[Ffmpeg-devel] Possibly wrong tags assigned in movenc.c

Michael Niedermayer michaelni
Mon May 30 19:04:08 CEST 2005


On Tuesday 24 May 2005 11:12, Nico Sabbi wrote:
> Michael Niedermayer wrote:
> >Hi
> >
> >On Wednesday 11 May 2005 17:08, Nico Sabbi wrote:
> >>Hi,
> >>according to IS-14496-1, when muxing to MP4 the tag assigned to H264 in
> >> the
> >>
> >>object_type field present in the DecoderConfigDescriptor is 0x21,
> >>while ffmpeg assigns 241 (in ff_mov_obj_type).
> >>
> >>Additionally, stream_type should be 0x4 for video
> >>and 0x5 for audio, instead movenc uses 0x11 and 0x15 respectively.
> >>
> >>Are the current values specific to quicktime?
> >
> >i would guess they are probably just wrong, do they cause problems with
> > any players? do the IS-14496-1 values cause problems with any players? if
> > later is not worse then we should change them, cvs commit or patch
> > welcome
> >
> >[...]
> I remember reading in this list that qt7 can't decode mp4 with h264 made
> by ffmpeg,
> so I compared the codes used by ffmpeg with the ones in the specs.
> It turns out that 0x11 and 0x15 were correct, so I added a comment to
> specify how
> that byte (the streamtype) is coded. The value for the object type is
> really wrong, though.
> At the moment I don't have a qt7 to test, if I find one I will report.
> It would be nice if some Mac user made some test with my patched
> attached and without
> to verify if it fixes qt7 playback.

apply it, we'll get bugreports if it doesnt work ...


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