vaapisink should not ignore the video alignment requested by avdec
The upper few rows in image from this pipeline are corrupt:
gst-launch-1.0 videotestsrc ! video/x-raw,width=1920,height=1080 ! avenc_mjpeg ! avdec_mjpeg ! vaapisink
The reason is, that avdec_mjpeg requests a video alignment with
GST_BUFFER_POOL_OPTION_VIDEO_ALIGNMENT but this is ignored in
vaapi should either provide buffers with the correct plane strides or return an error in
gst_vaapi_video_buffer_pool_set_config() (in this case
avdec_mjpeg will use its own buffers).