summaryrefslogtreecommitdiffstats
path: root/testing/web-platform/tests/webcodecs/videoDecoder-codec-specific.https.any.js
blob: 1c3b8f120dbf8843d6cb61d9b82812a2ced04631 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
// META: global=window,dedicatedworker
// META: variant=?av1
// META: variant=?vp8
// META: variant=?vp9
// META: variant=?h264_avc
// META: variant=?h264_annexb
// META: variant=?h265_hevc
// META: variant=?h265_annexb

const AV1_DATA = {
  src: 'av1.mp4',
  config: {
    codec: 'av01.0.04M.08',
    codedWidth: 320,
    codedHeight: 240,
    visibleRect: {x: 0, y: 0, width: 320, height: 240},
    displayWidth: 320,
    displayHeight: 240,
  },
  chunks: [
    {offset: 48, size: 1938}, {offset: 1986, size: 848},
    {offset: 2834, size: 3}, {offset: 2837, size: 47}, {offset: 2884, size: 3},
    {offset: 2887, size: 116}, {offset: 3003, size: 3},
    {offset: 3006, size: 51}, {offset: 3057, size: 25},
    {offset: 3082, size: 105}
  ]
};

const VP8_DATA = {
  src: 'vp8.webm',
  config: {
    codec: 'vp8',
    codedWidth: 320,
    codedHeight: 240,
    visibleRect: {x: 0, y: 0, width: 320, height: 240},
    displayWidth: 320,
    displayHeight: 240,
  },
  chunks: [
    {offset: 522, size: 4826}, {offset: 5355, size: 394},
    {offset: 5756, size: 621}, {offset: 6384, size: 424},
    {offset: 6815, size: 532}, {offset: 7354, size: 655},
    {offset: 8016, size: 670}, {offset: 8693, size: 2413},
    {offset: 11113, size: 402}, {offset: 11522, size: 686}
  ]
};

const VP9_DATA = {
  src: 'vp9.mp4',
  // TODO(sandersd): Verify that the file is actually level 1.
  config: {
    codec: 'vp09.00.10.08',
    codedWidth: 320,
    codedHeight: 240,
    displayAspectWidth: 320,
    displayAspectHeight: 240,
  },
  chunks: [
    {offset: 44, size: 3315}, {offset: 3359, size: 203},
    {offset: 3562, size: 245}, {offset: 3807, size: 172},
    {offset: 3979, size: 312}, {offset: 4291, size: 170},
    {offset: 4461, size: 195}, {offset: 4656, size: 181},
    {offset: 4837, size: 356}, {offset: 5193, size: 159}
  ]
};

const H264_AVC_DATA = {
  src: 'h264.mp4',
  config: {
    codec: 'avc1.64000b',
    description: {offset: 9490, size: 45},
    codedWidth: 320,
    codedHeight: 240,
    displayAspectWidth: 320,
    displayAspectHeight: 240,
  },
  chunks: [
    {offset: 48, size: 4140}, {offset: 4188, size: 604},
    {offset: 4792, size: 475}, {offset: 5267, size: 561},
    {offset: 5828, size: 587}, {offset: 6415, size: 519},
    {offset: 6934, size: 532}, {offset: 7466, size: 523},
    {offset: 7989, size: 454}, {offset: 8443, size: 528}
  ]
};

const H264_ANNEXB_DATA = {
  src: 'h264.annexb',
  config: {
    codec: 'avc1.64000b',
    codedWidth: 320,
    codedHeight: 240,
    displayAspectWidth: 320,
    displayAspectHeight: 240,
  },
  chunks: [
    {offset: 0, size: 4175}, {offset: 4175, size: 602},
    {offset: 4777, size: 473}, {offset: 5250, size: 559},
    {offset: 5809, size: 585}, {offset: 6394, size: 517},
    {offset: 6911, size: 530}, {offset: 7441, size: 521},
    {offset: 7962, size: 452}, {offset: 8414, size: 526}
  ]
};

const H265_HEVC_DATA = {
  src: 'h265.mp4',
  config: {
    codec: 'hev1.1.6.L60.90',
    description: {offset: 5821, size: 2406},
    codedWidth: 320,
    codedHeight: 240,
    displayAspectWidth: 320,
    displayAspectHeight: 240,
  },
  chunks: [
    {offset: 44, size: 2515}, {offset: 2559, size: 279},
    {offset: 2838, size: 327}, {offset: 3165, size: 329},
    {offset: 3494, size: 308}, {offset: 3802, size: 292},
    {offset: 4094, size: 352}, {offset: 4446, size: 296},
    {offset: 4742, size: 216}, {offset: 4958, size: 344}
  ]
};

const H265_ANNEXB_DATA = {
  src: 'h265.annexb',
  config: {
    codec: 'hev1.1.6.L60.90',
    codedWidth: 320,
    codedHeight: 240,
    displayAspectWidth: 320,
    displayAspectHeight: 240,
  },
  chunks: [
    {offset: 0, size: 4894}, {offset: 4894, size: 279},
    {offset: 5173, size: 327}, {offset: 5500, size: 329},
    {offset: 5829, size: 308}, {offset: 6137, size: 292},
    {offset: 6429, size: 352}, {offset: 6781, size: 296},
    {offset: 7077, size: 216}, {offset: 7293, size: 344}
  ]
};

// Allows mutating `callbacks` after constructing the VideoDecoder, wraps calls
// in t.step().
function createVideoDecoder(t, callbacks) {
  return new VideoDecoder({
    output(frame) {
      if (callbacks && callbacks.output) {
        t.step(() => callbacks.output(frame));
      } else {
        t.unreached_func('unexpected output()');
      }
    },
    error(e) {
      if (callbacks && callbacks.error) {
        t.step(() => callbacks.error(e));
      } else {
        t.unreached_func('unexpected error()');
      }
    }
  });
}

function createCorruptChunk(index) {
  let bad_data = CHUNK_DATA[index];
  for (var i = 0; i < bad_data.byteLength; i += 4)
    bad_data[i] = 0xFF;
  return new EncodedVideoChunk(
      {type: 'delta', timestamp: index, data: bad_data});
}

// Create a view of an ArrayBuffer.
function view(buffer, {offset, size}) {
  return new Uint8Array(buffer, offset, size);
}

async function checkImplements() {
  // Don't run any tests if the codec is not supported.
  assert_equals("function", typeof VideoDecoder.isConfigSupported);
  let supported = false;
  try {
    // TODO(sandersd): To properly support H.264 in AVC format, this should
    // include the `description`. For now this test assumes that H.264 Annex B
    // support is the same as H.264 AVC support.
    const support =
        await VideoDecoder.isConfigSupported({codec: CONFIG.codec});
    supported = support.supported;
  } catch (e) {
  }
  assert_implements_optional(supported, CONFIG.codec + ' unsupported');
}

let CONFIG = null;
let CHUNK_DATA = null;
let CHUNKS = null;
promise_setup(async () => {
  const data = {
    '?av1': AV1_DATA,
    '?vp8': VP8_DATA,
    '?vp9': VP9_DATA,
    '?h264_avc': H264_AVC_DATA,
    '?h264_annexb': H264_ANNEXB_DATA,
    '?h265_hevc': H265_HEVC_DATA,
    '?h265_annexb': H265_ANNEXB_DATA
  }[location.search];

  // Fetch the media data and prepare buffers.
  const response = await fetch(data.src);
  const buf = await response.arrayBuffer();

  CONFIG = {...data.config};
  if (data.config.description) {
    CONFIG.description = view(buf, data.config.description);
  }

  CHUNK_DATA = data.chunks.map((chunk, i) => view(buf, chunk));

  CHUNKS = CHUNK_DATA.map(
      (data, i) => new EncodedVideoChunk(
          {type: i == 0 ? 'key' : 'delta', timestamp: i, duration: 1, data}));
});

promise_test(async t => {
  await checkImplements();
  const support = await VideoDecoder.isConfigSupported(CONFIG);
  assert_true(support.supported, 'supported');
}, 'Test isConfigSupported()');

promise_test(async t => {
  await checkImplements();
  // TODO(sandersd): Create a 1080p `description` for H.264 in AVC format.
  // This version is testing only the H.264 Annex B path.
  const config = {
    codec: CONFIG.codec,
    codedWidth: 1920,
    codedHeight: 1088,
    displayAspectWidth: 1920,
    displayAspectHeight: 1080,
  };

  const support = await VideoDecoder.isConfigSupported(config);
  assert_true(support.supported, 'supported');
}, 'Test isConfigSupported() with 1080p crop');

promise_test(async t => {
  await checkImplements();
  // Define a valid config that includes a hypothetical `futureConfigFeature`,
  // which is not yet recognized by the User Agent.
  const config = {
    ...CONFIG,
    colorSpace: {primaries: 'bt709'},
    futureConfigFeature: 'foo',
  };

  // The UA will evaluate validConfig as being "valid", ignoring the
  // `futureConfigFeature` it  doesn't recognize.
  const support = await VideoDecoder.isConfigSupported(config);
  assert_true(support.supported, 'supported');
  assert_equals(support.config.codec, config.codec, 'codec');
  assert_equals(support.config.codedWidth, config.codedWidth, 'codedWidth');
  assert_equals(support.config.codedHeight, config.codedHeight, 'codedHeight');
  assert_equals(support.config.displayAspectWidth, config.displayAspectWidth, 'displayAspectWidth');
  assert_equals(support.config.displayAspectHeight, config.displayAspectHeight, 'displayAspectHeight');
  assert_equals(support.config.colorSpace.primaries, config.colorSpace.primaries, 'color primaries');
  assert_equals(support.config.colorSpace.transfer, null, 'color transfer');
  assert_equals(support.config.colorSpace.matrix, null, 'color matrix');
  assert_equals(support.config.colorSpace.fullRange, null, 'color range');
  assert_false(support.config.hasOwnProperty('futureConfigFeature'), 'futureConfigFeature');

  if (config.description) {
    // The description must be copied.
    assert_false(
        support.config.description === config.description,
        'description is unique');
    assert_array_equals(
        new Uint8Array(support.config.description, 0),
        new Uint8Array(config.description, 0), 'description');
  } else {
    assert_false(support.config.hasOwnProperty('description'), 'description');
  }
}, 'Test that isConfigSupported() returns a parsed configuration');

promise_test(async t => {
  await checkImplements();
  async function test(t, config, description) {
    await promise_rejects_js(
        t, TypeError, VideoDecoder.isConfigSupported(config), description);

    const decoder = createVideoDecoder(t);
    assert_throws_js(TypeError, () => decoder.configure(config), description);
    assert_equals(decoder.state, 'unconfigured', 'state');
  }

  await test(t, {...CONFIG, codedWidth: 0}, 'invalid codedWidth');
  await test(t, {...CONFIG, displayAspectWidth: 0}, 'invalid displayAspectWidth');
}, 'Test invalid configs');

promise_test(async t => {
  await checkImplements();
  const decoder = createVideoDecoder(t);
  decoder.configure(CONFIG);
  assert_equals(decoder.state, 'configured', 'state');
}, 'Test configure()');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);
  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);

  let outputs = 0;
  callbacks.output = frame => {
    outputs++;
    assert_equals(frame.timestamp, CHUNKS[0].timestamp, 'timestamp');
    assert_equals(frame.duration, CHUNKS[0].duration, 'duration');
    frame.close();
  };

  await decoder.flush();
  assert_equals(outputs, 1, 'outputs');
}, 'Decode a key frame');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);
  decoder.configure(CONFIG);

  // Ensure type value is verified.
  assert_equals(CHUNKS[1].type, 'delta');
  assert_throws_dom('DataError', () => decoder.decode(CHUNKS[1], 'decode'));
}, 'Decode a non key frame first fails');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);
  decoder.configure(CONFIG);
  for (let i = 0; i < 16; i++) {
    decoder.decode(new EncodedVideoChunk(
        {type: 'key', timestamp: 0, data: CHUNK_DATA[0]}));
  }
  assert_greater_than(decoder.decodeQueueSize, 0);

  // Wait for the first output, then reset the decoder.
  let outputs = 0;
  await new Promise(resolve => {
    callbacks.output = frame => {
      outputs++;
      assert_equals(outputs, 1, 'outputs');
      assert_equals(frame.timestamp, 0, 'timestamp');
      frame.close();
      decoder.reset();
      assert_equals(decoder.decodeQueueSize, 0, 'decodeQueueSize');
      resolve();
    };
  });

  decoder.configure(CONFIG);
  for (let i = 0; i < 4; i++) {
    decoder.decode(new EncodedVideoChunk(
        {type: 'key', timestamp: 1, data: CHUNK_DATA[0]}));
  }

  // Expect future outputs to come from after the reset.
  callbacks.output = frame => {
    outputs++;
    assert_equals(frame.timestamp, 1, 'timestamp');
    frame.close();
  };

  await decoder.flush();
  assert_equals(outputs, 5);
  assert_equals(decoder.decodeQueueSize, 0);
}, 'Verify reset() suppresses outputs');

promise_test(async t => {
  await checkImplements();
  const decoder = createVideoDecoder(t);
  assert_equals(decoder.state, 'unconfigured');

  decoder.reset();
  assert_equals(decoder.state, 'unconfigured');
  assert_throws_dom(
      'InvalidStateError', () => decoder.decode(CHUNKS[0]), 'decode');
  await promise_rejects_dom(t, 'InvalidStateError', decoder.flush(), 'flush');
}, 'Test unconfigured VideoDecoder operations');

promise_test(async t => {
  await checkImplements();
  const decoder = createVideoDecoder(t);
  decoder.close();
  assert_equals(decoder.state, 'closed');
  assert_throws_dom(
      'InvalidStateError', () => decoder.configure(CONFIG), 'configure');
  assert_throws_dom('InvalidStateError', () => decoder.reset(), 'reset');
  assert_throws_dom('InvalidStateError', () => decoder.close(), 'close');
  assert_throws_dom(
      'InvalidStateError', () => decoder.decode(CHUNKS[0]), 'decode');
  await promise_rejects_dom(t, 'InvalidStateError', decoder.flush(), 'flush');
}, 'Test closed VideoDecoder operations');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};

  let errors = 0;
  let gotError = new Promise(resolve => callbacks.error = e => {
    errors++;
    resolve(e);
  });
  callbacks.output = frame => { frame.close(); };

  const decoder = createVideoDecoder(t, callbacks);
  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);  // Decode keyframe first.
  decoder.decode(new EncodedVideoChunk(
      {type: 'key', timestamp: 1, data: new ArrayBuffer(0)}));

  await promise_rejects_dom(t, "EncodingError",
    decoder.flush().catch((e) => {
      assert_equals(errors, 1);
      throw e;
    })
  );

  let e = await gotError;
  assert_true(e instanceof DOMException);
  assert_equals(e.name, 'EncodingError');
  assert_equals(decoder.state, 'closed', 'state');
}, 'Decode empty frame');


promise_test(async t => {
  await checkImplements();
  const callbacks = {};

  let errors = 0;
  let gotError = new Promise(resolve => callbacks.error = e => {
    errors++;
    resolve(e);
  });

  let outputs = 0;
  callbacks.output = frame => {
    outputs++;
    frame.close();
  };

  const decoder = createVideoDecoder(t, callbacks);
  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);  // Decode keyframe first.
  decoder.decode(createCorruptChunk(2));

  await promise_rejects_dom(t, "EncodingError",
    decoder.flush().catch((e) => {
      assert_equals(errors, 1);
      throw e;
    })
  );

  assert_less_than_equal(outputs, 1);
  let e = await gotError;
  assert_true(e instanceof DOMException);
  assert_equals(e.name, 'EncodingError');
  assert_equals(decoder.state, 'closed', 'state');
}, 'Decode corrupt frame');

promise_test(async t => {
  await checkImplements();
  const decoder = createVideoDecoder(t);

  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);  // Decode keyframe first.
  decoder.decode(createCorruptChunk(1));

  let flushDone = decoder.flush();
  decoder.close();

  // Flush should have been synchronously rejected, with no output() or error()
  // callbacks.
  await promise_rejects_dom(t, 'AbortError', flushDone);
}, 'Close while decoding corrupt frame');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);

  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);

  let outputs = 0;
  callbacks.output = frame => {
    outputs++;
    frame.close();
  };

  await decoder.flush();
  assert_equals(outputs, 1, 'outputs');

  decoder.decode(CHUNKS[0]);
  await decoder.flush();
  assert_equals(outputs, 2, 'outputs');
}, 'Test decoding after flush');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);

  decoder.configure(CONFIG);
  decoder.decode(new EncodedVideoChunk(
      {type: 'key', timestamp: -42, data: CHUNK_DATA[0]}));

  let outputs = 0;
  callbacks.output = frame => {
    outputs++;
    assert_equals(frame.timestamp, -42, 'timestamp');
    frame.close();
  };

  await decoder.flush();
  assert_equals(outputs, 1, 'outputs');
}, 'Test decoding a with negative timestamp');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);

  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);
  decoder.decode(CHUNKS[1]);
  const flushDone = decoder.flush();

  // Wait for the first output, then reset.
  let outputs = 0;
  await new Promise(resolve => {
    callbacks.output = frame => {
      outputs++;
      assert_equals(outputs, 1, 'outputs');
      decoder.reset();
      frame.close();
      resolve();
    };
  });

  // Flush should have been synchronously rejected.
  await promise_rejects_dom(t, 'AbortError', flushDone);

  assert_equals(outputs, 1, 'outputs');
}, 'Test reset during flush');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);

  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);
  const flushDone = decoder.flush();

  let flushDoneInCallback;
  let outputs = 0;
  await new Promise(resolve => {
    callbacks.output = frame => {
      decoder.reset();
      frame.close();

      callbacks.output = frame => {
        outputs++;
        frame.close();
      };
      callbacks.error = e => {
        t.unreached_func('unexpected error()');
      };
      decoder.configure(CONFIG);
      decoder.decode(CHUNKS[0]);
      flushDoneInCallback = decoder.flush();

      resolve();
    };
  });

  // First flush should have been synchronously rejected.
  await promise_rejects_dom(t, 'AbortError', flushDone);
  // Wait for the second flush and check the output count.
  await flushDoneInCallback;
  assert_equals(outputs, 1, 'outputs');
}, 'Test new flush after reset in a flush callback');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);

  decoder.configure(CONFIG);
  decoder.decode(CHUNKS[0]);
  const flushDone = decoder.flush();
  let flushDoneInCallback;

  await new Promise(resolve => {
    callbacks.output = frame => {
      decoder.reset();
      frame.close();

      callbacks.output = frame => { frame.close(); };
      decoder.configure(CONFIG);
      decoder.decode(CHUNKS[0]);
      decoder.decode(createCorruptChunk(1));
      flushDoneInCallback = decoder.flush();

      resolve();
    };
  });

  // First flush should have been synchronously rejected.
  await promise_rejects_dom(t, 'AbortError', flushDone);
  // Wait for the second flush and check the error in the rejected promise.
  await promise_rejects_dom(t, 'EncodingError', flushDoneInCallback);
}, 'Test decoding a corrupt frame after reset in a flush callback');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  const decoder = createVideoDecoder(t, callbacks);

  decoder.configure({...CONFIG, optimizeForLatency: true});
  decoder.decode(CHUNKS[0]);

  // The frame should be output without flushing.
  await new Promise(resolve => {
    callbacks.output = frame => {
      frame.close();
      resolve();
    };
  });
}, 'Test low-latency decoding');

promise_test(async t => {
  await checkImplements();
  const callbacks = {};
  callbacks.output = frame => { frame.close(); };
  const decoder = createVideoDecoder(t, callbacks);

  // No decodes yet.
  assert_equals(decoder.decodeQueueSize, 0);

  decoder.configure(CONFIG);

  // Still no decodes.
  assert_equals(decoder.decodeQueueSize, 0);

  let lastDequeueSize = Infinity;
  decoder.ondequeue = () => {
    assert_greater_than(lastDequeueSize, 0, "Dequeue event after queue empty");
    assert_greater_than(lastDequeueSize, decoder.decodeQueueSize,
                        "Dequeue event without decreased queue size");
    lastDequeueSize = decoder.decodeQueueSize;
  };

  for (let chunk of CHUNKS)
    decoder.decode(chunk);

  assert_greater_than_equal(decoder.decodeQueueSize, 0);
  assert_less_than_equal(decoder.decodeQueueSize, CHUNKS.length);

  await decoder.flush();
  // We can guarantee that all decodes are processed after a flush.
  assert_equals(decoder.decodeQueueSize, 0);
  // Last dequeue event should fire when the queue is empty.
  assert_equals(lastDequeueSize, 0);

  // Reset this to Infinity to track the decline of queue size for this next
  // batch of decodes.
  lastDequeueSize = Infinity;

  for (let chunk of CHUNKS)
    decoder.decode(chunk);

  assert_greater_than_equal(decoder.decodeQueueSize, 0);
  decoder.reset();
  assert_equals(decoder.decodeQueueSize, 0);
}, 'VideoDecoder decodeQueueSize test');