Simple ID3 parsing test

Create a test file for metadata streams and add a basic test for parsing an ID3 tag. The parser is not implemented yet so this test fails.

+(function(window, videojs, undefined) {
+  'use strict';
+  /*
+    ======== A Handy Little QUnit Reference ========
+    http://api.qunitjs.com/
+
+    Test methods:
+    module(name, {[setup][ ,teardown]})
+    test(name, callback)
+    expect(numberOfAssertions)
+    stop(increment)
+    start(decrement)
+    Test assertions:
+    ok(value, [message])
+    equal(actual, expected, [message])
+    notEqual(actual, expected, [message])
+    deepEqual(actual, expected, [message])
+    notDeepEqual(actual, expected, [message])
+    strictEqual(actual, expected, [message])
+    notStrictEqual(actual, expected, [message])
+    throws(block, [expected], [message])
+  */
+
+  var metadataStream, stringToInts, stringToCString, id3Frame;
+
+  module('MetadataStream', {
+    setup: function() {
+      // metadataStream = new videojs.Hls.MetadataStream();
+    }
+  });
+
+  test('can construct a MetadataStream', function() {
+    ok(metadataStream, 'does not return null');
+  });
+
+  stringToInts = function(string) {
+    var result = [], i;
+    for (i = 0; i < string.length; i++) {
+      result[i] = string.charCodeAt(i);
+    }
+    return result;
+  };
+
+  stringToCString = function(string) {
+    return stringToInts(string).concat([0x00]);
+  };
+
+  id3Frame = function(type) {
+    var result = stringToInts(type).concat([
+      0x00, 0x00, 0x00, 0x00, // size
+      0xe0, 0x00 // flags. tag/file alter preservation, read-only
+    ]),
+        size = result.length - 10;
+
+    // append the fields of the ID3 frame
+    result.concat(Array.prototype.slice.call(arguments, 1));
+
+    // set the size
+    size = result.length - 10;
+    result[0] = (size >>> 24);
+    result[1] = (size >>> 16) & 0xff;
+    result[2] = (size >>>  8) & 0xff;
+    result[3] = (size)        & 0xff;
+
+    return result;
+  };
+
+  test('parses simple ID3 metadata out of PES packets', function() {
+    var events = [], id3Bytes, size;
+    // metadataStream.on('data', function(event) {
+    //   events.push(event);
+    // });
+
+    id3Bytes = new Uint8Array(stringToInts('ID3').concat([
+      0x03, 0x00,            // version 3.0 of ID3v2 (aka ID3v.2.3.0)
+      0x40,                  // flags. include an extended header
+      0x00, 0x00, 0x00, 0x00, // size. set later
+
+      // extended header
+      0x00, 0x00, 0x00, 0x01, // extended header size
+      0x00, 0x00,             // extended flags
+      0x00, 0x00, 0x00, 0x02, // size of padding
+      0xff                    // extended header payload
+
+      // frame 0
+      // http://id3.org/id3v2.3.0#User_defined_text_information_frame
+    ], id3Frame('WXXX',
+                [0x00], // text encoding. ISO-8859-1
+                stringToCString('ad tag URL'), // description
+                stringToInts('http://example.com/ad?v=1234&q=7')), // value
+    // frame 1
+    // custom tag
+    id3Frame('XINF',
+             [
+               0x04, 0x03, 0x02, 0x01 // arbitrary data
+             ]), [
+               0x00, 0x00             // padding
+             ]));
+
+    // set header size field
+    size = id3Bytes.byteLength - 10;
+    id3Bytes[6] = (size >>> 21) & 0xef;
+    id3Bytes[7] = (size >>> 14) & 0xef;
+    id3Bytes[8] = (size >>>  7) & 0xef;
+    id3Bytes[9] = (size)        & 0xef;
+
+    metadataStream.push({
+      trackId: 7,
+      pts: 1000,
+      dts: 1000,
+
+      // header
+      data: id3Bytes
+    });
+
+    equal(events.length, 1, 'parsed one tag');
+    equal(events[0].frames.length, 2, 'parsed two frames');
+    equal(events[0].frames[0].id, 'WXXX', 'parsed a WXXX frame');
+    equal(events[0].frames[1].id, 'XINF', 'parsed a user-defined frame');
+  });
+
+  // missing cases:
+  // unsynchronization
+  // CRC
+  // no extended header
+  // compressed frames
+  // encrypted frames
+  // frame groups
+
+})(window, videojs);

@@ -55,6 +55,7 @@
   <script src="h264-stream_test.js"></script>
   <script src="exp-golomb_test.js"></script>
   <script src="flv-tag_test.js"></script>
+  <script src="metadata-stream_test.js"></script>
   <script src="m3u8_test.js"></script>
   <script src="playlist-loader_test.js"></script>
   <script src="decrypter_test.js"></script>