I don’t know enough about ffmpeg or even h264 to have a lot of input on this, but while watching what VLC does with wireshark, it seems to open the stream stream (DESCRIBE, SETUP, PLAY, etc), and data starts flowing in, but VLC doesn’t display anything for quite a while. I assume this is waiting for keyframes(?).
UPDATE: i just googled what SPS and PPS was and found some more information: on stack overflow
