mp4 atom too large

[Lukas Tribus]

Hi Richard,


> I already checked there, I'm getting a different error ("mp4 atom too
> large" != "mp4 moov atom is too large")
> My error message seems to have been added in this patch
> http://nginx.org/download/patch.2012.mp4.txt
> In any case, the example given there gives a reasonable example, as
> '12583268' is around 12MB so increasing it by 2MB would not be an issue
> However in my case, the value given is '723640794' which is around 690MB
> which is bigger than the actual file!


I see. Is this limited to certain files, and can you reliable reproduce
this issue on those files? Can you rerun those files through a mp4
demuxer/muxer, so that the atom is rebuild? I believe there is a good
possibility that the atom in the mp4 files is bogus, either due to
a muxer bug or a truncated file.

You can do this with mp4box [1]:
  MP4Box -inter 500 -out output.mp4 input.mp4 

 
I looks like you are running on FreeBSD, can you clarify the release
and what platform you are running (x64, i586, or else?).

Also, reproducing this with fully enabled debugging will probably help
the developers (if this is really a bug in the mp4 module):

http://nginx.org/en/docs/debugging_log.html



> The same file works with the "other" mp4 module

That doesn't necessarly mean there is a bug in the nginx module, the
"other" module could just ignore bogus atom for example.



[1] http://gpac.wp.mines-telecom.fr/mp4box/



Regards,

Lukas