Opened 8 years ago

Last modified 8 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:

Description

From the documentation
http://www.mplayerhq.hu/DOCS/HTML-single/en/MPlayer.html
"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?)
http://otakuvideo.com/~quu/OtakuVideo-TearsOfReki-MPEG2.mpg
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 8 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:

[extension.mpg]
demuxer=lavf

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

comment:2 Changed 8 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 8 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 8 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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