| Index: third_party/WebKit/LayoutTests/webaudio/audioparam-automation-clamping.html
|
| diff --git a/third_party/WebKit/LayoutTests/webaudio/audioparam-automation-clamping.html b/third_party/WebKit/LayoutTests/webaudio/audioparam-automation-clamping.html
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..5b9d562299f7895416dd02df3d62c0599c83cae9
|
| --- /dev/null
|
| +++ b/third_party/WebKit/LayoutTests/webaudio/audioparam-automation-clamping.html
|
| @@ -0,0 +1,132 @@
|
| +<!doctype html>
|
| +<html>
|
| + <head>
|
| + <script src="../resources/js-test.js"></script>
|
| + <script src="resources/compatibility.js"></script>
|
| + <script src="resources/audio-testing.js"></script>
|
| + <title>Test Clamping of Automations</title>
|
| + </head>
|
| +
|
| + <body>
|
| + <script>
|
| + description("Test Clamping of Automations.");
|
| + window.jsTestIsAsync = true;
|
| +
|
| + // Some arbitrary sample rate for the offline context.
|
| + var sampleRate = 48000;
|
| +
|
| + // Duration of test (fairly arbitrary).
|
| + var renderDuration = 1;
|
| + var renderFrames = renderDuration * sampleRate;
|
| +
|
| + var audit = Audit.createTaskRunner();
|
| +
|
| + audit.defineTask("clamp", function (done) {
|
| + // Test clamping of automations. Most AudioParam limits are essentially
|
| + // unbounded, so clamping doesn't happen. For most other AudioParams,
|
| + // the behavior is sufficiently complicated with complicated outputs
|
| + // that testing them is hard. However the output behavior of the
|
| + // frequency parameter for a BiquadFilter is relatively simple. Use
|
| + // that as the test.
|
| + var context = new OfflineAudioContext(1, renderFrames, sampleRate);
|
| +
|
| + var source = context.createBufferSource();
|
| + source.buffer = createConstantBuffer(context, 1, 1);
|
| + source.loop = true;
|
| +
|
| + var filter = context.createBiquadFilter();
|
| + filter.type = "lowpass";
|
| +
|
| + source.connect(filter);
|
| + filter.connect(context.destination);
|
| +
|
| + var V0 = 880;
|
| + var T0 = 0;
|
| + filter.frequency.setValueAtTime(V0, T0);
|
| +
|
| + var V1 = -1000;
|
| + var T1 = renderDuration / 4;
|
| + filter.frequency.linearRampToValueAtTime(V1, T1);
|
| +
|
| + var V2 = 880;
|
| + var T2 = renderDuration / 2;
|
| + filter.frequency.linearRampToValueAtTime(V2, T2);
|
| +
|
| + source.start();
|
| +
|
| + context.startRendering().then(function (buffer) {
|
| + var result = buffer.getChannelData(0);
|
| + var success = true;
|
| +
|
| + // When the cutoff frequency of a lowpass filter is 0, nothing gets
|
| + // through. Hence the output of the filter between the clamping
|
| + // period should be exactly zero. This tests passes if the output is 0
|
| + // during the expected range.
|
| + //
|
| + // Compute when the frequency value of the biquad goes to 0. In
|
| + // general, t = (T0*V1 -T1*V0)/(V1-V0) (using the notation from the
|
| + // spec.)
|
| + var clampStartTime = solveLinearRamp(0, V0, T0, V1, T1);
|
| + var clampEndTime = solveLinearRamp(0, V1, T1, V2, T2);
|
| +
|
| + var clampStartFrame = Math.ceil(clampStartTime * sampleRate);
|
| + var clampEndFrame = Math.floor(clampEndTime * sampleRate);
|
| +
|
| + var clampedSignal = result.slice(clampStartFrame, clampEndFrame + 1);
|
| + var expectedSignal = new Float32Array(clampedSignal.length);
|
| + expectedSignal.fill(0);
|
| +
|
| + // Output should be zero.
|
| + success = Should("Clamped signal in frame range [" + clampStartFrame + ", " +
|
| + clampEndFrame + "]",
|
| + clampedSignal, {
|
| + verbose: true,
|
| + }).beCloseToArray(expectedSignal, 0);
|
| +
|
| + // Find the actual clamp range based on the output values.
|
| + var actualClampStart = result.findIndex(x => x === 0);
|
| + var actualClampEnd = actualClampStart + result.slice(actualClampStart).findIndex(
|
| + x => x != 0);
|
| +
|
| + // Verify that the expected clamping range is a subset of the actual range.
|
| + success = Should("Actual Clamp start (" + actualClampStart + ")",
|
| + actualClampStart).beLessThanOrEqualTo(clampStartFrame) && success;
|
| + success == Should("Actual Clamp end (" + actualClampEnd + ")",
|
| + actualClampEnd).beGreaterThanOrEqualTo(clampEndFrame) && success;
|
| +
|
| + if (success)
|
| + testPassed("Clamping of BiquadFilter.frequency automation performed correctly.")
|
| + else
|
| + testFailed(
|
| + "Clamping of BiquadFilter.frequency automation performed incorrectly.")
|
| +
|
| + }).then(done);
|
| + });
|
| +
|
| + // All done!
|
| + audit.defineTask("finish", function (done) {
|
| + finishJSTest();
|
| + done();
|
| + });
|
| +
|
| + audit.runTasks();
|
| +
|
| + function solveLinearRamp(v, v0, t0, v1, t1) {
|
| + // Solve the linear ramp equation for the time t at which the ramp
|
| + // reaches the value v. The linear ramp equation (from the spec) is
|
| + //
|
| + // v(t) = v0 + (v1 - v0) * (t - t0)/(t1 - t0)
|
| + //
|
| + // Find t such that
|
| + //
|
| + // v = v0 + (v1 - v0) * (t - t0)/(t1 - t0)
|
| + //
|
| + // Then
|
| + //
|
| + // t = (t0 * v1 - t1 * v0 + (t1 - t0) * v) / (v1 - v0)
|
| + //
|
| + return (t0 * v1 - t1 * v0 + (t1 - t0) * v) / (v1 - v0);
|
| + }
|
| + </script>
|
| + </body>
|
| +</html>
|
|
|
Chromium Code Reviews
Issue 2000423008:
Clamp AudioParam automations to the nominal range. (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master