converts m4a to ogg (lazy way to workaround an issue with most recent mpd from homebrew, which apparently does not like m4a)

to-ogg

#!/usr/bin/env bash

to-ogg() {
  local src=
  local dst=

  {
    [ ${#} == 0 ] && src=. && dst=.
  } || {
    [ ${#} == 1 ] &&
    [ -d "${1}" ] && src="${1}" && dst="${src}"
  } || {
    [ ${#} == 2 ] &&
    [ -d "${1}" ] && src="${1}" &&
    [ -d "${2}" ] && dst="${2}"
  } && {
    local log=`mktemp /tmp/to-ogg.XXXXXX`
    local src_file
    for src_file in "${src}"/*.m4a; do
      local dst_filename="${src_file##*/}"
      local dst_file="${dst}/${dst_filename%*m4a}ogg"
      [ -f "${dst_file}" ] && {
        echo "# skipping \"${src_file}\", \"${dst_file}\" already exists"
      } || {
        echo "# converting \"${src_file}\""
        ffmpeg -i "${src_file}" -acodec vorbis -strict -2 -aq 60 -vn -ac 2 "${dst_file}" 1>>"${log}" 2>&1 || echo "! converting \"${src_file}\" failed"
      }
    done
    echo "# [ log ${log} ]"
    return 0
  }
  echo "usage: to-ogg [<src-dir=./> [<dest-dir=src-dir>]]" 1>&2
  return 1
}