<!DOCTYPE html>
<html>
<head>
<title>MediaStream Insertable Streams - VideoTrackGenerator</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/webrtc/RTCPeerConnection-helper.js"></script>
</head>
<body>
<h1 class="instructions">Description</h1>
<p class="instructions">This test checks that generating video MediaStreamTracks from VideoTrackGenerator works as expected.</p>
<script id="scriptRoutines">
const pixelColour = [50, 100, 150, 255];
const height = 240;
const width = 320;
function makeVideoFrame(timestamp) {
const canvas = new OffscreenCanvas(width, height);
const ctx = canvas.getContext('2d', {alpha: false});
ctx.fillStyle = `rgba(${pixelColour.join()})`;
ctx.fillRect(0, 0, width, height);
return new VideoFrame(canvas, {timestamp, alpha: 'discard'});
}
async function getVideoFrame() {
const stream = await getNoiseStream({video: true});
const input_track = stream.getTracks()[0];
const processor = new MediaStreamTrackProcessor(input_track);
const reader = processor.readable.getReader();
const result = await reader.read();
input_track.stop();
return result.value;
}
function assertPixel(t, bytes, expected, epsilon = 5) {
for (let i = 0; i < bytes.length; i++) {
t.step(() => {
assert_less_than(Math.abs(bytes[i] - expected[i]), epsilon, "Mismatched pixel");
});
}
}
async function initiateSingleTrackCall(t, track, output) {
const caller = new RTCPeerConnection();
t.add_cleanup(() => caller.close());
const callee = new RTCPeerConnection();
t.add_cleanup(() => callee.close());
caller.addTrack(track);
t.add_cleanup(() => track.stop());
exchangeIceCandidates(caller, callee);
// Wait for the first track.
const e = await exchangeOfferAndListenToOntrack(t, caller, callee);
output.srcObject = new MediaStream([e.track]);
// Exchange answer.
await exchangeAnswer(caller, callee);
await waitForConnectionStateChange(callee, ['connected']);
}
</script>
<script>
async function createWorker(script) {
script = scriptRoutines.text + script + "self.postMessage('ready');";
const blob = new Blob([script], { type: 'text/javascript' });
const url = URL.createObjectURL(blob);
const worker = new Worker(url);
await new Promise(resolve => worker.onmessage = () => {
resolve();
});
URL.revokeObjectURL(url);
return worker;
}
promise_test(async t => {
const worker = await createWorker(`
const generator = new VideoTrackGenerator();
const videoFrame = makeVideoFrame(1);
const originalWidth = videoFrame.displayWidth;
const originalHeight = videoFrame.displayHeight;
self.onmessage = async (event) => {
if (event.data == "transfer") {
self.postMessage({ track: generator.track, originalWidth, originalHeight }, [generator.track]);
return;
}
if (event.data == "write frame") {
generator.writable.getWriter().write(videoFrame)
return;
}
if (event.data == "cleanup") {
videoFrame.close();
return;
}
}
`);
t.add_cleanup(() => worker.postMessage("cleanup"));
worker.postMessage("transfer");
const { track, originalWidth, originalHeight } = await new Promise(resolve => worker.onmessage = e => resolve(e.data));
t.add_cleanup(() => track.stop());
const video = document.createElement("video");
video.autoplay = true;
video.width = 320;
video.height = 240;
video.srcObject = new MediaStream([track]);
video.play();
// Wait for the video element to be connected to the generator and
// generate the frame.
video.onloadstart = () => worker.postMessage("write frame");
return new Promise((resolve)=> {
video.ontimeupdate = t.step_func(() => {
const canvas = document.createElement("canvas");
canvas.width = originalWidth;
canvas.height = originalHeight;
const context = canvas.getContext('2d');
context.drawImage(video, 0, 0);
// Pick a pixel in the centre of the video and check that it has the colour of the frame provided.
const pixel = context.getImageData(originalWidth/2, originalHeight/2, 1, 1);
assertPixel(t, pixel.data, pixelColour);
resolve();
});
});
}, 'Tests that frames are actually rendered correctly in a stream used for a video element.');
promise_test(async t => {
const worker = await createWorker(`
const generator = new VideoTrackGenerator();
const videoFrame = makeVideoFrame(1);
const originalWidth = videoFrame.displayWidth;
const originalHeight = videoFrame.displayHeight;
let intervalId;
self.onmessage = async (event) => {
if (event.data == "transfer") {
self.postMessage({ track: generator.track}, [generator.track]);
// Write frames for the duration of the test.
const writer = generator.writable.getWriter();
let timestamp = 0;
intervalId = setInterval(async () => {
timestamp++;
await writer.write(makeVideoFrame(timestamp));
}, 40);
return;
}
}
`);
worker.postMessage("transfer");
const { track } = await new Promise(resolve => worker.onmessage = e => resolve(e.data));
t.add_cleanup(() => track.stop());
const video = document.createElement('video');
video.autoplay = true;
video.width = width;
video.height = height;
video.muted = true;
await initiateSingleTrackCall(t, track, video);
return new Promise(resolve => {
video.requestVideoFrameCallback(t.step_func(() => {
const canvas = document.createElement('canvas');
canvas.width = width;
canvas.height = height;
const context = canvas.getContext('2d');
context.drawImage(video, 0, 0);
// Pick a pixel in the centre of the video and check that it has the
// colour of the frame provided.
const pixel = context.getImageData(width / 2, height / 2, 1, 1);
// Encoding/decoding can add noise, so increase the threshhold to 8.
assertPixel(t, pixel.data, pixelColour, 8);
resolve();
}));
});
}, 'Tests that frames are actually rendered correctly in a stream sent over a peer connection.');
promise_test(async t => {
const colorUL = [255, 0, 0, 255];
const colorUR = [255, 255, 0, 255];
const colorLL = [0, 255, 0, 255];
const colorLR = [0, 255, 255, 255];
const worker = await createWorker(`
const generator = new VideoTrackGenerator();
const videoFrame = makeVideoFrame(1);
const originalWidth = videoFrame.displayWidth;
const originalHeight = videoFrame.displayHeight;
let intervalId;
self.onmessage = async (event) => {
if (event.data == "transfer") {
self.postMessage({ track: generator.track}, [generator.track]);
const inputCanvas = new OffscreenCanvas(width, height);
const inputContext = inputCanvas.getContext('2d', {alpha: false});
// draw four quadrants
inputContext.fillStyle = \`rgba(${colorUL.join()})\`;
inputContext.fillRect(0, 0, width / 2, height / 2);
inputContext.fillStyle = \`rgba(${colorUR.join()})\`;
inputContext.fillRect(width / 2, 0, width / 2, height / 2);
inputContext.fillStyle = \`rgba(${colorLL.join()})\`;
inputContext.fillRect(0, height / 2, width / 2, height / 2);
inputContext.fillStyle = \`rgba(${colorLR.join()})\`;
inputContext.fillRect(width / 2, height / 2, width / 2, height / 2);
// Write frames for the duration of the test.
const writer = generator.writable.getWriter();
let timestamp = 0;
const intervalId = setInterval(async () => {
timestamp++;
await writer.write(new VideoFrame(inputCanvas, {timestamp: timestamp, alpha: 'discard'}));
}, 40);
return;
}
if (event.data.type === "getVideoFrame") {
const processor = new MediaStreamTrackProcessor({ track: event.data.track });
const reader = processor.readable.getReader();
const frame = (await reader.read()).value;
self.postMessage({frame}, [frame])
event.data.track.stop();
}
}
`);
worker.postMessage("transfer");
const { track } = await new Promise(resolve => worker.onmessage = e => resolve(e.data));
t.add_cleanup(() => track.stop());
const caller = new RTCPeerConnection();
t.add_cleanup(() => caller.close());
const callee = new RTCPeerConnection();
t.add_cleanup(() => callee.close());
const sender = caller.addTrack(track);
exchangeIceCandidates(caller, callee);
// Wait for the first track.
const e = await exchangeOfferAndListenToOntrack(t, caller, callee);
// Exchange answer.
await exchangeAnswer(caller, callee);
await waitForConnectionStateChange(callee, ['connected']);
const params = sender.getParameters();
params.encodings.forEach(e => e.scaleResolutionDownBy = 2);
sender.setParameters(params);
// The first frame may not have had scaleResolutionDownBy applied
const numTries = 5;
for (let i = 1; i <= numTries; i++) {
worker.postMessage({type:"getVideoFrame", track: e.track}, [e.track]);
const {frame: outputFrame} = await new Promise(resolve => worker.onmessage = e => resolve(e.data));
if (outputFrame.displayWidth !== width / 2) {
assert_less_than(i, numTries, `First ${numTries} frames were the wrong size.`);
outputFrame.close();
continue;
}
assert_equals(outputFrame.displayWidth, width / 2);
assert_equals(outputFrame.displayHeight, height / 2);
const outputCanvas = new OffscreenCanvas(width / 2, height / 2);
const outputContext = outputCanvas.getContext('2d', {alpha: false});
outputContext.drawImage(outputFrame, 0, 0);
outputFrame.close();
// Check the four quadrants
const pixelUL = outputContext.getImageData(width / 8, height / 8, 1, 1);
assertPixel(t, pixelUL.data, colorUL);
const pixelUR =
outputContext.getImageData(width * 3 / 8, height / 8, 1, 1);
assertPixel(t, pixelUR.data, colorUR);
const pixelLL =
outputContext.getImageData(width / 8, height * 3 / 8, 1, 1);
assertPixel(t, pixelLL.data, colorLL);
const pixelLR =
outputContext.getImageData(width * 3 / 8, height * 3 / 8, 1, 1);
assertPixel(t, pixelLR.data, colorLR);
break;
}
}, 'Tests that frames are sent correctly with RTCRtpEncodingParameters.scaleResolutionDownBy.');
</script>
</body>
</html>