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>
Forward declaring enums is not allowed by the C standard and aborts
compilation if the header file is included in a C++ project.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
A rendering mode can be "overlay" or "texture"'ed blit.
The former mode implies that a VA surface used for rendering can't be
re-used right away for decoding, so the sink shall make provisions to
retain the associated surface proxy until the next surface is to be
displayed.
The latter mode implies that the VA surface is implicitly copied to an
intermediate backing store, or back buffer of a frame buffer, so the
associated surface proxy can be disposed right away.
The VA display attributes are mapped to properties so that to maintain the
GStreamer terminology. Properties are to be identified by name, but internal
functions are available to lookup the property by the actual VA display
attribute type.
Move display types from gstvaapipluginutil.* to gstvaapidisplay.* so that
we could simplify characterization of a GstVaapiDisplay. Also rename "auto"
type to "any", and add a "display-type" attribute.
