[FFmpeg-devel] [PATCH] mov tkhd' width and height usage
Maksym Veremeyenko
verem
Mon Jan 17 13:51:44 CET 2011
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...
--
________________________________________
Maksym Veremeyenko
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