Damn iTunes Store...

to-flac.py

#!/usr/bin/python -u

# Quick and dirty script to transcode to FLAC all AAC-LC files
# rooted into the current working directory (subdirs incl.)

import os
import sys
import subprocess
import magic

def collect_aac_lc():
    cwd = os.path.abspath(os.getcwd())
    m4a = []
    m = magic.open(magic.MAGIC_NONE)
    m.load()
    for root, dirs, files in os.walk(cwd):
        for f in files:
            if f.endswith('.m4a'):
                fullpath = os.path.join(root, f)
                if m.file(fullpath).find('AAC-LC') > -1:
                    m4a.append(fullpath)
    m.close()
    return m4a

def convert_to_flac(aacs):
    errs = []
    for aac in aacs:
        (fn, _) = os.path.splitext(aac)
        flac = fn + '.flac'
        ps = subprocess.Popen(['/usr/bin/ffmpeg', '-i', aac, '-acodec', 'flac', flac], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        (stdout, stderr) = ps.communicate()
        if ps.returncode == 0:
            os.unlink(aac)
            sys.stdout.write(".")
        else:
            errs.append(aac)
            sys.stdout.write("!")
    return errs

if __name__ == '__main__':
    m4as = collect_aac_lc()
    l = len(m4as)
    if l == 0:
        print "[!] No AAC-LC files, exiting"
        sys.exit(1)
    else:
        print "[*] Found %d AAC-LC file%s" % (l, 's' if l > 1 else '')
    sys.stdout.write("[*] Transcoding")
    errs = convert_to_flac(m4as)
    print ""
    for f in errs:
        print "[!] %s was not transcoded successfully, kept" % (f,)
    print "[*] Done"
    sys.exit(0)