test_audioParamLinearRamp.html (1334B)
1 <!DOCTYPE HTML> 2 <html> 3 <head> 4 <title>Test AudioParam.linearRampToValue</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 V0 = 0.1; 14 var V1 = 0.9; 15 var T0 = 0; 16 17 var gTest = { 18 length: 2048, 19 numberOfChannels: 1, 20 createGraph(context) { 21 var sourceBuffer = context.createBuffer(1, 2048, context.sampleRate); 22 for (var i = 0; i < 2048; ++i) { 23 sourceBuffer.getChannelData(0)[i] = 1; 24 } 25 26 var source = context.createBufferSource(); 27 source.buffer = sourceBuffer; 28 29 var gain = context.createGain(); 30 gain.gain.setValueAtTime(V0, 0); 31 gain.gain.linearRampToValueAtTime(V1, 2048/context.sampleRate); 32 33 source.connect(gain); 34 35 source.start(0); 36 return gain; 37 }, 38 createExpectedBuffers(context) { 39 var T1 = 2048 / context.sampleRate; 40 var expectedBuffer = context.createBuffer(1, 2048, context.sampleRate); 41 for (var i = 0; i < 2048; ++i) { 42 var t = i / context.sampleRate; 43 expectedBuffer.getChannelData(0)[i] = V0 + (V1 - V0) * ((t - T0) / (T1 - T0)); 44 } 45 return expectedBuffer; 46 }, 47 }; 48 49 runTest(); 50 51 </script> 52 </pre> 53 </body> 54 </html>