[Live-devel] May be there are a frame duration problem in live.com with video ES

[Ross Finlayson]

>I have add an fprintf to "FramedSource" to store the frame duration value. 
>When I sum all frame duration after plying an Audio ES i find axectly the 
>same length of the Audio_ES. The problem is with Video_ES, I see that 
>there are many frame duration set to 0. Are those values correct?

Yes - because the 'frames' returned by "MPEG1or2VideoStreamFramer" are not 
actually complete video frames (pictures).  Instead, they are the various 
discrete components (video sequence headers, GOP headers, picture headers, 
and slices) that together make up a MPEG video frame.  (The reason for this 
is that these discrete components are what get packed into outgoing RTP 
packets - see RFC 2250.)

Only the last 'slice' of a MPEG video frame is actually given a duration 
(for the entire video frame) - see "MPEGVideoStreamFramer" (the parent class).

What's a bit confusing here is that the LIVE.COM code uses the term "frame" 
in a way which does not always correspond exactly to whole audio or video 
frames.


	Ross Finlayson
	LIVE.COM
	<http://www.live.com/>