The key NDI features you need to know

the

key NDI features you need to know.

NDI (Network Device Interface) is a freely available network protocol that allows audio, video and metadata signals to be transported and allows for control of devices. It is used in large broadcast environments but also in private settings for work and school in video presentations and live streams (with Adobe, Zoom and Microsoft Teams NDIcapable) and Pan-Tilt-Zoom (PTZ) cameras. PTZ cameras allow for editing from a direct feed from the captured video such as live TV. One ethernet cable can be used to integrate each piece of kit fully into the production system.

NDI was introduced to replace Serial Digital Interface (SDI) cabling in broadcasting, where SDI was limited to one directional signal causing difficulty to manage scale and transport. NDI brings higher quality imagery and multiple streams which allows for a smoother broadcast and video creation at a lower cost. This ease of communication and real-time camera switching saves time and money on post-production. If all cameras and production systems are connected to the same network, then the broadcasting can take place in different locations as they communicate in real-time.

The key features of NDI are compared with that of NDI X, which is a higher h.264 compressed option. NDI has a variable bitrate of 80-180Mpbps, which is an inconsistency of the number of bits per second that can be transmitted along a digital network. Compared to the use of the bitrate of the lower 8-20MBps NDI X, meaning there is a lower quality image in the video output. This is due to the NDI X being heavily compressed and having a higher latency which results from a delay before a transfer of data. ‘A usual concern of video over IP is latency, the NDI latency can be as low as 16 milliseconds which makes transitioning from SDI (Sustainable Development Index)/HDI (Human Development Index) workflows to NDI very straightforward.

The broadcast quality standard of the NDI can be compared with its Intra-frame encoding to the long GOP (Group Of Pictures) encoding featured in the NDI X which is necessary for high compression. The Intraframe coding data used within the NDI allows for little or no loss in quality so it would not severely limit its output unlike the NDI X. NDI supports alpha channel whereas NDI X does not, meaning the NDI is able to represent the degree of transparency of a colour and is used to determine how a pixel is rendered when blended with another. This provides us with more data on a local network as it is easy to route video signals across a network.

‘NDI makes it incredibly easy to route video signals across a network where historically it used to be accessible to only those who were kind of tech savvy.’ Kriss Hampton-Joyce