[MPlayer-users] conditional surround

[Alexander Roalter]

Some AC3-Tracks, which appear to be stereo, are Dolby Surround tracks. 
Using the -af surround filter, one can play these tracks on 4 channels, 
just like pressing the surround effect button on the audio receiver.

Now, how can I make this surround conditional? i.e. if I play a plain 
stereo file, I don't want the sound on 4 channels, but rather on the two 
front speakers...

-af surround does this with all the stereo tracks, but mplayer should 
know if it is a surround track (marked as AC3 2.0 (dolby) or a normal 
stereo track (AC3 2.0 (stereo)), when playing with -v (btw. this 
sometimes very useful output was visible a long time ago without the -v 
switch)

Something else, but also conditional: I can play PAL movies with -speed 
0.96 at the original 24 fps. But is there a possibility to make this 
also conditional, i.e. doing this only if the source material is 25fps? 
With my ever growing number of NTSC discs, i'll have to press the back 
key to get to speed =1.00 again, in order for these discs not to play 
too slowly.

-
cheers,
Alex