[FFmpeg-devel] MOV Muxer fix to respect the standard
Fri May 22 15:33:25 CEST 2009
> >> From what I recall, in many places MOV does use PASCAL strings
> > > (length
> >> + non \0), while MP4 changed this to be C strings (\0 terminated),
> >> which is about the only significant difference (sometimes I
> > > wondered if
> >> it's not just to crash MOV parsers).
> >> I don't have time, but you'll definitely want to check both QT and
> > > MP4
> >> specs for this.
> > ISO 14496-12 says null-terminated string, and QT says "counted
> > string", so they are incompatible. Of course, any size/termination
> > is
> > unnecessary since the string is the last element of the box and the
> > box size is known. Fools writing specs again...
> Fortunaletly, the box size is known otherwise any MP4/3GP/MOVdemuxer
> will fail to parse a file. However, There is a problem if the MOV
> backend of libavformat really want to be fully compliant with the
> following standards ISO 14496-12 and MOV.
> What I propose is to generate a correct 'hdlr' box depending on the
> format: name handler with PASCAL strings for MOV files and C strings
> 3GP/MP4 files.
> What do you think about this?
More information about the ffmpeg-devel