The script below does exactly this.
To use this script in linux:
0) make sure you have installed sox:
sudo apt-get install sox
1) paste the bash script code below into a new file called makeloops.sh and save it somewhere, e.g. ~/Downloads/ (the Downloads folder in your home directory, i.e. /home/me/Downloads)
2) make the bash script file executable:
chmod +x ~/Downloads/makeloops.sh
3) cd to the folder where your wav file (e.g. input.wav) is, e.g.:
cd ~/lmms/projects/your-lmms-project/
4) run makeloops.sh, e.g.:
. ~/Downloads/makeloops.sh input.wav 140 10 1
###### makeloops.sh (START COPYING BELOW THIS LINE) ####
#!/bin/bash
# INPUT PARAMETERS: $1==inputfile name (e.g. input.wav), $2==bpm (e.g. 140), $3==total measures of input file (e.g. 10), $4==loop length measures (e.g. 1), $5==loop folder name (e.g. loops)
#
# e.g. say you have a wav file, input.wav, that contains 10 measures *of equal length* of 140 BPM audio and you want to convert each measure to its own wav file loop:
#
# SEE "HELP" SECTION FOR EXAMPLE
#
EXPECTED_ARG_COUNT=5
# HELP
# IF NUMBER OF PARAMS < 5, OUTPUT HELP TEXT
if [ $# -ne $EXPECTED_ARG_COUNT ]
then
echo "";
echo "USAGE: makeloops.sh input-file-name BPM total-number-of-measures-in-input-file number-of-measures-for-loop-length loop-folder-name";
echo "";
echo "EXAMPLE: nickleus@mylaptop:/path/to/input/wav/file/$ . /path/to/makeloops.sh input.wav 140 10 1 loops";
echo "";
else
LOOPSTART=0;
BPS=$(echo $2/60|bc -l);
BEATS=$(echo 4*$4|bc -l);
LOOPLENGTH=$(echo $BEATS/$BPS | bc -l | awk '{printf("%.7f", $1);}'); # max 7 digits to the right of the decimal place for float numbers, no leading zeros on left side of decimal place
# INPUT ($2) 140 ($3) 10 ($4) 1
#echo $BPS # 2.33333333333333333333
#echo $BEATS # 4
#echo $LOOPLENGTH # 1.7142857
LOOPSFOLDER=$5;
mkdir $LOOPSFOLDER;
for (( w = 0 ; w < $3 ; w++ ));
do
sox -V4 "$1" "./$LOOPSFOLDER/$w.wav" trim $LOOPSTART $LOOPLENGTH;
LOOPSTART=$(echo $LOOPSTART+$LOOPLENGTH|bc -l);
done;
fi
###### (STOP COPYING ABOVE THIS LINE) ####
Note: If you don't want sox to run in full verbose mode, then just remove -V4; but it can be interesting to see what sox is actually doing during conversion.
