configure: check for GstVideoDecoder API.
configure: check for GstVideoDecoder API.

GstVideoDecoder API is part of an unreleased GStreamer 0.10 stack. In particular,
this is only available in git 0.10 branch or GStreamer >= 1.0 stack. Interested
parties may either use upstream git 0.10 branch or backport the necessary support
for GstVideoDecoder API, thus including helper tools like GstVideoCodecFrame et al.

gbeauchesne/gstreamer-vaapi,CapOM/gstreamer-vaapi,ceyusa/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,GStreamer/gstreamer-vaapi,GStreamer/gstreamer-vaapi,CapOM/gstreamer-vaapi,CapOM/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,ceyusa/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,01org/iotg-lin-gfx-gstreamer-vaapi