5. Mandatory-to-Implement Video Codec

For the definitions of "WebRTC browser", "WebRTC non-browser", and "WebRTC-compatible endpoint" as they are used in this section, please refer to Section 2.

WebRTC Browsers MUST implement the VP8 video codec as described in [RFC6386] and H.264 Constrained Baseline as described in [H264].

WebRTC Non-Browsers that support transmitting and/or receiving video MUST implement the VP8 video codec as described in [RFC6386] and H.264 Constrained Baseline as described in [H264].

NOTE: To promote the use of non-royalty-bearing video codecs, participants in the RTCWEB working group, and any successor working groups in the IETF, intend to monitor the evolving licensing landscape as it pertains to the two mandatory-to-implement codecs. If compelling evidence arises that one of the codecs is available for use on a royalty-free basis, the working group plans to revisit the question of which codecs are required for Non-Browsers, with the intention being that the royalty-free codec will remain mandatory to implement and the other will become optional.

These provisions apply to WebRTC Non-Browsers only. There is no plan to revisit the codecs required for WebRTC Browsers.

"WebRTC-compatible endpoints" are free to implement any video codecs they see fit. This follows logically from the definition of "WebRTC-compatible endpoint". It is, of course, advisable to implement at least one of the video codecs that is mandated for WebRTC browsers, and implementors are encouraged to do so.