Fix GstVaapiVideoBufferPool::reset_buffer() to reset the underlying
memory resources, and more particularly the VA surface proxy. Most
importantly, the GstVaapiVideoMeta is retained. Cached surface in
memory are released, thus triggering a new allocation the next time
we need to map the buffer.
If the video buffer pool config doesn't have new caps, then it's not
necessary to reinstantiate the allocator. That could be a costly
operation as we could do some extra heavy checking in there.
Implement GstVideoMeta::{,un}map() to support raw YUV buffer upload when
the last component is unmapped. Downloads are not supported yet. The aim
was to first support SW decoding + HW accelerated rendering (vaapisink).
e.g. for Wayland.
Add initial support for GstVaapiVideoMemory backed buffer pool. The memory
object currently holds a reference to GstVaapiVideoMeta.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
