third_party/WebKit/ManualTests/video-statistics.html

   1 <html>
   2 <head><title>WebKit video playback statistics</title></head>
   3 <body>
   4 <!-- inspired by --
   5   -- http://people.mozilla.org/~cpearce/paint-stats-demo.html -->
   6 <video src="http://movies.apple.com/movies/us/apple/ipoditunes/2007/touch/ads/apple_ipodtouch_touch_r640-9cie.mov" id="v" controls autoplay></video>
   7 <div id="log">
   8     Audio bytes decoded: 0 average p/s: 0<br>
   9     Video bytes decoded: 0 average p/s: 0<br>
  10     Decoded frames: 0 average p/s: 0<br>
  11     Dropped frames: 0 average p/s: 0<br>
  12 </div>
  13 <script>
  14
  15 var decodedFrames = 0;
  16 var decodedPerSec = 0;
  17 var audioBytesDecoded = 0;
  18 var audioBytesDecodedPerSec = 0;
  19 var videoBytesDecoded = 0;
  20 var videoBytesDecodedPerSec = 0;
  21 var droppedFrames = 0;
  22 var droppedFramesPerSec = 0;
  23
  24 function Mean() {
  25   this.count = 0;
  26   this.sum = 0;
  27
  28   this.record = function(val) {
  29     this.count++;
  30     this.sum += val;
  31   };
  32
  33   this.mean = function() {
  34     return this.count ? (this.sum / this.count).toFixed(3) : 0;
  35   };
  36 }
  37
  38
  39 var decodedMean = new Mean();
  40 var audioMean = new Mean();
  41 var videoMean = new Mean();
  42 var dropMean = new Mean();
  43
  44 function recalcRates() {
  45   var v = document.getElementById("v");
  46
  47   if (v.readyState <= HTMLMediaElement.HAVE_CURRENT_DATA || v.paused) {
  48     return;
  49   }
  50
  51   decodedPerSec = (v.webkitDecodedFrameCount - decodedFrames);
  52   decodedFrames = v.webkitDecodedFrameCount;
  53
  54   audioBytesDecodedPerSec = v.webkitAudioDecodedByteCount - audioBytesDecoded;
  55   audioBytesDecoded = v.webkitAudioDecodedByteCount;
  56
  57   videoBytesDecodedPerSec = v.webkitVideoDecodedByteCount - videoBytesDecoded;
  58   videoBytesDecoded = v.webkitVideoDecodedByteCount;
  59
  60   droppedFramesPerSec = v.webkitDroppedFrameCount - droppedFrames;
  61   droppedFrames = v.webkitDroppedFrameCount;
  62
  63   decodedMean.record(decodedPerSec);
  64   audioMean.record(audioBytesDecodedPerSec);
  65   videoMean.record(videoBytesDecodedPerSec);
  66   dropMean.record(droppedFramesPerSec);
  67
  68   var d = document.getElementById("log");
  69   d.innerHTML =
  70         "Audio bytes decoded: " + v.webkitAudioDecodedByteCount + " average p/s: " + audioMean.mean() + "<br>" +
  71         "Video bytes decoded: " + v.webkitVideoDecodedByteCount + " average p/s: " + videoMean.mean() + "<br>" +
  72         "Decoded frames: " + v.webkitDecodedFrameCount + " average p/s: " + decodedMean.mean() + "<br>" +
  73         "Dropped frames: " + v.webkitDroppedFrameCount + " average p/s: " + dropMean.mean() + "<br>";
  74 }
  75
  76 setInterval(recalcRates, 1000);
  77 </script>
  78 </body>
  79 </html>