Resize video output to match input dimensions.

chrome/test/data/webrtc/video_extraction.js

 /**
  * Copyright (c) 2012 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.
  */
 
 /**
  * The gStartedAt when the capturing begins. Used for timeout adjustments.
  * @private
  */
@@ skipping 34 matching lines @@
  * Starts the frame capturing.
  *
  * @param {!Object} The video tag from which the height and width parameters are
                     to be extracted.
  * @param {Number} The frame rate at which we would like to capture frames.
  * @param {Number} The duration of the frame capture in seconds.
  */
 function startFrameCapture(videoTag, frameRate, duration) {
   gFrameCaptureInterval = 1000 / frameRate;
   gCaptureDuration = 1000 * duration;
-  var width = videoTag.videoWidth;
-  var height = videoTag.videoHeight;
+  // Resize output element to input dimensions to not compare VGA output to HD

[phoglund_chromium, 2016/04/22 13:58:30]

That doesn't explain the background. What about:

// The WebRTC code is free to start in VGA, so make sure that the output
// video tag scales up to whatever the input size is (otherwise the video
// quality comparison will go poorly.

Also move the comment to above videoTag.width = width;

[pbos, 2016/04/22 14:04:42]

Done.

+  // input.
+  inputElement = document.getElementById("local-view");
+  var width = inputElement.videoWidth;
+  var height = inputElement.videoHeight;
+  videoTag.width = width;
+  videoTag.height = height;
 
   if (width == 0 || height == 0) {
     throw failTest('Trying to capture from ' + videoTag.id +
                    ' but it is not playing any video.');
   }
 
   console.log('Received width is: ' + width + ', received height is: ' + height
               + ', capture interval is: ' + gFrameCaptureInterval +
               ', duration is: ' + gCaptureDuration);
 
@@ skipping 121 matching lines @@
 }
 
 /**
  * @private
  */
 function updateProgressBar_(currentFrame) {
   progressBar.innerHTML =
     'Transferring captured frames: ' + '(' + currentFrame + '/' +
     gFrames.length + ')';
 }