66 lines
2 KiB
JavaScript
66 lines
2 KiB
JavaScript
let sampleRate = 44100.0;
|
|
|
|
let renderLengthSeconds = 4;
|
|
let delayTimeSeconds = 0.5;
|
|
let toneLengthSeconds = 2;
|
|
|
|
function createToneBuffer(context, frequency, numberOfCycles, sampleRate) {
|
|
let duration = numberOfCycles / frequency;
|
|
let sampleFrameLength = duration * sampleRate;
|
|
|
|
let audioBuffer = context.createBuffer(1, sampleFrameLength, sampleRate);
|
|
|
|
let n = audioBuffer.length;
|
|
let data = audioBuffer.getChannelData(0);
|
|
|
|
for (let i = 0; i < n; ++i)
|
|
data[i] = Math.sin(frequency * 2.0 * Math.PI * i / sampleRate);
|
|
|
|
return audioBuffer;
|
|
}
|
|
|
|
function checkDelayedResult(renderedBuffer, toneBuffer, should) {
|
|
let sourceData = toneBuffer.getChannelData(0);
|
|
let renderedData = renderedBuffer.getChannelData(0);
|
|
|
|
let delayTimeFrames = delayTimeSeconds * sampleRate;
|
|
let toneLengthFrames = toneLengthSeconds * sampleRate;
|
|
|
|
let success = true;
|
|
|
|
let n = renderedBuffer.length;
|
|
|
|
for (let i = 0; i < n; ++i) {
|
|
if (i < delayTimeFrames) {
|
|
// Check that initial portion is 0 (since signal is delayed).
|
|
if (renderedData[i] != 0) {
|
|
should(
|
|
renderedData[i], 'Initial portion expected to be 0 at frame ' + i)
|
|
.beEqualTo(0);
|
|
success = false;
|
|
break;
|
|
}
|
|
} else if (i >= delayTimeFrames && i < delayTimeFrames + toneLengthFrames) {
|
|
// Make sure that the tone data is delayed by exactly the expected number
|
|
// of frames.
|
|
let j = i - delayTimeFrames;
|
|
if (renderedData[i] != sourceData[j]) {
|
|
should(renderedData[i], 'Actual data at frame ' + i)
|
|
.beEqualTo(sourceData[j]);
|
|
success = false;
|
|
break;
|
|
}
|
|
} else {
|
|
// Make sure we have silence after the delayed tone.
|
|
if (renderedData[i] != 0) {
|
|
should(renderedData[j], 'Final portion at frame ' + i).beEqualTo(0);
|
|
success = false;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
should(
|
|
success, 'Delaying test signal by ' + delayTimeSeconds + ' sec was done')
|
|
.message('correctly', 'incorrectly')
|
|
}
|