convert_existing.py

import os
import logging
import logging.handlers
import subprocess as sp
import json
from multiprocessing.pool import ThreadPool

class AudioConverter:

    def __init__(self,file_name):
        self.file_name = file_name        
        self.FFMPEG_BIN = "ffmpeg"
        self.filepath, self.ext = os.path.splitext(self.file_name)

    def convert_to_m4a(self):
        """
        Converts a input file to m4a

        command: ffmpeg -i input.wav -c:a aac -b:a 160k output.m4a
        ffmpeg -i input.wav -c:a aac -b:a 160k output.m4a
        """
        codec = "aac"
        m4a_filename = self.filepath + ".m4a"
        command = [self.FFMPEG_BIN,
                   "-n",
                   "-i", self.file_name,
                   "-acodec", codec,
                   "-ab", "128k",
                   m4a_filename
                   ]

        return command

    def convert_to_mp3(self):
        """
        Converts a input file to mp3

        command: ffmpeg -n -i input.m4a -acodec libmp3lame -ab 128k output.mp3
        """
        if self.ext == ".mp3":
            return        

        codec = "libmp3lame"
        mp3_filename = self.filepath + ".mp3"

        command = [self.FFMPEG_BIN,
                   "-n",
                   "-i", self.file_name,
                   "-acodec", codec,
                   "-ab", "128k",
                   mp3_filename
                   ]
        return command

    def convert_to_ogg(self):
        """
        Converts a input file to ogg

        command: ffmpeg -n -i input.m4a -acodec libvorbis -aq 60 -vn -ac 2 output.ogg
        """
        if self.ext == ".ogg":
            return

        codec = "libvorbis"
        ogg_filename = self.filepath + ".ogg"

        command = [self.FFMPEG_BIN,
                   "-n",
                   "-i", self.file_name,
                   "-acodec", codec,
                   "-aq", "60",
                   "-vn",
                   "-ac", "2",
                   ogg_filename
                   ]

        return command


def load_config(config_file):
    """
    load the configuration from JSON file.
    """
    try:
        with open('settings.json', 'r') as f:
            return json.loads(f.read())
    except (IOError, Exception) as e:
        print '%s' % e
        exit()

def convert(command):
    try:
        log_file = open("audio_converter.log", 'a')
    except:
        log_file = open("audio_converter.log", 'w+')

    # for command in process_queue:
    try:
        proc = sp.Popen(command, stdout=log_file,
                    bufsize=10**5)
        proc.wait()
        if proc.returncode == 1:
            # file already exists
            err = "\n".join(["Audio conversion: %s\n" % command,
            "WARNING: file already exists "])
            del proc
            raise IOError(err)
        del proc

    except IOError as e:
        log_file.write(str(e))
    except Exception as e:
        log_file.write(str(e))

# Change the directory of audio files here
if __name__ == "__main__":
    # rootdir = os.getcwd()  #default:  get the current dir
    rootdir = load_config('settings.json')["dir_to_watch"]
    output_formats = [".mp3",".ogg"]

    all_files = []
    input_format = [".m4a",".wav"]
    num = None # set to the number of workers (defaults to the cpu count of the machine)
    tp = ThreadPool(num)

    for subdir, dirs, files in os.walk(rootdir):
        for file in files:
            filepath, ext = os.path.splitext(file)
            if ext in input_format:
                path_from_root = os.path.join(subdir, file)
                file_path = os.path.realpath(path_from_root)
                try: 
                    converter = AudioConverter(file_path)
                    # tp.apply_async(convert, (converter.convert_to_m4a(),) )
                    if ".mp3" in output_formats:
                        if not os.path.isfile(os.path.realpath(os.path.join(subdir, filepath+".mp3"))):
                            tp.apply_async(convert, (converter.convert_to_mp3(),) )
                    if ".ogg" in output_formats:
                        if not os.path.isfile(os.path.realpath(os.path.join(subdir, filepath+".ogg"))):
                            tp.apply_async(convert, (converter.convert_to_ogg(),) )
                except Exception as e:
                    print e
    
    tp.close()
    tp.join()