Recursively split directory of mp3s by X minute chunks. Requires ffmpeg.

split.sh

#!/bin/bash

min=10; #num minutes to split by

VERBOSE=false
QUIET=false
TEST=false

while getopts ':vqt:nh' opt; do
  case $opt in
    v) VERBOSE=true ;;
    q) QUIET=true   ;;
    t) min=$OPTARG  ;;
    n) TEST=true    ;;
    h) echo "Split MP3 files"; echo "Options:"; 
       echo "-v verbose"; echo "-q quiet"; echo "-n noop - test mode";
       echo "-t specify a time in minutes to split by. Default is "$min;
       exit 0;
       ;;
    \?) echo "Unexpected option -$OPTARG" >&2; exit 1; ;;
    :) echo "Option -$OPTARG requires an argument." >&2; exit 1; ;;
  esac
done

# http://stackoverflow.com/questions/12199631/convert-seconds-to-hours-minutes-seconds-in-bash
convertsecs() {
 ((h=${1}/3600))
 ((m=(${1}%3600)/60))
 ((s=${1}%60))
 printf "%02d:%02d:%02d\n" $h $m $s
}

SAVEIFS=$IFS
IFS=$(echo -en "\n\b")
for file in $(find . -name '*.mp3' -type f -not -path '*/\.*'); do
  #secLen=$(mdls "$file" | grep kMDItemDurationSeconds | awk '{print $3}')
  secLen=$(ffmpeg -i "$file" -codec copy 2>&1 | grep Duration | awk '{split(gensub(/\,/,"","g",$2),a,":"); print (a[1]*60*60)+(a[2]*60)+(a[3])}')
  splits=$(echo "($secLen/($min*60)) + 1" | bc )

  if [ $splits -lt 3 ]; then
    $QUIET || echo "Skipping small file: $file"
    continue
  fi
  
  $QUIET || echo 'Splitting file: '$file' | sec: '$secLen' | split: '$splits
  
  X=0; while( [ $X -lt $splits ] ); do
    start=$(convertsecs $((min*60*X)))
    output="$(echo $file"_pt"$(($X+1))".mp3")"

    $QUIET || $VERBOSE && echo "Split "$X" start: "$start

    $TEST || ffmpeg -v quiet -i "$file" -acodec copy -t 00:$min:00 -ss $start "$output"
    X=$((X+1))
  done; 
  #remove the orignal file
  $TEST || rm "$file"
done;
IFS=$SAVEIFS