Create FFMETADATA for ffmpeg from multiple files.

chapters.sh

#!/usr/bin/env bash
# FFMETADATA Chapter generator
# Pass multiple media files to this script to generate a generic FFMETADATA file
# Usage: ARTIST="My Artist" ALBUM="My Album" ./chapters.sh /path/to/*.wav > my.metadata
set -eo pipefail
ARTIST="${ARTIST:-ARTIST}"
ALBUM="${ALBUM:-ALBUM}"
end_stamp=0
begin_stamp=0
i=1
# output the metadata header
echo ';FFMETADATA'
echo "artist=${ARTIST}"
echo "album=${ALBUM}"
# build the chapter list from the arguments
while [ -f "$1" ]
do
  if [ $((0+${TITLED:-0})) -eq 0 ]
  then
    title="Chapter $i"
    # increment the counter
    i=$((i+1))
  else
    # attempt to clean up filenames (track numbers, extensions)
    title=$(basename "$1"|sed -r -e 's/^([0-9]+)?( - )?(.*)(\.[a-zA-Z0-9]{1,4})$/\3/')
    # remove the artist name, if that appears too
    title=$(echo -n ${title#$ARTIST}|sed -r -e 's/^ ?- //')
  fi
  # extract timestamp parts from ffprobe output
  read -r h m s ms < <(ffprobe "$1" 2>&1|grep Duration|awk '{print $2}'|sed -e 's/[\.:,]/ /g')
  # calculate the new ending
  end_stamp=$(($((end_stamp+$(($(($((10#$s+$(($((10#$m+$((10#$h*60))))*60))))*1000))+10#${ms:0:4}))))-1))
  # output this chapter
  echo '[CHAPTER]'
  echo 'TIMEBASE=1/1000'
  echo "START=$begin_stamp"
  echo "END=$end_stamp"
  echo "title=$title"
  # set next beginning based on previous end
  begin_stamp=$((end_stamp+1))
  # remove this file from the argument list
  shift 1
done