| <!doctype html> |
| <html> |
| <head> |
| <title>Test Biquad Tail-Time</title> |
| <script src="../../imported/w3c/web-platform-tests/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; |
| let renderFrames = renderSeconds * sampleRate; |
| |
| // For a peaking filter: |
| // b0 = 1 - alpha*A |
| // b1 = -2*cos(w0) |
| // b2 = 1 + alpha*A |
| // a0 = 1 + alpha/A |
| // a1 = -2*cos(w0) |
| // a2 = 1 - alpha/A |
| // |
| // where alpha = sin(w0)/(2*Q), w0 = 2*%pi*f0/Fs, and A = 10^(G/40) |
| // |
| // Equivalently a1 = -2*cos(w0)/(1+alpha/A), a2 = (1-alpha/A)/(1+alpha/A). |
| // The poles of this filter are at |
| // |
| // A*cos(w0)/(A + alpha) +/- sqrt(alpha^2-A^2*sin(w0)^2)/(A + alpha) |
| // |
| // But alpha^2-A^2*sin(w0)^2 = sin(w0)^2*(1/4/Q^2-1). |
| // Thus, the poles are complex if 1/(4*Q^2) < A^2; real and distinct if |
| // 1/(4*Q^2)>A^2; and repeated if 1/(4*Q^2) = A^2 or w0 = 0. |
| |
| // Array of tests to run. |descripton| is the task description for |
| // audit.define. |parameters| is option for |testTailTime|. |
| let tests = [ |
| { |
| descripton: |
| {label: 'peaking-complex-roots', description: 'complex roots'}, |
| parameters: { |
| prefix: 'Peaking complex roots', |
| // A gain of 40 gives A = 10. |
| filterOptions: |
| {type: 'peaking', Q: 10, gain: 40, frequency: sampleRate / 4}, |
| // Node computed tail frame is 2077.4 frames, which matches the |
| // actual tail, so tail output should be exactly zero. |
| threshold: 0 |
| } |
| }, |
| { |
| descripton: { |
| label: 'peaking-real-distinct-roots', |
| description: 'real distinct roots' |
| }, |
| parameters: { |
| prefix: 'Peaking real distinct roots', |
| filterOptions: { |
| type: 'peaking', |
| Q: 0.001, |
| gain: 40, |
| frequency: sampleRate / 4 |
| }, |
| // Node computed tail frame is 588 frames, which matches the actual |
| // tail, so tail output should be exactly zero. |
| threshold: 0 |
| } |
| }, |
| { |
| descripton: { |
| label: 'peaking-repeated-roots', |
| description: 'repeated real root' |
| }, |
| parameters: { |
| prefix: 'Peaking repeated roots', |
| filterOptions: |
| {type: 'peaking', Q: 1 / 2, gain: 0, frequency: sampleRate / 8}, |
| // Node computed tail frame is 0 frames, which matches the actual |
| // tail, so tail output should be exactly zero. |
| threshold: 0 |
| |
| } |
| }, |
| { |
| descripton: { |
| label: 'peaking-repeated-roots 2', |
| description: 'repeated real root' |
| }, |
| parameters: { |
| prefix: 'Peaking repeated roots 2', |
| filterOptions: {type: 'peaking', Q: 1, gain: 40, frequency: 0}, |
| // Node computed tail frame is 1 frames, which matches the actual |
| // tail, so tail output should be exactly zero. |
| threshold: 0 |
| } |
| } |
| ]; |
| |
| // Define an appropriate task for each test. |
| tests.forEach(entry => { |
| audit.define(entry.descripton, (task, should) => { |
| let context = new OfflineAudioContext(1, renderFrames, sampleRate); |
| testTailTime(should, context, entry.parameters).then(() => task.done()); |
| }); |
| }); |
| |
| audit.run(); |
| </script> |
| </body> |
| </html> |
