[rtcweb] Ericsson's position on codecs

[Bo Burman <[e-mail]>]

Hi,

The question of which codecs that should be supported in WebRTC [RTCWEB WG] has been discussed a long time with good opinions from different viewpoints. It will again be a subject in the Vancouver meeting and therefore we feel a need to recap Ericsson's position.

We believe that H.264 video codec should be a mandatory codec (at least one of what may be several): it is a good video codec, backed by a large vendor community and with a considerable footprint in end points. The patent landscape and the licensing situation is well known by now, which is nice in itself. Also, H.264 support is a requirement in some regulatory frameworks, such as emergency services, and we feel it would be preferable if WebRTC media framework can step-by-step consider such requirements, starting with the video codec.

Looking into the future a bit, we see H.265/HEVC video codec as a strong candidate to include in the default set, but we think it is too early to mandate it at this point. 

For audio, the situation is that we believe G.719 has a role for high quality audio in areas with no bandwidth restrictions or limited/no risk of blocking (packet loss or dropped connection). AMR narrow-band is playing a key role in mobile telephony and has a huge footprint. This makes it a candidate for being a default codec (one of them) for audio streams in mobile WebRTC implementations.

There is also a need for a high quality voice codec for situations with varying bandwidth, and we recognize that Opus is a candidate. We would however for the future also like to recommend that IETF include AMR-WB and EVS, since we expect them to be available in mobile chipsets.

This is written in absence of my colleagues who are more close to the codec technologies and who, had they been available and not on vacation, surely would have written the above in a better way. However, we hope it serves the intended purpose, namely to clarify Ericsson's position in the IETF WebRTC codec selection discussion.

Best Regards

Bo Burman

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Multimedia Technologies, Ericsson Research
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