[cairo] glitz - YUV - _glitz_pixel_transform_op_t stride

[Patrick Pailhes]

Dear David and Bill,

Thank you for your replies.

Bill, I think you are right, we can put a pointer to each half-line in
line2 and line3. This way, no need for the variable int stride.

Thanks again :)

Patrick

On 06/02/06, Bill Spitzak <spitzak at d2.com> wrote:
> Why not put a pointer to each half-line in the line2 and line3 pointers?
> Then it can do offset/2 for these and ignore the stride.
>
> Patrick Pailhes wrote:
>
> > typedef struct _glitz_pixel_transform_op {
> >     char                 *line, *line2, *line3;
> >     int                  offset;
> >     glitz_pixel_format_t *format;
> >     glitz_pixel_color_t  *color;
> > } glitz_pixel_transform_op_t;
> >
> > For YV12, Y is stored in line, V in line2 and U in line3. However,
> > for the IMC2 format, both V and U would be stored in the variable
> > line2. Now, I believe that we need an extra a variable in the
> > structure glitz_pixel_transform_op_t. This variable would hold the
> > stride of the YUV array (i.e. the width of the surface). The stride is
> > needed in order to retrieve the U components (see below):
>
>