This flag is obsolete. It was meant to explicitly enable/disable VA/GLX API
support, or fallback to TFP+FBO if this API is not found. Now, we check for
the VA/GLX API by default if --enable-glx is set. If this API is not found,
we now default to use TFP+FBO.
Note: TFP+FBO, i.e. using vaPutSurface() is now also a deprecated usage and
will be removed in the future. If GLX rendering is requested, then the VA/GLX
API shall be used as it covers most usages. e.g. AMD driver can't render to
an X pixmap yet.
This ensures the display name provided to gst_vaapi_display_*_new()
maps to the system defaults, instead of forcing "" that could be different
from the current DISPLAY name.
This new interface allows for upstream and downstream display sharing
that works in both static and dynamic pipelines.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>