| Index: LayoutTests/webaudio/audiobuffer-resample.html
|
| diff --git a/LayoutTests/webaudio/audiobuffer-resample.html b/LayoutTests/webaudio/audiobuffer-resample.html
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..0a56884cc427f8ea63ad2eb743d3078fcedec6ce
|
| --- /dev/null
|
| +++ b/LayoutTests/webaudio/audiobuffer-resample.html
|
| @@ -0,0 +1,140 @@
|
| +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
| +<html>
|
| + <head>
|
| + <script src="resources/compatibility.js"></script>
|
| + <script src="resources/audio-testing.js"></script>
|
| + <script src="../resources/js-test.js"></script>
|
| + </head>
|
| +
|
| + <body>
|
| + <div id="description"></div>
|
| + <div id="console"></div>
|
| +
|
| + <script>
|
| + // These are global to make debugging a little easier.
|
| + var context;
|
| + var buffer;
|
| + var source;
|
| + var renderedData;
|
| + var trueData;
|
| + var signalEnergy;
|
| + var noiseEnergy;
|
| + var maxError;
|
| +
|
| + // Context sample rate.
|
| + var sampleRate = 48000;
|
| + // The sample rate of the buffer.
|
| + var bufferRate = 3000;
|
| + // The audio buffer is a sine wave of this frequency.
|
| + var toneFrequency = 440;
|
| + // How long test is
|
| + var lengthInSeconds = 0.5;
|
| + // The maximum allowed peak error between the actual and true output. This value was
|
| + // experimentally determined for the given bufferRate.
|
| + var peakThreshold = 0.11;
|
| + // The minimum SNR allowed between the actual and true output.
|
| + var snrThreshold = 22.35;
|
| +
|
| + description("Test resampling of an AudioBuffer at " + bufferRate + " Hz");
|
| +
|
| + function log10(x) {
|
| + return Math.log(x)/Math.LN10;
|
| + }
|
| +
|
| + // Generate a sine wave in an AudioBuffer using the given |freq|. The AudioBuffer has the
|
| + // sample rate of |rate|.
|
| + function createSineBuffer(context, freq, rate) {
|
| + var buf = context.createBuffer(1, lengthInSeconds * rate, rate);
|
| + var omega = 2 * Math.PI * freq / rate;
|
| + var signal = buf.getChannelData(0);
|
| + var length = signal.length;
|
| + for (var k = 0; k < length; ++k)
|
| + signal[k] = Math.sin(omega * k);
|
| +
|
| + return buf;
|
| + }
|
| +
|
| + // Check the output against the expected output.
|
| + function checkResult(event) {
|
| + renderedData = event.renderedBuffer.getChannelData(0);
|
| + var length = renderedData.length;
|
| + // Generate a reference sine wave at the context rate
|
| + var trueReference = createSineBuffer(context, toneFrequency, context.sampleRate);
|
| + trueData = trueReference.getChannelData(0);
|
| +
|
| + // To compare the actual output against the reference, we compute the peak error and the
|
| + // SNR between the two.
|
| + signalEnergy = 0;
|
| + noiseEnergy = 0;
|
| + maxError = -1;
|
| +
|
| + var success = true;
|
| +
|
| + // Compute the peak error and the SNR.
|
| + for (var k = 0; k < length / 2; ++k) {
|
| + var diff = renderedData[k] - trueData[k];
|
| + noiseEnergy += diff * diff;
|
| + signalEnergy += trueData[k] * trueData[k];
|
| + if (Math.abs(diff) > maxError)
|
| + maxError = Math.abs(diff);
|
| + }
|
| +
|
| + var snr;
|
| +
|
| + if (noiseEnergy == 0)
|
| + snr = 1000;
|
| + else
|
| + snr = 10 * log10(signalEnergy / noiseEnergy);
|
| +
|
| + if (maxError < peakThreshold) {
|
| + testPassed("Peak error between actual and reference data below threshold of " +
|
| + peakThreshold + ".");
|
| + } else {
|
| + testFailed("Peak error of " + maxError + " exceeds threshold of " +
|
| + peakThreshold + ".");
|
| + success = false;
|
| + }
|
| +
|
| + if (snr > snrThreshold) {
|
| + testPassed("SNR exceeds threshold of " + snrThreshold + " dB.");
|
| + } else {
|
| + testFailed("SNR of " + snr + " is below the threshold of " + snrThreshold + ".");
|
| + success = false;
|
| + }
|
| +
|
| + if (success)
|
| + testPassed("AudioBuffer resampling is accurate for buffer rate of " +
|
| + bufferRate + " Hz.");
|
| + else
|
| + testFailed("AudioBuffer resampling is not accurate enough for buffer rate of " +
|
| + bufferRate + " Hz.");
|
| +
|
| + finishJSTest();
|
| + }
|
| +
|
| + function runTest() {
|
| + if (window.testRunner) {
|
| + testRunner.dumpAsText();
|
| + testRunner.waitUntilDone();
|
| + }
|
| +
|
| + window.jsTestIsAsync = true;
|
| +
|
| + context = new OfflineAudioContext(1, lengthInSeconds * sampleRate, sampleRate);
|
| +
|
| + // Create a sine wave in a buffer that's different from the context rate to test
|
| + // resampling.
|
| + buffer = createSineBuffer(context, toneFrequency, bufferRate);
|
| + source = context.createBufferSource();
|
| + source.buffer = buffer;
|
| + source.connect(context.destination);
|
| + source.start();
|
| +
|
| + context.oncomplete = checkResult;
|
| + context.startRendering();
|
| + }
|
| + runTest();
|
| + successfullyParsed = true;
|
| + </script>
|
| + </body>
|
| +</html>
|
|
|
Chromium Code Reviews
Issue 213153003:
Test resampling of AudioBuffers that have a different sample rate from the context (Closed)
Base URL: svn://svn.chromium.org/blink/trunk