| <!doctype html> |
| <html> |
| <head> |
| <title> |
| Test Silent Inputs to WaveShaperNode |
| </title> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/webaudio/resources/audit-util.js"></script> |
| <script src="/webaudio/resources/audit.js"></script> |
| </head> |
| <body> |
| <script id="layout-test-code"> |
| let audit = Audit.createTaskRunner(); |
| let sampleRate = 16000; |
| |
| // Identity curve for the wave shaper: the input value is mapped directly |
| // to the output value. |
| let identityCurve = [-1, 0, 1]; |
| let nonZeroCurve = [0.5, 0.5, 0.5]; |
| |
| audit.define( |
| { |
| label: 'test-0', |
| description: 'curve output is non-zero for silent inputs' |
| }, |
| (task, should) => { |
| let {context, source, shaper} = |
| setupGraph(nonZeroCurve, sampleRate, sampleRate); |
| |
| source.offset.setValueAtTime(0, 0); |
| |
| context.startRendering() |
| .then(audioBuffer => { |
| should( |
| audioBuffer.getChannelData(0), |
| 'WaveShaper with silent inputs and curve ' + |
| JSON.stringify(shaper.curve)) |
| .beConstantValueOf(0.5); |
| }) |
| .then(() => task.done()); |
| }); |
| |
| audit.define( |
| { |
| label: 'test-1', |
| description: '2x curve output is non-zero for silent inputs' |
| }, |
| (task, should) => { |
| let {context, source, shaper} = |
| setupGraph(nonZeroCurve, sampleRate, sampleRate); |
| |
| source.offset.setValueAtTime(0, 0); |
| shaper.overSample = '2x'; |
| |
| context.startRendering() |
| .then(audioBuffer => { |
| should( |
| audioBuffer.getChannelData(0), |
| 'WaveShaper with ' + shaper.overSample + |
| ' oversample, silent inputs, and curve ' + |
| JSON.stringify(shaper.curve)) |
| .beConstantValueOf(0.5); |
| }) |
| .then(() => task.done()); |
| }); |
| |
| audit.define( |
| { |
| label: 'test-2', |
| description: 'curve output is non-zero for no inputs' |
| }, |
| (task, should) => { |
| let {context, source, shaper} = |
| setupGraph(nonZeroCurve, sampleRate, sampleRate); |
| |
| source.disconnect(); |
| |
| context.startRendering() |
| .then(audioBuffer => { |
| should( |
| audioBuffer.getChannelData(0), |
| 'WaveShaper with no inputs and curve ' + |
| JSON.stringify(shaper.curve)) |
| .beConstantValueOf(0.5); |
| }) |
| .then(() => task.done()); |
| }); |
| |
| function setupGraph(curve, testFrames, sampleRate) { |
| let context = new OfflineAudioContext(1, testFrames, sampleRate); |
| let source = new ConstantSourceNode(context); |
| let shaper = new WaveShaperNode(context, {curve: curve}); |
| |
| source.connect(shaper).connect(context.destination); |
| |
| return {context: context, source: source, shaper: shaper}; |
| } |
| |
| audit.run(); |
| </script> |
| </body> |
| </html> |
