CanvasCaptureMediaStream-set-size-too-large.html

<!DOCTYPE html>
<title>setting too-large width after captureStream() does not produce invalid frames</title>
<link rel="help" href="https://crbug.com/1178292">
<script src=../../resources/testharness.js></script>
<script src=../../resources/testharnessreport.js></script>
<script>
'use strict';

const maxSize = 32767;

// Setting the canvas width or height too large when there is a canvas capture
// stream does not cause the stream to have frames exceeding Chrome's internal
// limits.
promise_test(async t => {
  const canvas = document.createElement('canvas');
  canvas.width = 160;
  canvas.height = 160;
  const ctx = canvas.getContext('2d');
  ctx.fillStyle = 'green';
  const stream = canvas.captureStream(0);
  const track = stream.getVideoTracks()[0];

  const intervalId = setInterval(() => {
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    track.requestFrame();
  }, 50);
  t.add_cleanup(() => { clearInterval(intervalId); });

  const video = document.createElement('video');
  video.srcObject = stream;
  t.add_cleanup(() => { video.src = ''; });
  let frameCount = 0;
  let callbackId;
  const newFrame = (ts, metadata) => {
    assert_less_than_equal(metadata.width, maxSize);
    assert_less_than_equal(metadata.height, maxSize);
    frameCount++;
    callbackId = video.requestVideoFrameCallback(newFrame);
  };
  callbackId = video.requestVideoFrameCallback(newFrame);
  t.add_cleanup(() => { video.cancelVideoFrameCallback(callbackId); });
  await video.play();

  await t.step_wait(() => {
    return frameCount > 0;
  }, 'await first frame');

  // Now generate frames that are too large.
  canvas.width = maxSize + 1;
  // The video element should stop getting frames, but there may still be frames in the pipeline.
  // Wait for them to flush out.
  await t.step_wait(() => {
    const flushed = frameCount === 0;
    frameCount = 0;
    return flushed;
  }, 'await old frames to be flushed out', 1000, 200);

  // Should not see any new frames when canvas is too large.
  // Since we're asserting that something *doesn't* happen, we need to use step_timeout.
  await new Promise(resolve => t.step_timeout(resolve, 5000));
  assert_equals(frameCount, 0, 'frames seen when canvas is too large');

  // Should resume frames after canvas size becomes valid again.
  frameCount = 0;
  canvas.width = 160;
  await t.step_wait(() => frameCount > 0, 'await resume of frames');
});
</script>
chromium/third_party/blink/web_tests/fast/mediacapturefromelement/CanvasCaptureMediaStream-set-size-too-large.html
