[FFmpeg-devel] [PATCH] Use tkhd matrix for proper display in mov

[Reimar Döffinger]

On Tue, May 27, 2008 at 02:49:24PM -0400, John Schmiederer wrote:
> > > Attached is a patch to account for the transformation matrix contained in the tkhd atom for proper display width/height.
> >
> > > The video
> > > http://samples.mplayerhq.hu/mov/tkhd_matrix/white_zombie_scrunch.mov
> > > plays at 160x240 when it should really be scaled to 320x240.
> >
> > > +    int i;
> > > +    int width;
> > > +    int height;
> > > +    float disp_transform[3];
> > > +    float display_matrix[3][3];
> >
> > please use integers, there is no need for floats.
> >
> Ok, I changed display_matrix to int, but left disp_transform as float to avoid any possible overflow from multiplying large ints.

Not sure if they are already accessible from libavformat, but we do have
function for multiplying two 16.16 fixed-point numbers correctly.