16 bpp video stream capture, render and createImageBitmap(video) using (CPU) shared memory buffers

content/test/data/media/depth_stream_test_utilities.js

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function getConstraintsForDevice(deviceLabel) {
+  return new Promise(function(resolve, reject) {
+    navigator.mediaDevices.enumerateDevices()
+    .then(function(devices) {
+      for (var i = 0; i < devices.length; ++i) {
+        if (deviceLabel == devices[i].label) {
+          return resolve({video:{deviceId: {exact: devices[i].deviceId},
+                                 width: {exact:96},
+                                 height: {exact:96}}
+                          });
+        }
+      }
+      return reject("Expected to have a device with label:" + deviceLabel);
+    })
+  });
+}
+
+function getFake16bitStream() {
+  return new Promise(function(resolve, reject) {
+    getConstraintsForDevice("fake_device_1")
+    .then(function(constraints) {
+      if (!constraints)
+        return reject("No fake device found");
+      return navigator.mediaDevices.getUserMedia(constraints);
+    }).then(function(stream) {
+      return resolve(stream);
+    });
+  });
+}
+
+function testVideoToImageBitmap(videoElementName, success, error)
+{
+  var bitmaps = {};
+  var video = $(videoElementName);
+  var canvas = document.createElement('canvas');
+  canvas.width = 96;
+  canvas.height = 96;
+  document.body.appendChild(canvas);
+  var p1 = createImageBitmap(video).then(function(imageBitmap) {
+    return runImageBitmapTest(imageBitmap, canvas, false); });
+  var p2 = createImageBitmap(video,
+      {imageOrientation: "none", premultiplyAlpha: "premultiply"}).then(
+          function(imageBitmap) {
+            return runImageBitmapTest(imageBitmap, canvas, false); });
+  var p3 = createImageBitmap(video,
+      {imageOrientation: "none", premultiplyAlpha: "default"}).then(
+          function(imageBitmap) {
+            return runImageBitmapTest(imageBitmap, canvas, false); });
+  var p4 = createImageBitmap(video,
+      {imageOrientation: "none", premultiplyAlpha: "none"}).then(
+          function(imageBitmap) {
+            return runImageBitmapTest(imageBitmap, canvas, false); });
+  var p5 = createImageBitmap(video,
+      {imageOrientation: "flipY", premultiplyAlpha: "premultiply"}).then(
+          function(imageBitmap) {
+            return runImageBitmapTest(imageBitmap, canvas, true); });
+  var p6 = createImageBitmap(video,
+      {imageOrientation: "flipY", premultiplyAlpha: "default"}).then(
+          function(imageBitmap) {
+            return runImageBitmapTest(imageBitmap, canvas, true); });
+  var p7 = createImageBitmap(video,
+      {imageOrientation: "flipY", premultiplyAlpha: "none"}).then(
+          function(imageBitmap) {
+            return runImageBitmapTest(imageBitmap, canvas, true); });
+  return Promise.all([p1, p2, p3, p4, p5, p6, p7]).then(success(), reason => {
+    return error({name: reason});
+  });
+}
+
+function runImageBitmapTest(bitmap, canvas, flipped) {
+  var context = canvas.getContext('2d');
+  context.drawImage(bitmap,0,0);
+  var imageData = context.getImageData(0, 0, canvas.width, canvas.height);
+  // Fake capture device 96x96 depth image is gradient. See also
+  // Draw16BitGradient in fake_video_capture_device.cc.
+  var color_step = 255.0 / (canvas.width + canvas.height);
+  var rowsColumnsToCheck = [[1, 1],
+                            [0, canvas.width - 1],
+                            [canvas.height - 1, 0],
+                            [canvas.height - 1, canvas.width - 1],
+                            [canvas.height / 2, canvas.width / 3]];
+
+  // Same value is expected for all color components.
+  if (imageData.data[0] != imageData.data[1] ||
+      imageData.data[0] != imageData.data[2])
+    return Promise.reject("Values " + imageData.data[0] + ", " +
+        imageData.data[1] + ", " + imageData.data[2] + " differ at top left");
+
+  // Calculate all reference points based on top left and compare.
+  for (var j = 0; j < rowsColumnsToCheck.length; ++j) {
+    var row = rowsColumnsToCheck[j][0];
+    var column = rowsColumnsToCheck[j][1];
+    var i = (canvas.width * row + column) * 4;
+    if (imageData.data[i] != imageData.data[i + 1] ||
+        imageData.data[i] != imageData.data[i + 2])
+      return Promise.reject("Values " + imageData.data[i] + ", " +
+          imageData.data[i + 1] + ", " + imageData.data[i + 2] +
+          " differ at index " + i);
+    var calculated = (imageData.data[0] +
+                      color_step * ((flipped ? -row : row) + column)) % 255;
+    if (Math.abs(calculated - imageData.data[i]) > 2)
+      return Promise.reject("Reference value " + imageData.data[i] +
+          " differs from calculated: " + calculated + " at index " + i +
+          ". TopLeft value:" + imageData.data[0]);
+  }
+  return true;
+}