[Live-devel] presentationTime and B-Frames

[Julian Lamberty]

Ross Finlayson schrieb:
>> How is the timeval structure mapped onto the 32bit presentation time in
>> the RTP packet, what interval do I have to add to fPresentationTime to
>> make RTP timestamp increase by 3600 (i.e. one frame duration @25Hz)?
>>     
>
> Receiving code should not need to care about RTP timestamps.  (Only 
> the LIVE555 RTP reception code needs to care about RTP timestamps.) 
> Instead, just use the presentation time that's given to each piece of 
> incoming data (from the "RTPSource" subclass).
>
>   
Ok, but there's still the problem how to sync an original audio stream 
to the transcoded corresponding video stream because the original 
timestamps are not preserved. Can this be worked around somehow? I know 
the standard requires a "random" offset to be added to the RTP 
timestamps. How can I keep synchronisation at the final receiver?