[FFmpeg-devel] [PATCH] mov tkhd' width and height usage

Ronald S. Bultje rsbultje
Thu Jan 20 17:53:05 CET 2011


2011/1/20 Maksym Veremeyenko <verem at m1stereo.tv>:
> Maksym Veremeyenko ???????(??):
>> Hi,
>> by default mov muxer setup width and height fields of *tkhd* atom as
>> visual representation of track that is mentioned in *ISO/IEC 14496-12*
>> (http://standards.iso.org/ittf/PubliclyAvailableStandards/c041828_ISO_IEC_14496-12_2005(E).zip)
>> [...]
>> width and height specify the track's visual presentation size as
>> fixed-point 16.16 values. These
>> ? need not be the same as the pixel dimensions of the images, which is
>> documented in the sample
>> ? description(s); all images in the sequence are scaled to this size,
>> before any overall transformation of
>> ? the track represented by the matrix. The pixel dimensions of the images
>> are the default values.
>> [...]
>> but *QuickTime File Format Specification* do not mention about it:
>> [...]
>> Track width
>> ? ? ? A 32-bit fixed-point number that specifies the width of this track
>> in pixels.
>> Track height
>> ? ? ? A 32-bit fixed-point number that indicates the height of this track
>> in pixels.
>> [...]
>> As result some software fault because of it want to read 768x576 plane
>> instead of 720x576. Furthermore QuickTime, FinalCut, Flipfactory set width
>> and height of *tkhd* equal to codec's width and height on exported mov
>> files.
>> Would it be a solution to set width and height equal to codec parameter
>> for mov format only (not mp4 etc..), please find attached patch...
> ping?

Is this a bug? Can you provide a commandline that produces a file that
quicktime fails to read without this patch and is fixed with it?


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