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test_delayNodeTailWithReconnect.html (3660B)

      1 <!DOCTYPE HTML>
      2 <html>
      3 <head>
      4  <title>Test tail time lifetime of DelayNode after input finishes and new input added</title>
      5  <script src="/tests/SimpleTest/SimpleTest.js"></script>
      6  <script type="text/javascript" src="webaudio.js"></script>
      7  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
      8 </head>
      9 <body>
     10 <pre id="test">
     11 <script class="testbody" type="text/javascript">
     12 
     13 SimpleTest.waitForExplicitFinish();
     14 
     15 // The buffer source will start on a block boundary, so keeping the signal
     16 // within one block ensures that it will not cross AudioProcessingEvent buffer
     17 // boundaries.
     18 const signalLength = 128;
     19 const bufferSize = 1024;
     20 // Delay should be long enough to allow CC to run
     21 var delayBufferCount = 50;
     22 var delayBufferOffset;
     23 const delayLength = delayBufferCount * bufferSize;
     24 
     25 var phase = "initial";
     26 var sourceCount = 0;
     27 var delayCount = 0;
     28 var oscillator;
     29 var delay;
     30 var source;
     31 
     32 function applySignal(buffer, offset) {
     33  for (var i = 0; i < signalLength; ++i) {
     34    buffer.getChannelData(0)[offset + i] = Math.cos(Math.PI * i / signalLength);
     35  }
     36 }
     37 
     38 function bufferIsSilent(buffer, out) {
     39  for (var i = 0; i < buffer.length; ++i) {
     40    if (buffer.getChannelData(0)[i] != 0) {
     41      if (out) {
     42        out.soundOffset = i;
     43      }
     44      return false;
     45    }
     46  }
     47  return true;
     48 }
     49 
     50 function onDelayOutput(e) {
     51  switch(phase) {
     52 
     53  case "initial":
     54    // Wait for oscillator sound to exit delay
     55    if (bufferIsSilent(e.inputBuffer))
     56      break;
     57 
     58    phase = "played oscillator";
     59    break;
     60 
     61  case "played oscillator":
     62    // First tail time has expired.  Start second source and remove references
     63    // to the delay and connected second source.
     64    oscillator.disconnect();
     65    source.connect(delay);
     66    source.start();
     67    source = null;
     68    delay = null;
     69    phase = "started second source";
     70    break;
     71 
     72  case "second tail time":
     73    if (delayCount == delayBufferCount) {
     74      var ctx = e.target.context;
     75      var expected = ctx.createBuffer(1, bufferSize, ctx.sampleRate);
     76      applySignal(expected, delayBufferOffset);
     77      compareBuffers(e.inputBuffer, expected);
     78      e.target.onaudioprocess = null;
     79      SimpleTest.finish();
     80    }
     81  }
     82 
     83  delayCount++;
     84 }
     85 
     86 function onSourceOutput(e) {
     87  switch(phase) {
     88  case "started second source":
     89    var out = {};
     90    if (!bufferIsSilent(e.inputBuffer, out)) {
     91      delayBufferCount += sourceCount;
     92      delayBufferOffset = out.soundOffset;
     93      phase = "played second source";
     94    }
     95    break;
     96  case "played second source":
     97    SpecialPowers.forceGC();
     98    SpecialPowers.forceCC();
     99    phase = "second tail time";
    100    e.target.onaudioprocess = null;
    101  }
    102 
    103  sourceCount++;
    104 }
    105 
    106 function startTest() {
    107  var ctx = new AudioContext();
    108  var delayDuration = delayLength / ctx.sampleRate;
    109  delay = ctx.createDelay(delayDuration);
    110  delay.delayTime.value = delayDuration;
    111  var processor1 = ctx.createScriptProcessor(bufferSize, 1, 0);
    112  delay.connect(processor1);
    113  processor1.onaudioprocess = onDelayOutput;
    114 
    115  // Signal to trigger initial tail time reference
    116  oscillator = ctx.createOscillator();
    117  oscillator.start(0);
    118  oscillator.stop(100/ctx.sampleRate);
    119  oscillator.connect(delay);
    120 
    121  // Short signal, not started yet, with a ScriptProcessor to detect when it
    122  // starts.  It should finish before garbage collection.
    123  var buffer = ctx.createBuffer(1, signalLength, ctx.sampleRate);
    124  applySignal(buffer, 0);
    125  source = ctx.createBufferSource();
    126  source.buffer = buffer;
    127  var processor2 = ctx.createScriptProcessor(bufferSize, 1, 0);
    128  source.connect(processor2);
    129  processor2.onaudioprocess = onSourceOutput;
    130 };
    131 
    132 startTest();
    133 </script>
    134 </pre>
    135 </body>
    136 </html>