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how to find so many MP4 formats

Posted: 08 Sep 2011 08:18
by manchesterunite
I'm studying MP4 demux code, and find that there are so many special cases handled in mp4.c.
after looking through ISOIEC14496 specs and APPLE's qtfileformat , I still cannot figure out some cases.

for example:

.....
if( !p_enda )
p_enda = MP4_BoxGet( p_sample, "enda" );

if( p_track->fmt.i_cat == AUDIO_ES && ( p_track->i_sample_size == 1 || p_track->i_sample_size == 2 ) ) // why sample_size=1 or 2 means something, where defines this situation???
{
.......

can anybody help me? tks!

Re: how to find so many MP4 formats

Posted: 08 Sep 2011 11:24
by Rémi Denis-Courmont
It's unlikely that whomever wrote that piece of code at some point in the past is both going to see your post and remember what exactly this does. You'd better read the file history in the version control.

Re: how to find so many MP4 formats

Posted: 09 Sep 2011 04:13
by manchesterunite
tks for your replay

I just expect someone who understand the code happened to come here.
whatever...

Re: how to find so many MP4 formats

Posted: 14 Sep 2011 00:57
by Jean-Baptiste Kempf
Use git blame to find who and why.

Re: how to find so many MP4 formats

Posted: 16 Sep 2011 10:14
by Sébastien Escudier