| Index: third_party/WebKit/LayoutTests/webaudio/BiquadFilter/tail-time-lowpass.html
|
| diff --git a/third_party/WebKit/LayoutTests/webaudio/BiquadFilter/tail-time-lowpass.html b/third_party/WebKit/LayoutTests/webaudio/BiquadFilter/tail-time-lowpass.html
|
| deleted file mode 100644
|
| index dc0426371a19453512c3f2f28e506d1650390190..0000000000000000000000000000000000000000
|
| --- a/third_party/WebKit/LayoutTests/webaudio/BiquadFilter/tail-time-lowpass.html
|
| +++ /dev/null
|
| @@ -1,168 +0,0 @@
|
| -<!doctype html>
|
| -<html>
|
| - <head>
|
| - <title>Test Biquad Tail-Time</title>
|
| - <script src="../../resources/testharness.js"></script>
|
| - <script src="../../resources/testharnessreport.js"></script>
|
| - <script src="../resources/audit-util.js"></script>
|
| - <script src="../resources/audit.js"></script>
|
| - <script src="../resources/biquad-filters.js"></script>
|
| - <script src="test-tail-time.js"></script>
|
| - </head>
|
| -
|
| - <body>
|
| - <script>
|
| - let audit = Audit.createTaskRunner();
|
| -
|
| - let sampleRate = 16384;
|
| - let renderSeconds = 1;
|
| -
|
| - // For a lowpass filter:
|
| - // b0 = (1-cos(w0))/2
|
| - // b1 = 1-cos(w0)
|
| - // b2 = (1-cos(w0))/2
|
| - // a0 = 1 + alpha
|
| - // a1 = -2*cos(w0)
|
| - // a2 = 1 - alpha
|
| - //
|
| - // where alpha = sin(w0)/(2*10^(Q/20)) and w0 = 2*%pi*f0/Fs.
|
| - //
|
| - // Equivalently a1 = -2*cos(w0)/(1+alpha), a2 = (1-alpha)/(1+alpha). The
|
| - // poles of this filter are at
|
| - //
|
| - // cos(w0)/(1+alpha) +/- sqrt(alpha^2-sin(w0)^2)/(1+alpha)
|
| - //
|
| - // But alpha^2-sin(w0)^2 = sin(w0)^2*(1/4/10^(Q/10) - 1). Thus the poles
|
| - // are complex if 1/4/10^(Q/10) < 1; real distinct if 1/4/10^(Q/10) > 1;
|
| - // and repeated if 1/4/10^(Q/10) = 1.
|
| -
|
| - // Array of tests to run. |descripton| is the task description for
|
| - // audit.define. |parameters| is option for |testTailTime|.
|
| - let tests = [
|
| - {
|
| - descripton:
|
| - {label: 'lpf-complex-roots', description: 'complex roots'},
|
| - sampleRate: sampleRate,
|
| - renderDuration: renderSeconds,
|
| - parameters: {
|
| - prefix: 'LPF complex roots',
|
| - filterOptions: {type: 'lowpass', Q: 40, frequency: sampleRate / 4}
|
| - },
|
| - // Node computed tail frame is 2079.4 which matches the real tail, so
|
| - // tail output should be exactly 0.
|
| - threshold: 0,
|
| - },
|
| - {
|
| - descripton: {
|
| - label: 'lpf-real-distinct-roots',
|
| - description: 'real distinct roots'
|
| - },
|
| - sampleRate: sampleRate,
|
| - renderDuration: renderSeconds,
|
| - parameters: {
|
| - prefix: 'LPF real distinct roots',
|
| - filterOptions:
|
| - {type: 'lowpass', Q: -50, frequency: sampleRate / 8}
|
| - },
|
| - // Node computed tail frame is 1699 which matches the real tail, so
|
| - // tail output should be exactly 0.
|
| - threshold: 0,
|
| - },
|
| - {
|
| - descripton:
|
| - {label: 'lpf-repeated-root', description: 'repeated real root'},
|
| - sampleRate: sampleRate,
|
| - renderDuration: renderSeconds,
|
| - parameters: {
|
| - prefix: 'LPF repeated roots (approximately)',
|
| - // For a repeated root, we need 1/4/10^(Q/10) = 1, or Q =
|
| - // -10*log(4)/log(10). This isn't exactly representable as a float,
|
| - // we the roots might not actually be repeated. In fact the roots
|
| - // are actually complex at 6.402396e-5*exp(i*1.570796).
|
| - filterOptions: {
|
| - type: 'lowpass',
|
| - Q: -10 * Math.log10(4),
|
| - frequency: sampleRate / 4
|
| - }
|
| - },
|
| - // Node computed tail frame is 2.9 which matches the real tail, so
|
| - // tail output should be exactly 0.
|
| - threshold: 0,
|
| - },
|
| - {
|
| - descripton: {label: 'lpf-real-roots-2', description: 'complex roots'},
|
| - sampleRate: sampleRate,
|
| - renderDuration: renderSeconds,
|
| - parameters: {
|
| - prefix: 'LPF repeated roots 2',
|
| - // This tests an extreme case where approximate impulse response is
|
| - // h(n) = C*r^(n-1) and C < 1/32768. Thus, the impulse response is
|
| - // always less than the response threshold of 1/32768.
|
| - filterOptions:
|
| - {type: 'lowpass', Q: -100, frequency: sampleRate / 4}
|
| - },
|
| - // Node computed tail frame is 0 which matches the real tail, so
|
| - // tail output should be exactly 0.
|
| - threshold: 0,
|
| - },
|
| - {
|
| - descripton: 'huge tail',
|
| - // The BiquadFilter has an internal maximum tail of 30 sec so we want
|
| - // to render for at least 30 sec to test this. Use the smallest
|
| - // sample rate we can to limit memory and CPU usage!
|
| - sampleRate: 3000,
|
| - renderDuration: 31,
|
| - parameters: {
|
| - prefix: 'LPF repeated roots (approximately)',
|
| - hugeTaileTime: true,
|
| - // For the record, for this lowpass filter, the computed tail time
|
| - // is approximately 2830.23 sec, with poles at
|
| - // 0.999998960442086*exp(i*0.209439510236777). This is very close to
|
| - // being marginally stable.
|
| - filterOptions: {
|
| - type: 'lowpass',
|
| - Q: 100,
|
| - frequency: 100,
|
| - },
|
| - // Node computed tail frame is 8.49069e6 which is clamped to 30 sec
|
| - // so tail output should be exactly 0 after 30 sec.
|
| - threshold: 0,
|
| - },
|
| - },
|
| - {
|
| - descripton: 'ginormous tail',
|
| - // Or this lowpass filter, the complex poles are actually computed to
|
| - // be on the unit circle so the tail infinite. This just tests that
|
| - // nothing bad happens in computing the tail time. Thus, any small
|
| - // sample rate and short duration for the test; the results aren't
|
| - // really interesting. (But they must pass, of course!)
|
| - sampleRate: 3000,
|
| - renderDuration: 0.25,
|
| - parameters: {
|
| - prefix: 'LPF repeated roots (approximately)',
|
| - filterOptions: {
|
| - type: 'lowpass',
|
| - Q: 500,
|
| - frequency: 100,
|
| - },
|
| - },
|
| - // Node computed tail frame is 90000 which matches the real tail, so
|
| - // tail output should be exactly 0.
|
| - threshold: 0,
|
| - }
|
| - ]
|
| -
|
| - // Define an appropriate task for each test.
|
| - tests.forEach(entry => {
|
| - audit.define(entry.descripton, (task, should) => {
|
| - let context = new OfflineAudioContext(
|
| - 1, entry.renderDuration * entry.sampleRate, entry.sampleRate);
|
| - testTailTime(should, context, entry.parameters)
|
| - .then(() => task.done());
|
| - });
|
| - });
|
| -
|
| - audit.run();
|
| - </script>
|
| - </body>
|
| -</html>
|
|
|
Chromium Code Reviews
Issue 2919503002:
Revert of Compute tail time from Biquad coefficients (Closed)
