How to convert ALAC to FLAC?

Solution 1:

Install ffmpeg:
```
sudo apt-get install ffmpeg
```
Files can be converted to FLAC from ALAC via the command ffmpeg -i audio.m4a -acodec flac audio.flac. To do this for a while directory of files go to that directory (cd path) and issue the following:
```
for f in *.m4a; do ffmpeg -i "$f" "${f%.m4a}.flac"; done
```
(Optional)
- Add replay gain to the FLAC files.
- If the conversion is successful you can remove the ALAC files.

For reference see https://superuser.com/a/329278/87552 and http://ubuntuforums.org/showthread.php?t=1500430.