| <!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 highshelf filter: |
| // b0 = A*[(A+1)+(A−1)*cos(w0)+2*as*sqrt(A)] |
| // b1 = 2*A*[(A-1)+(A+1)*cos(w0)] |
| // b2 = A*[(A+1)+(A−1)*cos(w0)-2*as*sqrt(A)] |
| // a0 = (A+1)-(A-1)*cos(w0)+2*as*sqrt(A) |
| // a1 = -2*[(A-1)-(A+1)*cos(w0)] |
| // a2 = (A+1)-(A-1)*cos(w0)-2*as*sqrt(A) |
| // |
| // where as = sin(w0)/sqrt(2), w0 = 2*%pi*f0/Fs, and A = 10^(G/40) |
| // |
| // The poles of this filter are |
| // |
| // -a2/(2*a0) +/- sqrt(a1^2-4*a0*a2)/(2*a0). |
| // |
| // Thus, the poles depend on the sign of d = a1^2-4*a0*a2 = |
| // 16*A*(as^2-sin(w0)^2) = -8*A*sin(w0)^2. Thus, the poles are always |
| // complex except if w0 = 0, in which case there is a repeated pole at 0. |
| |
| // Array of tests to run. |descripton| is the task description for |
| // audit.define. |parameters| is option for |testTailTime|. |
| let tests = [ |
| { |
| descripton: |
| {label: 'highshelf-complex-roots', description: 'complex roots'}, |
| parameters: { |
| prefix: 'Highshelf complex roots', |
| filterOptions: |
| {type: 'highshelf', gain: 40, frequency: sampleRate / 8}, |
| // Node computed tail frame is 18.6 frames, which matches the actual |
| // tail, so tail output should be exactly zero. |
| threshold: 0 |
| } |
| }, |
| { |
| descripton: { |
| label: 'highshelf-repeated-roots', |
| description: 'repeated real root' |
| }, |
| parameters: { |
| prefix: 'Highshelf repeated roots', |
| filterOptions: {type: 'highshelf', gain: 40, frequency: 0}, |
| // Node computed tail frame is 2 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> |
