| <!doctype html> |
| <html> |
| <head> |
| <script src="../resources/js-test.js"></script> |
| <script src="resources/compatibility.js"></script> |
| <script src="resources/audio-testing.js"></script> |
| <script src="resources/audioparam-testing.js"></script> |
| <title>Test Sampling for SetTargetAtTime</title> |
| </head> |
| |
| <body> |
| <script> |
| description("Test Sampling of SetTargetAtTime"); |
| |
| window.jsTestIsAsync = true; |
| // Some slow sample rate, but otherwise arbitrary. |
| var sampleRate = 12800; |
| |
| // Time constant for setTargetValue. Make it short, but is otherwise arbitrary. |
| var 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. |
| var initialGain = 10000; |
| |
| var 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(message, startFrame, threshold, initializeGainFunction) { |
| var context = new OfflineAudioContext(1, 256, sampleRate); |
| var source = context.createBufferSource(); |
| var b = context.createBuffer(1, 1, sampleRate); |
| b.getChannelData(0)[0] = 1; |
| source.buffer = b; |
| source.loop = true; |
| |
| var 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. |
| var 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. |
| var frame = Math.ceil(startFrame); |
| var v = 10000 * Math.exp(-(frame / sampleRate - startFrame / sampleRate) / timeConstant); |
| Should(message + ": Target value at frame " + frame, resultData[frame]).beCloseTo(v, threshold); |
| }); |
| } |
| |
| function initializeGainBySetter (g) { |
| g.gain.value = initialGain; |
| } |
| |
| function initializeGainBySetValue (g) { |
| g.gain.setValueAtTime(initialGain, 0); |
| } |
| |
| audit.defineTask("setValue;128.1", function (done) { |
| doTest("Initialize by setValueAtTime", 128.1, 3.6029e-8, initializeGainBySetValue).then(done); |
| }); |
| |
| audit.defineTask("setValue;0.1", function (done) { |
| doTest("Initialize by setValueAtTime", 0.1, 3.6029e-8, initializeGainBySetValue).then(done); |
| }); |
| |
| audit.defineTask("setValue;0.0", function (done) { |
| doTest("Initialize by setValueAtTime", 0, 3.6029e-8, initializeGainBySetValue).then(done); |
| }); |
| |
| audit.defineTask("setter;128.1", function (done) { |
| doTest("Initialize by setter", 128.1, 3.6029e-8, initializeGainBySetter).then(done); |
| }); |
| |
| audit.defineTask("setter;0.1", function (done) { |
| doTest("Initialize by setter", 0.1, 3.6029e-8, initializeGainBySetter).then(done); |
| }); |
| |
| audit.defineTask("setter;0.0", function (done) { |
| doTest("Initialize by setter", 0, 0, initializeGainBySetter).then(done); |
| }); |
| |
| |
| audit.defineTask("finish", function (done) { |
| finishJSTest(); |
| done(); |
| }); |
| |
| audit.runTasks(); |
| successfullyParsed = true; |
| </script> |
| </body> |
| </html> |
