mid-side stereo processing example

[Eric Wong <e@80x24.org>]

I just put this together based on an old SoX mailing list post:
http://mid.gmane.org/72D2BEA8-3801-41EF-9BF0-364EACAE4C05@music.mcgill.ca

Not sure if it's worth converting into Ruby and making it officially
a part of dtas (and possibly libifying it for splitfx...)
---------------------------- 8< ------------------------------
#!/bin/sh
# mid-side processing example, based on:
# http://mid.gmane.org/72D2BEA8-3801-41EF-9BF0-364EACAE4C05@music.mcgill.ca
usage () {
	echo >&2 "$0 INFILE <mid|side|stereo|merge>"
	exit 1
}
set -e
INFILE="$1"
test -n "$INFILE" || usage
TYPE=$2
test -n "$TYPE" || usage
shift 2
mid="remix 1,2"
side="remix 1v0.5,2v-0.5"
export SOX_OPTS=-V3
set -x
OUT=${OUT-"-t alsa"}
t="$TRIMFX"

case $TYPE in
mid) cmd="$mid" ;;
side) cmd="$side" ;;
merge)
	# Merge the Mid and Side signals into a stereo file:
	exec sox -M "|sox '$INFILE' -p $t $mid" "|sox '$INFILE' -p $t $side" \
		$OUT
	;;
stereo)
	# Convert Mid/Sid stereo to L/R stereo:
	exec sox -M "|sox '$INFILE' -p $t $mid" "|sox '$INFILE' -p $t $side" \
		$OUT remix -m 1,2 1,2i
	;;
esac
exec sox "$INFILE" $OUT $t $cmd
-- 
EW