media-source/mediasource-append-buffer.html - external/w3c/web-platform-tests - Git at Google

 <!DOCTYPE html>
 <!-- Copyright © 2016 Chromium authors and World Wide Web Consortium, (Massachusetts Institute of Technology, ERCIM, Keio University, Beihang). -->
 <html>
  <head>
  <title>SourceBuffer.appendBuffer() test cases</title>
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <script src="mediasource-util.js"></script>
  </head>
  <body>
  <div id="log"></div>
  <script>
  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test SourceBuffer.appendBuffer() event dispatching.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  assert_throws("InvalidStateError",
  function() { sourceBuffer.appendBuffer(mediaData); },
  "appendBuffer() throws an exception there is a pending append.");

  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test SourceBuffer.appendBuffer() call during a pending appendBuffer().");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "abort", "Append aborted.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  sourceBuffer.abort();

  assert_false(sourceBuffer.updating, "updating attribute is false");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test SourceBuffer.abort() call during a pending appendBuffer().");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);
  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");

  test.expectEvent(mediaSource, "sourceended", "MediaSource sourceended event");
  mediaSource.endOfStream();
  assert_equals(mediaSource.readyState, "ended", "MediaSource readyState is 'ended'");
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "ended", "MediaSource readyState is 'ended'");

  test.expectEvent(mediaSource, "sourceopen", "MediaSource sourceopen event");
  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_equals(mediaSource.readyState, "open", "MediaSource readyState is 'open'");
  assert_true(sourceBuffer.updating, "updating attribute is true");
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "open", "MediaSource readyState is 'open'");
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test SourceBuffer.appendBuffer() triggering an 'ended' to 'open' transition.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);
  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");

  test.expectEvent(mediaSource, "sourceended", "MediaSource sourceended event");
  mediaSource.endOfStream();
  assert_equals(mediaSource.readyState, "ended", "MediaSource readyState is 'ended'");
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "ended", "MediaSource readyState is 'ended'");

  test.expectEvent(mediaSource, "sourceopen", "MediaSource sourceopen event");
  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(new Uint8Array(0));

  assert_equals(mediaSource.readyState, "open", "MediaSource readyState is 'open'");
  assert_true(sourceBuffer.updating, "updating attribute is true");
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "open", "MediaSource readyState is 'open'");
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test zero byte SourceBuffer.appendBuffer() call triggering an 'ended' to 'open' transition.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "abort", "Append aborted.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");
  assert_equals(mediaSource.activeSourceBuffers.length, 0, "activeSourceBuffers.length");

  test.expectEvent(mediaSource.sourceBuffers, "removesourcebuffer", "sourceBuffers");
  mediaSource.removeSourceBuffer(sourceBuffer);

  assert_false(sourceBuffer.updating, "updating attribute is false");

  assert_throws("InvalidStateError",
  function() { sourceBuffer.appendBuffer(mediaData); },
  "appendBuffer() throws an exception because it isn't attached to the mediaSource anymore.");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test MediaSource.removeSourceBuffer() call during a pending appendBuffer().");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  assert_throws("InvalidStateError",
  function() { mediaSource.duration = 1.0; },
  "set duration throws an exception when updating attribute is true.");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test set MediaSource.duration during a pending appendBuffer() for one of its SourceBuffers.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener("error", test.unreached_func("Unexpected event 'error'"));
  mediaSource.addEventListener("sourceended", test.unreached_func("Unexpected event 'sourceended'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  assert_throws("InvalidStateError",
  function() { mediaSource.endOfStream(); },
  "endOfStream() throws an exception when updating attribute is true.");

  assert_equals(mediaSource.readyState, "open");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  assert_equals(mediaSource.readyState, "open");
  test.done();
  });
  }, "Test MediaSource.endOfStream() during a pending appendBuffer() for one of its SourceBuffers.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaElement.addEventListener('error', test.unreached_func("Unexpected event 'error'"));

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(mediaData);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  assert_throws("InvalidStateError",
  function() { sourceBuffer.timestampOffset = 10.0; },
  "set timestampOffset throws an exception when updating attribute is true.");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test set SourceBuffer.timestampOffset during a pending appendBuffer().");

  mediasource_test(function(test, mediaElement, mediaSource)
  {
  var sourceBuffer = mediaSource.addSourceBuffer(MediaSourceUtil.VIDEO_ONLY_TYPE);

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(new Uint8Array(0));

  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test appending an empty ArrayBufferView.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");

  var arrayBufferView = new Uint8Array(mediaData);

  assert_equals(arrayBufferView.length, mediaData.length, "arrayBufferView.length before transfer.");

  // Send the buffer as in a message so it gets neutered.
  window.postMessage( "test", "*", [arrayBufferView.buffer]);

  assert_equals(arrayBufferView.length, 0, "arrayBufferView.length after transfer.");

  sourceBuffer.appendBuffer(arrayBufferView);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test appending a neutered ArrayBufferView.");

  mediasource_test(function(test, mediaElement, mediaSource)
  {
  var sourceBuffer = mediaSource.addSourceBuffer(MediaSourceUtil.VIDEO_ONLY_TYPE);

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendBuffer(new ArrayBuffer(0));

  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test appending an empty ArrayBuffer.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");

  var arrayBuffer = mediaData.buffer.slice(0);

  assert_equals(arrayBuffer.byteLength, mediaData.buffer.byteLength, "arrayBuffer.byteLength before transfer.");

  // Send the buffer as in a message so it gets neutered.
  window.postMessage( "test", "*", [arrayBuffer]);

  assert_equals(arrayBuffer.byteLength, 0, "arrayBuffer.byteLength after transfer.");

  sourceBuffer.appendBuffer(arrayBuffer);

  assert_true(sourceBuffer.updating, "updating attribute is true");

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  test.done();
  });
  }, "Test appending a neutered ArrayBuffer.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  var initSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.init);
  var halfIndex = (initSegment.length + 1) / 2;
  var partialInitSegment = initSegment.subarray(0, halfIndex);
  var remainingInitSegment = initSegment.subarray(halfIndex);
  var mediaSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.media[0]);

  test.expectEvent(sourceBuffer, "updateend", "partialInitSegment append ended.");
  sourceBuffer.appendBuffer(partialInitSegment);

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaElement.readyState, mediaElement.HAVE_NOTHING);
  assert_equals(mediaSource.duration, Number.NaN);
  test.expectEvent(sourceBuffer, "updateend", "remainingInitSegment append ended.");
  test.expectEvent(mediaElement, "loadedmetadata", "loadedmetadata event received.");
  sourceBuffer.appendBuffer(remainingInitSegment);
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaElement.readyState, mediaElement.HAVE_METADATA);
  assert_equals(mediaSource.duration, segmentInfo.duration);
  test.expectEvent(sourceBuffer, "updateend", "mediaSegment append ended.");
  test.expectEvent(mediaElement, "loadeddata", "loadeddata fired.");
  sourceBuffer.appendBuffer(mediaSegment);
  });

  test.waitForExpectedEvents(function()
  {
  assert_greater_than_equal(mediaElement.readyState, mediaElement.HAVE_CURRENT_DATA);
  assert_equals(sourceBuffer.updating, false);
  assert_equals(mediaSource.readyState, "open");
  test.done();
  });
  }, "Test appendBuffer with partial init segments.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  var initSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.init);
  var mediaSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.media[0]);
  var halfIndex = (mediaSegment.length + 1) / 2;
  var partialMediaSegment = mediaSegment.subarray(0, halfIndex);
  var remainingMediaSegment = mediaSegment.subarray(halfIndex);

  test.expectEvent(sourceBuffer, "updateend", "InitSegment append ended.");
  test.expectEvent(mediaElement, "loadedmetadata", "loadedmetadata done.");
  sourceBuffer.appendBuffer(initSegment);

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaElement.readyState, mediaElement.HAVE_METADATA);
  assert_equals(mediaSource.duration, segmentInfo.duration);
  test.expectEvent(sourceBuffer, "updateend", "partial media segment append ended.");
  sourceBuffer.appendBuffer(partialMediaSegment);
  });

  test.waitForExpectedEvents(function()
  {
  test.expectEvent(sourceBuffer, "updateend", "mediaSegment append ended.");
  test.expectEvent(mediaElement, "loadeddata", "loadeddata fired.");
  sourceBuffer.appendBuffer(remainingMediaSegment);
  });

  test.waitForExpectedEvents(function()
  {
  assert_greater_than_equal(mediaElement.readyState, mediaElement.HAVE_CURRENT_DATA);
  assert_equals(mediaSource.readyState, "open");
  assert_equals(sourceBuffer.updating, false);
  test.done();
  });
  }, "Test appendBuffer with partial media segments.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  var initSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.init);
  var mediaSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.media[0]);

  assert_equals(mediaElement.readyState, mediaElement.HAVE_NOTHING);
  assert_equals(mediaSource.duration, Number.NaN);

  // readyState is changing as per the Initialization Segment Received algorithm.
  var loadedmetadataCalled = false;
  mediaElement.addEventListener("loadedmetadata", function metadata(e) {
  loadedmetadataCalled = true;
  e.target.removeEventListener(e.type, metadata);
  });
  sourceBuffer.addEventListener("updateend", test.step_func(function updateend(e) {
  assert_true(loadedmetadataCalled);
  assert_equals(mediaElement.readyState, mediaElement.HAVE_METADATA);
  e.target.removeEventListener(e.type, updateend);
  }));
  test.expectEvent(sourceBuffer, "updateend", "remainingInitSegment append ended.");
  test.expectEvent(mediaElement, "loadedmetadata", "loadedmetadata event received.");
  sourceBuffer.appendBuffer(initSegment);

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaElement.readyState, mediaElement.HAVE_METADATA);
  assert_equals(mediaSource.duration, segmentInfo.duration);
  // readyState is changing as per the Coded Frame Processing algorithm.
  var loadeddataCalled = false;
  mediaElement.addEventListener("loadeddata", function loadeddata(e) {
  loadeddataCalled = true;
  e.target.removeEventListener(e.type, loadeddata);
  });
  sourceBuffer.addEventListener("updateend", test.step_func(function updateend(e) {
  assert_true(loadeddataCalled);
  assert_greater_than_equal(mediaElement.readyState, mediaElement.HAVE_CURRENT_DATA);
  e.target.removeEventListener(e.type, updateend);
  }));
  test.expectEvent(sourceBuffer, "updateend", "mediaSegment append ended.");
  test.expectEvent(mediaElement, "loadeddata", "loadeddata fired.");
  sourceBuffer.appendBuffer(mediaSegment);
  });

  test.waitForExpectedEvents(function()
  {
  assert_greater_than_equal(mediaElement.readyState, mediaElement.HAVE_CURRENT_DATA);
  assert_equals(sourceBuffer.updating, false);
  assert_equals(mediaSource.readyState, "open");
  test.done();
  });
  }, "Test appendBuffer events order.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  var initSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.init);
  var partialInitSegment = initSegment.subarray(0, initSegment.length / 2);
  var mediaSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.media[0]);

  test.expectEvent(sourceBuffer, "updateend", "partialInitSegment append ended.");
  sourceBuffer.appendBuffer(partialInitSegment);

  test.waitForExpectedEvents(function()
  {
  // Call abort to reset the parser.
  sourceBuffer.abort();

  // Append the full intiialization segment.
  test.expectEvent(sourceBuffer, "updateend", "initSegment append ended.");
  sourceBuffer.appendBuffer(initSegment);
  });

  test.waitForExpectedEvents(function()
  {
  test.expectEvent(sourceBuffer, "updateend", "mediaSegment append ended.");
  test.expectEvent(mediaElement, "loadeddata", "loadeddata fired.");
  sourceBuffer.appendBuffer(mediaSegment);
  });

  test.waitForExpectedEvents(function()
  {
  test.done();
  });
  }, "Test abort in the middle of an initialization segment.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  test.expectEvent(mediaSource.sourceBuffers, "removesourcebuffer", "SourceBuffer removed.");
  mediaSource.removeSourceBuffer(sourceBuffer);
  test.waitForExpectedEvents(function()
  {
  assert_throws("InvalidStateError",
  function() { sourceBuffer.abort(); },
  "sourceBuffer.abort() throws an exception for InvalidStateError.");

  test.done();
  });
  }, "Test abort after removing sourcebuffer.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  var initSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.init);
  var mediaSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.media[0]);

  test.expectEvent(sourceBuffer, "updateend", "initSegment append ended.");
  sourceBuffer.appendBuffer(initSegment);

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "open", "readyState is open after init segment appended.");
  test.expectEvent(sourceBuffer, "updateend", "mediaSegment append ended.");
  sourceBuffer.appendBuffer(mediaSegment);
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(sourceBuffer.buffered.length, 1, "sourceBuffer has a buffered range");
  assert_equals(mediaSource.readyState, "open", "readyState is open after media segment appended.");
  test.expectEvent(mediaSource, "sourceended", "source ended");
  mediaSource.endOfStream();
  });

  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "ended", "readyState is ended.");
  assert_throws("InvalidStateError",
  function() { sourceBuffer.abort(); },
  "sourceBuffer.abort() throws an exception for InvalidStateError.");
  test.done();
  });

  }, "Test abort after readyState is ended following init segment and media segment.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");
  sourceBuffer.appendWindowStart = 1;
  sourceBuffer.appendWindowEnd = 100;
  sourceBuffer.appendBuffer(mediaData);

  test.waitForExpectedEvents(function()
  {
  assert_false(sourceBuffer.updating, "updating attribute is false");
  sourceBuffer.abort();
  assert_equals(sourceBuffer.appendWindowStart, 0, "appendWindowStart is reset to 0");
  assert_equals(sourceBuffer.appendWindowEnd, Number.POSITIVE_INFINITY,
  "appendWindowEnd is reset to +INFINITY");
  test.done();
  });
  }, "Test abort after appendBuffer update ends.");

  mediasource_test(function(test, mediaElement, mediaSource)
  {
  var sourceBuffer = mediaSource.addSourceBuffer(MediaSourceUtil.VIDEO_ONLY_TYPE);

  test.expectEvent(sourceBuffer, "updatestart", "Append started.");
  test.expectEvent(sourceBuffer, "update", "Append success.");
  test.expectEvent(sourceBuffer, "updateend", "Append ended.");

  assert_throws( { name: "TypeError"} ,
  function() { sourceBuffer.appendBuffer(null); },
  "appendBuffer(null) throws an exception.");
  test.done();
  }, "Test appending null.");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  mediaSource.removeSourceBuffer(sourceBuffer);

  assert_throws( { name: "InvalidStateError"} ,
  function() { sourceBuffer.appendBuffer(mediaData); },
  "appendBuffer() throws an exception when called after removeSourceBuffer().");
  test.done();
  }, "Test appending after removeSourceBuffer().");

  mediasource_testafterdataloaded(function(test, mediaElement, mediaSource, segmentInfo, sourceBuffer, mediaData)
  {
  // Media elements using MSE should not fire the stalled event. See discussion at
  // https://github.com/w3c/media-source/issues/88#issuecomment-374406928
  mediaElement.addEventListener("stalled", test.unreached_func("Unexpected 'stalled' event."));

  // Prime the media element with initial appends.
  var initSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.init);
  var mediaSegment = MediaSourceUtil.extractSegmentData(mediaData, segmentInfo.media[0]);
  test.expectEvent(sourceBuffer, "updateend", "initSegment append ended.");
  sourceBuffer.appendBuffer(initSegment);
  test.waitForExpectedEvents(function()
  {
  assert_equals(mediaSource.readyState, "open", "readyState is open after init segment appended.");
  test.expectEvent(sourceBuffer, "updateend", "mediaSegment append ended.");
  sourceBuffer.appendBuffer(mediaSegment);
  });

  // Verify state and wait for the 'stalled' event.
  test.waitForExpectedEvents(function()
  {
  assert_equals(sourceBuffer.buffered.length, 1, "sourceBuffer has a buffered range");
  assert_equals(mediaSource.readyState, "open", "readyState is open after media segment appended.");

  // Set timeout to 4 seconds. This creates an opportunity for UAs to _improperly_ fire the stalled event.
  // For media elements doing progressive download (not MSE), stalled is thrown after ~3 seconds of the
  // download failing to progress.
  test.step_timeout(function() { test.done(); }, 4000);
  });
  }, "Test slow appending does not trigger stalled events.");

  </script>
  </body>
 </html>