[Live-devel] waiting for SPS/PPS

[Ross Finlayson]

You didn’t say specifically *how* you are using the “LIVE555 Streaming Media” code, and what you are trying to do with it - but from the context of your message, I assume that you are using it to develop a RTSP server.


> It seems to be working fine but when I stream over RTSP, VLC is telling me that it hasn't gotten the SPS/PPS. It seems like I'm generating it ok, though clearly something is off. Perhaps you can tell me at what point the SPS & PPS are actually sent?

SPS and PPS are H.264 NAL units, just like those for video frame data.  The LIVE555 code does not generate them (to insert into an outgoing RTP stream); it is up to your H.264 source (i.e., encoder) to generate them.

However, the presence of "sprop-parameter-sets” in your SDP means that the LIVE555 RTSP server code *has* seen SPS and PPS NAL units - most likely at the very beginning of your stream.  So it seems that your encoder generated SPS and PPS NAL units once, at the very start, but not thereafter.

This should, however, be enough for VLC (as a RTSP client), because it gets the SPS and PPS from the SDP (returned by a RTSP “DESCRIBE” command) before it starts receiving the H.264/RTP stream.  I can’t help you with problems with VLC, but you should make sure that you are using the most up-to-date version.

You could also try using “openRTSP” as a RTSP client, and rename the resulting video output file to have a “.h264” video suffix before playing it with a video player.  (“openRTSP” also gets the SPS and PPS NAL units from the SDP, and prepends them to the video output file.)


Ross Finlayson
Live Networks, Inc.
http://www.live555.com/