Closed Bug 1138786 Opened 5 years ago Closed 4 years ago

A/V sync off by one second

Categories

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

x86
macOS
defect

Tracking

()

RESOLVED WORKSFORME

People

(Reporter: jya, Unassigned)

References

(Blocks 1 open bug)

Details

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
The sound bop can be heard around 1s after video playback stopped.
I wonder if bug 1137511 regressed this somehow?
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
The last a/v sync issue was bug 1132034, which turned out to be an audio issue.

Paul, does this ring a bell?
Flags: needinfo?(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.
Flags: needinfo?(padenot) → needinfo?(jyavenard)
My tests were done on macos. 

Will try other platforms tomorrow.
Flags: needinfo?(jyavenard)
Priority: -- → P2
Can you still reproduce this? I haven't seen it in a while.
Flags: needinfo?(jyavenard)
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.
Flags: needinfo?(jyavenard)
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.
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) ?
and open a bug, your issue has nothing to do with this bug report.
(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.
(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.
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.
It's working perfectly in Nightly and 42
Status: NEW → RESOLVED
Closed: 4 years ago
Resolution: --- → WORKSFORME
Flags: needinfo?(jyavenard)
Flags: needinfo?(jyavenard)
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