web_toolset/web/js/recordmp3.js

(function(window){

    var WORKER_PATH = '/js/recorderWorker.js';
    var encoderWorker = new Worker('/js/mp3Worker.js');
  
    var Recorder = function(source, cfg){
      var config = cfg || {};
      var bufferLen = config.bufferLen || 4096;
      var numChannels = config.numChannels || 2;
      this.context = source.context;
      this.node = (this.context.createScriptProcessor ||
                   this.context.createJavaScriptNode).call(this.context,
                   bufferLen, numChannels, numChannels);
      var worker = new Worker(config.workerPath || WORKER_PATH);
      worker.postMessage({
        command: 'init',
        config: {
          sampleRate: this.context.sampleRate,
          numChannels: numChannels
        }
      });
      var recording = false,
        currCallback;
  
      this.node.onaudioprocess = function(e){
        if (!recording) return;
        var buffer = [];
        for (var channel = 0; channel < numChannels; channel++){
            buffer.push(e.inputBuffer.getChannelData(channel));
        }
        worker.postMessage({
          command: 'record',
          buffer: buffer
        });
      }
  
      this.configure = function(cfg){
        for (var prop in cfg){
          if (cfg.hasOwnProperty(prop)){
            config[prop] = cfg[prop];
          }
        }
      }
  
      this.record = function(){
        recording = true;
      }
  
      this.stop = function(){
        recording = false;
      }
  
      this.clear = function(){
        worker.postMessage({ command: 'clear' });
      }
  
      this.getBuffer = function(cb) {
        currCallback = cb || config.callback;
        worker.postMessage({ command: 'getBuffer' })
      }
  
      this.exportWAV = function(cb, type){
        currCallback = cb || config.callback;
        type = type || config.type || 'audio/wav';
        if (!currCallback) throw new Error('Callback not set');
        worker.postMessage({
          command: 'exportWAV',
          type: type
        });
      }
  
      //Mp3 conversion
      worker.onmessage = function(e){
        var blob = e.data;
        //console.log("the blob " +  blob + " " + blob.size + " " + blob.type);
  
        var arrayBuffer;
        var fileReader = new FileReader();
  
        fileReader.onload = function(){
          arrayBuffer = this.result;
          var buffer = new Uint8Array(arrayBuffer),
          data = parseWav(buffer);
  
          console.log(data);
          console.log("Converting to Mp3");
          //log.innerHTML += "\n" + "Converting to Mp3";
  
          encoderWorker.postMessage({ cmd: 'init', config:{
              mode : 3,
              channels:1,
              samplerate: data.sampleRate,
              bitrate: data.bitsPerSample
          }});
  
          encoderWorker.postMessage({ cmd: 'encode', buf: Uint8ArrayToFloat32Array(data.samples) });
          encoderWorker.postMessage({ cmd: 'finish'});
          encoderWorker.onmessage = function(e) {
              if (e.data.cmd == 'data') {
  
                  console.log("Done converting to Mp3");
                  //log.innerHTML += "\n" + "Done converting to Mp3";
  
                  /*var audio = new Audio();
                  audio.src = 'data:audio/mp3;base64,'+encode64(e.data.buf);
                  audio.play();*/
  
                  //console.log ("The Mp3 data " + e.data.buf);
  
                  var mp3Blob = new Blob([new Uint8Array(e.data.buf)], {type: 'audio/mp3'});
                  uploadAudio(mp3Blob);
  
                  var url = 'data:audio/mp3;base64,'+encode64(e.data.buf);
                  var li = document.createElement('li');
                  var au = document.createElement('audio');
                  var hf = document.createElement('a');
  
                  au.controls = true;
                  au.src = url;
                  hf.href = url;
                  hf.download = 'audio_recording_' + new Date().getTime() + '.mp3';
                  hf.innerHTML = hf.download;
                  li.appendChild(au);
                  li.appendChild(hf);
                  recordingslist.appendChild(li);
  
              }
          };
        };
  
        fileReader.readAsArrayBuffer(blob);
  
        currCallback(blob);
      }
  
  
      function encode64(buffer) {
          var binary = '',
              bytes = new Uint8Array( buffer ),
              len = bytes.byteLength;
  
          for (var i = 0; i < len; i++) {
              binary += String.fromCharCode( bytes[ i ] );
          }
          return window.btoa( binary );
      }
  
      function parseWav(wav) {
          function readInt(i, bytes) {
              var ret = 0,
                  shft = 0;
  
              while (bytes) {
                  ret += wav[i] << shft;
                  shft += 8;
                  i++;
                  bytes--;
              }
              return ret;
          }
          if (readInt(20, 2) != 1) throw 'Invalid compression code, not PCM';
          if (readInt(22, 2) != 1) throw 'Invalid number of channels, not 1';
          return {
              sampleRate: readInt(24, 4),
              bitsPerSample: readInt(34, 2),
              samples: wav.subarray(44)
          };
      }
  
      function Uint8ArrayToFloat32Array(u8a){
          var f32Buffer = new Float32Array(u8a.length);
          for (var i = 0; i < u8a.length; i++) {
              var value = u8a[i<<1] + (u8a[(i<<1)+1]<<8);
              if (value >= 0x8000) value |= ~0x7FFF;
              f32Buffer[i] = value / 0x8000;
          }
          return f32Buffer;
      }
  
      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(data);
                  log.innerHTML += "\n" + data;
              });
          };
          reader.readAsDataURL(mp3Data);
      }
  
      source.connect(this.node);
      this.node.connect(this.context.destination);    //this should not be necessary
    };
  
    /*Recorder.forceDownload = function(blob, filename){
      console.log("Force download");
      var url = (window.URL || window.webkitURL).createObjectURL(blob);
      var link = window.document.createElement('a');
      link.href = url;
      link.download = filename || 'output.wav';
      var click = document.createEvent("Event");
      click.initEvent("click", true, true);
      link.dispatchEvent(click);
    }*/
  
    window.Recorder = Recorder;
  
  })(window);