| Index: LayoutTests/webaudio/resources/oscillator-testing.js
|
| diff --git a/LayoutTests/webaudio/resources/oscillator-testing.js b/LayoutTests/webaudio/resources/oscillator-testing.js
|
| index 68e6b9fe14c809f9601f6ba9e7fdad25e8452de0..67f67877a3b404734c74fe10c5fff6367b01d016 100644
|
| --- a/LayoutTests/webaudio/resources/oscillator-testing.js
|
| +++ b/LayoutTests/webaudio/resources/oscillator-testing.js
|
| @@ -9,6 +9,40 @@
|
| //
|
| // QUESTION: Why does the very end of the generated signal appear to get slightly weaker?
|
| // ANSWER: This is an artifact of the algorithm to avoid aliasing.
|
| +//
|
| +// QUESTION: Since the tests compare the actual result with an expected reference file, how are the
|
| +// reference files created?
|
| +// ANSWER: Create an html with the following contents in the webaudio directory. Then run a layout
|
| +// test on this file. A new file names "<file>-actual.wav" is created that contains the new result
|
| +// that can be used as the new expected reference file. Replace the "sine" below with the
|
| +// oscillator type that you want to use.
|
| +//
|
| +// <!DOCTYPE html>
|
| +// <html>
|
| +// <head>
|
| +// <script type="text/javascript" src="resources/audio-testing.js"></script>
|
| +// <script type="text/javascript" src="resources/oscillator-testing.js"></script>
|
| +// </head>
|
| +// <body>
|
| +// <script>
|
| +// window.onload = init;
|
| +//
|
| +// function init() {
|
| +// if (!window.testRunner)
|
| +// return;
|
| +//
|
| +// context = new OfflineAudioContext(1, sampleRate * lengthInSeconds, sampleRate);
|
| +// generateExponentialOscillatorSweep(context, "sine");
|
| +//
|
| +// context.oncomplete = finishAudioTest;
|
| +// context.startRendering();
|
| +//
|
| +// testRunner.waitUntilDone();
|
| +// }
|
| +//
|
| +// </script>
|
| +// </body>
|
| +// </html>
|
|
|
| var sampleRate = 44100.0;
|
| var nyquist = 0.5 * sampleRate;
|
| @@ -17,13 +51,27 @@ var lowFrequency = 10;
|
| var highFrequency = nyquist + 2000; // go slightly higher than nyquist to make sure we generate silence there
|
| var context = 0;
|
|
|
| +// Mostly for debugging
|
| +
|
| +// An AudioBuffer for the reference (expected) result.
|
| +var reference = 0;
|
| +
|
| +// The actual rendered data produced by the test.
|
| +var renderedData = 0;
|
| +
|
| +// Signal power of the reference
|
| +var signalPower = 0;
|
| +
|
| +// Noise power of the difference between the reference and actual result.
|
| +var noisePower = 0;
|
| +
|
| function generateExponentialOscillatorSweep(context, oscillatorType) {
|
| var osc = context.createOscillator();
|
| if (oscillatorType == "custom") {
|
| // Create a simple waveform with three Fourier coefficients.
|
| // Note the first values are expected to be zero (DC for coeffA and Nyquist for coeffB).
|
| var coeffA = new Float32Array([0, 1, 0.5]);
|
| - var coeffB = new Float32Array([0, 0, 0]);
|
| + var coeffB = new Float32Array([0, 0, 0]);
|
| var wave = context.createPeriodicWave(coeffA, coeffB);
|
| osc.setPeriodicWave(wave);
|
| } else {
|
| @@ -42,3 +90,75 @@ function generateExponentialOscillatorSweep(context, oscillatorType) {
|
| osc.frequency.setValueAtTime(10, 0);
|
| osc.frequency.exponentialRampToValueAtTime(highFrequency, lengthInSeconds);
|
| }
|
| +
|
| +function calculateSNR(sPower, nPower)
|
| +{
|
| + if (nPower == 0 && sPower > 0) {
|
| + return 1000;
|
| + }
|
| + return 10 * Math.log10(sPower / nPower);
|
| +}
|
| +
|
| +function loadReferenceAndRunTest(oscType) {
|
| + var bufferLoader = new BufferLoader(
|
| + context,
|
| + [ "oscillator-" + oscType + "-expected.wav" ],
|
| + function (bufferList) {
|
| + reference = bufferList[0].getChannelData(0);
|
| + generateExponentialOscillatorSweep(context, oscType);
|
| + context.oncomplete = checkResult;
|
| + context.startRendering();
|
| + });
|
| +
|
| + bufferLoader.load();
|
| +}
|
| +
|
| +function checkResult (event) {
|
| + renderedData = event.renderedBuffer.getChannelData(0);
|
| + // Compute signal to noise ratio between the result and the reference. Also keep track
|
| + // of the max difference (and position).
|
| +
|
| + var maxError = -1;
|
| + var errorPosition = -1;
|
| + var diffCount = 0;
|
| +
|
| + for (var k = 0; k < renderedData.length; ++k) {
|
| + var diff = renderedData[k] - reference[k];
|
| + noisePower += diff * diff;
|
| + signalPower += reference[k] * reference[k];
|
| + if (Math.abs(diff) > maxError) {
|
| + maxError = Math.abs(diff);
|
| + errorPosition = k;
|
| + }
|
| + // The reference file is a 16-bit WAV file, so we will never get an exact match
|
| + // between it and the actual floating-point result.
|
| + if (diff > 1/waveScaleFactor) {
|
| + diffCount++;
|
| + }
|
| + }
|
| +
|
| + var snr = calculateSNR(signalPower, noisePower);
|
| + if (snr < thresholdSNR) {
|
| + testFailed("Expected SNR of " + thresholdSNR + " dB, but actual SNR is " + snr + " dB");
|
| + } else {
|
| + testPassed("Exceeded SNR threshold of " + thresholdSNR + " dB");
|
| + }
|
| +
|
| + if (maxError > thresholdDiff) {
|
| + testFailed("Maximum difference of " + (maxError * waveScaleFactor) + " at "
|
| + + errorPosition + " exceeded threshold of " + (thresholdDiff * waveScaleFactor)
|
| + + " ulp (16-bits)");
|
| + } else {
|
| + testPassed("Maximum difference below threshold of "
|
| + + (thresholdDiff * waveScaleFactor) + " ulp (16-bits)");
|
| + }
|
| + if (diffCount > thresholdDiffCount) {
|
| + testFailed(diffCount + " differences found but expected no more than " + thresholdDiffCount);
|
| + } else {
|
| + testPassed("Number of differences between actual and expected result is less than " + thresholdDiffCount);
|
| + }
|
| +
|
| + finishJSTest();
|
| +}
|
| +
|
| +
|
|
|
Chromium Code Reviews
Issue 720293002:
Replace oscillator tests with more robust tests (Closed)
Base URL: svn://svn.chromium.org/blink/trunk