| <!DOCTYPE html> |
| <html> |
| <head> |
| <title> |
| oscillator-late-start.html |
| </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> |
| </head> |
| <body> |
| <script id="layout-test-code"> |
| let audit = Audit.createTaskRunner(); |
| |
| let sampleRate = 44100; |
| let renderLength = 1; |
| |
| let context; |
| let node; |
| |
| // Test the oscillator node is rendered correctly when the start time of |
| // start() call is in the past in terms of the context time. |
| audit.define('initialize', (task, should) => { |
| should( |
| () => context = new OfflineAudioContext( |
| 1, sampleRate * renderLength, sampleRate), |
| 'Creating offline context for testing') |
| .notThrow(); |
| should(() => { |
| // Set up a dummy signal path to keep the audio context running and |
| // spend processing time before calling start(0). |
| let osc = context.createOscillator(); |
| let silent = context.createGain(); |
| |
| osc.connect(silent); |
| silent.connect(context.destination); |
| silent.gain.setValueAtTime(0.0, 0); |
| osc.start(); |
| |
| node = context.createOscillator(); |
| node.connect(context.destination); |
| }, 'Creating graph for testing').notThrow(); |
| task.done(); |
| }); |
| |
| audit.define('test-late-start', (task, should) => { |
| // The node's start time will be clamped to the render quantum boundary |
| // >0.1 sec. Thus the rendered buffer will have non-zero frames. |
| // See issue: crbug.com/462167 |
| let suspendTime = 0.1; |
| let suspendFrame = 128 * Math.floor(0.1 * context.sampleRate / 128); |
| |
| context.suspend(suspendTime).then(() => { |
| node.start(0); |
| context.resume(); |
| }); |
| |
| // Start rendering and verify result: this verifies if 1) the rendered |
| // buffer contains at least one non-zero value and 2) the non-zero value |
| // is found later than the first output sample. |
| context.startRendering() |
| .then(buffer => { |
| let channelData = buffer.getChannelData(0); |
| let nonZeroValueIndex = channelData.findIndex(x => x != 0); |
| |
| should( |
| nonZeroValueIndex, |
| 'The index (' + nonZeroValueIndex + |
| ') of first non-zero output value') |
| .beGreaterThanOrEqualTo(suspendFrame); |
| |
| should( |
| channelData.slice(0, suspendFrame), |
| 'Output[0:' + (suspendFrame - 1) + ']') |
| .beConstantValueOf(0); |
| }) |
| .then(() => task.done()); |
| ; |
| }); |
| |
| audit.run(); |
| </script> |
| </body> |
| </html> |
