<!DOCTYPE html>
<html>

<head>
  <script src="../resources/js-test.js"></script>
  <script src="resources/compatibility.js"></script>
  <script src="resources/audio-testing.js"></script>
  <script src="resources/audiobuffersource-testing.js"></script>
  <script src="resources/buffer-loader.js"></script>
</head>

<body>
  <script>
    description('AudioBufferSourceNode: oscillator-driven playbackRate modulation.');
    window.jsTestIsAsync = true;

    var sampleRate = 44100;
    var duration = 0.25;

    var context = new OfflineAudioContext(1, sampleRate * duration, sampleRate);
    var referenceBuffer;

    var audit = Audit.createTaskRunner();

    // Task: Load the reference file asynchronously. In order to create a new
    // reference file, use the task 'generate-reference' below.
    audit.defineTask('load-reference', function (done) {
      var loader = new BufferLoader(context, [
        'audiobuffersource-playbackrate-modulation-expected.wav'
        ], function (bufferList) {
          referenceBuffer = bufferList[0];
          done();
        });

      loader.load();
    });


    // Task: Render the actual buffer and compare with the reference.
    audit.defineTask('generate-verify', function (done) {
      
      // With this setting, the playback rate will be changing continuously and
      // repeatedly within the range of [0, 200] around 100Hz, based on the
      // input from the oscillator.
      createSawtoothWithModulation(context, 'playbackRate', 100, 100);

      context.startRendering().then(function (renderedBuffer) {
        var actual = renderedBuffer.getChannelData(0);
        var expected = referenceBuffer.getChannelData(0);

        // Compare two buffers with arbitrary (yet reasonable) constraints.
        // There parameters are determined by try bot experiments.
        compareBuffersWithConstraints(actual, expected, {
          thresholdSNR: 92.72,
          thresholdDiffULP: 0.985,
          thresholdDiffCount: 0,
          bitDepth: 16
        });

      }).then(done);
    });

    // Task: Create a new reference audio file. See .runTasks() below to run
    // this task.
    audit.defineTask('generate-reference', function (done) {
      if (!window.testRunner) {
        done();
        return;
      }

      // With this setting, the playback rate will be changing continuously and
      // repeatedly within the range of [0, 200] around 100Hz, based on the
      // input from the oscillator.
      createSawtoothWithModulation(context, 'playbackRate', 100, 100);

      // |finishAudioTest| will automatically create a reference audio file from
      // the OAC rendering if the reference file does not exist.
      context.oncomplete = finishAudioTest;
      context.startRendering();
      testRunner.waitUntilDone();

      done();
    });

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

    window.onload = function () {
      audit.runTasks(
        'load-reference',
        'generate-verify',
        'finish'
      );
    };

    // Use this task to generate a new reference audio file. Make sure to
    // comment out .runTasks() above before use this.
    // audit.runTasks('generate-reference');

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

</html>