> My first NAL analyzed by bitstream analyzer.
> 
> !! Found NAL at offset 4 (0x0004), size 18 (0x0012) 
> XX 00 00 00 01 67 42 80 1E 95 A0 50 7C 84 00 00 0F 
> 
> ==================== NAL ====================
>  forbidden_zero_bit : 0 
>  nal_ref_idc : 3 
>  nal_unit_type : 7 ( Sequence parameter set ) 
> ======= SPS =======
>  profile_idc : 66 
>  constraint_set0_flag : 1 
> .
> .
> .
> 
> It is not discrete NAL unit.

OK, let me explain this a different way:

You want to control the rate at which you transmit NAL units.  I.e., you want 
to set “fPresentationTime” explicitly, and transmit NAL units at a rate that 
you choose (about 9 frames per second).

THEREFORE, you MUST use a “H264VideoStreamDiscreteFramer” to do this.  You 
CANNOT use a “H264VideoStreamFramer”.

The reason for this is that a “H264VideoStreamFramer” parses the H.264 video 
byte stream itself, and sets “fPresentationTime” (and 
“fDurationInMicroseconds”) ITSELF, based on the timing information (frame rate) 
that it deduces from the H.264 video byte stream that it is being fed.  In your 
case, this deduced frame rate is NOT ~9 frames per second.  Instead, it is 25 
frames per second, I think.

Once again, because you want to set “fPresentationTime” yourself, and 
explicitly control the rate at which you transmit NAL units, you MUST use a 
“H264VideoStreamDiscreteFramer”.  This means that you will have to do your own 
parsing of your H.264 video data, and feed the NAL units - one at a time, and 
WITHOUT a 0x00 0x00 0x00 0x01 ‘start code’ - to your 
“H264VideoStreamDiscreteFramer”.


(Unfortunately, we’ve probably now reached the limit for how much assistance I 
can provide you ‘for free’ on this mailing list.  If your company is interested 
in having me consult further on your project, then please have your management 
let me know (via separate email).)

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


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