[M4IF Technotes] MP4 files analysis with Dumpster

[Olivier Amato]

Guy,
> I guess you are referring to Apple's Dumpster program?

Absolutely.
> It does not permit
> any editing of the file and since it is inteded for QuickTime files, is is
> limited to reading the atom structure and basic quicktime-based
descriptors.
> Still, it is usefull for browsing the content of an MP4 file to a certain
> degree, but it won't decode MPEG-4 descriptors (such as iods, the Initial
> Object Descriptor).

Actually, somebody from ResonateMP4 showed me yesterday how to analyze and
modify an MP4 file ( produced by a company's encoder ) and make it playable
on several players ( DivX, Envivio, Dicas ). I think he just modified the
time indication of each frame but I'm not sure because I don't know MPEG-4
specifications deeply enough ( but I can give you his contact if you want
more informations ... ).
That's why I'd like to better know what it is possible to do and what it is
not possible to do with Dumpster ...
>   I suggest reading the MPEG-4 standard (14496-1:2001) and looking at
> mpeg4ip for another dumper.

OK, I'll take a look at mpeg4ip.
Thanks for your answer.
Regards,
Olivier