Question about rtx in RTCRtpCapabiltiies and RTCRtpParameters from Bernard Aboba on 2016-05-12 (public-webrtc@w3.org from May 2016)

From: Bernard Aboba <Bernard.Aboba@microsoft.com>
Date: Thu, 12 May 2016 14:50:35 +0000
To: "public-webrtc@w3.org" <public-webrtc@w3.org>
Message-ID: <DM2PR21MB0075BA2A76E2E79251A2AF35EC730@DM2PR21MB0075.namprd21.prod.outlook.com>

PR: https://github.com/w3c/webrtc-pc/pull/631

The question has arisen as to whether the "rtx" codec has a single or multiple entries in RTCRtpCapabilities.codecs[] and RTCRtpParameters.codecs[].

My reading is that in WebRTC 1.0, there is a single entry for capabilities, and multiple entries for parameters, one for each media codec that is retransmitted.

Taylor has pointed out that this implies that "no browser would have a reason to support re-transmitting only a subset of the supported codecs."

Are people ok with that assumption?

In ORTC, we currently do allow multiple "rtx" entries in capabilities, so it would be possible to indicate that RTX can only be applied to some codecs, but not others.

Received on Thursday, 12 May 2016 14:51:05 UTC