Hi Ming, On Mon, 21. Mar 07:27, Ming Qian wrote: > Hi Andriy, > > What do you think of this patch? > > The Initialization flow defined in > linux/Documentation/userspace-api/media/v4l/dev-decoder.rst > 1. Set the coded format on OUTPUT via VIDIOC_S_FMT(). > 2. Allocate source (bytestream) buffers via VIDIOC_REQBUFS() on OUTPUT. > 3. Start streaming on the OUTPUT queue via VIDIOC_STREAMON(). > 4. This step only applies to coded formats that contain resolution > information in the stream. Continue queuing/dequeuing bytestream buffers > to/from the OUTPUT queue via VIDIOC_QBUF() and VIDIOC_DQBUF(). The buffers > will be processed and returned to the client in order, until required > metadata to configure the CAPTURE queue are found. This is indicated by the > decoder sending a V4L2_EVENT_SOURCE_CHANGE event with changes set to > V4L2_EVENT_SRC_CH_RESOLUTION. > Note: A client capable of acquiring stream parameters from the > bytestream on its own may attempt to set the width and height of the OUTPUT > format to non-zero values matching the coded size of the stream, skip this > step and continue with the Capture Setup sequence. > > 5. Continue with the Capture Setup sequence. > > In ffmpeg's implementation, ffmpeg will set non-zero width and height on > output queue, so the step 4 should be skipped, and setup the capture queue > directly. > So the flow should be: > 1. Set the coded format and valid resolution on OUTPUT via VIDIOC_S_FMT(). > 2. Allocate source (bytestream) buffers via VIDIOC_REQBUFS() on OUTPUT. > 3. Start streaming on the OUTPUT queue via VIDIOC_STREAMON(). > 5. Continue with the Capture Setup sequence. > > And this patch is just following the above flow. > > Ming
The v4 version didn't work for me on odroid xu4 http://ffmpeg.org/pipermail/ffmpeg-devel/2022-January/290679.html I haven't had time retest but don't think anything has changed. -- Andriy _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
