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<!DOCTYPE HTML>
<html>
<head>
<title>Test ScriptProcessorNode with passthrough</title>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<script type="text/javascript" src="webaudio.js"></script>
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<pre id="test">
<script class="testbody" type="text/javascript">
// We do not use our generic graph test framework here because
// the testing logic here is sort of complicated, and would
// not be easy to map to OfflineAudioContext, as ScriptProcessorNodes
// can experience delays.
SimpleTest.waitForExplicitFinish();
addLoadEvent(function() {
var context = new AudioContext();
var buffer = null;
var sourceSP = context.createScriptProcessor(2048);
sourceSP.addEventListener("audioprocess", function(e) {
// generate the audio
for (var i = 0; i < 2048; ++i) {
// Make sure our first sample won't be zero
e.outputBuffer.getChannelData(0)[i] = Math.sin(440 * 2 * Math.PI * (i + 1) / context.sampleRate);
e.outputBuffer.getChannelData(1)[i] = Math.sin(880 * 2 * Math.PI * (i + 1) / context.sampleRate);
}
// Remember our generated audio
buffer = e.outputBuffer;
sourceSP.removeEventListener("audioprocess", arguments.callee);
});
function findFirstNonZeroSample(buffer) {
for (var i = 0; i < buffer.length; ++i) {
if (buffer.getChannelData(0)[i] != 0) {
return i;
}
}
return buffer.length;
}
var sp = context.createScriptProcessor(2048);
sourceSP.connect(sp);
var spWrapped = SpecialPowers.wrap(sp);
ok("passThrough" in spWrapped, "ScriptProcessorNode should support the passThrough API");
spWrapped.passThrough = true;
sp.onaudioprocess = function() {
ok(false, "The audioprocess event must never be dispatched on the passthrough ScriptProcessorNode");
};
var sp2 = context.createScriptProcessor(2048);
sp.connect(sp2);
sp2.connect(context.destination);
var emptyBuffer = context.createBuffer(1, 2048, context.sampleRate);
sp2.onaudioprocess = function(e) {
// Because of the initial latency added by the second script processor node,
// we will never see any generated audio frames in the first callback.
compareChannels(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0));
compareChannels(e.inputBuffer.getChannelData(1), emptyBuffer.getChannelData(0));
sp2.onaudioprocess = function(e) {
var firstNonZero = findFirstNonZeroSample(e.inputBuffer);
ok(firstNonZero <= 2048, "First non-zero sample within range");
compareChannels(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0), firstNonZero);
compareChannels(e.inputBuffer.getChannelData(1), emptyBuffer.getChannelData(0), firstNonZero);
compareChannels(e.inputBuffer.getChannelData(0), buffer.getChannelData(0), 2048 - firstNonZero, firstNonZero, 0);
compareChannels(e.inputBuffer.getChannelData(1), buffer.getChannelData(1), 2048 - firstNonZero, firstNonZero, 0);
if (firstNonZero == 0) {
// If we did not experience any delays, the test is done!
sp2.onaudioprocess = null;
SimpleTest.finish();
} else if (firstNonZero != 2048) {
// In case we just saw a zero buffer this time, wait one more round
sp2.onaudioprocess = function(e) {
compareChannels(e.inputBuffer.getChannelData(0), buffer.getChannelData(0), firstNonZero, 0, 2048 - firstNonZero);
compareChannels(e.inputBuffer.getChannelData(1), buffer.getChannelData(1), firstNonZero, 0, 2048 - firstNonZero);
compareChannels(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0), undefined, firstNonZero);
compareChannels(e.inputBuffer.getChannelData(1), emptyBuffer.getChannelData(0), undefined, firstNonZero);
sp2.onaudioprocess = null;
SimpleTest.finish();
};
}
};
};
});
</script>
</pre>
</body>
</html>