I've got a Dolby Digital (ac3) file and I'm able to extract channels one by one like this:
-map_channel 0.0.4 -channel_layout mono -sn -b:a 128k -ac 1
For example, this extracts the back left channel.
I want to make a good stereo sound from the front three channels (Front, Center, Right) without the back channels - I'm going to play those through another amp. My thoughts are copying some/all of the center channel onto the left/right channels of the stereo output?
I can't downsample 5.1 to 2 in one go because I don't want the back left/right channels to bleed into the front. I want a stereo output of the three front channels, if that helps.
This is the ac3 channel layout:
0 FRONT_LEFT 1 FRONT_RIGHT 2 FRONT_CENTER 3 LOW_FREQUENCY 4 BACK_LEFT 5 BACK_RIGHT
Help is greatly appreciated. Thank you!