Separating the channels in a 5.1 stream into separate streams

[FallenAngelII]

So, I've noticed that with some movies, the filmmakers program the audiotrack so that all of the speech go into certain channels while the music goes into others, so if you listen to one such audiotrack on stereo equipment with, for example, VLCPlayer on the right settings, you can get either a Karaoke Stream or a Speech/Vocals Only Stream.

For exampling, viewing "Disney's Hercules" in this manners gives me the movie with instrumentals only, essentially giving me a karaoke track for the musical numbers. Inversely, viewing "Glee" (ripped from the HDTV feed) instead gives me a track where the main vocalists' voices are greatly amplified over that of the music and background singers.

So I was wondering if there's a way to separate the channels in a 5.1 channel audio track. For example, if I only wanted Channels 1 and 2 or just 3 or 3, 4 and 5, mixing it up to get the karaoke/vocal track I want. The program would probably have to be able to handle AC3 and also have give the user the ability to pick and choose which channels to rip.

I want to know this in order to be able to create karaoke tracks.

[AlanHK]

HeadAC3he can remix AC3 however you like.
Open AC3, click "Options".

[netmask56]

The convention is to mix important dialog center stage, in part to maintain the same acoustic time delay for theatre audience sitting on the extreme right rear and extreme left rear. If you had dialog stage left then the sound would arrive at the left rear of the theatre before reaching the right rear. Very early stereo mixes suffered from this in the large barns that existed back then. Not so important now with smaller theatres and better acoustics but the convention remains with few exceptions.