Re: [rtcweb] Feedback messages (and problem with RTP usage document)

[Magnus Westerlund <[e-mail]>]

On 2014-01-14 17:55, Bernard Aboba wrote:
> I'd prefer choice A.  It makes sense to me for all fb message
> recommendations to be handled within the same document.  Right now RPSI
> and SLI are discussed in the RTP usage document, but are OPTIONAL, 
> Since there will be substantial benefits in terms of interoperability, 
> I'd like to see commonly used fb messages RECOMMENDED for implementation
> (since implementation is not required in the codec documents a MUST is
> probably too much).

I definitely wants more feedback on this. But, I think I am not
disagreeing with your view. Most of the video codecs that there exist
RTP payload formats today can use SLI and RPSI. RPSI don't make sense
for Motion JPEG and the video/raw or video/SMPTE292M that don't use
reference structures and SLI should be possible to use with also the RAW
formats so that has even wider applicability.

>  
> It might also be appropriate to include a general statement that WebRTC
> implementations supporting a particular video codec need to conform to
> the requirements of the codec specification with respect to fb messages. 

This, I don't see a problem with such a statement. Do you have a text
proposal?

>  
> I am indifferent to whether the RTP usage document includes a reference
> to the VP8 or H265 payload specifications or not (I'd suggest that
> either reference be non-normative). RFC 6184 does not have a section on
> fb messages similar to the ones in the VP8 and H265 payload specs, so
> that will not be of much help.

I would like to avoid these and let these be part of the
draft-ietf-rtcweb-audio and draft-ietf-rtcweb-video documents. The
intention with this structure was to enable piece wise revisioning if
required without needing to open up questions of all the media formats
at the same time. And that RTP usage changes would not require having to
deal with media format changes unless required.

Cheers

Magnus Westerlund

----------------------------------------------------------------------
Multimedia Technologies, Ericsson Research EAB/TVM
----------------------------------------------------------------------
Ericsson AB                | Phone  [phone]
Färögatan 6                | Mobile [phone]
SE-164 80 Stockholm, Sweden| mailto: [e-mail]
----------------------------------------------------------------------