welll/record-encode-audio-from-browser

(function(window) {

  var recordWavWorker = new Worker('js/enc/wav/recorderWorker.js');
  var encoderMp3Worker = new Worker('js/enc/mp3/mp3Worker.js');

  var Recorder = function(source) {

    var bufferLen = 4096;
    var recording = false;

    this.context = source.context;

    /*
      ScriptProcessorNode createScriptProcessor (optional unsigned long bufferSize = 0,
       optional unsigned long numberOfInputChannels = 2, optional unsigned long numberOfOutputChannels = 2 );
    */

    this.node = (this.context.createScriptProcessor || this.context.createJavaScriptNode).call(this.context, bufferLen, 1, 1);
    this.node.connect(this.context.destination); //this should not be necessary

    this.node.onaudioprocess = function(e) {

      if (!recording)
        return;

      var channelLeft = e.inputBuffer.getChannelData(0);

      console.log('onAudioProcess' + channelLeft.length);

      encoderMp3Worker.postMessage({
        command: 'encode',
        buf: channelLeft
      });

      recordWavWorker.postMessage({
        command: 'record',
        buffer: channelLeft
      });

    }

    source.connect(this.node);

    this.record = function() {

      if (recording)
        return false;

      recording = true;

      var sampleRate = this.context.sampleRate;

      console.log("Initializing WAV");
      log.innerHTML += "\n" + "Creating Empty WAV";

      recordWavWorker.postMessage({
        command: 'init',
        config: {
          sampleRate: sampleRate
        }
      });

      console.log("Initializing to Mp3");
      log.innerHTML += "\n" + "Creating Empty Mp3:" + sampleRate;

      encoderMp3Worker.postMessage({
        command: 'init',
        config: {
          channels: 1,
          mode: 3 /* means MONO*/ ,
          samplerate: 22050,
          bitrate: 64,
          insamplerate: sampleRate
        }
      });

    }

    this.stop = function() {

      if (!recording)
        return;

      recordWavWorker.postMessage({
        command: 'finish'
      });

      encoderMp3Worker.postMessage({
        command: 'finish'
      });

      recording = false;

    }

    encoderMp3Worker.onmessage = function(e) {

      var command = e.data.command;

      console.log('encoderMp3Worker - onmessage: ' + command);

      switch (command) {
        case 'data':
          var buf = e.data.buf;
          console.log('Receiving data from mp3-Encoder');

          //maybe you want to send to websocket channel, as:
          //https://github.com/akrennmair/speech-to-server

          break;
        case 'mp3':
          var buf = e.data.buf;
          endFile(buf, 'mp3');
          // Removed the terminate of the worker - terminate does not allow multiple recordings
          //encoderMp3Worker.terminate();
          //encoderMp3Worker = null;
          break;
      }

    };

    recordWavWorker.onmessage = function(e) {

      var command = e.data.command;

      console.log('recordWavWorker - onmessage: ' + command);

      switch (command) {
        case 'wav':
          endFile(e.data.buf, 'wav');
          break;
      }

    };

    function endFile(blob, extension) {

      console.log("Done converting to " + extension);
      log.innerHTML += "\n" + "Done converting to " + extension;

      console.log("the blob " + blob + " " + blob.size + " " + blob.type);

      var url = URL.createObjectURL(blob);
      var li = document.createElement('li');
      var hf = document.createElement('a');
      hf.href = url;
      hf.download = new Date().toISOString() + '.' + extension;
      hf.innerHTML = hf.download;
      li.appendChild(hf);

      var au = document.createElement('audio');
      au.controls = true;
      au.src = url;
      li.appendChild(au);

      // Upload file to server - uncomment below
      // uploadAudio(blob);
      // console.log("File uploaded");
      // log.innerHTML += "\n" + "File uploaded";

      recordingslist.appendChild(li);

    }

  };
    function uploadAudio(mp3Data){
        var reader = new FileReader();
        reader.onload = function(event){
            var fd = new FormData();
            var mp3Name = encodeURIComponent('audio_recording_' + new Date().getTime() + '.mp3');
            console.log("mp3name = " + mp3Name);
            fd.append('fname', mp3Name);
            fd.append('data', event.target.result);
            $.ajax({
                type: 'POST',
                url: 'upload.php',
                data: fd,
                processData: false,
                contentType: false
            }).done(function(data) {
                console.log('Upload.php');
            });
        };      
        reader.readAsDataURL(mp3Data);
    }
    
  window.Recorder = Recorder;

})(window);