[Ffmpeg-devel] Re: .mp4 demuxer broken?

Michael Niedermayer michaelni
Tue Mar 21 19:51:55 CET 2006


On Tue, Mar 21, 2006 at 04:31:15PM +0100, Baptiste COUDURIER wrote:
> Michael Niedermayer wrote:
> > Hi
> > 
> > ffmpeg -i CDR-Dinner_LAN_800k.mp4
> > (http://www.mplayerhq.hu/MPlayer/samples/MPEG-4/CDR-Dinner_LAN_800k.mp4)
> > 
> > fails, but it does work woth an old binary ffmpeg (dunno from when) laying
> > around
> > 
> Fixed. Patch attached. Michael I got a problem with getting codec from
> codec_bmp_tags since it will register 'mp4s' as video.
> 3 solutions here :
> - remove 'mp4s' from codec_bmp_tags

sadly thats not possible as its used by some old? M$ mp4 in asf encoder

> - only search into mov_video_tags.

not good either

> - do what I go atm, ignore 'mp4s' in video section. But then ugliness is
> coming back.

yes, maybe add a mov_data_tags table, while somewhat of an overkill it
avoids the ugliness, but the sigle check is fine too 

> What do you think ?
> Another problem spotted : many mp4 containing aac does not have a valid
> sample rate, is there a way to force decoding first frame to let faad
> init stream parameters ?

yes, setting sample_rate to 0 if FAAD is available and the codec is AAC 
should do the trick, if not then look at av_find_stream_info() and
try_decode_frame() and faad.c



More information about the ffmpeg-devel mailing list