Why video/x-h264?

[Nicolas Dufresne]

Le mercredi 15 juin 2022 à 03:46 +1000, John McDermott via gstreamer-devel a
écrit :
> Hi
> 
> I see that the element video/x-264 is often used in pipelines. For instance:
> `rtspsrc location = rtsp://192.168.0.61:8554/quality_h264 latency=0 !
> rtph264depay ! h264parse ! video/x-h264,stream-format=avc ! queue` What is
> `video/x-264` for? The pipeline seems to work even without it. Is the element
> optional?

I believe you meant x-h264 (missing an 'h'). In the snippet you pasted, it looks
like the reason would be to force AVCc stream-format. This is elementary stream
of H.264, were the NAL (the H.264 unit) is prefix with the size of the NAL.
Another format is "byte-stream" also known as Annex B., in which case each NAL
is prefix with a well known sequence ([00, 00, 00, 01] or [00, 00, 00, 00, 01]).



regards,
Nicolas