Properly parse the IV in m3u8 AES-128 encryption method, and actually use it to decrypt if present

@@ -305,6 +305,9 @@
         event.attributes = parseAttributes(match[1]);
         // parse the IV string into a Uint32Array
         if (event.attributes.IV) {
+          if (event.attributes.IV.substring(0,2) == '0x')
+            event.attributes.IV = event.attributes.IV.substring(2);
+
           event.attributes.IV = event.attributes.IV.match(/.{8}/g);
           event.attributes.IV[0] = parseInt(event.attributes.IV[0], 16);
           event.attributes.IV[1] = parseInt(event.attributes.IV[1], 16);
@@ -436,7 +439,8 @@
               // setup an encryption key for upcoming segments
               key = {
                 method: entry.attributes.METHOD || 'AES-128',
-                uri: entry.attributes.URI
+                uri: entry.attributes.URI,
+                iv: entry.attributes.IV || null
               };
             },
             'media-sequence': function() {

@@ -704,11 +704,13 @@ videojs.Hls.prototype.drainBuffer = function(event) {
     } else {
       // if the media sequence is greater than 2^32, the IV will be incorrect
       // assuming 10s segments, that would be about 1300 years
+      var theIv = segment.key.iv;
+      if (theIv === null) {
+        theIv = new Uint32Array([0, 0, 0, mediaIndex + playlist.mediaSequence]);
+      }
       bytes = videojs.Hls.decrypt(bytes,
                                   segment.key.bytes,
-                                  new Uint32Array([
-                                    0, 0, 0,
-                                    mediaIndex + playlist.mediaSequence]));
+                                  theIv);
     }
   }