vaapipostproc: advertise crop meta is handled
Advertise to upstream that vaapipostproc can handle crop meta.
When used in conjunction with videocrop plugin, the videocrop plugin will only do in-place transform on the crop meta when vaapipostproc advertises the ability to handle it. This allows vaapipostproc to apply the crop meta on the output buffer using vaapi acceleration. Without this advertisement, the videocrop plugin will crop the output buffer directly via software methods, which is not what we desire.
vaapipostproc will not apply the crop meta if downstream advertises crop meta handling; vaapipostproc will just forward the crop meta to downstream. If crop meta is not advertised by downstream, then vaapipostproc will apply the crop meta.
Examples:
- vaapipostproc will forward crop meta to vaapisink
gst-launch-1.0 videotestsrc \
! videocrop left=10 \
! vaapipostproc \
! vaapisink
- vaapipostproc will do the cropping
gst-launch-1.0 videotestsrc \
! videocrop left=10 \
! vaapipostproc \
! identity drop-allocation=1 \
! vaapisink