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> 80
