[Live-devel] synchronisation in a multithreading application

[Eric Peters]

Hello to all,

I have written an application which decodes a DVD with some different 
audio tracks (different languages for example). Now I want to stream 
this video and audio tracks over RTP using liveMedia. So it should be 
possible on the client side to see the movie in different languages.

For example I stream the movie and the audio multicast on the following 
ports:
audio1 (english): 6666
audio2 (german):  6668
audio3 (french):  6670
video:            8888

So, when I use a sdp-file which includes audio on port 6668 and video on 
port 8888 I want to see the movie in german.

Now my question: This is an multithreading application. I read the FAQ 
for threads and I have for each streaming instance my own 
UsageEnvironment and TaskScheduler. But on the client side I have 
problems to synchronize the audio and video tracks.

Is this synchronisation possible at all when I use independent 
UsageEnvironment and TaskScheduler? Or aren't the UsageEnvironments and 
TaskSchedulers completely independent from each other?

How can I synchronize the audio and video track? Which timestamps/values 
schould I use for synchronisation?

Thanks in advance
Eric