- From: Bernard Aboba <Bernard.Aboba@microsoft.com>
- Date: Wed, 15 Oct 2014 22:14:17 +0000
- To: Peter Thatcher <pthatcher@google.com>, Iņaki Baz Castillo <ibc@aliax.net>
- CC: "public-ortc@w3.org" <public-ortc@w3.org>
Peter said:
The codecPayloadType is not specified in the RtpRtxParameters. The
RtpRtxParameters are per-encoding, while the payload types are not.
Payload types are specified in RtpParameters. Only the codec name is
referenced in the RtpEncodingParameters. The RTX payload type should
be specified in the RtpCodecParameters, not in the RtpRtxParameters.
The spec currently says for RtpCodecParameters: "The codecs to send or
receive (could include RTX and CN as well)." So, if you want an RTX
payload type, put it in there. While it's not explicitly called out,
I assume the "formats" dictionary could have an APT=OTHER_PAYLOAD_TYPE
key/value pair.
[BA] As Peter says, support for RTX, CN (as well as RED) would be indicated within RTCRtpCodecCapability, and configured in RTCRtpCodecParameters.
We probably should add additional details about what would be expected in these situations.
For example, within RTCRtpCodecCapability provided for RTX or RED, some attributes (such as
rtcpFeedback, maxTemporalLayers, maxSpatiaLayers, etc. do not make sense and therefore
would not be returned in .getCapabilities.
dictionary RTCRtpCodecCapability {
DOMString name;
DOMString kind;
unsigned long clockRate;
payloadtype preferredPayloadType;
unsigned long numChannels;
sequence<RTCRtcpFeedback> rtcpFeedback;
Dictionary parameters;
Dictionary options;
unsigned short maxTemporalLayers = 0;
unsigned short maxSpatialLayers = 0;
boolean svcMultiStreamSupport;
};
dictionary RTCRtpCodecParameters {
DOMString name;
payloadtype payloadType;
unsigned long clockRate;
unsigned long numChannels;
sequence<RTCRtcpFeedback> rtcpFeedback;
Dictionary parameters;
};
Received on Wednesday, 15 October 2014 22:14:47 UTC