chromium/src/third_party/blink/manual_tests/webaudio/multichannel.html - manifest_repos/chromium_src - Git at Google

 <!doctype html>
 <html>
   <head>
     <title>Test multichannel support.</title>
     <style type="text/css">
       body {
         margin: 2em;
       }
       .manual-test-ui {
         font-family: Arial;
         padding: 1em;
         border: 1px solid #999;
       }
       .manual-test-ui button {
         padding: 1em;
         font-size: 1em;
       }
     </style>
   </head>

   <body>
     <h1>Test Multichannel Audio Output</h1>

     <p>Tests that multichannel audio output (> 8 channels) is working correctly.
       This test cannot be run with an offline audio context because it requires
       an actual audio hardware with the multichannel capability.</p>

     <p>Press "Start Test Tone" to run the test. You should hear an one-second
       sine tone from all the available audio output channels from the channel 1
       to the last channel.</p>

     <p>Note that this test only works on OSX because CoreAudio driver supports
       the multichannel streams (more than 2) on a single audio device whereas
       other platforms do not.</p>

     <p>CRBUG issue: <a href="https://code.google.com/p/chromium/issues/detail?id=424795" target="_blank">
       424795</a></p>

     <div class="manual-test-ui">
       <p>Max Channel Count: <span id="eMaxChannelCount">2</span></p>
       <p>Currently playing: <span id="eChannelIndex">NONE</span></p>
       <button id="eButton" onclick="startTestTones()">Start Test Tone</button>
     </div>

     <script type="text/javascript">
       // Silent interval between the test tones.
       var testToneInterval = 0.1;

       // The safe range for the equal loudness of sinusoid is roughly between
       // 200 ~ 1000Hz, which is A3(57) ~ C6(84). In this test, the starting
       // pitch is 220Hz and the interval is the whole tone. (2 MIDI pitch)
       // With 16 speakers, the last test tone will play the MIDI pitch of
       // F6(89), which is 1396Hz.
       var startMIDIPitch = 57;

       var eMaxChannelCount = document.querySelector('#eMaxChannelCount');
       var eButton = document.querySelector('#eButton');
       var eChannelIndex = document.querySelector('#eChannelIndex');

       var context = new AudioContext();
       var maxChannelCount = context.destination.maxChannelCount;

       // Sets the destination properties for multichannel access.
       context.destination.channelCount = maxChannelCount;
       context.destination.channelCountMode = 'explicit';
       context.destination.channelInterpretation = 'discrete';

       // The ChannelMerger for the individual channel access.
       var merger = context.createChannelMerger(maxChannelCount);
       merger.channelCountMode = 'explicit';
       merger.channelInterpretation = 'discrete';
       merger.connect(context.destination);

       eMaxChannelCount.textContent = maxChannelCount;

       // Convert the MIDI pitch to frequency.
       function midi2freq(midiPitch) {
         return 440 * Math.pow(2, (midiPitch - 69) / 12);
       }

       // Play a test tone for the specified amount of duration at the channel.
       function playTestToneAtChannel(channelIndex, gain, duration) {
         var osc = context.createOscillator();
         var amp = context.createGain();
         osc.connect(amp);
         amp.connect(merger, 0, channelIndex);

         osc.onended = function () {
           var nextChannelIndex = channelIndex + 1;
           if (nextChannelIndex < maxChannelCount)
             playTestToneAtChannel(nextChannelIndex, gain, duration);
           else
             endTestTone();
         };

         // The pitch for each speaker goes up as the channel index increases.
         // Note that the interval is 2, whole tone.
         osc.frequency.value = midi2freq(startMIDIPitch + channelIndex * 2);

         // The channel index starts from 1.
         eChannelIndex.textContent = 'Channel #' + (channelIndex + 1);

         var now = context.currentTime;
         var toneDuration = duration - testToneInterval;

         // Add fade in and out to avoid the click noise.
         amp.gain.setValueAtTime(0.0, now);
         amp.gain.linearRampToValueAtTime(gain, now + toneDuration * 0.1);
         amp.gain.setValueAtTime(gain, now + toneDuration * 0.9);
         amp.gain.linearRampToValueAtTime(0.0, now + toneDuration);

         osc.start(now);
         osc.stop(now + duration);
       }

       // When the button is clicked the button to produce the test sound,
       // the button is grayed out so one cannot press again until the tone is
       // over. (producing sounds multiple times in a short period time will
       // hurt the speaker).
       function startTestTones() {
         eButton.disabled = true;

         // Math.SQRT1_2(=0.707..) is -3dB. This is necessary because 1.0
         // amplitude can cause overload/distortion on some speakers.
         playTestToneAtChannel(0, Math.SQRT1_2, 1.0);
       }

       // The button needs to be active back again when the test tone is over.
       // The index number in DIV should also be reset.
       function endTestTone() {
         eButton.disabled = false;
         eChannelIndex.textContent = 'NONE';
       }
     </script>
   </body>
 </html>
	<!doctype html>
	<html>
	<head>
	<title>Test multichannel support.</title>
	<style type="text/css">
	body {
	margin: 2em;
	}
	.manual-test-ui {
	font-family: Arial;
	padding: 1em;
	border: 1px solid #999;
	}
	.manual-test-ui button {
	padding: 1em;
	font-size: 1em;
	}
	</style>
	</head>

	<body>
	<h1>Test Multichannel Audio Output</h1>

	<p>Tests that multichannel audio output (> 8 channels) is working correctly.
	This test cannot be run with an offline audio context because it requires
	an actual audio hardware with the multichannel capability.</p>

	<p>Press "Start Test Tone" to run the test. You should hear an one-second
	sine tone from all the available audio output channels from the channel 1
	to the last channel.</p>

	<p>Note that this test only works on OSX because CoreAudio driver supports
	the multichannel streams (more than 2) on a single audio device whereas
	other platforms do not.</p>

	<p>CRBUG issue: <a href="https://code.google.com/p/chromium/issues/detail?id=424795" target="_blank">
	424795</a></p>

	<div class="manual-test-ui">
	<p>Max Channel Count: <span id="eMaxChannelCount">2</span></p>
	<p>Currently playing: <span id="eChannelIndex">NONE</span></p>
	<button id="eButton" onclick="startTestTones()">Start Test Tone</button>
	</div>

	<script type="text/javascript">
	// Silent interval between the test tones.
	var testToneInterval = 0.1;

	// The safe range for the equal loudness of sinusoid is roughly between
	// 200 ~ 1000Hz, which is A3(57) ~ C6(84). In this test, the starting
	// pitch is 220Hz and the interval is the whole tone. (2 MIDI pitch)
	// With 16 speakers, the last test tone will play the MIDI pitch of
	// F6(89), which is 1396Hz.
	var startMIDIPitch = 57;

	var eMaxChannelCount = document.querySelector('#eMaxChannelCount');
	var eButton = document.querySelector('#eButton');
	var eChannelIndex = document.querySelector('#eChannelIndex');

	var context = new AudioContext();
	var maxChannelCount = context.destination.maxChannelCount;

	// Sets the destination properties for multichannel access.
	context.destination.channelCount = maxChannelCount;
	context.destination.channelCountMode = 'explicit';
	context.destination.channelInterpretation = 'discrete';

	// The ChannelMerger for the individual channel access.
	var merger = context.createChannelMerger(maxChannelCount);
	merger.channelCountMode = 'explicit';
	merger.channelInterpretation = 'discrete';
	merger.connect(context.destination);

	eMaxChannelCount.textContent = maxChannelCount;

	// Convert the MIDI pitch to frequency.
	function midi2freq(midiPitch) {
	return 440 * Math.pow(2, (midiPitch - 69) / 12);
	}

	// Play a test tone for the specified amount of duration at the channel.
	function playTestToneAtChannel(channelIndex, gain, duration) {
	var osc = context.createOscillator();
	var amp = context.createGain();
	osc.connect(amp);
	amp.connect(merger, 0, channelIndex);

	osc.onended = function () {
	var nextChannelIndex = channelIndex + 1;
	if (nextChannelIndex < maxChannelCount)
	playTestToneAtChannel(nextChannelIndex, gain, duration);
	else
	endTestTone();
	};

	// The pitch for each speaker goes up as the channel index increases.
	// Note that the interval is 2, whole tone.
	osc.frequency.value = midi2freq(startMIDIPitch + channelIndex * 2);

	// The channel index starts from 1.
	eChannelIndex.textContent = 'Channel #' + (channelIndex + 1);

	var now = context.currentTime;
	var toneDuration = duration - testToneInterval;

	// Add fade in and out to avoid the click noise.
	amp.gain.setValueAtTime(0.0, now);
	amp.gain.linearRampToValueAtTime(gain, now + toneDuration * 0.1);
	amp.gain.setValueAtTime(gain, now + toneDuration * 0.9);
	amp.gain.linearRampToValueAtTime(0.0, now + toneDuration);

	osc.start(now);
	osc.stop(now + duration);
	}

	// When the button is clicked the button to produce the test sound,
	// the button is grayed out so one cannot press again until the tone is
	// over. (producing sounds multiple times in a short period time will
	// hurt the speaker).
	function startTestTones() {
	eButton.disabled = true;

	// Math.SQRT1_2(=0.707..) is -3dB. This is necessary because 1.0
	// amplitude can cause overload/distortion on some speakers.
	playTestToneAtChannel(0, Math.SQRT1_2, 1.0);
	}

	// The button needs to be active back again when the test tone is over.
	// The index number in DIV should also be reset.
	function endTestTone() {
	eButton.disabled = false;
	eChannelIndex.textContent = 'NONE';
	}
	</script>
	</body>
	</html>