[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[AVT] using RTCP for sending payload information in versteeg and levin rapid synchronization drafts



Hi guys,

Draft http://tools.ietf.org/id/draft-versteeg-avt-rapid-synchronization-for-rtp-01.txt suggests a new use for RTCP feedback messages.

More specifically in section 7.2.1. This message is used to carry information from the payload that is not available very often as described in the paragraph. My understanding is that there will be a similar case with H.264 parameter sets which are not sent with every I-frame and are required in order to decode the stream.

For H.264 we suggested in 3984bis that a codec refresh point will include the parameter sets, this is sent as a response to  FIR CCM request (the video switch case). I think that here they would not want to retransmission server to send FIR back to the multicast source.

 

 

A similar issue is in http://tools.ietf.org/id/draft-levin-avt-rtcp-burst-00.txt that in section 7 have for each message an extension field that is left open without specifying what it will be used for and can be used for similar information.

 

The general problem is the same in both cases since some of the information is available early in the media stream and is not repeated as often as I frames but still is needed for synchronization. The problem of joining mid-stream is similar to the video switch case in MCUs.

 

I am looking for feedback if this is a good use for RTCP based on the RTCP guideline drafts, and if not any are there any suggestions.

Thanks

Roni Even

 

_______________________________________________
Audio/Video Transport Working Group
avt at ietf.org
https://www.ietf.org/mailman/listinfo/avt