tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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delay-testing.js (2022B)

      1 let sampleRate = 44100.0;
      2 
      3 let renderLengthSeconds = 4;
      4 let delayTimeSeconds = 0.5;
      5 let toneLengthSeconds = 2;
      6 
      7 function createToneBuffer(context, frequency, numberOfCycles, sampleRate) {
      8  let duration = numberOfCycles / frequency;
      9  let sampleFrameLength = duration * sampleRate;
     10 
     11  let audioBuffer = context.createBuffer(1, sampleFrameLength, sampleRate);
     12 
     13  let n = audioBuffer.length;
     14  let data = audioBuffer.getChannelData(0);
     15 
     16  for (let i = 0; i < n; ++i)
     17    data[i] = Math.sin(frequency * 2.0 * Math.PI * i / sampleRate);
     18 
     19  return audioBuffer;
     20 }
     21 
     22 function checkDelayedResult(renderedBuffer, toneBuffer, should) {
     23  let sourceData = toneBuffer.getChannelData(0);
     24  let renderedData = renderedBuffer.getChannelData(0);
     25 
     26  let delayTimeFrames = delayTimeSeconds * sampleRate;
     27  let toneLengthFrames = toneLengthSeconds * sampleRate;
     28 
     29  let success = true;
     30 
     31  let n = renderedBuffer.length;
     32 
     33  for (let i = 0; i < n; ++i) {
     34    if (i < delayTimeFrames) {
     35      // Check that initial portion is 0 (since signal is delayed).
     36      if (renderedData[i] != 0) {
     37        should(
     38            renderedData[i], 'Initial portion expected to be 0 at frame ' + i)
     39            .beEqualTo(0);
     40        success = false;
     41        break;
     42      }
     43    } else if (i >= delayTimeFrames && i < delayTimeFrames + toneLengthFrames) {
     44      // Make sure that the tone data is delayed by exactly the expected number
     45      // of frames.
     46      let j = i - delayTimeFrames;
     47      if (renderedData[i] != sourceData[j]) {
     48        should(renderedData[i], 'Actual data at frame ' + i)
     49            .beEqualTo(sourceData[j]);
     50        success = false;
     51        break;
     52      }
     53    } else {
     54      // Make sure we have silence after the delayed tone.
     55      if (renderedData[i] != 0) {
     56        should(renderedData[j], 'Final portion at frame ' + i).beEqualTo(0);
     57        success = false;
     58        break;
     59      }
     60    }
     61  }
     62 
     63  should(
     64      success, 'Delaying test signal by ' + delayTimeSeconds + ' sec was done')
     65      .message('correctly', 'incorrectly')
     66 }