Ok thanks for your replay... i do this command sequence: mplayer -dvd X -alang it -channels 6 -dumpaudio a52dec -o wav6 $AC3FILE | oggenc -r -R48000 -C6 - -o $OGGFILE I obtain a ogg file with 6 channels but the channels are inverted... why? and when a play the ogg file when start it i lissen a "beep" why??