1449272 - offerToReceiveAudio and offerToReceiveVideo create m-sections in reverse order

Status: RESOLVED FIXED

(Core :: WebRTC: Signaling, enhancement, P2)

Description

[Nils Ohlmeier [:drno]]

Since Fx 59 if pc.createOffer({ offerToReceiveAudio: true, offerToReceiveVideo: true }) gets called you get an SDP with the video m-section coming first and the audio m-section being second.

This probably comes as a surprise for some services out there and can not be explained with the API calling addTrack or addTranceiver in the wrong order.

Comment 1

[Byron Campen [:bwc]]

Attachment: Bug 1449272 - Part 1: Update test-case to expect the audio transceiver first when using both offerToReceiveAudio and offerToReceiveVideo.

Review commit: https://reviewboard.mozilla.org/r/232172/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/232172/

Comment 2

[Byron Campen [:bwc]]

Attachment: Bug 1449272 - Part 2: When using both offerToReceiveAudio and offerToReceiveVideo, create the audio transceiver first.

Review commit: https://reviewboard.mozilla.org/r/232174/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/232174/

Comment 3

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Comment on attachment 8963277 [details]
Bug 1449272 - Part 1: Update test-case to expect the audio transceiver first when using both offerToReceiveAudio and offerToReceiveVideo.

https://reviewboard.mozilla.org/r/232172/#review240386

Lgtm if we lose the comment.

::: dom/media/tests/mochitest/test_peerConnection_transceivers.html:407
(Diff revision 1)
> -    if (options.offerToReceiveAudio) {
> +    // NOTE: The ordering here is not laid out in the spec at all, this is
> +    // firefox specific.

We should remove this comment. I believe the spec covers this on account of [1]:

  "For each 'offerToReceive<Kind>' member in options with kind"

and [2]

  "dictionary members ... are ordered lexicographically by the Unicode codepoints that comprise their identifiers"


[1] http://w3c.github.io/webrtc-pc/#legacy-configuration-extensions
[2] https://heycam.github.io/webidl/#idl-dictionaries

Comment 4

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Comment on attachment 8963278 [details]
Bug 1449272 - Part 2: When using both offerToReceiveAudio and offerToReceiveVideo, create the audio transceiver first.

https://reviewboard.mozilla.org/r/232174/#review240388

Lgtm.

Comment 5

[Byron Campen [:bwc]]

Comment on attachment 8963277 [details]
Bug 1449272 - Part 1: Update test-case to expect the audio transceiver first when using both offerToReceiveAudio and offerToReceiveVideo.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/232172/diff/1-2/

Comment 6

[Byron Campen [:bwc]]

Comment on attachment 8963278 [details]
Bug 1449272 - Part 2: When using both offerToReceiveAudio and offerToReceiveVideo, create the audio transceiver first.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/232174/diff/1-2/

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/22dad8af6e63
Part 1: Update test-case to expect the audio transceiver first when using both offerToReceiveAudio and offerToReceiveVideo. r=jib
https://hg.mozilla.org/integration/autoland/rev/2dcd83b1d5d3
Part 2: When using both offerToReceiveAudio and offerToReceiveVideo, create the audio transceiver first. r=jib

Comment 8

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/22dad8af6e63
https://hg.mozilla.org/mozilla-central/rev/2dcd83b1d5d3