target is a classic test target used to determine spatial resolution of imaging sensors and imaging systems.
The measure of how closely lines can be resolved in an image is called spatial resolution, and it depends on properties of the system creating the image, not just the pixel resolution in pixels per inch (ppi). For practical purposes the clarity of the image is decided by its spatial resolution, not the number of pixels in an image. In effect, spatial resolution refers to the number of independent pixel values per unit length. The spatial resolution of computer monitors is generally 72 to 100 lines per inch, corresponding to pixel resolutions of 72 to 100 ppi. With scanners, optical resolution is sometimes used to distinguish spatial resolution from the number of pixels per inch. In geographic information systems (GISs), spatial resolution is measured by the ground sample distance (GSD) of an image, the pixel spacing on the Earth's surface. In astronomy one often measures spatial resolution in data points per arcsecond subtended at the point of observation, since the physical distance between objects in the image depends on their distance away and this varies widely with the object of interest. On the other hand, in electron microscopy, line or fringe resolution refers to the minimum separation detectable between adjacent parallel lines (e.g. between planes of atoms), while point resolution instead refers to the minimum separation between adjacent points that can be both detected and interpreted e.g. as adjacent columns of atoms, for instance. The former often helps one detect periodicity in specimens, while the latter (although more difficult to achieve) is key to visualizing how individual atoms interact. In Stereoscopic 3D images, spatial resolution could be defined as the spatial information recorded or captured by two viewpoints of a stereo camera (left and right camera). The effects of spatial resolution on overall perceived resolution of an image on a person's mind are yet not fully documented. It could be argued that such "spatial resolution" could add an image that then would not depend solely on pixel count or Dots per inch alone, when classifying and interpreting overall resolution of an given photographic image or video frame.
Image resolution
53
Distinguishable squares A measure integrating spatial resolution, and also the area of an image, is the hypothetical maximal number of distinguishable squares that could be fitted in an image. It is an estimate of how much information there can potentially be in an image. The maximal number of distinguishable squares for a camera can be estimated by standardized square-pattern images, with a pixel-based example shown at right. Such pixel-based images may vary slightly with the pixel-rendering, brightness and other factors of the display device. It basically consists of a "model area" with a known amount of squares (for example, the model area at right has 10,000 squares, created by 100 x 100 pixels of mixed black and white pattern). The method is to take pictures of the screen with increasing distance, and digitally zooming into the model area (to avoid making the eye the limiting factor), and the image at maximal distance where individual squares can still be distinguishable is selected. In this image, the number of squares in the model area is multiplied by the image area and divided by the model area as it appears in the image. Both of these areas can be given as their widths multiplied by their heights, and may be measured equally well in centimeters, inches or pixels, as long as the other area is measured in the same units for the same image.
Model area of 10,000 squares for determining distinguishable squares a camera.
In the example at right, the entire image was 3264 x 2448 pixels (8 megapixel), and the model area in it covered 322 x 322 pixels at the point where the squares were barely distinguishable, resulting in an estimate of approximately 770,000 distinguishable squares. The quality or amount of graphical information in an image does not significantly increase by rendering it in more than approximately 4 to 8 times the amount of distinguishable squares, with a higher pixel count having a risk of only making the image being of excessive data size.
Image resolution
54
Spectral resolution Color images distinguish light of different spectra. Multi-spectral images resolve even finer differences of spectrum or wavelength than is needed to reproduce color. That is, they can have higher spectral resolution. that is the strength of each band that is created ( Lihongeni mulama: 2008)
Temporal resolution Movie cameras and high-speed cameras can resolve events at different points in time. The time resolution used for movies is usually 15 to 30 frames per second (frames/s), while high-speed cameras may resolve 100 to 1000 frames/s, or even more. Many cameras and displays offset the color components relative to each other or mix up temporal with spatial resolution:
digital camera (Bayer color filter array)
LCD (Triangular pixel geometry)
CRT (shadow mask)
Radiometric resolution Radiometric resolution determines how finely a system can represent or distinguish differences of intensity, and is usually expressed as a number of levels or a number of bits, for example 8 bits or 256 levels that is typical of computer image files. The higher the radiometric resolution, the better subtle differences of intensity or reflectivity can be represented, at least in theory. In practice, the effective radiometric resolution is typically limited by the noise level, rather than by the number of bits of representation.
Resolution in various media This is a list of traditional, analog horizontal resolutions for various media. The list only includes popular formats, not rare formats, and all values are approximate (rounded to the nearest 10), since the actual quality can vary machine-to-machine or tape-to-tape. For ease-of-comparison, all values are for the NTSC system. (For PAL systems, replace 480 with 576.) • Analog and early digital • • • • • •
350×240 : Video CD 300×480 : Umatic, Betamax, VHS, Video8 350×480 : Super Betamax, Betacam (pro) 420×480 : LaserDisc, Super VHS, Hi8 500×480 : Analog broadcast 670×480 : Enhanced Definition Betamax
• Digital • 720×480 : D-VHS, DVD, miniDV, Digital8, Digital Betacam (pro) • 720×480 : Widescreen DVD (anamorphic) • 1280×720 : D-VHS, HD DVD, Blu-ray, HDV (miniDV)
Image resolution • • • • • •
1440×1080 : HDV (miniDV) 1920×1080 : HDV (miniDV), AVCHD, HD DVD, Blu-ray, HDCAM SR (pro) 2048×1080 : 2K Digital Cinema 4096×2160 : 4K Digital Cinema 7680×4320 : UHDTV Sequences from newer films are scanned at 2,000, 4,000, or even 8,000 columns, called 2K, 4K, and 8K, for quality visual-effects editing on computers.
• Film • 35 mm film is scanned for release on DVD at 1080 or 2000 lines as of 2005. • The actual resolution of 35 mm camera original negatives is the subject of much debate. Measured resolutions of negative film have ranged from 25-200 lp/mm, which equates to a range of 325 lines for 2-perf, to (theoretically) over 2300 lines for 4-perf shot on T-Max 100.[3] [4] [5] Archivists generally agree that 4k scanning of 35mm is more than adequate for archival purposes. [6] • IMAX, including IMAX HD and OMNIMAX: approximately 10,000×7000 (7000 lines) resolution.
References [1] CIPA DCG-001-Translation-2005 (http:/ / www. cipa. jp/ english/ hyoujunka/ kikaku/ pdf/ DCG-001_E. pdf) Guideline for Noting Digital Camera Specifications in Catalogs. "The term 'Resolution' shall not be used for the number of recorded pixels" [2] ANSI/I3A IT10.7000-2004 (http:/ / webstore. ansi. org/ ansidocstore/ product. asp?sku=ANSI/ I3A+ IT10. 7000-2004) Photography - Digital Still Cameras - Guidelines for Reporting Pixel-Related Specifications [3] (http:/ / motion. kodak. com/ motion/ uploadedFiles/ TI2647. pdf)Kodak 500t Film spec sheet [4] (http:/ / www. arri. de/ fileadmin/ media/ arri. com/ downloads/ Camera/ Tutorials/ SystemsTechnologyBrochure. pdf)An analysis of film resolution [5] (http:/ / www. normankoren. com/ Tutorials/ MTF1A. html)Explanation of MTF [6] (http:/ / www. prestocentre. eu/ sites/ www. prestocentre. eu/ files/ DFT-SCANITY-white-paper. pdf)
External links • Spatial resolution of ionizing particle sensors (http://meroli.web.cern.ch/meroli/Lecture_SpatialResolution. html); Spatial resolution of particle detectors used in High Energy Physics Experiments. • Pixel & Resolution Tables (http://fred.dsimprove.be/__offSite/pixel/); practical tables, and theory for beginner's education about resolution issues in digital imaging, photo and printing - Sorry, broken link as of may 20th, 2011 • Luminous Landscape's Res-Demyst (http://www.luminous-landscape.com/tutorials/understanding-series/ res-demyst.shtml); on why pixel count is not always a good proxy for resolution • Do Sensors “Outresolve” Lenses? (http://luminous-landscape.com/tutorials/resolution.shtml); on lens and sensor resolution interaction.
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AVCHD
AVCHD AVCHD (Advanced Video Coding High Definition)[1] is a file-based format for the digital recording and playback of high-definition video, which stores video on DVD discs, hard disk drives, non-removable solid-state memory, and removable flash memory such as Secure Digital and Memory Stick cards.[2] AVCHD and its logo are trademarks of Panasonic and Sony.[3]
History Developed jointly by Sony and Panasonic, the format was introduced in 2006 primarily for use in high definition consumer camcorders.[4] Panasonic released the first professional AVCHD camcorder in autumn of 2008, followed by Sony in the first quarter of 2010. Favorable comparisons of AVCHD against HDV and XDCAM EX[5] [6] solidified perception of AVCHD as a format acceptable for professional usage. Compared to HDV 720p, AVCHD uses a more advanced compression format (AVC vs. MPEG-2.) At 720p resolution, AVCHD has an even greater advantage over HDV, due to a higher video bitrate (18.3 Mbit/s CBR) vs (up to 24 Mbit/s VBR.) Unlike the competing HDV format, which primarily recorded to magnetic tape, AVCHD recorded video to a random-access filesystem, simplifying the process of downloading footage to PC. In 2011, a new revision of the specification, AVCHD 2.0, was announced. It added support for 1080p50, 1080p60, and stereoscopic (3D) video, and increases the maxmimum system bitrate to 28Mbps in these new modes.)
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AVCHD
57
Overview For video compression, AVCHD uses the MPEG-4 AVC/H.264 (AVC) standard, supporting a variety of standard, high definition, and stereoscopic (3D) video resolutions. For audio compression, supports both Dolby AC-3 (Dolby Digital) and uncompressed linear PCM audio. Stereo and multichannel surround (5.1) are both supported. Aside from recorded audio and video, AVCHD includes features to improve media presentation: menu navigation, slide shows and subtitles. The menu navigation system is similar to DVD-video, allowing access to individual videos from a common intro screen. Slide shows are prepared from a sequence of AVC still frames, and can be accompanied by a background audio track. Subtitles are used in some camcorders to timestamp the recordings.
File organization on Panasonic and Canon solid-state AVCHD camcorders
Audio, video, subtitle, and ancillary streams are multiplexed into an MPEG transport stream and stored on media as binary files. Usually, memory cards and HDDs use the FAT file system, while optical discs employ UDF or ISO9660. At the file system level, the structure of AVCHD is derived from the Blu-ray Disc specification, but is not identical to it. In particular, it uses legacy "8.3" file naming convention, while Blu-ray Discs utilize long filenames (this may be caused by the fact that FAT implementations utilizing long file names are patented by Microsoft and are licensed on a per unit sold basis[7] ). Another difference is location of the BDMV directory, which contains media files. On a DVD-based camcorder the BDMV directory is placed at the root level, as on the Blu-ray Disc. On the HDD-based Canon HG10 camcorder the BDMV directory is located in the AVCHD directory, which is placed at the root level.[8] Solid-state Panasonic and Canon camcorders nest the AVCHD directory inside the PRIVATE directory.[9] Following a standard agreed upon by many still camera manufacturers, solid-state camcorders have a root-level DCIM directory for still images.[10] AVCHD has been designed to be compatible with Blu-ray Disc format[4] and can be authored without re-encoding on Blu-ray or DVD discs, though not all Blu-ray Disc players are compatible with AVCHD video authored on DVD media, a format known as AVCHD disc. AVCHD recordings can be transferred to a computer by connecting the camcorder via the USB connection. Removable media like SDHC and Memory Stick cards or DVD discs can be read on a computer directly. Copying files from an AVCHD camcorder or from removable media can be performed faster than from a tape-based camcorder, because the transfer speed is not limited by realtime playback. Just as editing DVCPROÂ HD and HDV video once demanded an expensive high-end computer, AVCHD editing software requires powerful machines. Compared to HDV, AVCHD requires 2-4x the processing power for realtime
AVCHD playback, placing a greater burden on the computer's CPU and graphics card. Improvements in multi-core computing and graphics processor acceleration bring AVCHD playback to mainstream desktops and laptops.
Media AVCHD specification allows using recordable DVD discs, memory cards, non-removable solid-state memory and hard disk drives as recording media.
DVD disc When AVCHD standard was first announced, recordable DVD disc was the only recording medium.[4] To reduce camcorder size, manufacturers opted for a 8 cm disc, sometimes called miniDVD. Recording capacity of a 8 cm disc ranges from 1.4 GB for a single-sided single layer disc to 5.2 GB for a double-sided double layer disc. Pros: • DVDs are familiar to most consumers, thus considered user-friendly. Conventional 12 cm disc (left) compared to 8 cm disc (right) • Recordable DVDs are relatively cheap. • Recorded disc can be played back in most Blu-ray Disc players. • Discs can be used for long-term storage of recorded video. Cons: • • • • • • •
• • • •
The longevity of recordable DVDs is argued to be much shorter than expected.[11] Rewritable DVDs cost more than write-once discs. DVDs have to be "finalized" to be played back on set-top players (though DVD-RWs can be unfinalized again). Double-layer recording is less robust than single-layer recording. To use both sides of a double-sided disc it must be flipped over, because camcorders have pickup from one side only. AVCHD DVDs cannot be played back on regular DVD players. The AVCHD specification limits data rate for DVD-based AVCHD camcorders to 18 Mbit/s, but no DVD-based AVCHD camcorder manufactured to date is capable of recording at data rate higher than 12 Mbit/s (Canon, Sony) or 13 Mbit/s (Panasonic). A single-sided single-layer 8 cm DVD can fit only 15 minutes of video at 12 Mbit/s, 14 minutes at 13 Mbit/s. DVD pickup mechanism is very susceptible to vibration. 8 cm DVDs cannot be used in many slot-loading drives and may even damage the drive. The capacity of DVD discs has reached its limit.
As capacity of memory cards grew while their price dropped, DVD discs quickly fell out of favor. No DVD-based AVCHD camcorders have been produced since 2008. While DVD discs are no longer used for acquisition, they are becoming popular as distribution media. Many authoring programs offer "AVCHD" profile for recording high definition video on a DVD disc. Such AVCHD discs are incompatible with regular DVD-Video players, but can be played in many Blu-ray Disc players. A conventional single-layer 12 cm DVD disc can store approximately half an hour of video recorded at 18 Mbit/s.
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AVCHD
59
Hard disk drive A hard disk drive was added as an optional recording medium to AVCHD specification shortly after the new video standard had been announced.[2] Presently, capacity of built-in HDDs ranges from 30 GB to 240 GB. Pros: • Higher capacity than other media types, which allows for longer continuous recording.
Canon HG10 HDD-based AVCHD camcorder
Cons: • Sensitive to atmospheric pressure. The HDD may fail if the camcorder is used at altitudes above 3000 metres (9800 ft). • Vulnerable to mechanical shock or fast movement. • All HDD-based AVCHD camcorders employ non-removable disks. To transfer video to a computer the camcorder must be connected with a USB cable. Most camcorders require using an AC power adapter for this operation. • The sound of moving magnetic heads may be heard in the recorded video when recording in quiet environment. • Replacing a damaged HDD requires disassembling a camcorder and cannot be done by a consumer.
Solid-state memory card Many tapeless camcorders record to memory cards, such as SD/SDHC cards or "Memory Stick" cards. Solid-state memory cards offer rewritable storage in a compact form factor with no moving parts. With transfer speeds ranging from 10 MByte/s to 20 Mbyte/s, it takes about 1 minute to transfer 1 GB of video.[12] Panasonic and Sony chose removable flash memory as recording media in their professional AVCHD lineups, AVCCAM and NXCAM respectively. Pros:
Canon HF100 camcorder with a partially inserted Secure Digital card
• • • • • • •
Compact and lightweight. Does not require time for spin-up and initialization. Not vulnerable to magnetic fields. Can withstand a wider range of air pressure, humidity and vibration than HDDs. Can be easily backed up to DVD for viewing and for long-term archiving.[9] Can store mixed media content, including still images like snapshot photos and still-frame captures. The recording section contains no moving parts, thus operation is almost silent; also a camera can be made more compact and less prone to mechanical damage in case of being dropped. • Most new computers, some TVs and Blu-ray Disc players, as well as many personal portable media players have built-in card readers and can play AVCHD video directly from a card. Cons: • More expensive per minute of recording than a built-in HDD or DVD media. • Cards may wear out more rapidly than expected.[13] dead link
AVCHD • Not reliable for long term storage, especially the cards made with MLC technology, because of narrower acceptable level of discharge compared to SLC cards.[14] • Vulnerable to electrical damage, such as static discharge. • A bad memory card can cause data corruption, causing loss of one or more clips. • Loss of data can occur if a card is removed or power is turned off while the card is being recorded to. • Older card readers designed for MMC and SD cards may not read high capacity cards. • Easy to misplace due to small form factor.
Non-removable solid-state memory Some AVCHD camcorders come with built-in solid-state memory either as a sole media, or in addition to other media. Pros: • Allows making a camcorder smaller if no other media is used. • Always available for recording, in case other type of media is full or missing. Cons: • Because recording media is non-removable, a camcorder must be connected to a computer with a USB cable to transfer video. Usage of an AC power adapter is often needed as well. • Non-removable media cannot be shared, sent or stored separately of the camcorder. • If damaged or worn out, non-removable media cannot be replaced like a memory card.
Video formats AVCHD specification supports a number of video resolutions, including standard definition, high definition, and stereoscopic (3D) video. (See table below.) However, most many recorders only support a subset of the video resolutions defined in the AVCHD specification. The licensing body of the specification defines a variety of trademarks to label products compliant with a specific set of features or capabilities. In general, consumer AVCHD recorders typically support only a handful of the video resolutions allowed in the AVCHD standard, and are usually limited to AC-3 audio. Playback equipment and professional recorders generally support all resolutions.
Standard definition recording (AVCHD-SD) AVCHD-SD is a standard definition video format that employs AVC video compression. The shoulder-mount Panasonic HDC-MDH1, available on Southern-Asian markets[15] , as well as its AG-AC7 cousin are capable of recording AVCHD-SD video. Several new models from JVC like the GZ-HM650, GZ-HM670 and GZ-HM690 can record AVCHD-SD video too. AVCHD-SD is not directly compatible with most consumer DVD players, but can be played on a Blu-ray Disc player. Panasonic also offers MJPEG and iFrame formats in other consumer models to record standard definition video. The professional AG-HMC80 and the AG-AC160 camcorders can record DV video. Sony camcorders that offer standard definition recording use MPEG-2 compression in a format that is compatible with the DVD-Video specification. Canon AVCHD camcorders do not record standard definition video, although some newer models can re-encode high definition video into standard definition video compatible with DVD-Video standard.
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61
720p The AVCHD specification supports 720-line progressive recording mode at frame rates of 24 and 60 frames/s for 60Â Hz models and 50 frames/s for 50Â Hz models. Many of digital compact cameras made by Panasonic, such as the DMC-ZS3/DMC-TZ7, DMC-FT1, DMC-FZ35/DMC-FZ38, and DMC-ZS-7/TZ-10 offer 720p video recording with effective frame rate of 25 or 30 frames/s in a format called AVCHD Lite (see below). In the professional market, the AG-HMC150 and AG-HMC40 were the first AVCHD models to offer 720p recording in addition to 1080i and 1080p. They have been joined with the NXCAM models from Sony.
1080i All AVCHD camcorders except for AVCHD Lite models are capable of recording 1080i interlaced video. For some models this is the only recording mode offered. Early models captured anamorphic video with horizontal resolution reduced to 1440 pixels. Newer models offer higher data rate and full 1920x1080 resolution, while in some cases keeping the anamorphic format for use with lower recording data rates. Interlaced video had been originally designed for watching on a cathode-ray tube television set. Material recorded for interlaced presentation may exhibit combing or ghosting when it is rescaled, filmed out or watched on a computer or another progressive-scan device without proper deinterlacing.
An example of interlace combing
All modern flat-panel television sets have a built-in deinterlacing engine to cope with interlaced video. When watching interlaced video on a computer some software video players blend two fields of each interlaced frame together, causing combing; when such video is scaled down it may exhibit ghosting instead of combing.[16] Better codecs and media players either use content-adaptive algorithms or allow choosing a deinterlacing scheme manually.[17] Video hosting websites like YouTube use progressive scanning for streaming videos, and automatically deinterlace interlaced videos. Automatic deinterlacing does not always produces the best possible quality, thus YouTube suggests its users deinterlace their videos prior to uploading.[18] Some 1080i AVCHD camcorders can capture progressive video and record it within an interlaced stream, borrowing techniques from television industry. In particular, Progressive segmented frame (PsF) is utilized in some Panasonic (25p Digital Cinema), Canon (PF25, PF30) and Sony camcorders. The 2:3 pulldown technique is used in some 60Â Hz versions of Canon (PF24) and Panasonic (24p Digital Cinema) camcorders and in the Panasonic GH1 hybrid digital still/video camera for recording 24-frame progressive video. Most editing tools treat progressive video recorded within an interlaced stream as interlaced, though some editing systems and most standalone Blu-ray Disc players are capable of recognizing the pulldown pattern to recover the original frames using the process known as inverse telecine.
AVCHD
62
1080p In the consumer market, 60 Hz variants of some Canon, Panasonic and Sony models are capable of recording native 1080p24 video. In the professional and prosumer markets, AVCHD camcorders such as the Panasonic AG-HMC150, the Panasonic AG-HMC40, the Sony HDR-AX2000 and the Sony HXR-NX5U, are capable of recording in all three high definition formats: 1080i, 1080p and 720p. Sony camcorders do not support film-like frame rates — 24p, 25p, 30p — in 720p mode. In 2010, Panasonic introduced a new lineup of consumer AVCHD camcorders with 1080-line 50p/60p progressive-scan mode (frame rate depending on region).[19] While this mode is not compliant with current AVCHD specification, it uses the same compression schemes for video and audio, the same container files and the same folder structure as AVCHD-compliant recordings.[20] Panasonic advised that not all players that support AVCHD playback could play 1080-line 50p/60p video.[21]
Native Progressive logo (Canon)
Progressive Recording logo (Sony)
In 2011 Sony introduced consumer and professional AVCHD models also capable of 1080-line 50p/60p video recording. Like Panasonic, Sony uses AVCHD folder structure and container files for storing video, with the same maximum bitrate of 28 Mbit/s. Panasonic models have no special marks for progressive-scan capability. Canon models, capable of native 24p recording, have a prominent 24p Native Progressive mark.[22] Sony models capable of 50p/60p recording or of 24p recording are also identified with appropriate marks.
Branding Panasonic and Sony developed several brand names for their professional as well as simplified versions of AVCHD.
AVCHD Lite AVCHD Lite identifies a subset of AVCHD format, in which HD-recording is limited to 720p/30.[23] The 720p/30 video is recorded in the AVCHD 720p/60 format by storing every other frame, and using a bitstream flag to tell the playback device to play each frame twice. Announced in January 2009, the Panasonic DMC-ZS3/DMC-FT1/DMC-TZ7 digital cameras were the first digital cameras to offer AVCHD-lite movie mode. Since then, Panasonic has added AVCHD-lite to more of its digital cameras, such as the Lumix GF1 Micro Four Thirds, Panasonic Lumix DMC-G2, Lumix DMC-FZ35/38, Lumix DMC-TZ10/ZS7, Panasonic Lumix DMC-FX75, Panasonic LX5, LEICA D-LUX 5, LEICA V-LUX 2.
AVCCAM AVCCAM is the name of the professional AVCHD camcorder product line from Panasonic's Broadcast division, and is a marketing brand for "AVCHD with professional features."[24] These professional features include 1/4-inch progressive 3CCD sensor, XLR microphone input, variable-rate overcranking (up to 2.5x at 1080p24), uncompressed PCM audio, solid-state media, and recording at AVCHD's maximum bitrate (24Mbps.) The aforementioned features are not exclusive to AVCCAM. For example, 3CMOS is available in Panasonic's high-end consumer camcorders, while 24Mbps is widely available from rival manufacturers (Canon, JVC, and Sony.)
AVCHD
NXCAM NXCAM is the name of Sony's professional video lineup employing the AVCHD format.[25] NXCAM offers 1080i, 1080p and 720p recording modes with data rate up to 24 Mbit/s. Unlike AVCCAM, NXCAM does not offer film-like frame rates — 24p, 25p, 30p — in 720p mode. NXCAM camcorders, as well as consumer Sony AVCHD camcorders unveiled in 2010, record onto widespread SDHC cards as well as onto Memory Stick Pro Duo/Pro HG Duo cards.
Playing back AVCHD video Recorded AVCHD video can be played back in a variety of ways: • Direct playback — video can be played on a television set from a camcorder through HDMI or component-video cable. • AVCHD disc — AVCHD video, recorded onto DVD disc can be played on most Blu-ray Disc players[9] or on a PlayStation 3 gaming console. • Blu-ray disc — AVCHD video, recorded onto Blu-ray disc can be played on any Blu-ray Disc player. • AVCHD memory card — AVCHD video, recorded on an SDHC or Memory Stick card can be played on select Blu-ray Disc players, HDTV sets, on a PlayStation 3 gaming console and on some other set-top media players. • USB playback — video files, recorded on an external storage device like a hard disk drive or a USB "stick" can be played on select Blu-ray Disc players, HDTV sets, PlayStation 3 gaming console, set-top media players and from a computer. • Computer playback — any media and target format that is supported by a particular computer hardware and software can be watched on a computer monitor or TV set. Presently, the default media players from Apple (QuickTime) will not play AVCHD natively, additional (free) software is required.[26] Some Windows 7 editions are able to import and play AVCHD video natively, having files with extensions M2TS, MTS and M2T pre-registered in the system. (Windows 7 starter edition does not support AVCHD files itself, and a third-party player must be installed.[27] ) In editions of Windows 7 which do support AVCHD files, Windows Media Player is able to index content of these files, while Windows Explorer is able to create thumbnails for each clip.[28] Windows 7 does not support importing of AVCHD video metadata such as thumbnail images, playlists, and clip index files. Joining AVCHD video files during the import is not supported either.[28] Notably, the open-source VLC media player will play AVCHD video files, as well as a wide variety of additional formats, and is freely available for most modern operating systems and some mobile platforms.
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AVCHD
Compatibility within brands There is a known incompatibility within the Panasonic brand. The original HD Writer importing and editing software, which was shipped from 2006 to 2008, cannot recognize the current 1080i format or the newer formats like 1080p50 or 1080p60. The newer HD Writer AE can read the newer 1080i format and versions 2 and higher can read 1080p (in both frame rates).
AVCHD as distribution format DVD disc with AVCHD video recorded on it is known as AVCHD disc.[29] AVCHD discs cannot be played in a standard DVD player, but can be played in many Blu-ray Disc players.[4] Smooth playback is not guaranteed if overall data rate exceeds 18 Mbit/s. It is possible to create simple menus similar to menus used for DVD-video discs. AVCHD content can also be recorded on SDHC cards and played by many television sets, Blu-ray Disc players and media consoles. Data rate on memory cards is officially limited to 24 Mbit/s. Blu-ray Disc media is not supported by AVCHD specification, though some software packages allow authoring AVCHD content on Blu-ray Discs. AVCHD encoding and container are compatible with Blu-ray AVCHD disc icon (Sony) Disc format, but the naming convention is different. For better compatibility with Blu-ray Disc players, AVCHD video can be converted into Blu-ray Disc format without re-encoding audio/video streams. The resultant disc will play in any Blu-ray Disc player including those that do not explicitly support the AVCHD format. Many software vendors support AVCHD mastering. In particular: • • • • • • • • • •
Cyberlink PowerProducer can author a compliant AVCHD disc, or BDMV on DVD media.[30] Ulead DVD MovieFactory Plus 6 with HD Power Pack can master AVCHD discs with menus.[31] Various Sonic products can author AVCHD discs using HD/BD Plug-in.[32] [33] [34] Compressor 3.5 is capable of authoring AVCHD discs; subtitles are not supported.[35] [36] Nero Vision 9 can create an AVCHD disc with data rate up to 18 Mbit/s, or an AVCHD-compliant folder for distribution on an HDD or a memory card with data rate up to 24 Mbit/s.[37] Sony DVD Architect 5 can author AVCHD-compliant discs with menus using AVC encoding as well as non-standard discs using MPEG-2 encoding. In both cases data rate is limited to 18 Mbit/s. Panasonic HD Writer AE can author AVCHD content on DVD discs, BD discs and on SD cards.[38] MultiAVCHD can author AVCHD discs as well as Panasonic-compliant AVCHD memory cards.[39] Magix Movie Edit Pro 15 Plus with updates can author AVCHD content on DVD discs, BD discs.[40] Pinnacle Studio 11.1.2 and higher offers AVCHD disc output.[41]
Blu-ray Disc players with "AVCHD" logo play AVCHD discs authored either on 8 cm or 12 cm DVD discs. Players without such a logo are not guaranteed to play AVCHD discs.
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Compatibility with Blu-ray Disc players Although AVCHD shares many format similarities with Blu-ray Disc, it is not part of the Blu-ray specification. Consequently, AVCHD-playback is not universally supported across all Blu-ray Disc players. In addition, non-standard developments such as 1080-line 50p/60p recording mode employed in some camcorders, are neither AVCHD- nor Blu-ray compliant. As the creators of AVCHD, Sony and Panasonic support AVCHD playback in their Blu-ray Disc players. In particular, the Sony BDP-S1, Sony BDP-S300, Sony BD507, the Panasonic DMP-BD10, the Panasonic DMP-BD30K, the Panasonic DMP-BD35, the Panasonic DMP-BD60K, the Panasonic DMP-BD80K, and the PlayStation 3 can play AVCHD discs. In addition, some Panasonic and JVC Blu-ray Disc players (e.g. Panasonic DMP-BD60K, Panasonic DMP-BD80K) support AVCHD playback from SDHC memory cards. In one instance, AVCHD playback was removed from a Blu-ray Disc player already on the market, the Samsung BD-P1200. Firmware update 2.3 removed AVCHD support from the BD-P1200.[42]
Blu-ray Disc players known to play AVCHD discs Make and model
Media
Full HD[1]
LG BD570
Recordable DVD
Yes
Regular AVCHD as well as FullHD video can be played.
LG BD370
Recordable DVD
Yes
No playback from USB
Oppo BDP-83
Recordable DVD, USB
No info
Supports AVCHD playback from a USB device; also supports the main [44] menu.
Oppo BDP-93
Recordable DVD, USB
Yes
Supports AVCHD playback including FullHD videos (firmware revision [45] 1108).
Panasonic DMP-BD60 [47] /BD80
Recordable DVD, SD card
Partial
Panasonic [49] DMP-BD85/BD65/BD45
Recordable DVD, SD card
No info
Pioneer BDP-51FD
Recordable DVD
Partial
DVDs recorded in the AVCHD format can be played. [51] plays with hiccups.
Pioneer BDP-320
Recordable DVD
Yes
DVDs recorded in the AVCHD format can be played. [53] can be played (firmware revision 3.69a).
Samsung BD-P1400
Recordable DVD
No info
Seiki BD660
Recordable DVD
Yes
Plays AVCHD discs including FullHD (firmware release BDP V4.2 [55] F6).
Sony BDP-S270/S370/S470/S570
Recordable DVD, USB
Yes
Plays AVCHD, including FullHD, from DVD and USB media (firmware [56] [57] release M04.R.735).
Sony PlayStation 3
Recordable DVD, others?
Yes
[58]
Toshiba BDX2000
Recordable DVD, SD card
No info
[46]
Comment [43]
FullHD video plays with hiccups from a DVD-R disc, plays normally from [48] an SD card.
[50]
[52]
FullHD video
FullHD videos
[54]
Supports playback of AVCHD discs as of firmware release 1.6.
[59]
Supports playback of AVCHD format files recorded on disc or SD card
1 In the table above FullHD means a capability to play back 1080p50 or 1080p60 videos, depending on region.
A more extensive list of Blu-ray players that support AVCHD is listed here [60].
AVCHD
Hardware products Canon Depending on model, Canon camcorders offer 1080-line interlaced, PsF, and native 24p recording. • • • •
HR10 (DVD) 2007: HG10 (40 GB HDD) April 2008: HF10 (SDHC, built-in 16GB flash memory), HF100 (SDHC) September 2008: HF11 (SDHC, built-in 32GB flash memory), HG20 (60GB HDD, SDHC), HG21 (120GB HDD, SDHC) • January 2009: HF S10 (SDHC, built-in 32GB flash memory), HF S100 (SDHC), HF20 (SDHC, built-in 32GB flash memory), HF200 (SDHC) • August 2009: HF S11 (SDHC, built-in 64GB flash memory, wired LANC remote capability) • January 2010: HF S21 (two SDHC slots, 64GB flash memory, electronic viewfinder), HF S20 (two SDHC slots, 32GB flash memory),[61] HF S200 (two SDHC slots); HF M31 (SDHC, 32GB flash memory), HF M30 (SDHC, 8GB flash memory), HF M300 (SDHC); HF R11 (32GB flash memory), HF R10 (SDHC, 8GB flash memory), HF R100 (SDHC)
Hitachi • 2008: DZ-BD10HA (Three-media recording: Blu-ray Disc, AVCHD on HDD, AVCHD on SDHC)[62]
JVC • June 2008: GZ-HD10 (HDD, MicroSDHC), GZ-HD30/GZ-HD40(HDD, MicroSDHC card, dual AVCHD and TOD recording) • January 2009: GZ-HD320 (120 GB HDD, MicroSD), GZ-HD300 (60 GB HDD, MicroSD), GZ-HM200 (dual SDHC) • February 2009: GZ-X900 (SD/SDHC card) • September 2009: GZ-HM300, GZ-HM400 • December 2009: GZ-HD620 • March 2010: GZ-HM1 • Spring 2011: GZ-HM30 (pre-released December 2010)
Leica Camera Digital still cameras • 2010:LEICA D-LUX 5, LEICA V-LUX 2
Panasonic Panasonic AVCHD camcorders offer interlaced, progressive scan or native progressive recording and combinations of these modes depending on a particular model. 1080-line and 720-line recording is possible depending on a model. Panasonic AVCHD camcorders use AVC with High Profile @ Level 4.0 for all modes except 1080p50/1080p60, which are encoded with High Profile @ Level 4.2. Maximum data rate is limited to 24 Mbit/s for AVCCAM models, to 17 Mbit/s for most consumer models and to 28 Mbit/s for 1080p50/1080p60 recording modes. • December 2006: HDC-DX1 (DVD), HDC-SD1 (SDHC)[63] • HDC-SD3 (SDHC, available in Japan only) • AG-HSC1U (SDHC, comes with portable 40 GB HDD storage) • August 2007: HDC-SD5 (SDHC), HDC-SX5 (DVD, SDHC), HDC-SD7 (SDHC)[64]
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AVCHD • • • • • • • • • • • •
January 2008: HDC-SD9 (SDHC), HDC-HS9 (60 GB HDD, SDHC)[65] April 2008: AG-HMC70 (SDHC)[66] June 2008: HDC-SD100 (SDHC), HDC-HS100 (60 GB HDD, SDHC)[67] September 2008: AG-HMC150 (SDHC)[68] January 2009: HDC-HS300 (120 GB HDD), HDC-HS200 (80 GB HDD), HDC-TM300 (32 GB built-in flash memory, SDHC), HDC-SD300 (SDHC, available in Europe only), HDC-SD200 (SDHC). June 2009: HDC-TM30/HDC-TM10 (32 GB built-in flash memory, SDHC), HDC-SD10 (SDHC) June 2009: HDC-TM350 (64 GB built-in flash memory, SDHC, available in Japan and as of October 2009, from Panasonic Stores across the UK) September 2009: AG-HMC40 (SDHC)[69] February 2010: HDC-TM700/HDC-SD700/HDC-HS700 (introduced 1080p60/1080p50 modes, depending on region)[70] March 2010: HDC-SD60/HDC-TM60/HDC-HS60[71] December 2010 (announced): AG-AF100/AG-AF101/AG-AF102 (4/3" large sensor camera)[72] April 2011: AG-AC130/AG-AC160 [73]
In 2009 Panasonic introduced AVCHD Lite and AVCHD to selected members of its Lumix line of digital cameras: • 2009: DMC-ZS3/TZ7*, DMC-TS1/DMC-FT1* (AVCHD Lite) • • • • •
2009: DMC-GH1 (AVCHD) 2010: Lumix DMC-ZS7/TZ10*, DMC-G2 (AVCHD lite) 2010: Lumix DMC-GH2, DMC-GF2 (AVCHD) 2011: Lumix DMC-ZS10/TZ20* (AVCHD lite) 2011: Lumix DMC-FX77/FX78*, DMC-TS3*, DMC-FZ47/48*, DMC-G3/GF3 (AVCHD)
* to avoid European specific tax, Panasonic digital cameras for this market are limited to 30 minutes recording.
Sony Consumer Sony AVCHD camcorders released before 2011 could record 1080-line interlaced video only, while the prosumer HDR-AX2000 and professional HXR-NX5 cameras were capable of recording in interlaced and progressive formats.[74] Released in March 2011, the Sony NEX-FS100 is the first professional NXCAM camcorder capable of 1080p50/p60 recording; [75] consumer-grade HandyCam NEX-VG20 followed in August 2011.[76] The list of AVCHD camcoders includes: • • • • • • • • • • •
September 2006: HDR-UX1 (DVD), HDR-UX3/UX5 (DVD), HDR-UX7 (DVD) October 2006: HDR-SR1 (30 GB HDD) June 2007: HDR-SR5 (40 GB HDD), HDR-SR7 (60 GB HDD) July 2007: HDR-SR5C (100 GB HDD), HDR-SR8 (100 GB HDD) Summer 2007: HDR-CX7 (Memory Stick Duo) March 2008: HDR-SR10 (40GB HDD, Memory Stick), HDR-SR11 (60 GB HDD, Memory Stick), HDR-SR12 (120 GB HDD, Memory Stick) HDR-TG1/TG3/TG7 (Memory Stick Duo) August 2008: HDR-CX12 (Memory Stick Duo) March 2009: HDR-XR520V (240 GB HDD), HDR-XR500V (120 GB HDD Version) March 2009: HDR-XR200V (120 GB HDD) March 2009: HDR-XR200VE (120 GB HDD + GPS)
• March 2009: HDR-XR100 (80 GB HDD) • July 2009: HDR-CX500E, HDR-CX520E • October 2009: HDR-CX105 (8GB Memory Stick Duo)
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AVCHD • January 2010: HXR-NX5, HDR-AX2000.[77] • March 2010: HDR-XR550 (240 GB HDD) • June 2010: Sony NEX-5, NEX-5C (without Eye-Fi support), of both models, variants with AVCHD 1080 50i and AVCHD 1080 60i only exist • July 2010: Sony HXR-MC50E.[78] • March 2011: Sony NEX-FS100 • August 2011: NEX-VG20 In 2010 Sony introduced AVCHD to selected members of its Cybershot line of digital cameras. • January 2010: Sony DSC-HX5V (GPS+COMPASS) , HX5V-E (European version, limited to 30 minutes recording due to European specific taxes)
Software Codecs • ffdshow is a free, Open Source collection of codecs, including an AVCHD decoder. • CoreAVC is an H.264 decoder for Windows, which can decode AVCHD as well as a variety of other H.264 formats.
Converters • Avidemux is a free open-source program that can be used to edit or convert AVCHD and AVCHD Lite files. It is also capable of demuxing and remuxing the audio and video streams into several different container formats including AVI, MP4, and MKV. (When converting AVCHD Lite .mts files from the Panasonic Lumix DMC-ZS3, the framerate must be manually set to 29.97.) • Badaboom is a media converter that uses NVIDIA GPUs to accelerate conversion of AVCHD to mobile devices. • HandBrake will convert AVCHD Lite format to MP4 and MKV (tested on OSX; other versions available), AVI and OGM are supported in versions before 0.9.4. • Roxio Toast 10 Titanium on Mac OS X will convert AVCHD to most computer formats presently available. • Total video converter is a converter for most video formats, including converting from AVCHD and burning AVCHD disc.
Editors The following video-editing software features support for the AVCHD format: • Avid Media Composer (from version 5.0)supports AVCHD through as a transcoded to import. AMA linking is not currently supported. • Adobe Premiere Pro (from version CS4 onwards). • Elemental Accelerator is a third party plug-in for Adobe Premiere Pro CS4 that converts AVCHD to various H.264 or MPEG-2 formats. • Adobe Premiere Elements (from version 7 onwards; only supports import, no AVCHD output) • Apple's Final Cut Pro X natively supports AVCHD through Import From Camera. • Apple's Final Cut Pro for Mac OS X. The latest version of Final Cut Pro 7 claims better integration with Apple's other professional applications and improved codec support for editing HD, DV and SD video formats, including encoding presets for devices such as iPod, Apple TV, and Blu-ray Discs. • Apple's Final Cut Express 4, Final Cut Pro 6.0.1, and iMovie '08-'09 (iMovie is bundled with all new Apple computers; Final Cut Express and Pro are sold separately) do not support editing of AVCHD clips directly. Imported AVCHD clips are automatically converted into the Apple Intermediate Codec format, which requires
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AVCHD more hard disk space (40GB per hour as opposed to 13.5GB per hour for Standard Definition DV), a more powerful machine (an Intel-based Mac), and a more recent OS (Mac OS X 10.5). Final Cut Pro 6.0.5 "logs and transfers" the footage from AVCHD to AppleProRes by default and also gives the option of converting to the Apple Intermediate Codec. It does not allow native transferring of the *.m2ts clips nor directly editing them. The latest release of Apple's iLife suite (specifically, iMovie) has added support for AVCHD Lite cameras and camcorders.[79] [80] It automatically imports AVCHD files when attaching a supported camera to the computer, and it can import older MTS or M2TS files that have been rewrapped (see above) e.g. as m4v. • AVS Video Editor supports videos from HD-cameras(HD Video (inc. AVCHD, MPEG-2 HD and WMV HD), TOD, MOD, M2TS.) Burn AVCHD video to CD-R/RW, DVD+/-R, DVD+/-RW, DVD-RAM, Double/Dual Layer on Windows XP, 2003, Vista, 7 (no Mac OS/Linux support). • Blender supports the AVCHD format on Windows and Linux systems (using a FFmpeg decoder). Blender has a little-known, very powerful video editing system with infinite layer bit-depth and integration with the 3D editing component. BlenderAVC streamlines the process of importing the files, as it is difficult and bug-prone without AVS scripts. Blender supports proxy editing at down to 25% scaling, which helps when editing AVCHD video, which is slow. • Corel VideoStudio supports importing, rendering and burning of AVCHD format in Windows system. • Elecard AVC HD Editor [81] affords reordering, trimming and merging of AVCHD clips without the need for transcoding. • Cyberlink PowerDirector 7 is capable of editing AVCHD natively, without transcoding, intermediate formats or proxy files. Using a patented technique (SVRT), AVCHD clips can be edited and output losslessly to AVCHD or Blu-ray Disc. PowerDirector also supports GPU encoding acceleration on both ATI and NVidia graphics platforms. PowerDirector can output the finished movie to a variety of video formats, DVD, AVCHD on DVD, or Blu-ray Disc. • Grass Valley's Edius 5.5 and Edius Neo 2 • Microsoft's Windows Live Movie Maker (importing only) • Dayang's Montage Extreme [ME] 1.2 • Nero Ultra Edition Enhanced (from version 7 onwards) includes the Nero Vision editor and the Nero Showtime player, which both support AVCHD files. NeroVision can author DVDs in the AVCHD format. • Pinnacle Studio Plus (from version 11 onwards) • Sony Vegas 7.0e • Vegas Pro (from version 8 onwards) • Vegas Movie Studio Platinum (from version 8 onwards) • Kdenlive for Linux and BSD platforms • Openshot Video editor for Linux • Other developers have pledged their support but it may still take some time for the implementation.
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AVCHD
70
Open Source codecs The following open source codecs can decode AVCHD files: • ffdshow tryouts, revision 1971 May 23, 2008, will decode AVC (H.264) format video.[82] • libavcodec (part of FFmpeg project) is a codec library that supports AVCHD. It is used in Jahshaka and Blender, notably.
Specifications Video Subtype Frame size in pixels
High Definition (AVCHD-HD) 1920×1080
Standard Definition (AVCHD-SD)
1280 x 720
720×480
720×576
29.97, interlaced
59.94, progressive
29.97, interlaced
25, interlaced
25, interlaced
50, progressive
1440×1080 Frame rate
23.976, progressive 23.976, progressive Frame aspect ratio
16:9
4:3, 16:9
Video Compression Luminance sampling frequency
MPEG-4 AVC/H.264 74.25 MHz
74.25 MHz
13.5 MHz
55.7 MHz Chroma sampling format
4:2:0
Quantization
8 bits (both luminance and chrominance) Audio (Dolby Digital)
AC-3 Compression
Dolby Digital (AC-3)
AC-3 channel mode
1-5.1 channels
AC-3 compressed bitstream rate
64 to 640 kbit/s Audio (PCM)
PCM linear PCM channel mode PCM bitrate
PCM uncompressed audio 1-7.1 channels 1.5 Mbit/s (2 channels) System
Stream type System data rate
MPEG transport stream up to 18 Mbit/s (DVD media) up to 24 Mbit/s (all other media)
File extension (generally) Media
mts (on camcorder), m2ts (after import to computer) 8 cm optical media (DVD) SD/SDHC Memory Card "Memory Stick" Built-in hard-disk or flash Media
13.5 MHz
AVCHD
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Specification addendum (AVCHD revision 2.0) AVCHD 2.0 adds support for the following recording modes: Video Subtype Frame size in pixels Frame rate
1080p50/1080p60 (AVCHD 2.0) 1440×1080
Stereoscopic 3D (AVCHD 3D)
1920×1080
59.94, progressive 50, progressive
1280 x 720
59.94, progressive 23.976, progressive 25, interlaced 50, progressive
Frame aspect ratio
16:9
Video Compression
MPEG-4 AVC/H.264
Luminance sampling frequency
111.4 MHz
1920×1080
148.5 MHz
29.97, interlaced
74.25 MHz
Chroma sampling format
4:2:0
Quantization
8 bits (both luminance and chrominance) Audio (Dolby Digital)
AC-3 Compression
Dolby Digital (AC-3)
AC-3 channel mode
1-5.1 channels
AC-3 compressed bitstream rate
64 to 640 kbit/s Audio (PCM)
PCM linear PCM channel mode PCM bitrate
PCM uncompressed audio 1-7.1 channels 1.5 Mbit/s (2 channels) System
Stream type System data rate File extension (generally) Media
MPEG transport stream up to 28 Mbit/s mts (on camcorder), m2ts (after import to computer) SD/SDHC Memory Card "Memory Stick" Built-in hard-disk or flash Media
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[32] "Burning High-def DVDs & Blu-ray Discs with Creator 2009" (http:/ / mymoments. roxio. com/ enu/ articles/ pc/ burning_& _copy,video/ 2008/ 09/ burning_highdef_dvds__bluray_discs_with_creator_2009. html). . [33] "Toast 9 HD/BD Plug-in: affordable high-def DVD and Blu-ray Disc video authoring for Toast 9" (http:/ / www. roxio. com/ enu/ products/ toast9/ plugin/ overview. html). . [34] "Roxio Launches Toast 10 Titanium Discs with Creator 2009" (http:/ / www. sonic. com/ about/ press/ news/ 2009/ 01/ toast10-launch. aspx). . [35] "Compressor 3 User Manual" (http:/ / manuals. info. apple. com/ en_US/ Compressor_3_User_Manual. pdf). . [36] "Final Cut Server 1.5: Blu-ray Disc and AVCHD output options only available in Compressor 3.5 with Final Cut Studio (2009)" (http:/ / support. apple. com/ kb/ TS2863). . [37] "Nero 9 FAQ: AVCHD" (http:/ / www. nero. com/ enu/ support-nero9-faq. html?s=sub& t=AVCHD). . [38] "Panasonic HDC-TM300 review (in Russian)" (http:/ / www. ixbt. com/ divideo/ panasonic-hdc-tm300. shtml). . [39] "MultiAVCHD authoring tool" (http:/ / multiavchd. deanbg. com/ ). . [40] "Magix Movie Edit Pro" (http:/ / www. magix. com/ ). . [41] "Pinnacle Studio 11.1.2 release update" (http:/ / www. pinnaclesys. com/ PublicSite/ us/ Products/ Consumer+ Products/ Home+ Video/ Studio+ Family/ Studio+ Plus+ 11+ Support/ Download+ Area/ Drivers+ -+ Updates/ Studio+ 11_1_2+ patch. htm?mode=documents& Display=1). . [42] "02fx4dude" (2008-04-28). "Samsung BDP1200 discussion" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=13746816#post13746816). avsforum.com. . [43] "powjunky" (2011-01-07). "1080p60 playback discussion thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19781834#post19781834). avsforum.com. . [44] "Which Blu-ray Disc players support AVCHD USB playback?" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?t=1136999). 2009. . [45] "1080p60 playback discussion thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19588485#post19588485). avsforum.com. . [46] "DMP-BD60 Blu-ray Disc™ Player Specifications" (http:/ / www. panasonic. com/ apps/ match-maker/ assets/ pdf/ bluray/ DMP-BD60. pdf). 2009. . [47] "DMP-BD80 Blu-ray Disc™ Player Specifications" (http:/ / www. panasonic. com/ apps/ match-maker/ assets/ pdf/ bluray/ DMP-BD80. pdf). 2009. .
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[48] "Rendering 1080p60 video for playback on Panasonic Blu-ray Disc players" (http:/ / www. avsforum. com/ avs-vb/ showpost. php?p=19304404& postcount=3134). 2010. . [49] "DMP-BD85/BD65/BD45 Blu-ray DiscTM Player Specifications" (http:/ / www. panasonic. com/ apps/ match-maker/ assets/ pdf/ bluray/ VideoBD65. pdf). 2010. . [50] "Pioneer BDP-51FD operating instructions, p. 10" (http:/ / www. pioneerelectronics. com/ StaticFiles/ Manuals/ Home/ BDP-51FD_OperatingInstructions0708. pdf). . [51] "flint350" (2010-12-02). "1080p60 playback discussion thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19590009#post19590009). avsforum.com. . [52] "Pioneer BDP-51FD product brochure" (http:/ / www. pioneerelectronics. com/ ephox/ StaticFiles/ PUSA/ Files/ BDP-320. pdf). . [53] "v1rtu0s1ty" (2010-12-02). "1080p60 playback discussion thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19656051#post19656051). avsforum.com. . [54] "SRussell" (2008-03-13). "Samsung BDP1400 Discussion Thread" (http:/ / www. avsforum. com/ avs-vb/ showpost. php?p=13369247& postcount=5374). avsforum.com. . [55] "msgohan". "1080p60 playback discussion thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19588740#post19588740). avsforum.com. . [56] "Quidsane". "The Panasonic HDC-HS/SD/TM700 owners thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19672058#post19672058). avsforum.com. . [57] "TNO821". "1080p60 playback discussion thread" (http:/ / www. avsforum. com/ avs-vb/ showthread. php?p=19730948#post19730948). avsforum.com. . [58] "AVCHD Enabled Blu-ray players" (http:/ / www. homedvd. ca/ resources/ avchd_player). . [59] "Blu-ray Disc Player BDX2000KU owner's manual" (http:/ / www. tacp. toshiba. com/ tacpassets-images/ models/ bdx2000/ docs/ bdx2000_om_e. pdf) (PDF). Toshiba Corp.. 2009. . page 7. [60] http:/ / www. homedvd. ca/ resources/ avchd_player [61] "Canon U.S.A. Introduces a Powerful New VIXIA Lineup to Meet the Needs of Every User" (http:/ / www. usa. canon. com/ cusa/ about_canon?pageKeyCode=pressreldetail& docId=0901e02480134098). Canon. 2010-01-05. . Retrieved 24 December 2010. [62] 30GB HDD hybrid camcorder with built-in hard disc drive (http:/ / www. hitachibd. com/ media/ pdfs/ DZBD10HA Spec Sheet. pdf), [63] Panasonic Consumer Electronics Company (2006-11-08). "Panasonic debuts world's first SD memory card HD video camera supporting AVCHD Format and introduces another AVCHD video camera using 8-cm DVDs" (http:/ / panasonic. co. jp/ corp/ news/ official. data/ data. dir/ en061108-3/ en061108-3. html). Press release. . [64] Panasonic Consumer Electronics Company (2007-08-01). "Panasonic introduces three new 3CCD Full-HD camcorders" (http:/ / panasonic. co. jp/ corp/ news/ official. data/ data. dir/ en070801-3/ en070801-3. html). Press release. . [65] Panasonic Consumer Electronics Company (2008-01-06). "Panasonic unveils two new AVCHD camcorders with new face detection and intelligent shooting guide" (http:/ / www2. panasonic. com/ webapp/ wcs/ stores/ servlet/ prModelDetail?storeId=11301& catalogId=13251& itemId=215166& modelNo=Content01052008070307494& surfModel=Content01052008070307494). Press release. . [66] Panasonic Consumer Electronics Company (2008-02-13). "Panasonic ships industry's first professional AVCHD shoulder-mount camcorder" (http:/ / www2. panasonic. com/ webapp/ wcs/ stores/ servlet/ prModelDetail?storeId=11301& catalogId=13251& itemId=226164& modelNo=Content02192008094929330& surfModel=Content02192008094929330). Press release. . [67] Panasonic Consumer Electronics Company (2008-06-18). "Panasonic introduces two first AVCHD camcorders with a 3MOS system" (http:/ / www2. panasonic. com/ webapp/ wcs/ stores/ servlet/ prModelDetail?storeId=11301& catalogId=13251& itemId=260737& modelNo=Content06182008020838075& surfModel=Content06182008020838075). Press release. . [68] Panasonic Consumer Electronics Company (2008-07-31). "Panasonic unveils pricing and ship date for the AG-HMC150 camcorder" (http:/ / studiodaily. com/ main/ news/ 9774. html). Press release. . [69] Panasonic Consumer Electronics Company (2009-04-19). "Panasonic unveils AG-HMC40, low cost professional AVCCAM handheld camcorder" (http:/ / www2. panasonic. com/ webapp/ wcs/ stores/ servlet/ prModelDetail?storeId=11301& catalogId=13251& itemId=342251& modelNo=Content04162009020819466& surfModel=Content04162009020819466& cm_sp=Homepage News And Press-_-PNA-_-04/ 19/ 09-Panasonic Unveils AG). Press release. . [70] http:/ / www. panasonic. co. uk/ html/ en_GB/ Products/ Camcorders/ HD+ Camcorders/ HDC-TM700/ Specification/ 3422367/ index. html [71] http:/ / www. panasonic. co. uk/ html/ en_GB/ Products/ Camcorders/ 1MOS+ HD+ Camcorders/ HDC-TM60/ Specification/ 3297048/ index. html?trackInfo=true [72] http:/ / www2. panasonic. com/ webapp/ wcs/ stores/ servlet/ prModelDetail?storeId=11301& catalogId=13251& itemId=407080& modelNo=Content04082010101919040& surfModel [73] http:/ / www. broadcastingcable. com/ article/ 466585-NAB_Panasonic_Unveils_New_Cameras. php [74] Sony HDR-AX2000 (http:/ / www. docs. sony. com/ release/ specs/ HDRAX2000_mksp. pdf) [75] Sony NEX-FS100 (http:/ / pro. sony. com/ bbsc/ ssr/ cat-broadcastcameras/ cat-nxcam/ product-NEXFS100UK/ ) [76] [http://store.sony.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&productId=8198552921666376733 Sony HandyCam NEX-VG20 [77] SONY unveils new solid state camcorders (http:/ / news. sel. sony. com/ en/ press_room/ consumer/ digital_imaging/ camcorders/ release/ 56305. html)
AVCHD [78] Sony Product Information (http:/ / www. sony. co. uk/ biz/ view/ ShowProduct. action?product=HXR-MC50E& site=biz_en_GB& pageType=Overview& category=NXCamcorders) [79] "iMovie 8.0.3" (http:/ / support. apple. com/ downloads/ iMovie_8_0_3). Apple Inc.. 2009-06-04. . [80] "Final Cut Express 4 User Manual" (http:/ / manuals. info. apple. com/ en/ Final_Cut_Express_4_User_Manual. pdf) (PDF). Cupertino, CA, USA: Apple Inc.. 2007. . Search for "AVCHD". [81] http:/ / www. elecard. com/ en/ products/ end-user-software/ editing/ avchd-editor. html [82] "ffdshow tryouts: The Official Website" (http:/ / ffdshow-tryout. sourceforge. net/ ). .
External links • AVCHD Official Consortium Web site (http://www.avchd-info.org/)
High-definition video High-definition video or HD video refers to any video system of higher resolution than standard-definition (SD) video, and most commonly involves display resolutions of 1,280×720 pixels (720p) or 1,920×1,080 pixels (1080i/1080p). This article discusses the general concepts of high-definition video, as opposed to its specific applications in television broadcast (HDTV), video recording formats (HDCAM, HDCAM-SR, DVCPRO HD, D5 HD, AVC-Intra, XDCAM HD, HDV, and AVCHD), the optical disc delivery system Blu-ray Disc, and the video tape format D-VHS.
History 1936–1980s From a historical perspective, the first electronic scanning format 405 lines was the first "high definition" television system as the previous mechanical systems had far fewer scanning lines. From 1939, the US and other European countries experimented with 441 lines and 605 lines until the Federal Communications Commission (FCC) mandated 525 lines for the US from 1941. In wartime France, René Barthélemy experimented with higher definitions, reaching 1015 and even 1042 lines. Official French transmissions finally began with 819 lines from late 1949; however, this standard was abandoned in 1984 upon the adoption of 625-line colour on the TF1 network.
1980s Modern HD specifications date to the early 1970s, when Japanese engineers developed the HighVision 1,125-line interlaced TV standard (also called MUSE) that ran at 60 frames per second. The Sony HDVS system was presented at an international meeting of television engineers in Algiers, April of 1981 and Japan's NHK presented its analog HDTV system at a Swiss conference in 1983. The NHK system was standardized in the United States as Society of Motion Picture and Television Engineers (SMPTE) standard #240M in the early 1990s, but abandoned later on when it was replaced by a DVB analog standard. HighVision video is still usable for HDTV video interchange, but there is almost no equipment around to perform this function. Attempts at shoehorning in HighVision into a 6 MHz broadcast channel were mostly unsuccessful. All attempts at using this format for terrestrial TV transmission were forsaken by the mid-1990s. The Europeans developed HD-MAC (1,250 lines, 50 Hz) as a video standard; however, it never took off as a terrestrial video transmission format. HD-MAC was never designated for video interchange except by the European Broadcasting Union. The current high-definition video standards in North America were developed during the course of the advanced television process initiated by the Federal Communications Commission in 1987 at the request of American
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broadcasters. In essence, the end of the 1980s was a death knell for most analog high definition technologies that had developed up to that time.
1990s The FCC process, led by the Advanced Television Systems Committee (ATSC) adopted a range of standards from interlaced 1,080-line video (a technical descendant of the original analog NHK 1125/30 Hz system) with a maximum frame rate of 30 Hz, and 720-line video, progressively scanned, with a maximum frame rate of 60 Hz. In the end, however, the DVB standard of resolutions (1080, 720, 480) and respective frame rates (24, 25, 30) were adopted in conjunction with the Europeans that were also involved in the same standardization process. The FCC officially adopted the ATSC transmission standard (which included both HD and SD video standards) in 1996, with the first broadcasts on October 28, 1998.
2000s In the early 2000s, it looked as if DVB would be the video standard far into the future. However, both Brazil and China have adopted alternative standards for high-definition video that preclude the interoperability that was hoped for after decades of largely non-interoperable analog TV broadcasting.
Technical details High definition video (prerecorded and broadcast) is defined threefold, by: • The number of lines in the vertical display resolution. High-definition television (HDTV) resolution is 1,080 or 720 lines. In contrast, regular digital television (DTV) is 480 lines (upon which NTSC is based, 480 visible scanlines out of 525) or 576 lines (upon which PAL/SECAM are based, 576 visible scanlines out of 625). However, since HD is broadcast digitally, its introduction sometimes coincides with the introduction of DTV. Additionally, current DVD quality is not high-definition, although the high-definition disc systems Blu-ray Disc and the defunct HD DVD are.
This chart shows the most common display resolutions, with the color of each resolution type indicating the display ratio (e.g., red indicates a 4:3 ratio)
• The scanning system: progressive scanning (p) or interlaced scanning (i). Progressive scanning redraws an image frame (all of its lines) when refreshing each image. Interlaced scanning draws the image field every other line or "odd numbered" lines during the first image refresh operation, and then draws the remaining "even numbered" lines during a second refreshing. Interlaced scanning yields greater image resolution if subject is not moving, but loses up to half of the resolution and suffers "combing" artifacts when subject is moving. • The number of frames or fields per second. The 720p60 format is 1,280 × 720 pixels, progressive encoding with 60 frames per second (60 Hz). The 1080i50 format is 1920 × 1080 pixels, interlaced encoding with 50 fields per second. Two interlaced fields formulate a single frame, because the two fields of one frame are temporally shifted. Frame pulldown and segmented frames are special techniques that allow transmitting full frames by means of interlaced video stream. For commercial naming of the product, either the frame rate or the field rate is dropped; e.g., a "1080i television set" label indicates only the image resolution.[1] Often, the rate is inferred from the context, usually assumed to be either 50 or 60, except for 1080p, which denotes 1080p24, 1080p25, and 1080p30, but also 1080p50 and 1080p60.
High-definition video
76
A frame or field rate can also be specified without a resolution. For example 24p means 24 progressive scan frames per second and 50i means 25 interlaced frames per second, consisting of 50 interlaced fields per second. Most HDTV systems support some standard resolutions and frame or field rates. The most common are noted below. High-definition signals require a high-definition television or computer monitor in order to be viewed. High-definition video has an aspect ratio of 16:9 (1.78:1). The aspect ratio of regular widescreen film shot today is typically 1.85:1 or 2.39:1 (sometimes traditionally quoted at 2.35:1). Standard-definition television (SDTV) has a 4:3 (1.33:1) aspect ratio, although in recent years many broadcasters have transmitted programs "squeezed" horizontally in 16:9 anamorphic format, in hopes that the viewer has a 16:9 set which stretches the image out to normal-looking proportions, or a set which "squishes" the image vertically to present a "letterbox" view of the image, again with correct proportions.
Common high-definition video modes Video mode
Frame size in pixels (W×H)
Pixels per image1 Scanning type
Frame rate (Hz)
720p
1,280×720
921,600
Progressive
23.976, 24, 25, 29.97, 30, 50, 59.94, 60, 72
1080i
1,920×1,080
2,073,600
Interlaced
25 (50 fields/s), 29.97 (59.94 fields/s), 30 (60 fields/s)
1080p
1,920×1,080
2,073,600
Progressive
23.976, 24, 25, 29.97, 30, 50, 59.94, 60
Extra high-definition video modes Video mode
Frame size in pixels (W×H)
Pixels per image1 Scanning type
2K
2,048×1,536
3,145,728
Progressive
2160p
3,840×2,160
8,294,400
Progressive
4K
4,096×3,072
12,582,912
Progressive
2540p
4,520×2,540
11,480,800
Progressive
4320p
7,680×4,320
33,177,600
Progressive
Frame rate (Hz)
50, 60
Note: 1 Image is either a frame or, in case of interlaced scanning, two fields. (EVEN and ODD)
HD content High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, high definition disc (BD), internet downloads and the latest generation of video game consoles. • Most computers are capable of HD or higher resolutions over VGA, DVI, and/or HDMI. • The optical disc standard Blu-ray Disc can provide enough digital storage to store hours of HD video content. DVDs look best on screens that are smaller than 36 inches (91 cm), so they are not always up to the challenge of today's high-definition (HD) sets. Storing and playing HD movies requires a disc that holds more information, like a Blu-ray Disc.
High-definition video
Types of recorded media The high resolution photographic film used for cinema projection is exposed at the rate of 24 frames per second but usually projected at 48, each frame getting projected twice helping to minimise flicker. One exception to this was the 1986 National Film Board of Canada short film Momentum, which briefly experimented with both filming and projecting at 48 frame/s, in a process known as IMAX HD. Depending upon available bandwidth and the amount of detail and movement in the image, the optimum format for video transfer is either 720p24 or 1080p24. When shown on television in PAL system countries, film must be projected at the rate of 25 frames per second by accelerating it by 4.1 per cent. In NTSC standard countries, the projection rate is 30 frames per second, using a technique called 3:2 pull-down. One film frame is held for three video fields (1/20 of a second), and the next is held for two video fields (1/30 of a second) and then the process is repeated, thus achieving the correct film projection rate with two film frames shown in 1/12 of a second. Older (pre-HDTV) recordings on video tape such as Betacam SP are often either in the form 480i60 or 576i50. These may be upconverted to a higher resolution format (720i), but removing the interlace to match the common 720p format may distort the picture or require filtering which actually reduces the resolution of the final output. Non-cinematic HDTV video recordings are recorded in either the 720p or the 1080i format. The format used is set by the broadcaster (if for television broadcast). In general, 720p is more accurate with fast action, because it progressively scans frames, instead of the 1080i, which uses interlaced fields and thus might degrade the resolution of fast images. 720p is used more for Internet distribution of high-definition video, because computer monitors progressively scan; 720p video has lower storage-decoding requirements than either the 1080i or the 1080p. This is also the medium for high-definition broadcasts around the world and 1080p is used for Blu-ray movies.
HD in filmmaking Film as a medium has inherent limitations, such as difficulty of viewing footage whilst recording, and suffers other problems, caused by poor film development/processing, or poor monitoring systems. Given that there is increasing use of computer-generated or computer-altered imagery in movies, and that editing picture sequences is often done digitally, some directors have shot their movies using the HD format via high-end digital video cameras. Whilst the quality of HD video is very high compared to SD video, and offers improved signal/noise ratios against comparable sensitivity film, film remains able to resolve more image detail than current HD video formats. In addition some films have a wider dynamic range (ability to resolve extremes of dark and light areas in a scene) than even the best HD cameras. Thus the most persuasive arguments for the use of HD are currently cost savings on film stock and the ease of transfer to editing systems for special effects. Depending on the year and format a movie was filmed in, the exposed image can vary greatly in size. Sizes range from as big as 24 mm × 36 mm for VistaVision/Technirama 8 perforation cameras (same as 35 mm still photo film) going down through 18 mm × 24 mm for Silent Films or Full Frame 4 perforations cameras to as small as 9 mm × 21 mm in Academy Sound Aperture cameras modified for the Techniscope 2 perforation format. Movies are also produced using other film gauges, including 70 mm films (22 mm × 48 mm) or the rarely used 55 mm and CINERAMA. The four major film formats provide pixel resolutions (calculated from pixels per millimeter) roughly as follows: • • • •
Academy Sound (Sound movies before 1955): 15 mm × 21 mm (1.375) = 2,160 × 2,970 Academy camera US Widescreen: 11 mm × 21 mm (1.85) = 1,605 × 2,970 Current Anamorphic Panavision ("Scope"): 17.5 mm × 21 mm (2.39) = 2,485 × 2,970 Super-35 for Anamorphic prints: 10 mm × 24 mm (2.39) = 1,420 × 3,390
In the process of making prints for exhibition, this negative is copied onto other film (negative → interpositive → internegative → print) causing the resolution to be reduced with each emulsion copying step and when the image
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High-definition video
78
passes through a lens (for example, on a projector). In many cases, the resolution can be reduced down to 1/6 of the original negative's resolution (or worse). Note that resolution values for 70 mm film are higher than those listed above.
HD on the World Wide Web/HD Streaming A number of online video streaming/on demand and digital download services offer HD video, among them YouTube, Vimeo, Hulu, Amazon Video On Demand, Netflix Watch Instantly, and others. Due to heavy compression, the image detail produced by these formats are far below that of broadcast HD, and often even inferior to DVD-Video (3-9 Mbit/s MP2) upscaled to the same image size.[2] The following is a chart of numerous online services and their HD offering:
World Wide Web HD resolutions Source
Codec
Amazon Video On Demand (formerly "Unbox")
VC-1
[5]
BBC iPlayer
Highest resolution (W×H)
[3]
[4]
1,280×720
[6]
[7]
H.264
1,280×720
Total bit rate/bandwidth
Video bit rate
Audio bit rate
[4]
2.5 Mbit/s
[6]
3.2 Mbit/s
[6]
3 Mbit/s
[6]
192 kbit/s
Blockbuster Online CBS.com CBS.com
[8]
[9]
/TV.com (720p)
1,280×720
[8]
1,920×1,080 [10]
Hulu iPlayerHD
[9]
/TV.com (1080p)
[13]
[11]
On2 Flash VP6
1,280×720
FLV, Quicktime H.264, [14] MP4 H.264
1,920×1,080
[17]
[17]
QuickTime H.264
Netflix Watch Instantly
VC-1
1,280×720
PlayStationStore Movies & TV Shows
H.264/MPEG-4 [23] AVC
1,920×1,080
Vimeo
H.264
Vudu
H.264
[24] [28]
YouTube
1,280×720
[20]
[16]
5 Mbit/s
[18] 4Mbps [21]
5 Mbit/s
[23]
[25] [29]
1,920×1,080
[33]
4,096x2,304
2.6 Mbit/s and [22] 3.8 Mbit/s 8 Mbit/s
[26]
1,920×1,080
1,920×1,080 H.264/MPEG-4 AVC
[12]
2.5 Mbit/s
[23]
[31]
Zune Video (formerly "Xbox Live Marketplace Video Store")
[9]
3.5 Mbit/s
[15]
iTunes/Apple TV
[19]
[9]
2.5 Mbit/s
4 Mbit/s [30]
4.5 Mbit/s
[32]
3 Mbit/s
[23]
256 kbit/s
[27]
320 kbit/s
High-definition video
HD in video gaming The PlayStation 3 game console can output to native 1080p through both component and HDMI cables. The Xbox 360 can output 1080p over HDMI but games can only run at 720p upscaled to 1080p. The Wii can output up to 480p (enhanced-definition) over component which while not technically HD is very useful for HDTVs as it avoids de-interlacing artefacts. Native 1080p produces a sharper and clearer picture compared to upscaled 1080p. Besides increasing the visual quality of games, users can also download HD movies and video clips from the PlayStation Network or Xbox Live Marketplace services to their respective consoles. The PlayStation 3 can also play Blu-ray Discs which hold HD data. Though only a handful of games available can render in 1080p, all games on the Xbox 360 and PlayStation 3 can be upscaled up to this resolution. Xbox 360 and PlayStation 3 games are labeled with their output resolution on the back of their packaging, although on Xbox 360 this usually indicates the resolution it will upscale to, not the native resolution of the game. Also as the Xbox 360 did not originally support 1080p (it did not have an HDMI port), earlier games that said 720p on the box can now be upscaled to 1080p. Due to the versatility of the PC as a gaming platform, almost all recent PC games can be rendered in 1,920Ă&#x2014;1,080 or higher. The PlayStation 2 and the original Xbox had HD support, but few games of that era took advantage of this feature. The original Xbox however only had HD support enabled in NTSC regions. Nintendo's new console, the Wii U, supports HD.
HD in video surveillance High definition (HD) video is becoming the norm in the surveillance industry as an increasing number of manufacturers of security cameras now claim to offer HD cameras. It is understandable since the need for high resolution, colour fidelIty, and frame rate is more acute for surveillance purposes to ensure that the quality of the video output is of an acceptable standard that can be used both for preventative surveillance as well as for evidence purposes.
References [1] "The HDTV Progressive Frame Rate Clarification Initiative" (http:/ / gadget-minded. blogspot. com/ 2006/ 11/ progressive-hd-framerate-initiative. html). . [2] "Why HD movie downloads are a big lie" (http:/ / www. zdnet. com/ blog/ ou/ why-hd-movie-downloads-are-a-big-lie/ 511). Ziff-Davis. 2007-04-31. . Retrieved 2010-06-28. [3] "Amazon.com -- News Release" (http:/ / phx. corporate-ir. net/ phoenix. zhtml?c=176060& p=irol-newsArticle& ID=903244& highlight=). Amazon.com. 2006-09-07. . Retrieved 2009-10-16. "...using the ultra-efficient VC-1 Advanced Profile codec." [4] "Amazon.com: Help > Digital Products > Amazon Video On Demand" (http:/ / www. amazon. com/ gp/ help/ customer/ display. html?nodeId=3748& #speed). Amazon.com. . Retrieved 2009-10-16. "Our 2.5 Mbps HD files are streamed in high-quality 720p resolution." [5] http:/ / www. bbc. co. uk/ iplayer/ [6] "What do I need to know about HD on BBC iPlayer?" (http:/ / iplayerhelp. external. bbc. co. uk/ help/ about_iplayer/ watch_hd). BBC. . Retrieved 2009-12-16. "We use h.264 with a bitrate of 3.2Mbps and 192kbps audio" [7] "What do I need to know about HD on BBC iPlayer?" (http:/ / iplayerhelp. external. bbc. co. uk/ help/ about_iplayer/ watch_hd). BBC. . Retrieved 2009-12-16. "In order to be classed as "true" high definition, we encode in at least 1280x720 resolution, or 720p." [8] http:/ / www. cbs. com/ [9] "CBS.com - HD Video - System Requirements" (http:/ / www. cbs. com/ hd/ sys_requirements. shtml). CBS.com. . Retrieved 2009-10-16. [10] "Hulu - About" (http:/ / www. hulu. com/ about/ media_faq#technology). Hulu. . Retrieved 2009-10-16. "Hulu videos are streamed as Flash video files (FLV files). These files are encoded using the On2 Flash VP6 codec..." [11] "Hulu - About" (http:/ / www. hulu. com/ about/ media_faq#technology). Hulu. . Retrieved 2009-10-16. "HD videos on Hulu are streamed at 1280 x 720 resolution." [12] "Hulu - About" (http:/ / www. hulu. com/ about/ media_faq#technology). Hulu. . Retrieved 2009-10-16. "Hulu currently supports four different streams including 480kbps, 700kbps, 1,000kbps (an H.264 encode that is not on On2 VP6) and 2.5Mbps."
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High-definition video [13] http:/ / www. iplayerhd. com/ [14] "Learn More About iPlayerHD" (http:/ / iplayerhd. com/ Learn-More. aspx). iPlayerHD.com. . Retrieved 2009-12-16. "We support FLV and H264 as MOV and MP4." [15] "Learn More About iPlayerHD" (http:/ / iplayerhd. com/ Learn-More. aspx). iPlayerHD.com. . Retrieved 2009-12-16. "iPlayerHD will deliver video at any resolution including SD 720 x 480, and HD 480, 720 and 1080." [16] "Learn More About iPlayerHD" (http:/ / iplayerhd. com/ Learn-More. aspx). iPlayerHD.com. . Retrieved 2009-12-16. "Your video will be delivered at bit-rates up to 5,000 kbps or 5 mbps." [17] "Video quality reference table from best to worst" (http:/ / att. macrumors. com/ attachment. php?attachmentid=99997& d=1201708357). . [18] Malley, Aidan (2008-09-10). "AppleInsider - iTunes HD videos low bitrate, include iPod-ready versions" (http:/ / www. appleinsider. com/ articles/ 08/ 09/ 10/ itunes_hd_videos_low_bitrate_include_ipod_ready_versions. html). AppleInsider. . Retrieved 2009-10-16. "A standard 720p file downloaded either through iTunes or an Apple TV consumes about 4Mbps of data" [19] Hunt, Neil (2008-11-06). "The Official Netflix Blog: Encoding for streaming" (http:/ / blog. netflix. com/ 2008/ 11/ encoding-for-streaming. html). Netflix. . Retrieved 2009-10-16. "...but settled on second-generation HD encodes with VC1AP" [20] Hunt, Neil (2008-11-06). "The Official Netflix Blog: Encoding for streaming" (http:/ / blog. netflix. com/ 2008/ 11/ encoding-for-streaming. html). Netflix. . Retrieved 2009-10-16. "Today we have rights to deliver about 400 streams in HD (720p)." [21] "HD on your Netflix Ready Device" (http:/ / www. netflix. com/ WiMessage?msg=59). Netflix. . Retrieved 2010-02-08. "A high-speed internet connection at time of playback (typically 5 Mbps or higher)" [22] Hunt, Neil (2008-11-06). "The Official Netflix Blog: Encoding for streaming" (http:/ / blog. netflix. com/ 2008/ 11/ encoding-for-streaming. html). Netflix. . Retrieved 2009-10-16. "second-generation HD encodes ... at 2600kbps and 3800kbps" [23] Dipert, Brian (2008-07-17). "Online Video Content Distribution: Sony's PlayStation 3 Enters The Ring (Albeit With A Sound-Hampered Hand Tied Behind Its Back)" (http:/ / www. edn. com/ blog/ 400000040/ post/ 910030091. html). EDN. . Retrieved 2009-10-16. [24] "Vimeo - Compression guidelines on Vimeo" (http:/ / staging. vimeo. com/ help/ compression). Vimeo. . Retrieved 2009-10-16. "For best results, we recommend using H.264 (sometimes referred to as MP4) for the video codec and AAC (short for Advanced Audio Codec) for the audio codec." [25] "Vimeo - Compression guidelines on Vimeo" (http:/ / staging. vimeo. com/ help/ compression). Vimeo. . Retrieved 2009-10-16. "640x480 for standard definition 4:3 video, 853x480 for widescreen DV, or 1920x1080 for high definition." [26] "Vimeo - Compression guidelines on Vimeo" (http:/ / staging. vimeo. com/ help/ compression). Vimeo. . Retrieved 2009-10-16. "Use 2000 kbits/sec for standard definition 4:3 video, 3000 kbits/sec for widescreen DV, or 5000 kbits/sec for high definition footage." [27] "Vimeo - Compression guidelines on Vimeo" (http:/ / staging. vimeo. com/ help/ compression). Vimeo. . Retrieved 2009-10-16. "You'll want to set the bit rate to 320 kbps and the sample rate to 44.100 kHz." [28] Sturgeon, Shane (2008-02-21). "Showdown: Apple TV vs. VUDU" (http:/ / www. hdtvmagazine. com/ columns/ 2008/ 02/ showdown_apple_tv_vs_vudu. php). HDTV Magazine. . Retrieved 2009-11-05. "...all HD content is ... encoded with H.264 High Profile" [29] "Streaming Requirements" (http:/ / speedtest. vudu. com/ cdn1/ ). Vudu. . Retrieved 2010-02-09. "HDX (1080p)" [30] "Streaming Requirements" (http:/ / speedtest. vudu. com/ cdn1/ ). Vudu. . Retrieved 2010-02-09. "HDX (1080p) requires 4500 kbps" [31] "Instant HD Entertainment with Zune on Xbox" (http:/ / www. xbox. com/ en-US/ live/ features/ zune. htm). Xbox.com. . Retrieved 2010-02-09. "HD videos are provided in 1080p." [32] "Instant HD Entertainment with Zune on Xbox" (http:/ / www. xbox. com/ en-US/ live/ features/ zune. htm). Xbox.com. . Retrieved 2010-02-09. "Instant on HD in full 1080p streaming available with select movies, and requires HDMI cable, HDCP-compliant 1080p display, and 3 mbps broadband speed." [33] "What's bigger than 1080p? 4K video comes to YouTube" (http:/ / youtube-global. blogspot. com/ 2010/ 07/ whats-bigger-than-1080p-4k-video-comes. html). 2010-07-09. . "Today at the VidCon 2010 conference, we announced support for videos shot in 4K"
Further reading • Images formats for HDTV (http://tech.ebu.ch/docs/techreview/trev_299-ive.pdf)PDF (549 KiB), article from the EBU Technical Review . • High Definition for Europe - a progressive approach (http://tech.ebu.ch/docs/techreview/trev_300-wood. pdf)PDF (207 KiB), article from the EBU Technical Review . • High Definition (HD) Image Formats for Television Production (http://tech.ebu.ch/docs/tech/tech3299. pdf)PDF (117 KiB), technical report from the EBU • Digital Terrestrial HDTV Broadcasting in Europe (http://tech.ebu.ch/docs/tech/tech3312.pdf)PDF, technical report from the EBU
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High-definition video
External links â&#x20AC;˘ ATSC (http://www.atsc.org/guide_default.html)]
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Article Sources and Contributors
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Vector_Video_Standards_3.svg: *Vector_Video_Standards2.svg: Original uploader was XXV at en.wikipedia Later version(s) were uploaded by Jjalocha, Aihtdikh at en.wikipedia. derivative work: Leebyron (talk) derivative work: Flooch (talk) Image:Progressive scan hdtv.svg Source: http://en.wikipedia.org/w/index.php?title=File:Progressive_scan_hdtv.svg License: Creative Commons Attribution 3.0 Contributors: Michael Gauthier File:Fatty watching himself on TV.jpg Source: http://en.wikipedia.org/w/index.php?title=File:Fatty_watching_himself_on_TV.jpg License: Creative Commons Attribution 2.0 Contributors: Abujoy, CalistaZ, Love Krittaya, Mattes, Salix Image:C64 startup animiert.gif Source: http://en.wikipedia.org/w/index.php?title=File:C64_startup_animiert.gif License: unknown Contributors: Alexander.stohr, Bayo, Gedeon, Grandy02, StuartBrady, Tiptoety, WikipediaMaster, 6 anonymous edits Image:CGA CompVsRGB Text.png Source: http://en.wikipedia.org/w/index.php?title=File:CGA_CompVsRGB_Text.png License: Public Domain Contributors: Original uploader was NewRisingSun at en.wikipedia Image:HAM6example.png Source: http://en.wikipedia.org/w/index.php?title=File:HAM6example.png License: unknown Contributors: Marko75, Mdwh, Pixel8, Sfan00 IMG, 3 anonymous edits Image:Torak.gif Source: http://en.wikipedia.org/w/index.php?title=File:Torak.gif License: Public Domain Contributors: Retron Image:Square 200x200.svg Source: http://en.wikipedia.org/w/index.php?title=File:Square_200x200.svg License: Public Domain Contributors: Yarnalgo Image:Resolution illustration.png Source: http://en.wikipedia.org/w/index.php?title=File:Resolution_illustration.png License: Public Domain Contributors: Cfalonso, Korrigan Image:1951 USAF Resolution Test Target.JPG Source: http://en.wikipedia.org/w/index.php?title=File:1951_USAF_Resolution_Test_Target.JPG License: Creative Commons Attribution-Sharealike 3.0 Contributors: USAF Image:Matakis - blurred.jpg Source: http://en.wikipedia.org/w/index.php?title=File:Matakis_-_blurred.jpg License: Creative Commons Zero Contributors: Mikael Häggström Image:MARTAKIS1.jpg Source: http://en.wikipedia.org/w/index.php?title=File:MARTAKIS1.jpg License: Public Domain Contributors: Universal Music Greece, uploaded on their behalf by Bratopoulosm File:100x100 black and white pixels.png Source: http://en.wikipedia.org/w/index.php?title=File:100x100_black_and_white_pixels.png License: Creative Commons Zero Contributors: Mikael Häggström File:Distinguishable squares.png Source: http://en.wikipedia.org/w/index.php?title=File:Distinguishable_squares.png License: Creative Commons Zero Contributors: Mikael Häggström Image:Bayer matrix.svg Source: http://en.wikipedia.org/w/index.php?title=File:Bayer_matrix.svg License: Public Domain Contributors: Amada44 Image:Lcd_display_dead_pixel.jpg Source: http://en.wikipedia.org/w/index.php?title=File:Lcd_display_dead_pixel.jpg License: Creative Commons Attribution-ShareAlike 3.0 Unported Contributors: Selçuk Oral (drumex) Image:Shadow_mask_closeup_cursor.jpg Source: http://en.wikipedia.org/w/index.php?title=File:Shadow_mask_closeup_cursor.jpg License: Creative Commons Attribution-ShareAlike 3.0 Unported Contributors: Selçuk Oral (drumex) File:Advanced Video Coding High Definition.svg Source: http://en.wikipedia.org/w/index.php?title=File:Advanced_Video_Coding_High_Definition.svg License: Public Domain Contributors: Original uploader was Zeus at en.wikipedia Image:AVCHD actual file structure.svg Source: http://en.wikipedia.org/w/index.php?title=File:AVCHD_actual_file_structure.svg License: Creative Commons Attribution 3.0 Contributors: Jffner,Mikus Image:DVDs-12cm-8cm.jpg Source: http://en.wikipedia.org/w/index.php?title=File:DVDs-12cm-8cm.jpg License: Creative Commons Attribution-Sharealike 3.0 Contributors: Please credit to "diskdepot.co.uk"; uploaded by employee Disde on their behalf Image:HG10.png Source: http://en.wikipedia.org/w/index.php?title=File:HG10.png License: GNU Free Documentation License Contributors: RedAndr Image:Canon hf100 with memory card.jpg Source: http://en.wikipedia.org/w/index.php?title=File:Canon_hf100_with_memory_card.jpg License: Creative Commons Attribution-Sharealike 3.0 Contributors: Mikus (talk) Image:Interlaced video frame (car wheel).jpg Source: http://en.wikipedia.org/w/index.php?title=File:Interlaced_video_frame_(car_wheel).jpg License: Public Domain Contributors: Mikus (talk). 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