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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
| commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
| tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/buffer-resampling.html | |
| parent | Initial commit. (diff) | |
| download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip | |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/buffer-resampling.html')
| -rw-r--r-- | testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/buffer-resampling.html | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/buffer-resampling.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/buffer-resampling.html new file mode 100644 index 0000000000..c181ceb8e0 --- /dev/null +++ b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/buffer-resampling.html @@ -0,0 +1,101 @@ +<!doctype html> +<html> + <head> + <title>Test Extrapolation at end of AudibBuffer in an AudioBufferSourceNode</title> + <script src="/resources/testharness.js"></script> + <script src="/resources/testharnessreport.js"></script> + <script src="/webaudio/resources/audit-util.js"></script> + <script src="/webaudio/resources/audit.js"></script> + </head> + <body> + <script> + let audit = Audit.createTaskRunner(); + + const sampleRate = 48000; + + // For testing we only need a few render quanta. + const renderSamples = 512 + + // Sample rate for our buffers. This is the lowest sample rate that is + // required to be supported. + const bufferRate = 8000; + + // Number of samples in each AudioBuffer; this is fairly arbitrary but + // should be less than a render quantum. + const bufferLength = 30; + + // Frequency of the sine wave for testing. + const frequency = 440; + + audit.define( + { + label: 'interpolate', + description: 'Interpolation of AudioBuffers to context sample rate' + }, + (task, should) => { + // The first channel is for the interpolated signal, and the second + // channel is for the reference signal from an oscillator. + let context = new OfflineAudioContext({ + numberOfChannels: 2, + length: renderSamples, + sampleRate: sampleRate + }); + + let merger = new ChannelMergerNode( + context, {numberOfChannels: context.destination.channelCount}); + merger.connect(context.destination); + + // Create a set of AudioBuffers which are samples from a pure sine + // wave with frequency |frequency|. + const nBuffers = Math.floor(context.length / bufferLength); + const omega = 2 * Math.PI * frequency / bufferRate; + + let frameNumber = 0; + let startTime = 0; + + for (let k = 0; k < nBuffers; ++k) { + // let buffer = context.createBuffer(1, bufferLength, + // bufferRate); + let buffer = new AudioBuffer( + {length: bufferLength, sampleRate: bufferRate}); + let data = buffer.getChannelData(0); + for (let n = 0; n < bufferLength; ++n) { + data[n] = Math.sin(omega * frameNumber); + ++frameNumber; + } + // Create a source using this buffer and start it at the end of + // the previous buffer. + let src = new AudioBufferSourceNode(context, {buffer: buffer}); + + src.connect(merger, 0, 0); + src.start(startTime); + startTime += buffer.duration; + } + + // Create the reference sine signal using an oscillator. + let osc = new OscillatorNode( + context, {type: 'sine', frequency: frequency}); + osc.connect(merger, 0, 1); + osc.start(0); + + context.startRendering() + .then(audioBuffer => { + let actual = audioBuffer.getChannelData(0); + let expected = audioBuffer.getChannelData(1); + + should(actual, 'Interpolated sine wave') + .beCloseToArray(expected, {absoluteThreshold: 9.0348e-2}); + + // Compute SNR between them. + let snr = 10 * Math.log10(computeSNR(actual, expected)); + + should(snr, `SNR (${snr.toPrecision(4)} dB)`) + .beGreaterThanOrEqualTo(37.17); + }) + .then(() => task.done()); + }); + + audit.run(); + </script> + </body> +</html> |