[Ffmpeg-devel] Interesting; lavformat muxer in mencoder

[Rich Felker]

On Mon, Feb 27, 2006 at 06:02:44PM +0100, Erik Slagter wrote:
> I just noticed, that if I use the lavf muxer in mencoder, and ignore all
> warnings, hehe, the produced file cannot be played by mplayer itself.
> The file has (as usual) h264 video and aac sound. Okay, that's fair
> enough, but the interesting part is the error message:
> 
> h264 @ 0x4135f8a8]avcC too short  0.034 122/122  0%  0%  1.2% 0 0 44%
> 
> My idea was, that if mencoder uses ffmpeg's mp4 muxer (yeah, all
> up2date), it would also include a correct avcc (avcc patch not in cvs,
> included locally from pending patch). This is more or less confirmed
> because mplayer DOES play files muxed with the ffmpeg program. Gpac also
> crashes on the mencoder output, while it runs fine on ffmpeg's output.
> 
> This looks like a bug in the interface between mencoder and libavformat?
> Anyone tried this, either with or without the avcc patch?
> 
> Or is the mp4-from-libavformat-in-mencoder-muxer known broken?

Either you are using an ancient version of mencoder or you LIED to
mencoder, because in any modern version it required the
-lavfopts i_certify_that_my_video_stream_does_not_use_b_frames
option in order to work at all.

Simple answer: DO NOT USE the lavf muxer in mencoder. It does not
work. If you want it to work, submit a patch to add parser/framer
support to it to get the correct pts values from the frames.

Rich