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Test Info:
<!DOCTYPE HTML>↩
<html>↩
<head>↩
<script src="/tests/SimpleTest/SimpleTest.js"></script>↩
<script type="text/javascript" src="webaudio.js"></script>↩
<script type="text/javascript" src="head.js"></script>↩
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />↩
</head>↩
<body>↩
<pre id="test">↩
<script class="testbody" type="text/javascript">↩
/**↩
* Sets up a stereo BufferSource and plumbs it through different gain node↩
* configurations. A control gain path with no changes to gain is used along↩
* with 2 other paths which should increase their gain. The result should be↩
* that audio travelling along the increased gain paths is louder than the↩
* control path.↩
*/↩
↩
SimpleTest.waitForExplicitFinish();↩
SimpleTest.requestFlakyTimeout(↩
"This test uses a live audio context and uses a setTimeout to schedule a " +↩
"change to the graph.");↩
addLoadEvent(function() {↩
let context = new AudioContext();↩
↩
let numChannels = 2;↩
let sampleRate = context.sampleRate;↩
// 60 seconds to mitigate timing issues on slow test machines↩
let recordingLength = 60;↩
let bufferLength = sampleRate * recordingLength;↩
let gainExplicitlyIncreased = false;↩
let sourceFinished = false;↩
↩
// Create source buffer↩
let sourceBuffer = context.createBuffer(numChannels, bufferLength, sampleRate);↩
for (let i = 0; i < bufferLength; ++i) {↩
sourceBuffer.getChannelData(0)[i] = 1;↩
sourceBuffer.getChannelData(1)[i] = 1;↩
}↩
let source = context.createBufferSource();↩
source.buffer = sourceBuffer;↩
↩
let gainNoChange = context.createGain();↩
let gainExplicitAssignment = context.createGain();↩
let gainSetValueAtTime = context.createGain();↩
↩
// All gain nodes start of with the same gain↩
gainNoChange.gain.value = 0.25;↩
gainExplicitAssignment.gain.value = 0.25;↩
gainSetValueAtTime.gain.value = 0.25;↩
↩
// Connect source to gain nodes:↩
// source--> gainNoChange↩
// |-> gainExplicitAssignment↩
// \-> gainSetValueAtTime↩
source.connect(gainNoChange);↩
source.connect(gainExplicitAssignment);↩
source.connect(gainSetValueAtTime);↩
↩
let destNoChange = context.createMediaStreamDestination();↩
let destExplicitAssignement = context.createMediaStreamDestination();↩
let destSetValueAtTime = context.createMediaStreamDestination();↩
↩
let sourceNoChange = context.createMediaStreamSource(destNoChange.stream);↩
let sourceExplicitAssignement = context.createMediaStreamSource(destExplicitAssignement.stream);↩
let sourceSetValueAtTime = context.createMediaStreamSource(destSetValueAtTime.stream);↩
↩
// Connect gain nodes to our intermediate streams:↩
// source--> gainNoChange -> destNoChange -> sourceNoChange↩
// |-> gainExplicitAssignment -> destExplicitAssignement -> sourceExplicitAssignement↩
// \-> gainSetValueAtTime -> destSetValueAtTime -> sourceSetValueAtTime↩
gainNoChange.connect(destNoChange);↩
gainExplicitAssignment.connect(destExplicitAssignement);↩
gainSetValueAtTime.connect(destSetValueAtTime);↩
↩
// Create analysers for each path↩
let analyserNoChange = context.createAnalyser();↩
let analyserExplicitAssignment = context.createAnalyser();↩
let analyserSetValueAtTime = context.createAnalyser();↩
↩
// Connect our intermediate media streams to analysers:↩
// source--> gainNoChange -> destNoChange -> sourceNoChange -> analyserNoChange↩
// |-> gainExplicitAssignment -> destExplicitAssignement -> sourceExplicitAssignement -> analyserExplicitAssignment↩
// \-> gainSetValueAtTime -> destSetValueAtTime -> sourceSetValueAtTime -> analyserSetValueAtTime↩
sourceNoChange.connect(analyserNoChange);↩
sourceExplicitAssignement.connect(analyserExplicitAssignment);↩
sourceSetValueAtTime.connect(analyserSetValueAtTime);↩
↩
// Two seconds in, increase gain for setValueAt path↩
gainSetValueAtTime.gain.setValueAtTime(0.5, 2);↩
↩
// Maximum values seen at each analyser node, will be updated by↩
// checkAnalysersForMaxValues() during test.↩
let maxNoGainChange = 0;↩
let maxExplicitAssignment = 0;↩
let maxSetValueAtTime = 0;↩
↩
// Poll analysers and check for max values↩
function checkAnalysersForMaxValues() {↩
let findMaxValue =↩
(array) => array.reduce((a, b) => Math.max(Math.abs(a), Math.abs(b)));↩
↩
let dataArray = new Float32Array(analyserNoChange.fftSize);↩
analyserNoChange.getFloatTimeDomainData(dataArray);↩
maxNoGainChange = Math.max(maxNoGainChange, findMaxValue(dataArray));↩
↩
analyserExplicitAssignment.getFloatTimeDomainData(dataArray);↩
maxExplicitAssignment = Math.max(maxExplicitAssignment, findMaxValue(dataArray));↩
↩
analyserSetValueAtTime.getFloatTimeDomainData(dataArray);↩
maxSetValueAtTime = Math.max(maxSetValueAtTime, findMaxValue(dataArray));↩
↩
// End test if we've met our conditions↩
// Add a small amount to initial gain to make sure we're not getting↩
// passes due to rounding errors.↩
let epsilon = 0.01;↩
if (maxExplicitAssignment > (maxNoGainChange + epsilon) &&↩
maxSetValueAtTime > (maxNoGainChange + epsilon)) {↩
source.stop();↩
}↩
}↩
↩
source.onended = () => {↩
sourceFinished = true;↩
info(`maxNoGainChange: ${maxNoGainChange}`);↩
info(`maxExplicitAssignment: ${maxExplicitAssignment}`);↩
info(`maxSetValueAtTime: ${maxSetValueAtTime}`);↩
ok(gainExplicitlyIncreased,↩
"Gain should be explicitly assinged during test!");↩
// Add a small amount to initial gain to make sure we're not getting↩
// passes due to rounding errors.↩
let epsilon = 0.01;↩
ok(maxExplicitAssignment > (maxNoGainChange + epsilon),↩
"Volume should increase due to explicit assignment to gain.value");↩
ok(maxSetValueAtTime > (maxNoGainChange + epsilon),↩
"Volume should increase due to setValueAtTime on gain.value");↩
SimpleTest.finish();↩
};↩
↩
// Start the graph↩
source.start(0);↩
↩
// We'll use this callback to check our analysers for gain↩
function animationFrameCb() {↩
if (sourceFinished) {↩
return;↩
}↩
requestAnimationFrame(animationFrameCb);↩
checkAnalysersForMaxValues();↩
}↩
↩
// Using timers is gross, but as of writing there doesn't appear to be a↩
// nicer way to perform gain.value = 0.5 on our node. When/if we support↩
// suspend(time) on offline contexts we could potentially use that instead.↩
↩
// Roughly 2 seconds through our source buffer (setTimeout flakiness) increase↩
// our gain on gainExplicitAssignment path.↩
window.setTimeout(() => {↩
gainExplicitAssignment.gain.value = 0.5;↩
// Make debugging flaky timeouts in test easier↩
info("Gain explicitly set!")↩
gainExplicitlyIncreased = true;↩
// Start checking analysers, we do this only after changing volume to avoid↩
// possible starvation of this timeout from requestAnimationFrame calls.↩
animationFrameCb();↩
}, 2000);↩
});↩
↩
</script>↩
</pre>↩
</body>↩
</html>↩