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diff --git a/dom/media/webaudio/test/blink/test_biquadFilterNodeTail.html b/dom/media/webaudio/test/blink/test_biquadFilterNodeTail.html new file mode 100644 index 0000000000..cc170df2a5 --- /dev/null +++ b/dom/media/webaudio/test/blink/test_biquadFilterNodeTail.html @@ -0,0 +1,76 @@ +<!DOCTYPE HTML> +<html> +<head> + <title>Test BiquadFilterNode All Pass Filter</title> + <script src="/tests/SimpleTest/SimpleTest.js"></script> + <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" /> +</head> +<body> +<pre id="test"> +<script src="audio-testing.js"></script> +<script src="biquad-filters.js"></script> +<script src="biquad-testing.js"></script> +<script src="webaudio.js" type="text/javascript"></script> +<script class="testbody" type="text/javascript"> + +SimpleTest.waitForExplicitFinish(); + +addLoadEvent(function() { + // A high sample rate shows the issue more clearly. + var sampleRate = 192000; + // Some short duration because we don't need to run the test for very long. + var testDurationSec = 0.5; + var testDurationFrames = testDurationSec * sampleRate; + + // Amplitude experimentally determined to give a biquad output close to 1. (No attempt was + // made to produce exactly 1; it's not needed.) + var sourceAmplitude = 100; + + // The output of the biquad filter should not change by more than this much between output + // samples. Threshold was determined experimentally. + var glitchThreshold = 0.01292; + + // Test that a Biquad filter doesn't have it's output terminated because the input has gone + // away. Generally, when a source node is finished, it disconnects itself from any downstream + // nodes. This is the correct behavior. Nodes that have no inputs (disconnected) are + // generally assumed to output zeroes. This is also desired behavior. However, biquad + // filters have memory so they should not suddenly output zeroes when the input is + // disconnected. This test checks to see if the output doesn't suddenly change to zero. + var context = new OfflineAudioContext(1, testDurationFrames, sampleRate); + + // Create an impulse source. + var buffer = context.createBuffer(1, 1, context.sampleRate); + buffer.getChannelData(0)[0] = sourceAmplitude; + var source = context.createBufferSource(); + source.buffer = buffer; + + // Create the biquad filter. It doesn't really matter what kind, so the default filter type + // and parameters is fine. Connect the source to it. + var biquad = context.createBiquadFilter(); + source.connect(biquad); + biquad.connect(context.destination); + + source.start(); + + context.startRendering().then(function(result) { + // There should be no large discontinuities in the output + var buffer = result.getChannelData(0); + var maxGlitchIndex = 0; + var maxGlitchValue = 0.0; + for (var i = 1; i < buffer.length; i++) { + var diff = Math.abs(buffer[i-1] - buffer[i]); + if (diff >= glitchThreshold) { + if (diff > maxGlitchValue) { + maxGlitchIndex = i; + maxGlitchValue = diff; + } + } + } + ok(maxGlitchIndex == 0, 'glitches detected in biquad output: maximum glitch at ' + maxGlitchIndex + ' with diff of ' + maxGlitchValue); + SimpleTest.finish(); + }) +}); +</script> +</pre> +</body> +</html> |