1 files changed, 25 insertions, 1 deletions
diff --git a/client/lib/util.js b/client/lib/util.js
index 31c3d3a..e47b343 100644
--- a/client/lib/util.js
+++ b/client/lib/util.js
@@ -54,6 +54,30 @@ function requestAudioContext (fn) {
 	}
 }
 
+function dataURItoBlob(dataURI) {
+  // convert base64 to raw binary data held in a string
+  // doesn't handle URLEncoded DataURIs - see SO answer #6850276 for code that does this
+  var byteString = atob(dataURI.split(',')[1]);
+
+  // separate out the mime component
+  var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0]
+
+  // write the bytes of the string to an ArrayBuffer
+  var ab = new ArrayBuffer(byteString.length);
+
+  // create a view into the buffer
+  var ia = new Uint8Array(ab);
+
+  // set the bytes of the buffer to the correct values
+  for (var i = 0; i < byteString.length; i++) {
+      ia[i] = byteString.charCodeAt(i);
+  }
+
+  // write the ArrayBuffer to a blob, and you're done
+  var blob = new Blob([ab], {type: mimeString});
+  return blob;
+
+}
 function ftom(f) {
   // return (Math.log(f) - Math.log(261.626)) / Math.log(2) + 4.0
   return 69 + 12 * Math.log2(f / 440)
@@ -68,5 +92,5 @@ function tap (fn) {
   }
 }
 
-export { choice, mod, browser, requestAudioContext, ftom, mtof, tap }
+export { choice, mod, browser, requestAudioContext, ftom, mtof, tap, dataURItoBlob }