1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/webaudio/test/test_pannerNodeHRTFSymmetry.html Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,104 @@
1.4 +<!DOCTYPE HTML>
1.5 +<html>
1.6 +<head>
1.7 + <title>Test left/right symmetry and block-offset invariance of HRTF panner</title>
1.8 + <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
1.9 + <script type="text/javascript" src="webaudio.js"></script>
1.10 + <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
1.11 +</head>
1.12 +<body>
1.13 +<pre id="test">
1.14 +<script class="testbody" type="text/javascript">
1.15 +
1.16 +SimpleTest.waitForExplicitFinish();
1.17 +
1.18 +const blockSize = 128;
1.19 +const bufferSize = 4096; // > HRTF panner latency
1.20 +
1.21 +var ctx = new AudioContext();
1.22 +
1.23 +function isChannelSilent(channel) {
1.24 + for (var i = 0; i < channel.length; ++i) {
1.25 + if (channel[i] != 0.0) {
1.26 + return false;
1.27 + }
1.28 + }
1.29 + return true;
1.30 +}
1.31 +
1.32 +function startTest() {
1.33 + var leftPanner = ctx.createPanner();
1.34 + var rightPanner = ctx.createPanner();
1.35 + leftPanner.setPosition(-1,0,0);
1.36 + rightPanner.setPosition(1,0,0);
1.37 +
1.38 + // Test that PannerNode processes the signal consistently irrespective of
1.39 + // the offset in the processing block. This is done by inserting a delay of
1.40 + // less than a block size before one panner.
1.41 + const delayTime = 0.7 * blockSize / ctx.sampleRate;
1.42 + var leftDelay = ctx.createDelay(delayTime);
1.43 + leftDelay.delayTime.value = delayTime;
1.44 + leftDelay.connect(leftPanner);
1.45 + // and compensating for the delay after the other.
1.46 + var rightDelay = ctx.createDelay(delayTime);
1.47 + rightDelay.delayTime.value = delayTime;
1.48 + rightPanner.connect(rightDelay);
1.49 +
1.50 + // Feed the panners with a signal having some harmonics to fill the spectrum.
1.51 + var oscillator = ctx.createOscillator();
1.52 + oscillator.frequency.value = 110;
1.53 + oscillator.type = "sawtooth";
1.54 + oscillator.connect(leftDelay);
1.55 + oscillator.connect(rightPanner);
1.56 + oscillator.start(0);
1.57 +
1.58 + // Switch the channels on one panner output, and it should match the other.
1.59 + var splitter = ctx.createChannelSplitter();
1.60 + leftPanner.connect(splitter);
1.61 + var merger = ctx.createChannelMerger();
1.62 + splitter.connect(merger, 0, 1);
1.63 + splitter.connect(merger, 1, 0);
1.64 +
1.65 + // Invert one signal so that mixing with the other will find the difference.
1.66 + var gain = ctx.createGain();
1.67 + gain.gain.value = -1.0;
1.68 + merger.connect(gain);
1.69 +
1.70 + var processor = ctx.createScriptProcessor(bufferSize, 2, 0);
1.71 + gain.connect(processor);
1.72 + rightDelay.connect(processor);
1.73 + processor.onaudioprocess =
1.74 + function(e) {
1.75 + compareBuffers(e.inputBuffer,
1.76 + ctx.createBuffer(2, bufferSize, ctx.sampleRate));
1.77 + e.target.onaudioprocess = null;
1.78 + SimpleTest.finish();
1.79 + }
1.80 +}
1.81 +
1.82 +function prepareTest() {
1.83 + // A PannerNode will produce no output until it has loaded its HRIR
1.84 + // database. Wait for this to load before starting the test.
1.85 + var processor = ctx.createScriptProcessor(bufferSize, 2, 0);
1.86 + var panner = ctx.createPanner();
1.87 + panner.connect(processor);
1.88 + var oscillator = ctx.createOscillator();
1.89 + oscillator.connect(panner);
1.90 + oscillator.start(0);
1.91 +
1.92 + processor.onaudioprocess =
1.93 + function(e) {
1.94 + if (isChannelSilent(e.inputBuffer.getChannelData(0)))
1.95 + return;
1.96 +
1.97 + oscillator.stop(0);
1.98 + panner.disconnect();
1.99 + e.target.onaudioprocess = null;
1.100 + startTest();
1.101 + };
1.102 +}
1.103 +prepareTest();
1.104 +</script>
1.105 +</pre>
1.106 +</body>
1.107 +</html>
