1 files changed, 103 insertions, 0 deletions
diff --git a/testing/web-platform/tests/webcodecs/video-encoder-utils.js b/testing/web-platform/tests/webcodecs/video-encoder-utils.js
new file mode 100644
index 0000000000..0838260d31
--- /dev/null
+++ b/testing/web-platform/tests/webcodecs/video-encoder-utils.js
@@ -0,0 +1,103 @@
+async function checkEncoderSupport(test, config) {
+  assert_equals("function", typeof VideoEncoder.isConfigSupported);
+  let supported = false;
+  try {
+    const support = await VideoEncoder.isConfigSupported(config);
+    supported = support.supported;
+  } catch (e) {}
+
+  assert_implements_optional(supported, 'Unsupported config: ' +
+                             JSON.stringify(config));
+}
+
+function fourColorsFrame(ctx, width, height, text) {
+  const kYellow = "#FFFF00";
+  const kRed = "#FF0000";
+  const kBlue = "#0000FF";
+  const kGreen = "#00FF00";
+
+  ctx.fillStyle = kYellow;
+  ctx.fillRect(0, 0, width / 2, height / 2);
+
+  ctx.fillStyle = kRed;
+  ctx.fillRect(width / 2, 0, width / 2, height / 2);
+
+  ctx.fillStyle = kBlue;
+  ctx.fillRect(0, height / 2, width / 2, height / 2);
+
+  ctx.fillStyle = kGreen;
+  ctx.fillRect(width / 2, height / 2, width / 2, height / 2);
+
+  ctx.fillStyle = 'white';
+  ctx.font = (height / 10) + 'px sans-serif';
+  ctx.fillText(text, width / 2, height / 2);
+}
+
+// Paints |count| black dots on the |ctx|, so their presence can be validated
+// later. This is an analog of the most basic bar code.
+function putBlackDots(ctx, width, height, count) {
+  ctx.fillStyle = 'black';
+  const dot_size = 20;
+  const step = dot_size * 2;
+
+  for (let i = 1; i <= count; i++) {
+    let x = i * step;
+    let y = step * (x / width + 1);
+    x %= width;
+    ctx.fillRect(x, y, dot_size, dot_size);
+  }
+}
+
+// Validates that frame has |count| black dots in predefined places.
+function validateBlackDots(frame, count) {
+  const width = frame.displayWidth;
+  const height = frame.displayHeight;
+  let cnv = new OffscreenCanvas(width, height);
+  var ctx = cnv.getContext('2d', {willReadFrequently: true});
+  ctx.drawImage(frame, 0, 0);
+  const dot_size = 20;
+  const step = dot_size * 2;
+
+  for (let i = 1; i <= count; i++) {
+    let x = i * step + dot_size / 2;
+    let y = step * (x / width + 1) + dot_size / 2;
+    x %= width;
+
+    if (x)
+      x = x -1;
+    if (y)
+      y = y -1;
+
+    let rgba = ctx.getImageData(x, y, 2, 2).data;
+    const tolerance = 60;
+    if ((rgba[0] > tolerance || rgba[1] > tolerance || rgba[2] > tolerance)
+      && (rgba[4] > tolerance || rgba[5] > tolerance || rgba[6] > tolerance)
+      && (rgba[8] > tolerance || rgba[9] > tolerance || rgba[10] > tolerance)
+      && (rgba[12] > tolerance || rgba[13] > tolerance || rgba[14] > tolerance)) {
+      // The dot is too bright to be a black dot.
+      return false;
+    }
+  }
+  return true;
+}
+
+function createFrame(width, height, ts = 0) {
+  let duration = 33333;  // 30fps
+  let text = ts.toString();
+  let cnv = new OffscreenCanvas(width, height);
+  var ctx = cnv.getContext('2d');
+  fourColorsFrame(ctx, width, height, text);
+  return new VideoFrame(cnv, { timestamp: ts, duration });
+}
+
+function createDottedFrame(width, height, dots, ts) {
+  if (ts === undefined)
+    ts = dots;
+  let duration = 33333;  // 30fps
+  let text = ts.toString();
+  let cnv = new OffscreenCanvas(width, height);
+  var ctx = cnv.getContext('2d');
+  fourColorsFrame(ctx, width, height, text);
+  putBlackDots(ctx, width, height, dots);
+  return new VideoFrame(cnv, { timestamp: ts, duration });
+}