1138786 - A/V sync off by one second

Status: RESOLVED WORKSFORME

(Core :: Audio/Video, defect, P2)

Description

[Jean-Yves Avenard [:jya]]

http://people.mozilla.org/~jyavenard/tests/mse_mp4/bipbop.html?eos=1&eosat=-1&duration=-1&init=0

the sound "bop" is heard on the visual Bip clue and vice-versa.

This was spot on last week when I last worked on 1137576

Comment 1

[Jean-Yves Avenard [:jya]]

The sound bop can be heard around 1s after video playback stopped.

Comment 2

[Bobby Holley (:bholley)]

I wonder if bug 1137511 regressed this somehow?

Comment 3

[Jean-Yves Avenard [:jya]]

Actually, I'm seeing it in aurora (38.0a2) as well. 
It's a bit bizarre, right in the first few seconds, you can hear bip/bop in close succession. and A/V sync is wrong from then.

Chrome plays it perfectly. Should also not that when I rewind in chrome, it goes back to frame 0 ; while we show frame 24 as first frame and start playback at frame 8

Comment 4

[Bobby Holley (:bholley)]

The last a/v sync issue was bug 1132034, which turned out to be an audio issue.

Paul, does this ring a bell?

Comment 5

[Paul Adenot (:padenot)]

(In reply to Bobby Holley (:bholley) from comment #4)
> The last a/v sync issue was bug 1132034, which turned out to be an audio
> issue.
> 
> Paul, does this ring a bell?

Which platform is this? My bug was about Windows Vista/7/8/10 only.

Comment 6

[Jean-Yves Avenard [:jya]]

My tests were done on macos. 

Will try other platforms tomorrow.

Comment 7

[Ralph Giles (:rillian)]

Can you still reproduce this? I haven't seen it in a while.

Comment 8

[Jean-Yves Avenard [:jya]]

I can reproduce it with the linked URL.

It's rather bizarre. the first time you play it, few video frames are skipped and then it appears in sync during the last few seconds.
if you rewind to the beginning and play again, it's off by 1s again.

Chrome shows a different behaviour: it's a tad off at first, but if you rewind and play it again: a/v sync is perfect.

Safari plays it perfectly.

Comment 9

[bull500]

On Nightly 41.0a1 (2015-06-22) Fedora 22, there is no sound.
It seems as if the sound is disabled, the speaker icon is greyed out in the video. Only way to mute/unmute is to right click on the video but it seems to have no effect.  

I have MSE enabled for everything except webM.

Comment 10

[Jean-Yves Avenard [:jya]]

it's currently not a supported configuration.

there are ways via ffmpeg (and have to make sure ffmpeg support is enabled). do you have ffmpeg installed (and prefed on) ?

Comment 11

[Jean-Yves Avenard [:jya]]

and open a bug, your issue has nothing to do with this bug report.

Comment 12

[bull500]

(In reply to Jean-Yves Avenard [:jya] from comment #10)
> it's currently not a supported configuration.
> 
> there are ways via ffmpeg (and have to make sure ffmpeg support is enabled).
> do you have ffmpeg installed (and prefed on) ?

ah maybe not doing it right.  
I just stumbled on this bug and found this issue.
I have the "media.fragmented-mp4.ffmpeg.enabled" set to true and gstreamer-ffmpeg-0.10.13-15.fc22.x86_64; ffmpeg-libs-2.6.3-1.fc22.x86_64 packages installed.

Comment 13

[Jean-Yves Avenard [:jya]]

(In reply to bull500 from comment #12)
> ah maybe not doing it right.  
> I just stumbled on this bug and found this issue.
> I have the "media.fragmented-mp4.ffmpeg.enabled" set to true and
> gstreamer-ffmpeg-0.10.13-15.fc22.x86_64; ffmpeg-libs-2.6.3-1.fc22.x86_64
> packages installed.

It's either gstreamer or it's ffmpeg that's going to be used.
You'll need to disable gstreamer.

Comment 14

[Jean-Yves Avenard [:jya]]

When I wrote it's an unsupported configuration ; 41 doesn't support MSE with combined audio/video like that original link is using.

You'll need to use 42 or later.

Comment 15

[Jean-Yves Avenard [:jya]]

It's working perfectly in Nightly and 42