dumpaudio

#!/bin/bash
# marbu's dumpaudio helper powered by ffmpeg

show_help() {
  echo -e "Usage: dumpaudio [-c codec] input-files\n"
  echo """Options:
  -c   codec to encode dumped stream with
  -d   debug mode 
  -h   this message"""
}

die() {
  echo "error: $1" 1>&2
  exit 1
}

guess_codec() {
  ffmpeg -i ${FILE} 2>&1 | \
  grep 'Stream.\+Audio:' | \
  sed 's/^.*Stream #[0-9\.:()a-z]\+: Audio: \([a-z0-9]\+\).*/\1/'
}

strip_suffix() {
  echo $FILE | sed 's/\(.*\)\.[^\.]\+$/\1/'
}

do_dump() {
  $DEBUG ffmpeg -i ${FILE} ${OPTIONAL} ${OUTFILE}
}

# just extract without encoding
run_extract() {
  OUTFILE="${STRIPPED}.${GUESSED}"
  OPTIONAL="-acodec copy"
  do_dump
}

run_convert() {
  OUTFILE="${STRIPPED}.${CODEC}"
  do_dump
}

run_dump() {
  FILE=$1 # input audio file
  GUESSED=$(guess_codec)
  STRIPPED=$(strip_suffix)
  if [[ ! $CODEC ]]; then
    run_extract
    return
  fi
  if [[ $CODEC = $GUESSED ]]; then
    run_extract
  else
    run_convert 
  fi
}

#
# main
#

if [[ $# = 0 ]]; then
  show_help
  exit
fi

while getopts "dhc:" OPT; do
  case $OPT in
    d)    DEBUG=echo;;
    c)    CODEC=$OPTARG;;
    h)    show_help;
          exit;;
  esac
done

shift $(($OPTIND-1))

for i in $@; do
  run_dump "$i"
done