[Live-devel] H264 working in openRTSP but not testRTSPClient

[Ross Finlayson]

> Thanks for the info. From reading your linked threads, it seems I should contact the camera manufacturer (hiQview) and tell them they should modify their cameras to send smaller NAL units.

More specifically, they should break up large ‘key frame’ NAL units into a sequence of smaller ‘slice’ NAL units.  If they can’t do that, then they should instead send smaller ‘key frame’ NAL units (even if that means lowering the resolution and/or picture size of the video).

> I did notice that openRTSP calls:
>     subsession->rtpSource()->setPacketReorderingThresholdTime();

That affects only streams where (i) network packets can be reordered, and (ii) these reordered packets can be delayed by more than 100 ms.  I.e., it’s relevant to almost no streams.

> And also
>     setReceiveBufferTo()

That changes the amount of socket buffering in the receiver’s OS.  (The default value is 50 kBytes.)  Increasing it *might* make it less likely that these very large ‘key frame’ NAL units (with their bursts of RTP packets) will be dropped by the receiver’s OS.  It won’t do anything about *network* packet loss, however.  If a packet (for one of these large ‘key frame’ NAL units) gets lost on the network, then the whole ‘NAL unit’ will be unusable by the receiver.  (And the larger the NAL unit, the more likely it is that that will happen.)


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