| <!DOCTYPE html> |
| <html> |
| <head> |
| <title> |
| Test Sampling for SetTargetAtTime |
| </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/audioparam-testing.js"></script> |
| </head> |
| <body> |
| <script id="layout-test-code"> |
| // Some slow sample rate, but otherwise arbitrary. |
| let sampleRate = 12800; |
| |
| // Time constant for setTargetValue. Make it short, but is otherwise |
| // arbitrary. |
| let timeConstant = 10 / sampleRate; |
| |
| // Defaut initial gain for test. Arbitrary, but we want it large so the |
| // changes look large, even if the relative change isn't. |
| let initialGain = 10000; |
| |
| let audit = Audit.createTaskRunner(); |
| |
| // Test sampling of setTargetAtTime that starts at |startFrame|. A gain |
| // node is used for testing. |initializeGainFunction| initializes the |
| // gain value. |
| function doTest( |
| should, message, startFrame, threshold, initializeGainFunction) { |
| let context = new OfflineAudioContext(1, 256, sampleRate); |
| let source = context.createBufferSource(); |
| let b = context.createBuffer(1, 1, sampleRate); |
| b.getChannelData(0)[0] = 1; |
| source.buffer = b; |
| source.loop = true; |
| |
| let gain = context.createGain(); |
| // Initialize the value of the gain node appropriately. |
| initializeGainFunction(gain); |
| gain.gain.setTargetAtTime(0, startFrame / sampleRate, timeConstant); |
| |
| source.connect(gain); |
| gain.connect(context.destination); |
| |
| source.start(); |
| |
| return context.startRendering().then(function(resultBuffer) { |
| // Verify that the sampling of the setTargetAtTime automation was done |
| // correctly. We just look at the sample just past the start of the |
| // automation. |
| let resultData = resultBuffer.getChannelData(0); |
| // Compute the true result at the frame just past startFrame and |
| // verify that the actual rendered result is within |threshold| of the |
| // expected value. |
| let frame = Math.ceil(startFrame); |
| let v = 10000 * |
| Math.exp( |
| -(frame / sampleRate - startFrame / sampleRate) / |
| timeConstant); |
| should( |
| resultData[frame], message + ': Target value at frame ' + frame) |
| .beCloseTo(v, {threshold: threshold}); |
| }); |
| } |
| |
| function initializeGainBySetter(g) { |
| g.gain.value = initialGain; |
| } |
| |
| function initializeGainBySetValue(g) { |
| g.gain.setValueAtTime(initialGain, 0); |
| } |
| |
| audit.define('setValue;128.1', (task, should) => { |
| doTest( |
| should, 'Initialize by setValueAtTime', 128.1, 3.6029e-8, |
| initializeGainBySetValue) |
| .then(() => task.done()); |
| }); |
| |
| audit.define('setValue;0.1', (task, should) => { |
| doTest( |
| should, 'Initialize by setValueAtTime', 0.1, 3.6029e-8, |
| initializeGainBySetValue) |
| .then(() => task.done()); |
| }); |
| |
| audit.define('setValue;0.0', (task, should) => { |
| doTest( |
| should, 'Initialize by setValueAtTime', 0, 3.6029e-8, |
| initializeGainBySetValue) |
| .then(() => task.done()); |
| }); |
| |
| audit.define('setter;128.1', (task, should) => { |
| doTest( |
| should, 'Initialize by setter', 128.1, 3.6029e-8, |
| initializeGainBySetter) |
| .then(() => task.done()); |
| }); |
| |
| audit.define('setter;0.1', (task, should) => { |
| doTest( |
| should, 'Initialize by setter', 0.1, 3.6029e-8, |
| initializeGainBySetter) |
| .then(() => task.done()); |
| }); |
| |
| audit.define('setter;0.0', (task, should) => { |
| doTest(should, 'Initialize by setter', 0, 0, initializeGainBySetter) |
| .then(() => task.done()); |
| }); |
| |
| audit.run(); |
| </script> |
| </body> |
| </html> |
