[MPlayer-dev-eng] Re: Last call for pre8

[Matthias Wieser]

Am Samstag, 29. April 2006 15:35 schrieb Roberto Togni:
> On Sat, 29 Apr 2006 11:53:05 +0200
> Matthias Wieser <mwieser at gmx.de> wrote:
>
> [...]
>
> > I have a problem related to another common mobile video format:
> > Mpeg4+aac in a MP4 container.
> >
> > I'm using
> > mencoder /big/Medien/Video/test.mpg \
> >  -oac faac -faacopts br=96 \
> >  -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:vbitrate=300 \
> >  -of lavf -lavfopts
> > i_certify_that_my_video_stream_does_not_use_b_frames:format=mp4 \
> >  -endpos 10 -o test.mp4
> >
> > ffmpeg:
> > ffmpeg -y -i /big/Medien/Video/test.mpg  -b 300 -t 10 -ac 1 -ab 96
> > -acodec aac -vcodec mpeg4 test-ffmpeg.mp4
> >
> > The two resulting videos can both be played with mplayer and the player
> > of the mobile phone (Nokia 6280). But the latter one does not play any
> > sound with the mencoder generated file. The ffmpeg file works perfectly
> > with both players.
> >
> > mplayer -v shows some differences, especially the ESDS MPEG4
> > Descriptors are mission in the mencoder generated file:
> >
> > diff mencoder.txt ffmpeg.txt
> > [...]
> >
> > > ESDS MPEG4 Decoder Specific Descriptor (2Bytes)
> > > ESDS MPEG4 Sync Layer Config Descriptor (1Bytes)
> > >  -> predefined: 2
> >
> > [...]
> > < Fourcc: mp4v  Codec: ''
> > ---
> >
> > > Fourcc: mp4v  Codec: 'mpeg4'
> >
> > [...]
> >
> > Maybe there is a MP4 containter bug in mencoder?
>
> Is it related to the faad2 update and/or is it a regression since pre7?

I don't think that it has something to do with faad as the problem is not 
related to mplayers decoding but to mencoders encoding (faac).

> If not, unless you have a trivial patch to fix it, I'm not going to
> delay the release for it, it's just one more bug.

That's fine with me, I just wanted to mention this bug so that it becomes 
known. It's very nice that mencoder can create mp4 containers now, but 
unfortunately it's not working 100%. But with ffmpeg a workaround exists.

Regards,
  Matthias

p.s. If you want, I can upload sample videos created by ffmpeg (working) and 
mencoder (not working on the mobile phone).