Opened 10 years ago

Last modified 10 years ago

#1777 new defect

Badly interleaved MPEG-2 PS causing audio/video sync problems

Reported by: hquu@… Owned by: reimar
Priority: normal Component: demuxer
Version: HEAD Severity: normal
Keywords: Cc: compn
Blocked By: Blocking:
Reproduced by developer: Analyzed by developer:


From the documentation
"The player is rock solid playing damaged MPEG files"

I found an MPEG-2 file (Actually a bunch that were encoded 6+ years ago) that when played with VLC or Windows Media Player, the audio and video sync is fine, but when played through mplayer, the audio starts to early. This was tested under Linux, OSX, and Windows.

Here is an example video (can I attach 104 meg files?)
play this file with the default demuxer, and with the lavf demuxer. The audio should not start until the title screen is done.

This problem was shared on the #mplayer channel on effnet, but dismissed because the sync was due to a broken file. I originally went on to do other testing, but when re reading the docs, I came across that sentence... that mplayer played damaged files.

if the lavf demuxer is able to play it fine, but the default mplayer one can't... then I would think the default demuxer is not sufficiently robust.

Change History (4)

comment:1 Changed 10 years ago by compn

  • Cc patriotact@… added

you can set demuxer lavf for mpeg files by adding the following to the bottom of your config file:


otherwise will have to wait for nico (mpg demuxer maintainer) to look at this.
you can upload samples to
maybe make a dir, bug1777 then upload the file into it.

comment:2 Changed 10 years ago by reimar

Could you also try with -vc mpeg12 ?
There is a problem with the parser (which is not used with -demuxer lavf) possibly not splitting the first frames which with the FFmpeg decoder means they get lost...

comment:3 Changed 10 years ago by hquu@…

I will upload the sample file later tonight.

Yea, I can switch to the lavf demuxer and the problem goes away (which is what I was told to do on IRC) which solves my problem. Was mainly bringing this bug report up to help mplayer itself, since I figured that problem videos would be a boon to coders, something to test against.

I tried "mplayer -vc mpeg12 OtakuVideo?-TearsOfReki?-MPEG2.mpg" and the audio/video desync was still happening.

comment:4 Changed 10 years ago by hquu@…

I uploaded two files into that directory... the MPEG-2 file which has the sync problem... and a smaller MPEG-1 copy that plays fine as a reference

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