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comparison: content/media/webaudio/test/test_audioParamGain.html
content/media/webaudio/test/test_audioParamGain.html
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:07c2e0cc3b08 |
|---|---|
| 1 <!DOCTYPE HTML> | |
| 2 <html> | |
| 3 <head> | |
| 4 <title>Test AudioParam with pre-gain </title> | |
| 5 <script type="text/javascript" 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 SimpleTest.waitForExplicitFinish(); | |
| 14 | |
| 15 var ctx = new AudioContext(); | |
| 16 var source = ctx.createOscillator(); | |
| 17 var lfo = ctx.createOscillator(); | |
| 18 var lfoIntensity = ctx.createGain(); | |
| 19 var effect = ctx.createGain(); | |
| 20 var sp = ctx.createScriptProcessor(2048, 1); | |
| 21 | |
| 22 source.frequency.value = 440; | |
| 23 lfo.frequency.value = 2; | |
| 24 // Very low gain, so the LFO should have very little influence | |
| 25 // on the source, its RMS value should be close to the nominal value | |
| 26 // for a sine wave. | |
| 27 lfoIntensity.gain.value = 0.0001; | |
| 28 | |
| 29 lfo.connect(lfoIntensity); | |
| 30 lfoIntensity.connect(effect.gain); | |
| 31 source.connect(effect); | |
| 32 effect.connect(sp); | |
| 33 | |
| 34 sp.onaudioprocess = function(e) { | |
| 35 var buffer = e.inputBuffer.getChannelData(0); | |
| 36 var rms = 0; | |
| 37 for (var i = 0; i < buffer.length; i++) { | |
| 38 rms += buffer[i] * buffer[i]; | |
| 39 } | |
| 40 | |
| 41 rms /= buffer.length; | |
| 42 rms = Math.sqrt(rms); | |
| 43 | |
| 44 // 1 / Math.sqrt(2) is the theoretical RMS value for a sine wave. | |
| 45 ok(fuzzyCompare(rms, 1 / Math.sqrt(2)), | |
| 46 "Gain correctly applied to the AudioParam."); | |
| 47 | |
| 48 ctx = null; | |
| 49 sp.onaudioprocess = null; | |
| 50 lfo.stop(0); | |
| 51 source.stop(0); | |
| 52 | |
| 53 SimpleTest.finish(); | |
| 54 } | |
| 55 | |
| 56 lfo.start(0); | |
| 57 source.start(0); | |
| 58 | |
| 59 </script> | |
| 60 </pre> | |
| 61 </body> |
