Mediademuxer: buffer can increase
av_read_frame only return one frame of the video buffer. However, if the CPU is too slow to decode (should not happen, but still), frames can just be stored and the video buffer can increase with a big maximum.
This should never happen. If the video buffer gets too big, the video will have a big delay.
But we also should not hide other problems. So, potential solution:
Check the size of the internal video buffer and log if too big before flushing.