// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// These must match with how the video and canvas tags are declared in html.
const VIDEO_TAG_WIDTH = 320;
const VIDEO_TAG_HEIGHT = 240;
// Fake video capture background green is of value 135.
const COLOR_BACKGROUND_GREEN = 135;
// Logs a success message to the console.
function logSuccess() {
console.log('Test Success');
}
function detectVideoPlayingWithExpectedResolution(
videoElementName, video_width, video_height, alignment) {
return detectVideo(
videoElementName, function(pixels, previous_pixels, videoElement) {
return hasExpectedResolution(
videoElement, video_width, video_height, alignment) &&
isVideoPlaying(pixels, previous_pixels);
});
}
function detectVideoPlaying(videoElementName) {
return detectVideo(videoElementName, isVideoPlaying);
}
function detectVideoWithDimensionPlaying(
videoElementName, video_width, video_height) {
return detectVideoWithDimension(
videoElementName, isVideoPlaying, video_width, video_height);
}
function detectVideoStopped(videoElementName) {
return detectVideo(videoElementName, function(pixels, previous_pixels) {
return !isVideoPlaying(pixels, previous_pixels);
});
}
function detectBlackVideo(videoElementName) {
return detectVideo(videoElementName, function(pixels, previous_pixels) {
return isVideoBlack(pixels);
});
}
function detectUniformColorVideoWithDimensionPlaying(
videoElementName, video_width, video_height) {
return detectVideoWithDimension(
videoElementName, function(pixels, previous_pixels) {
return isVideoPlaying(pixels, previous_pixels) &&
arePixelsUniformColor(pixels) &&
arePixelsUniformColor(previous_pixels);
}, video_width, video_height);
}
function detectVideo(videoElementName, predicate) {
return detectVideoWithDimension(
videoElementName, predicate, VIDEO_TAG_WIDTH, VIDEO_TAG_HEIGHT);
}
function detectVideoWithDimension(
videoElementName, predicate, video_width, video_height) {
console.log('Looking at video in element ' + videoElementName);
return new Promise((resolve, reject) => {
var width = video_width;
var height = video_height;
var videoElement = $(videoElementName);
var oldPixels = [];
var startTimeMs = new Date().getTime();
var waitVideo = setInterval(function() {
var canvas = $(videoElementName + '-canvas');
if (canvas == null) {
console.log(
'Waiting for ' + videoElementName + '-canvas' +
' to appear');
return;
}
var context = canvas.getContext('2d', {willReadFrequently: true});
context.drawImage(videoElement, 0, 0);
var pixels = context.getImageData(0, 0, width, height / 3).data;
// Check that there is an old and a new picture with the same size to
// compare and use the function |predicate| to detect the video state in
// that case.
// There's a failure(?) mode here where the video generated claims to
// have size 2x2. Don't consider that a valid video.
if (oldPixels.length == pixels.length &&
predicate(pixels, oldPixels, videoElement)) {
console.log('Done looking at video in element ' + videoElementName);
console.log('DEBUG: video.width = ' + videoElement.videoWidth);
console.log('DEBUG: video.height = ' + videoElement.videoHeight);
clearInterval(waitVideo);
resolve({
'width': videoElement.videoWidth,
'height': videoElement.videoHeight
});
}
oldPixels = pixels;
var elapsedTime = new Date().getTime() - startTimeMs;
if (elapsedTime > 3000) {
startTimeMs = new Date().getTime();
console.log(
'Still waiting for video to satisfy ' + predicate.toString());
console.log('DEBUG: video.width = ' + videoElement.videoWidth);
console.log('DEBUG: video.height = ' + videoElement.videoHeight);
}
}, 200);
});
}
function waitForConnectionToStabilize(peerConnection) {
return new Promise((resolve, reject) => {
peerConnection.onsignalingstatechange =
function(event) {
if (peerConnection.signalingState == 'stable') {
peerConnection.onsignalingstatechange = null;
resolve();
}
}
});
}
function waitForConnectionToStabilizeIfNeeded(peerConnection) {
return new Promise((resolve, reject) => {
if (peerConnection.signalingState == 'stable') {
resolve();
return;
}
return waitForConnectionToStabilize(peerConnection).then(resolve);
});
}
function hasExpectedResolution(
videoElement, expected_width, expected_height, alignment) {
if (videoElement.videoWidth == expected_width &&
videoElement.videoHeight == expected_height) {
return true;
}
if (!alignment)
return false;
expected_width -= expected_width % alignment;
expected_height -= expected_height % alignment;
return videoElement.videoWidth == expected_width &&
videoElement.videoHeight == expected_height;
}
// This very basic video verification algorithm will be satisfied if any
// pixels are changed.
function isVideoPlaying(pixels, previousPixels) {
for (var i = 0; i < pixels.length; i++) {
if (pixels[i] != previousPixels[i]) {
return true;
}
}
return false;
}
// Checks if the frame is black. |pixels| is in RGBA (i.e. pixels[0] is the R
// value for the first pixel).
function isVideoBlack(pixels) {
var threshold = 20;
var accumulatedLuma = 0;
for (var i = 0; i < pixels.length; i += 4) {
// Ignore the alpha channel.
accumulatedLuma += rec709Luma_(pixels[i], pixels[i + 1], pixels[i + 2]);
if (accumulatedLuma > threshold * (i / 4 + 1))
return false;
}
return true;
}
// |pixels| is in RGBA (i.e. pixels[0] is the R value for the first pixel).
function arePixelsUniformColor(pixels) {
if (pixels.length < 4) {
throw new Error('expected at least one pixel');
}
var reference_r = pixels[0];
var reference_g = pixels[1];
var reference_b = pixels[2];
var reference_a = pixels[3];
for (var i = 4; i < pixels.length; i += 4) {
if (pixels[i + 0] != reference_r) {
console.log('red value at pixel ' + i + ' does not match reference');
return false;
}
if (pixels[i + 1] != reference_g) {
console.log('green value at pixel ' + i + ' does not match reference');
return false;
}
if (pixels[i + 2] != reference_b) {
console.log('blue value at pixel ' + i + ' does not match reference');
return false;
}
if (pixels[i + 3] != reference_a) {
console.log('alpha value at pixel ' + i + ' does not match reference');
return false;
}
}
return true;
}
// Checks if the given color is within 1 value away from COLOR_BACKGROUND_GREEN.
function isAlmostBackgroundGreen(color) {
if (Math.abs(color - COLOR_BACKGROUND_GREEN) > 1)
return false;
return true;
}
// Use Luma as in Rec. 709: Y′709 = 0.2126R + 0.7152G + 0.0722B;
// See http://en.wikipedia.org/wiki/Rec._709.
function rec709Luma_(r, g, b) {
return 0.2126 * r + 0.7152 * g + 0.0722 * b;
}
// This function matches |left| and |right| and fails the test if the
// values don't match using normal javascript equality (i.e. the hard
// types of the operands aren't checked).
function assertEquals(expected, actual) {
if (actual != expected) {
throw new Error('expected \'' + expected + '\', got \'' + actual + '\'.');
}
}
function assertNotEquals(expected, actual) {
if (actual === expected) {
throw new Error('expected \'' + expected + '\', got \'' + actual + '\'.');
}
}
function assertTrue(booleanExpression, description) {
if (!booleanExpression) {
throw new Error(description);
}
}
function assertFalse(booleanExpression, description) {
if (!!booleanExpression) {
throw new Error(description);
}
}
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