commit a416f1c7a93ea45c98bdcdca187aed182e428761
author Henrik Boström <hbos@webrtc.org> Tue Feb 25 10:56:54 2025
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Feb 25 13:22:19 2025
tree e91e38675d5122a39db7a1475dd586f41c1fa276
parent b9e8c0e0623008182f21368b162a881fd2962de1

Fix rid 'send pt=X' bug and re-enable test.

When creating an offer, the send PT is the payload type of the codec
that we're advertising that we would like to send. It comes from the
RidDescription's list of payload types (= integers prior to this CL)
which is controlled from the API with `RTCRtpEncodingParameters.codec`.

The problem was that the encodings[i].codec -> PT conversion step in
sdp_offer_answer.cc's GetMediaDescriptionOptionsForTransceiver() was
based on `transceiver->sender_internal()->GetSendCodecs()` whose PTs
are inconsistent with the payload types that gets assigned to the media
section in a later step using PayloadTypeSuggester.

To fix this, the RidDescription is updated to have a list of `codecs`
instead of a list of `payload_types` and the "codec -> PT" conversation
step is...
1. Moved to SimulcastSdpSerializer and using lookup from
   MediaContentDescription as opposed to blindly trusting `codec.id`
   making PT inconsistencies impossible.
2. Uses IsSameRtpCodecIgnoringLevel() instead of MatchesRtpCodec(),
   ensuring codec match does not fail if the MediaContentDescription's
   list of codecs is not specifying default parameters (e.g. see
   SdpOfferAnswerTest.SimulcastAnswerWithPayloadType not specifying
   profile-id fails if MatchesRtpCodec is used).

Another drive-by bugfix is we no longer remove entire RIDs if all PTs in
the RID are invalid, see TestDeserializeRemovesRidsWithInvalidCodec.

Bug: webrtc:362277533
Change-Id: Ic11ecf2a85e6d8db7fc269bc53c3ac11d5d8b127
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/378284
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43982}