FLAC -> ALAC convesion script with downsampling to 16bit/44100kHz

f2a

#!/usr/bin/env bash
set -e

f2a () {
if [ -z $1 ]; then
  echo "usage: $0 dir"
  return 1
fi

for file in "$1"/*.flac; do
  echo -n "."
  ffmpeg -i "$file" -sample_fmt s16p -map 0:a -ar 44100 -acodec alac "${file%.*}.m4a"
done
}

f2a $1

To make the usage more convenient, I've also made it available as a shell command (I use .zsh):

1. created a directory for shell scripts which I want to make callable from the shell
2. put the content of the script above in a file in that directory
3. added these two lines to my .zshrc:

fpath=($ZSH_SCRIPTS_HOME $fpath);
autoload -U $fpath[1]/*(.:t)

Then I could call it from the shell like this: f2a <directory with flacs>

A brief explanation of the ffmpeg args:

• -map 0:a – to only include audio streams (e.g. when there's a cover stream in the source flac)
• -sample_fmt s16p -ar 44100 – output sample rate / discretisation level adjustment

Was first using this script, then changed it to only use afconvert, but then decided to simply use ffmpeg