A script to move music from one dir to another, and reencode m4a files to mp3 in the process

mp3move.py

import contextlib
import multiprocessing
import os
import shutil
import subprocess
import sys

REALLY = True

FFMPEG = r'c:\Users\Mike\Desktop\ffmpeg-20160325-git-585cfab-win64-static\bin\ffmpeg.exe'

QUEUE_SIZE = 4
NUM_PROCESSES = 3
STOP_QUEUE = ('stop', None)


class FfmpegRunner(object):
    def __init__(self, queue, proc_id):
        self.queue = queue
        self.proc_id = proc_id
        print "Created runner", proc_id

    def work(self):
        print "Started {}".format(self.proc_id)
        while True:
            req = self.queue.get()
            if req == STOP_QUEUE:
                print '  <{}> Stopping.'.format(self.proc_id)
                break
            else:
                path, dest_path = req
                print '  <{}> Encoding...'.format(self.proc_id)
                reencode(path, dest_path)
                print '  <{}> Done.'.format(self.proc_id)


class FfmpegPool(object):
    def __init__(self):
        self.queue = multiprocessing.Queue(QUEUE_SIZE)
        self.procs = [
            multiprocessing.Process(target=FfmpegRunner(self.queue, x).work)
            for x in range(NUM_PROCESSES)]
        [p.start() for p in self.procs]

    def reencode(self, path, dest_path):
        self.queue.put((path, dest_path))

    def stop(self):
        for _ in range(len(self.procs)):
            self.queue.put(STOP_QUEUE)
        for proc in self.procs:
            proc.join()


@contextlib.contextmanager
def ffmpegPool():
    pool = FfmpegPool()
    yield pool
    pool.stop()

def mkdirp(path):
    if REALLY:
        if not os.path.exists(path):
            os.makedirs(path)
    else:
        print "os.makdirs", path


def copy(path, dest_path):
    if REALLY:
        shutil.copyfile(path, dest_path)
    else:
        print "copyfile", path, dest_path


def reencode(path, dest_path):
    if REALLY:
        subprocess.call([FFMPEG, '-i', path, '-q:a', '0', dest_path])
    else:
        print "reencode", path, dest_path


def get_files(src):
    all_files = []
    for root, dirs, files in os.walk(src):
        all_files.extend([
            os.path.join(root, f)
            for f in files
            if not "DS_Store" in f
                and not ':' in f
                and not f.endswith('.')])
    return tuple(sorted(all_files))

def new_path(src, dest, path):
    rel = os.path.relpath(path, src)
    new = os.path.join(dest, rel)
    if new.endswith('.m4a'):
        new = new[:-3] + '.mp3'

    if len(new) > 4096:
        print "fail:", new_path(p)
        assert False

    left = new
    while True:
        left, right = os.path.split(left)
        if len(right) > 260:
            print "fail:", right, "in", p
            assert False
        if not left or not right:
            break
    return new

def needs_reencode(path):
    return path.endswith('.m4a')

def main():
    dirs_made = set()
    src, dest = sys.argv[1:3]
    print "{} -> {}".format(src, dest)
    paths = get_files(src)
    num_paths = len(paths)
    mapped = [(p, new_path(src, dest, p)) for p in paths]
    with ffmpegPool() as pool:
        for i, (p, dest_path) in enumerate(mapped):
            if os.path.exists(dest_path):
                continue
            print "[{:4d}/{:4d}] {}\n -> {}".format(i + 1, num_paths, p, dest_path)

            dirpath, filename = os.path.split(dest_path)
            if dirpath not in dirs_made:
                mkdirp(dirpath)
                dirs_made.add(dirpath)

            if needs_reencode(p):
                pool.reencode(p, dest_path)
            else:
                copy(p, dest_path)

if __name__=="__main__":
    main()