[FFmpeg-devel] FFMPEG/GPAC compatibility for mp4 'text' box

Baptiste Coudurier baptiste.coudurier
Mon Oct 11 21:48:00 CEST 2010


On 10/11/2010 05:40 AM, Romain Bouqueau wrote:
> Dear FFMPEG developers,
> I am a GPAC (gpac.sourceforge.net) maintainer, trying to make our
> frameworks compatible :)
> This mail concerns the implementation of the Apple-specific 'text' box.
> We implemented it following this specification:
> http://developer.apple.com/library/mac/#documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-BBCJAJEA
> FFMPEG generates streams using this 'text' box. However this leads to
> "extra NULL bytes" at the end of 'text' boxes which are inconsistent
> with the above mentioned spec.

I'm not sure where do you reference to. If you mean the 'stsd' atom, 
then I don't see where some "extra NULL bytes" could be written.

Looking at the document you referenced, I would see that we could miss 
some bytes, not have some extra.

Can you please clarify ? Thanks a lot.


Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer                                  http://www.ffmpeg.org

More information about the ffmpeg-devel mailing list