866121 - Race condition on multiple `video.mozSrcObject=stream` assignments

Status: RESOLVED INACTIVE

(Core :: Audio/Video: Playback, defect)

Description

[Stephan Thamm]

Assign mutiple streams to one <video> shortly after another (video.mozSrcObject = a; ideo.mozSrcObject = b).

The streams are both rendered. The image flickers between the images of the streams. Only the second stream should be rendered.

Comment 1

[Stephan Thamm]

Attachment: Test with static video

The static video does not get played although it is assigned after the user media. Not completely sure whether this is the same bug because there is no flickering.

Comment 2

[Jason Smith [:jsmith]]

I'm definitely seeing the variant flashing you are citing in the attached test case.

Roc - Any ideas?

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

(In reply to Stephan Thamm from comment #1)
> The static video does not get played although it is assigned after the user
> media. Not completely sure whether this is the same bug because there is no
> flickering.

The static video should not play because srcObject takes priority over 'src' if both are present. So I don't think comment #1 is a bug. Comment #0 might be a bug but I don't see a testcase for that.

Comment 4

[Stephan Thamm]

It is hard to put together a small demo because there have to be at least 2 streams. 

We put an old version of our web app online. I know that this is not perfect, but it should reproduce the bug:

URL:      https://mozilla.palava.tv/#/test
Username: mozilla
Password: bugreport

This link will put you directly into the room "test". The link in the upper right corner will not work as it points to the current version without the bug.

The second person joining should see the bug.

At first the local stream is displayed and then the stream of the person already in the room. Our fix was waiting two seconds (one was not enough) before allowing another stream to be attached to the video tag.

I hope this helps to clear things up.

Comment 5

[Randell Jesup [:jesup] (needinfo me)]

Old bug and much has changed since then.  Is this still an issue?

Comment 6

[Nils Ohlmeier [:drno]]

Mass closing do to inactivity.
Feel free to re-open if still needed.