[Live-devel] H264 streaming problem

gather bzbz gbzbz at yahoo.com
Wed Feb 25 14:27:53 PST 2009




<QUOTE>
The problem is that special headers called SPS and PPS (sequence
parameter set and picture parameter set) are not included in the file. 
Those headers may be carried in-band (which is probably not your case)
or in the SDP.
My guess is that your source sent them in the SDP and not in-band (in
the RTP stream), and that's why they are not found in the file.
<QUOTE>

Now I am trying to understand the live555 codes,

1. the SPS and PPS NALs are treated the same way as the DATA NALs, right?
I mean, looking at the void H264FUAFragmenter::doGetNextFrame() in H264VideoRTPSink.cpp, do we need to actually parse the fInputBuffer for SPS and PPS? I assume that SPS and PPS NALs are small enough to be deliver "as is". 

2. My understanding is that, most sources will give single NAL per frame, so it is normally the case that currentNALUnitEndsAccessUnit() returns TRUE. The FUA mode means, even in single NAL/frame case, the NAL may be too big for the MTU to carry, but we usually do not need to do anything special because the void H264FUAFragmenter::doGetNextFrame() in H264VideoRTPSink.cpp has done all the job.

Thanks


      


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