test_audioBufferSourceNodeOffset.html (1563B)
1 <!DOCTYPE HTML> 2 <html> 3 <head> 4 <title>Test the offset property on AudioBufferSourceNode</title> 5 <script src="/tests/SimpleTest/SimpleTest.js"></script> 6 <script type="text/javascript" src="webaudio.js"></script> 7 <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" /> 8 </head> 9 <body> 10 <pre id="test"> 11 <script class="testbody" type="text/javascript"> 12 13 var fuzz = 0.3; 14 15 if (navigator.platform.startsWith("Mac")) { 16 // bug 895720 17 fuzz = 0.6; 18 } 19 20 SimpleTest.waitForExplicitFinish(); 21 addLoadEvent(function() { 22 var samplesFromSource = 0; 23 var context = new AudioContext(); 24 var sp = context.createScriptProcessor(256); 25 26 sp.onaudioprocess = function(e) { 27 samplesFromSource += e.inputBuffer.length; 28 } 29 30 var buffer = context.createBuffer(1, context.sampleRate, context.sampleRate); 31 for (var i = 0; i < context.sampleRate; ++i) { 32 buffer.getChannelData(0)[i] = Math.sin(440 * 2 * Math.PI * i / context.sampleRate); 33 } 34 35 var source = context.createBufferSource(); 36 37 source.onended = function() { 38 // The timing at which the audioprocess and ended listeners are called can 39 // change, hence the fuzzy equal here. 40 var errorRatio = samplesFromSource / (0.5 * context.sampleRate); 41 ok(errorRatio > (1.0 - fuzz) && errorRatio < (1.0 + fuzz), 42 "Correct number of samples received (expected: " + 43 (0.5 * context.sampleRate) + ", actual: " + samplesFromSource + ")."); 44 SimpleTest.finish(); 45 }; 46 47 source.buffer = buffer; 48 source.connect(sp); 49 source.start(0, 0.5); 50 }); 51 52 </script> 53 </pre> 54 </body> 55 </html>