[MPlayer-users] Trouble with Mp3 audio in MP4 containers

[WireSpot]

On 12/20/05, The Wanderer <inverseparadox at comcast.net> wrote:
> The internal MPlayer demuxer for MP4 files has some holes in its
> understanding of what constitutes an audio stream. Use '-demuxer 35' to
> tell MPlayer to use the libavformat demuxer, and the audio should play
> back fine.
>
> The only MP4 files I have for which I need to use that option also have
> a somewhat unusual internal label for the audio stream, such that
> libavformat will not detect it as MP3; for those files, I have to also
> specify '-ac +ffmp3'.
>
> The libavformat demuxer also appears to have a mistaken idea of what
> frame rate the files I have should be played back at; it plays them at
> 30000/1001, which is much too fast. Specifying '-fps 24000/1001' fixes
> the problem, without introducing any new ones.

Bah, I had to use all three:
-ac +ffmp3 -demuxer 35 -fps 24000/1001

And the A/V was still off so I had to tweak it some more.

FWIW, in case anyone else runs into this problem, here's the
workaround: remux to MKV with mpeg4ip 1.4 and mkvtoolnix 1.6.5.

Extract the audio from the MP4 file with mp4creator (from mpeg4ip),
since mkvmerge (from mkvtoolnix) complains about garbage in the audio
track. Then use mkvmerge to merge the video from the original file
with the separate mp3 file. You get a working MKV instantly.

Since this is apparently a known problem with MPlayer, should I keep
trying to upload my sample file? If the answer is yes, can anyone tell
me why I can't write to incoming/ ?