read mpeg stream

[livedevel]

How does vlc generate a mpg file from a stream using rtp / rfc 2250(rtp-header for mpeg).

in ethereal i´ve seen that the stream is multiplexed in two. one for audio the other for video.

can someone tell me where i can get a good description how these two streams are generated?
Is it descripte in the ISO/IEC 11172-* standard for mpeg?

i know the questions are common, but i need to understand the organisation of the multiplexed streams!

thanks

[Corto]

I have the same problem, but the ISO/IEC 11172 is licensed and i hav not yet find free informations on the web.
The uniq solution that i found is to read applications source code.
Good Luck.
Marc.