Bash script to convert base note sound to full octave .

pitch_shift

#!/bin/bash

#   Using: Sox
#
#   If not installed :
#   sudo apt-get install sox libsox-fmt-mp3
#

if [ ! -f $1 ]
    then
        echo "Bad filename."
        exit
    fi

# There are 12 semitones to an octave,
# Measured in 100ths of a semitone.
# so that would mean +/- 1200 for one octave.
# Info : 
# http://en.wikipedia.org/wiki/Semitone
declare -A notes=( 
    [c]=0 [cs]=76 [d]=193 [ds]=310
    [e]=386 [f]=503 [fs]=579 [g]=696
    [gs]=772 [a]=889 [as]=1006 [b]=1082 )

for note in ${!notes[@]};
    do
        # sox <infile> <outfile> pitch <shift>
        sox $1 ${note}$2.mp3 pitch ${notes[${note}]}
    done