The Tor Browser: content/media/webaudio/test/test_delayNodeTailWithReconnect.html@44a2da4a2ab2 (annotated)

content/media/webaudio/test/test_delayNodeTailWithReconnect.html@44a2da4a2ab2 (annotated)

content/media/webaudio/test/test_delayNodeTailWithReconnect.html

Fri, 16 Jan 2015 04:50:19 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 04:50:19 +0100
branch: TOR_BUG_9701
changeset 13: 44a2da4a2ab2
permissions: -rw-r--r--

Replace accessor implementation with direct member state manipulation, by
request https://trac.torproject.org/projects/tor/ticket/9701#comment:32

 <!DOCTYPE HTML>
 <html>
 <head>
   <title>Test tail time lifetime of DelayNode after input finishes and new input added</title>
   <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
   <script type="text/javascript" src="webaudio.js"></script>
   <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
 </head>
 <body>
 <pre id="test">
 <script class="testbody" type="text/javascript">
 SimpleTest.waitForExplicitFinish();
 // The buffer source will start on a block boundary, so keeping the signal
 // within one block ensures that it will not cross AudioProcessingEvent buffer
 // boundaries.
 const signalLength = 128;
 const bufferSize = 1024;
 // Delay should be long enough to allow CC to run
 var delayBufferCount = 50;
 var delayBufferOffset;
 const delayLength = delayBufferCount * bufferSize;
 var phase = "initial";
 var sourceCount = 0;
 var delayCount = 0;
 var oscillator;
 var delay;
 var source;
 function applySignal(buffer, offset) {
   for (var i = 0; i < signalLength; ++i) {
     buffer.getChannelData(0)[offset + i] = Math.cos(Math.PI * i / signalLength);
   }
 }
 function bufferIsSilent(buffer, out) {
   for (var i = 0; i < buffer.length; ++i) {
     if (buffer.getChannelData(0)[i] != 0) {
       if (out) {
         out.soundOffset = i;
       }
       return false;
     }
   }
   return true;
 }
 function onDelayOutput(e) {
   switch(phase) {
   case "initial":
     // Wait for oscillator sound to exit delay
     if (bufferIsSilent(e.inputBuffer))
       break;
     phase = "played oscillator";
     break;
   case "played oscillator":
     // First tail time has expired.  Start second source and remove references
     // to the delay and connected second source.
     oscillator.disconnect();
     source.connect(delay);
     source.start();
     source = null;
     delay = null;
     phase = "started second source";
     break;
   case "second tail time":
     if (delayCount == delayBufferCount) {
       var ctx = e.target.context;
       var expected = ctx.createBuffer(1, bufferSize, ctx.sampleRate);
       applySignal(expected, delayBufferOffset);
       compareBuffers(e.inputBuffer, expected);
       e.target.onaudioprocess = null;
       SimpleTest.finish();
     }
   }
   delayCount++;
 }
 function onSourceOutput(e) {
   switch(phase) {
   case "started second source":
     var out = {};
     if (!bufferIsSilent(e.inputBuffer, out)) {
       delayBufferCount += sourceCount;
       delayBufferOffset = out.soundOffset;
       phase = "played second source";
     }
     break;
   case "played second source":
     SpecialPowers.forceGC();
     SpecialPowers.forceCC();
     phase = "second tail time";
     e.target.onaudioprocess = null;
   }
   sourceCount++;
 }
 function startTest() {
   var ctx = new AudioContext();
   var delayDuration = delayLength / ctx.sampleRate;
   delay = ctx.createDelay(delayDuration);
   delay.delayTime.value = delayDuration;
   var processor1 = ctx.createScriptProcessor(bufferSize, 1, 0);
   delay.connect(processor1);
   processor1.onaudioprocess = onDelayOutput;
   processor1.connect(ctx.destination); // work around bug 916387
   // Signal to trigger initial tail time reference
   oscillator = ctx.createOscillator();
   oscillator.start(0);
   oscillator.stop(100/ctx.sampleRate);
   oscillator.connect(delay);
   // Short signal, not started yet, with a ScriptProcessor to detect when it
   // starts.  It should finish before garbage collection.
   var buffer = ctx.createBuffer(1, signalLength, ctx.sampleRate);
   applySignal(buffer, 0);
   source = ctx.createBufferSource();
   source.buffer = buffer;
   var processor2 = ctx.createScriptProcessor(bufferSize, 1, 0);
   source.connect(processor2);
   processor2.onaudioprocess = onSourceOutput;
   processor2.connect(ctx.destination); // guard against bug 916387
 };
 startTest();
 </script>
 </pre>
 </body>
 </html>

The Tor Browser / annotate

content/media/webaudio/test/test_delayNodeTailWithReconnect.html@44a2da4a2ab2 (annotated)

content/media/webaudio/test/test_delayNodeTailWithReconnect.html