Add image_generate_full() function to create interleaved color rectangles.
If flags is zero, the whole frame is generated with a unique pattern. If
flags is non-zero, then each field is handled individually.
On some platforms, vaPutImage() would fail even if it does not involve
color format conversion or scaling, whereas copying raw pixels through
vaDeriveImage() could work instead.
Fix new internal video format API, based on GstVideoFormat, to not
clobber with system symbols. So replace the gst_video_format_* prefix
with gst_vaapi_video_format_ prefix, even if the format type remains
GstVideoFormat.
Add the necessary helpers in GstVaapiDisplay to determine whether subpictures
with global alpha are supported or not. Also add accessors in GstVaapiSubpicture
to address this feature.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
