Merged in feature/SEREC-30 (pull request #9)

[SEREC-30] Generating Blob object form recorded audio

README.markdown

@@ -175,6 +175,11 @@ Recorder JS Interface
 
 * name - of the recording
 
+**getBlob**: returns WAV data of recording in form of [Blob](https://developer.mozilla.org/en-US/docs/Web/API/Blob)
+object which can be used to send recorded audio to server (via JavaScript) or save on user's local drive
+
+* name - of the recording
+
 *Returns number of seconds as float. For paused recording returns pause position, for stopped recording returns 0.*
 
 **observeLevel**: starts dispatching `microphone_level` events

html/js/recorder.js

@@ -2,6 +2,8 @@
 (function(global) {
   var Recorder;
 
+  var RECORDED_AUDIO_TYPE = "audio/wav";
+
   Recorder = {
     recorder: null,
     recorderOriginalWidth: 0,
@@ -90,7 +92,12 @@
 
     getBase64: function(name) {
       var data = Recorder.recorder.getBase64(name);
-      return 'data:audio/wav;base64,' + data;
+      return 'data:' + RECORDED_AUDIO_TYPE + ';base64,' + data;
+    },
+
+    getBlob: function(name) {
+      var base64Data = Recorder.getBase64(name).split(',')[1];
+      return base64toBlob(base64Data, RECORDED_AUDIO_TYPE);
     },
 
     getCurrentTime: function(name) {
@@ -157,6 +164,29 @@
     }
   };
 
+  function base64toBlob(b64Data, contentType, sliceSize) {
+    contentType = contentType || '';
+    sliceSize = sliceSize || 512;
+
+    var byteCharacters = atob(b64Data);
+    var byteArrays = [];
+
+    for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
+      var slice = byteCharacters.slice(offset, offset + sliceSize);
+
+      var byteNumbers = new Array(slice.length);
+      for (var i = 0; i < slice.length; i++) {
+        byteNumbers[i] = slice.charCodeAt(i);
+      }
+
+      var byteArray = new Uint8Array(byteNumbers);
+      byteArrays.push(byteArray);
+    }
+
+    return new Blob(byteArrays, {type: contentType});
+  }
+
+
   global.FWRecorder = Recorder;