1729110 - getSynchronizationSources() intermittently drops SSRC for video

Status: RESOLVED DUPLICATE of bug 1654112

(Core :: WebRTC: Networking, defect, P2)

Description

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

+++ This bug was initially created as a clone of Bug #1727800 +++

STR:

1. Open https://jsfiddle.net/jib1/tj0x3sv1, allow cam + mic, and wait

Expected result:

audio: 0 CSRCs, 0 SSRCs. video: 0 CSRCs, 0 SSRCs.
checking
connected
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
(repeats forever)

Actual result:

audio: 0 CSRCs, 0 SSRCs. video: 0 CSRCs, 0 SSRCs.
checking
connected
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 0 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 0 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 1 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 0 SSRCs.
audio: 0 CSRCs, 1 SSRCs. video: 0 CSRCs, 0 SSRCs.

Note the intermittent 0 SSRCs for video only.

Regression range

23:09.52 INFO: Last good revision: a77ca5bd6b7c49099c672e103771ca2bf077cc40 (2020-05-14)
23:09.52 INFO: First bad revision: f340bbb582d16c083344b1370bd4e4d4caf5fb17 (2020-05-15)
23:09.52 INFO: Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=a77ca5bd6b7c49099c672e103771ca2bf077cc40&tochange=f340bbb582d16c083344b1370bd4e4d4caf5fb17
:
:
23:16.71 INFO: There are no build artifacts for these changesets (they are probably too old).

Unfortunately, mozregression was not conclusive.

Oddly, this almost goes back to the introduction of SSRC for video, but not quite. The 2020-05-14 version had video working reliably, as far as I could tell. It's possible this was a fluke, though a tested it for a good minute.

Comment 1

[Nico Grunbaum [:ng, @chew:mozilla.org]]

Jan-Ivar, could you give it a shot with our latest libwebrtc merge build?
https://treeherder.mozilla.org/jobs?repo=try&revision=17012af0de0bd9b4b38d4735c183a537cd1fdce8

Comment 2

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

I'm not able to reproduce with the build in comment 1. 👍

Comment 3

[Andreas Pehrson [:pehrsons]]

Might want to look again later, I have made changes that are not in that build to the threading model (refactored how ssrcs are set), ssrc switching and GetRtpSources (used internally for getSynchronizationSources), all on the conduits.

Comment 4

[Andreas Pehrson [:pehrsons]]

jib, can you verify again now that bug 1654112 has landed?

Comment 5

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

Confirmed fixed.