<!DOCTYPE html>
<html>

<head>
  <title>Test AudioBufferSourceNode looping without explicit duration</title>
  <script src="../resources/js-test.js"></script>
  <script src="resources/compatibility.js"></script>
  <script src="resources/audio-testing.js"></script>
</head>

<body>
  <script>
    description("Test AudioBufferSourceNode looping without explicit duration");
    window.jsTestIsAsync = true;

    // Reasonably low sample rate for the optimum test speed.
    var sampleRate = 4096;

    var audit = Audit.createTaskRunner();

    // Task: create a short linear ramp and enable looping.  The test will
    // verify that the ramp was looped the appropriate number of times.
    audit.defineTask('loop-count', function (done) {
      // How many loops of the source we want to render. Any whole number
      // greater than 1 will work.
      var loopCount = 4;
      var sourceFrames = 8;
      var renderFrames = sourceFrames * loopCount;

      var context = new OfflineAudioContext(1, renderFrames, sampleRate);
      var source = context.createBufferSource();
      var linearRampBuffer = createLinearRampBuffer(context, sourceFrames);

      source.buffer = linearRampBuffer;
      source.connect(context.destination);

      // Enable looping and start the source with an offset, but without a
      // duration.  In this case, the source should loop "forever".
      // See crbug.com/457009.
      source.loop = true;
      source.start(0, 0);

      context.startRendering().then(function (renderedBuffer) {
        var badIndex = -1;
        var success = true;

        var actual = renderedBuffer.getChannelData(0);
        var linearRamp = linearRampBuffer.getChannelData(0);

        // Manually create a |loopCount| copies of linear ramps.
        var expected = new Float32Array(linearRamp.length * loopCount);
        for (var i = 0; i < loopCount; i++)
          expected.set(linearRamp, linearRamp.length * i);

        // The actual output should match the created loop.
        Should('The output of actual and expected loops', actual)
          .beEqualToArray(expected);
      }).then(done);
    });

    // Task: Test that looping an AudioBufferSource works correctly if the
    // source is started and the buffer is assigned later, but before the source
    // would start.
    audit.defineTask('delayed-start', function (done) {
      var renderDuration = 2;
      var context = new OfflineAudioContext(2, sampleRate * renderDuration, sampleRate);
      var linearRampBuffer = createLinearRampBuffer(context, 128);

      var normal = context.createBufferSource();
      var delayed = context.createBufferSource();
      var merger = context.createChannelMerger(2);

      // Connect the normally started source to the left channel, and the
      // delayed to the right channel.
      normal.connect(merger, 0, 0);
      delayed.connect(merger, 0, 1);
      merger.connect(context.destination);

      normal.buffer = linearRampBuffer;
      normal.loop = true;
      delayed.loop = true;

      normal.start(1, 0);
      delayed.start(1, 0);

      // Assign the buffer to the delayed source node at 0.5 second.
      context.suspend(0.5).then(function () {
        delayed.buffer = linearRampBuffer;
        context.resume();
      });

      context.startRendering().then(function (buffer) {
        // The left and right channel must match regardless of the timing
        // of buffer assignment.
        Should('The content of the left and right channel',
          buffer.getChannelData(0)).beEqualToArray(buffer.getChannelData(1));
      }).then(done);
    });

    audit.defineTask('finish', function (done) {
      finishJSTest();
      done();
    });

    audit.runTasks(
      'loop-count',
      'delayed-start',
      'finish'
    );

    successfullyParsed = true;
  </script>
</body>

</html>