Join many MP3, OGG, and FLAC files into one WAV or FLAC

Question

I have 33 audio files, each about 11 seconds long, and I'd like to merge them into one lossless file. How can I do this efficiently (i.e. without cut-pasting in Audacity 33 times)?

Answer 1

You can do this with ffmpeg and sox:

for i in *.mp3 *.ogg *.flac
do
  ffmpeg -i "$i" "$i.wav"
done

sox *.wav combined.wav

Answer 2

If you start with only lossless files, you can use use shntool:

shntool join *.flac

Answer 3

Assuming you want to merge them alphabetically, by filename:

for f in ./*.{ogg,flac,mp3}; do echo "'$f'" >> inputs.txt; done
ffmpeg -f concat -i inputs.txt output.wav

The for loop puts all the filenames in a file called inputs.txt, one-per-line, and the second one uses ffmpeg's concat demuxer to merge the files.