Create HTML5 <audio> compatible files out of MP3 using ffmpeg

gistfile1.txt

# -*- coding: utf8 -*-
import os
import subprocess

def create_prelisten_ogg(mp3, ogg):
    """
    Run en-code for a single file

    Do 48 kbit files for prelisten.
    """

    FFMPEG = os.environ['FFMPEG']
    cmdline = [ FFMPEG, '-y', '-i', mp3, '-acodec', 'libvorbis', '-ar', '22050', '-ac', '1', '-ab', '48000', ogg ]
    return subprocess.call(cmdline)

def create_prelisten_aac(mp3, aac):
    """
    Run en-code for a single file

    Do 48 kbit files for prelisten.
    """

    FFMPEG = os.environ['FFMPEG']
    cmdline = [ FFMPEG, '-y', '-i', mp3, '-acodec', 'libfaac', '-ar', '22050', '-ac', '1', '-ab', '48000', aac ]
    return subprocess.call(cmdline)


 getBrowserAudioFormat : function(url) {

        var audio = document.createElement("audio");

        var needAAC = audio.canPlayType('audio/mp4; codecs="mp4a.40.5"') !== "";
        var needOGG = audio.canPlayType('audio/ogg; codecs="vorbis"') !== "";

        if(needOGG) {
            url = url.replace(".mp3", ".ogg");
        } else if(needAAC){
            url = url.replace(".mp3", ".m4a");
        } else {
            console.error("Could not detect prelisten audio format support");
        }

        return url;
    },