[MPlayer-users] [BUGS] Problems with MPlayer 1.0pre7 mpeg muxer

[Giacomo Comes]

On Mon, Oct 03, 2005 at 09:44:16AM -0400, Giacomo Comes wrote:
> On Sat, Oct 01, 2005 at 03:11:07PM +0200, Nico Sabbi wrote:
> > Giacomo Comes wrote:
> > 
> > >
> > >
> > >Problem 2.
> > >mpegs telecined AND with B-frames does not play on some hardware DVD 
> > >player.
> > >
> > >Example:
> > >mencoder -of mpeg -mpegopts format=dvd:telecine -ovc lavc -lavcopts 
> > >vcodec=mpeg2video:vrc_buf_size=1835:keyint=12:vrc_maxrate=7500:vbitrate=7500:vmax_b_frames=2 -o NTSC.mpg -ofps 24000/1001 source.avi -vf scale=720:480,harddup -oac lavc -lavcopts acodec=ac3:abitrate=192
> > >
> > >On my DVD player, DVD and SVCD telecined and with B-frames created with 
> > >mencoder
> > >do not play correctly (sync problem).
> > >The same DVD player plays fine the same kind of mpegs created with 
> > >mpeg2enc/mplex.
> > >
> > > 
> > >
> > 
> > the attached patch should fix the telecine problems.
> > Please, test and report, both with 0/1/2 b-frames.
> 
> I have done yesterday a quick test with SVCD mpegs
> with 0/1/2 b-frames. The patch works.
> 
> I will continue to do tests with DVD and submit a full report
> probably tomorrow.

Ok, here is a full report about the patch.

What I'm going to say apply to both MPlayer 1.0pre7 and CVS.

The patch works in the sense that now my DVD player can play
SVCD and DVD that are telecined AND with B-frames.
Without the patch such mpegs created with mencoder plays 
very badly (for example for SVCD the audio plays at normal 
speed and the video plays at 80% speed, about every 15 seconds
the audio stops to let the video come back in sync and then the 
proces repeats).

But, with the patch applied, I have observed another problem.
I have done a SVCD created with the patched mencoder.

The playback on my DVD player starts fine but then slowly
the audio anticipates the video. After 1-1.5 minutes
the delay can reach 1 second, and at some point the video 
accelerate to come back in sync.

I have observed this phenomen with:
telecined mpeg (0 B-frames)
non telecined mpeg (30000/1001 fps) without B-frames
non telecined mpeg (30000/1001 fps) with B-frames

The same kind of mpegs plays fine on the DVD player if I use 
the unpatched mencoder to create them.

Of course, in all the cases, mplayer never has problem in playing
such mpegs.

It would be good if somebody else could test the patch.
I don't think I'm doing something wrong, but it could be.

Nico, can it be that the patch while fixing a bug, introduces
another one? Or simply make more evident another bug already
present (I was able to see the bug also with the unpatched mencoder 1.0pre7
using no telecine and no B-frames)?

If you need specific tests please let me know.

Giacomo