tools/perf/page_sets/image_decoding_cases/yuv_decoding.html

   1 <!DOCTYPE html>
   2 <html>
   3 <head>
   4   <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
   5   <title>JPEG image decoding</title>
   6 </head>
   7 <body>
   8 <img id="myimg">
   9 <script>
  10 var image_width = 1024;
  11 var image_height = 1024;
  12 var nb_images = 200;
  13 var urls = [];
  14
  15 for (i = 0; i < nb_images; ++i) {
  16     var canvas = document.createElement("canvas");
  17     canvas.width = image_width;
  18     canvas.height = image_height;
  19     var ctx = canvas.getContext("2d");
  20     ctx.fillStyle = "rgb("+
  21         Math.floor(Math.random()*256)+","+
  22         Math.floor(Math.random()*256)+","+
  23         Math.floor(Math.random()*256)+")";
  24     ctx.fillRect(0,0,image_width,image_height);
  25     // If quality is 1, then we get YUV 444 encoding
  26     // If quality is <1, then we get YUV 420 encoding
  27     urls[i] = canvas.toDataURL("image/jpeg", 0.99);
  28 }
  29
  30 var idx = 0;
  31 function redraw() {
  32     document.getElementById("myimg").src = urls[idx];
  33     idx++;
  34     if (idx >= nb_images) { idx = 0; }
  35     window.setTimeout(redraw, 1);
  36 }
  37 window.setTimeout(redraw, 1);
  38 </script>
  39 </body>
  40 </html>