[Live-devel] question about the live555 RTP sending speed

[Malte Tancred]

On 23 sep 2008, at 15.11, Ross Finlayson wrote:

> The transmission speed is determined by the value of the  
> "fDurationInMicroseconds" variable.  Your "*Framer* object (in this  
> case, your "H264VideoStreamFramer" subclass) needs to properly set  
> this for each H.264 NAL unit that it delivers.



I suppose this is correct. However, "properly set" doesn't necessarily
mean what you first think it means. These are my findings:

- all NAL units that belong to the same frame, except the last NAL
   unit in that frame, should have a duration of 0 (zero).

- the last NAL unit in each frame should have a duration matching
   that of its frame.

- all NAL units in a frame should have the same presentation time.

(Please note that what I call "frame" above is called an "access unit"
in the liveMedia library)


What brought my attention to this was the following message to the list,
regarding zero duration "frames" delivered by the MPEG stream framer:

   http://lists.live555.com/pipermail/live-devel/2004-April/000650.html


Regards,
Malte