src/third_party/web_platform_tests/webaudio/the-audio-api/the-waveshapernode-interface/curve-tests.html - cobalt - Git at Google

 <!doctype html>
 <html>
 <head>
 	<title>WaveShaperNode interface - Curve tests | WebAudio</title>

 	<script type="text/javascript" src="../../../resources/testharness.js"></script>
 	<script type="text/javascript" src="../../../resources/testharnessreport.js"></script>
 	<script type="text/javascript" src="../../js/vendor-prefixes.js"></script>
 </head>
 <body>
 	<div id="log">
 	</div>

 	<script type="text/javascript">
 		var sampleRate=44100.0;
 		var tolerance=0.01;

 		/*
 		Testing that -1, 0 and +1 map correctly to curve (with 1:1 correlation)
 		=======================================================================
 		From the specification:
 			The input signal is nominally within the range -1 -> +1.
 			Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
 				to the center value of the curve array.
 		*/
 		(function() {
 			var threeElementCurve=[2.0, -3.0, 4.0];
 			var inputData=[-1.0, 0, 1.0];
 			var expectedData=[2.0, -3.0, 4.0];
 			executeTest(threeElementCurve, inputData, expectedData, "Testing that -1, 0 and +1 map correctly to curve (with 1:1 correlation)");
 		})();

 		/*
 		Testing interpolation (where inputs don't correlate directly to curve elements)
 		===============================================================================
 		From the specification:
 			The implementation must perform linear interpolation between adjacent points in the curve.
 		*/
 		(function() {
 			var threeElementCurve=[2.0, -3.0, 4.0];
 			var inputData=[-0.5, +0.5, +0.75];
 			var expectedData=[-0.5, +0.5, +2.25];
 			executeTest(threeElementCurve, inputData, expectedData, "Testing interpolation (where inputs don't correlate directly to curve elements)");
 		})();

 		/*
 		Testing out-of-range inputs (should be mapped to the first/last elements of the curve)
 		======================================================================================
 		From the specification:
 			Any sample value less than -1 will correspond to the first value in the curve array.
 			Any sample value greater than +1 will correspond to the last value in the curve array.
 		*/
 		(function() {
 			var threeElementCurve=[2.0, -3.0, 4.0];
 			var inputData=[-1.5, +1.5];
 			var expectedData=[2.0, 4.0];
 			executeTest(threeElementCurve, inputData, expectedData, "Testing out-of-range inputs (should be mapped to the first/last elements of the curve)");
 		})();

 		/*
 		Testing a 2-element curve (does not have a middle element)
 		==========================================================
 		From the specification:
 			Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
 				to the center value of the curve array.
 			The implementation must perform linear interpolation between adjacent points in the curve.
 		*/
 		(function() {
 			var twoElementCurve=[2.0, -2.0];
 			var inputData=[-1.0, 0, 1.0];
 			var expectedData=[2.0, 0.0, -2.0];
 			executeTest(twoElementCurve, inputData, expectedData, "Testing a 2-element curve (does not have a middle element)");
 		})();

 		/*
 		Testing a 4-element curve (does not have a middle element)
 		==========================================================
 		From the specification:
 			Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
 				to the center value of the curve array.
 			The implementation must perform linear interpolation between adjacent points in the curve.
 		*/
 		(function() {
 			var fourElementCurve=[1.0, 2.0, 4.0, 7.0];
 			var inputData=[-1.0, 0, 1.0];
 			var expectedData=[1.0, 3.0, 7.0];
 			executeTest(fourElementCurve, inputData, expectedData, "Testing a 4-element curve (does not have a middle element)");
 		})();

 		/*
 		Testing a huge curve
 		====================
 		From the specification:
 			Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
 				to the center value of the curve array.
 		*/
 		(function() {
 			var bigCurve=[];
 			for(var i=0;i<=60000;i++) { bigCurve.push(i/3.5435); }
 			var inputData=[-1.0, 0, 1.0];
 			var expectedData=[bigCurve[0], bigCurve[30000], bigCurve[60000]];
 			executeTest(bigCurve, inputData, expectedData, "Testing a huge curve");
 		})();

 		/*
 		Testing single-element curve (boundary condition)
 		=================================================
 		From the specification:
 			Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
 				to the center value of the curve array.
 			Any sample value less than -1 will correspond to the first value in the curve array.
 			Any sample value greater than +1 will correspond to the last value in the curve array.
 			The implementation must perform linear interpolation between adjacent points in the curve.
 		Note:
 			I found a post on the W3C audio mailing list (from one of the Chris's) that suggested it would be feasible
 				to use the WaveShaperNode to create constant values.
 		*/
 		(function() {
 			var oneElementCurve=[1.0];
 			var inputData=[-1.0, 0, 1.0, -2.0, 2.0];
 			var expectedData=[1.0, 1.0, 1.0, 1.0, 1.0];
 			executeTest(oneElementCurve, inputData, expectedData, "Testing single-element curve (boundary condition)");
 		})();

 		/*
 		Testing null curve (should return input values)
 		===============================================
 		From the specification:
 			Initially the curve attribute is null, which means that the WaveShaperNode will pass its input to its output
 				without modification.
 		*/
 		(function() {
 			var inputData=[-1.0, 0, 1.0, 2.0];
 			var expectedData=[-1.0, 0.0, 1.0, 2.0];
 			executeTest(null, inputData, expectedData, "Testing null curve (should return input values)");
 		})();

 		/*
 		Testing zero-element curve (unspecified result)
 		===============================================
 		From the specification:
 			Unspecified result (I assume it will be treated in the same way as a null curve).
 		Note:
 			Mozilla test_waveShaperNoCurve.html indicates they expect same results as a null curve.
 		*/
 		(function() {
 			var zeroElementCurve=[];
 			var inputData=[-1.0, 0, 1.0, 2.0];
 			var expectedData=[-1.0, 0.0, 1.0, 2.0];
 			executeTest(zeroElementCurve, inputData, expectedData, "Testing zero-element curve (unspecified result)");
 		})();


 		/**
 		* Function that does the actual testing (using an asynchronous test).
 		* @param {?Array.<number>} curveData - Array containing values for the WaveShaper curve.
 		* @param {!Array.<number>} inputData - Array containing values for the input stream.
 		* @param {!Array.<number>} expectedData - Array containing expected results for each of the corresponding inputs.
 		* @param {!string} testName - Name of the test case.
 		*/
 		function executeTest(curveData, inputData, expectedData, testName) {
 			var stTest=async_test("WaveShaperNode - "+testName);

 			// Create offline audio context.
 			var ac=new OfflineAudioContext(1, inputData.length, sampleRate);

 			// Create the WaveShaper and its curve.
 			var waveShaper=ac.createWaveShaper();
 			if(curveData!=null) {
 				var curve=new Float32Array(curveData.length);
 				for(var i=0;i<curveData.length;i++) { curve[i]=curveData[i]; }
 				waveShaper.curve=curve;
 			}
 			waveShaper.connect(ac.destination);

 			// Create buffer containing the input values.
 			var inputBuffer=ac.createBuffer(1, Math.max(inputData.length, 2), sampleRate);
 			var d=inputBuffer.getChannelData(0);
 			for(var i=0;i<inputData.length;i++) { d[i]=inputData[i]; }

 			// Play the input buffer through the WaveShaper.
 			var src=ac.createBufferSource();
 			src.buffer=inputBuffer;
 			src.connect(waveShaper);
 			src.start();

 			// Test the outputs match the expected values.
 			ac.oncomplete=function(ev) {
 				var d=ev.renderedBuffer.getChannelData(0);

 				stTest.step(function() {
 					for(var i=0;i<expectedData.length;i++) {
 						var curveText="null";
 						if(curve!=null) {
 							if(curveData.length<20) {
 								curveText=curveData.join(",");
 							} else {
 								curveText="TooBigToDisplay ("+(curveData.length-1)+" elements)";
 							}
 						}
 						var comment="Input="+inputData[i]+", Curve=["+curveText+"] >>> ";
 						assert_approx_equals(d[i], expectedData[i], tolerance, comment);
 					}
 				});

 				stTest.done();
 			};
 			ac.startRendering();
 		}
 	</script>
 </body>
 </html>
	<!doctype html>
	<html>
	<head>
	<title>WaveShaperNode interface - Curve tests \| WebAudio</title>

	<script type="text/javascript" src="../../../resources/testharness.js"></script>
	<script type="text/javascript" src="../../../resources/testharnessreport.js"></script>
	<script type="text/javascript" src="../../js/vendor-prefixes.js"></script>
	</head>
	<body>
	<div id="log">
	</div>

	<script type="text/javascript">
	var sampleRate=44100.0;
	var tolerance=0.01;

	/*
	Testing that -1, 0 and +1 map correctly to curve (with 1:1 correlation)
	=======================================================================
	From the specification:
	The input signal is nominally within the range -1 -> +1.
	Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
	to the center value of the curve array.
	*/
	(function() {
	var threeElementCurve=[2.0, -3.0, 4.0];
	var inputData=[-1.0, 0, 1.0];
	var expectedData=[2.0, -3.0, 4.0];
	executeTest(threeElementCurve, inputData, expectedData, "Testing that -1, 0 and +1 map correctly to curve (with 1:1 correlation)");
	})();

	/*
	Testing interpolation (where inputs don't correlate directly to curve elements)
	===============================================================================
	From the specification:
	The implementation must perform linear interpolation between adjacent points in the curve.
	*/
	(function() {
	var threeElementCurve=[2.0, -3.0, 4.0];
	var inputData=[-0.5, +0.5, +0.75];
	var expectedData=[-0.5, +0.5, +2.25];
	executeTest(threeElementCurve, inputData, expectedData, "Testing interpolation (where inputs don't correlate directly to curve elements)");
	})();

	/*
	Testing out-of-range inputs (should be mapped to the first/last elements of the curve)
	======================================================================================
	From the specification:
	Any sample value less than -1 will correspond to the first value in the curve array.
	Any sample value greater than +1 will correspond to the last value in the curve array.
	*/
	(function() {
	var threeElementCurve=[2.0, -3.0, 4.0];
	var inputData=[-1.5, +1.5];
	var expectedData=[2.0, 4.0];
	executeTest(threeElementCurve, inputData, expectedData, "Testing out-of-range inputs (should be mapped to the first/last elements of the curve)");
	})();

	/*
	Testing a 2-element curve (does not have a middle element)
	==========================================================
	From the specification:
	Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
	to the center value of the curve array.
	The implementation must perform linear interpolation between adjacent points in the curve.
	*/
	(function() {
	var twoElementCurve=[2.0, -2.0];
	var inputData=[-1.0, 0, 1.0];
	var expectedData=[2.0, 0.0, -2.0];
	executeTest(twoElementCurve, inputData, expectedData, "Testing a 2-element curve (does not have a middle element)");
	})();

	/*
	Testing a 4-element curve (does not have a middle element)
	==========================================================
	From the specification:
	Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
	to the center value of the curve array.
	The implementation must perform linear interpolation between adjacent points in the curve.
	*/
	(function() {
	var fourElementCurve=[1.0, 2.0, 4.0, 7.0];
	var inputData=[-1.0, 0, 1.0];
	var expectedData=[1.0, 3.0, 7.0];
	executeTest(fourElementCurve, inputData, expectedData, "Testing a 4-element curve (does not have a middle element)");
	})();

	/*
	Testing a huge curve
	====================
	From the specification:
	Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
	to the center value of the curve array.
	*/
	(function() {
	var bigCurve=[];
	for(var i=0;i<=60000;i++) { bigCurve.push(i/3.5435); }
	var inputData=[-1.0, 0, 1.0];
	var expectedData=[bigCurve[0], bigCurve[30000], bigCurve[60000]];
	executeTest(bigCurve, inputData, expectedData, "Testing a huge curve");
	})();

	/*
	Testing single-element curve (boundary condition)
	=================================================
	From the specification:
	Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
	to the center value of the curve array.
	Any sample value less than -1 will correspond to the first value in the curve array.
	Any sample value greater than +1 will correspond to the last value in the curve array.
	The implementation must perform linear interpolation between adjacent points in the curve.
	Note:
	I found a post on the W3C audio mailing list (from one of the Chris's) that suggested it would be feasible
	to use the WaveShaperNode to create constant values.
	*/
	(function() {
	var oneElementCurve=[1.0];
	var inputData=[-1.0, 0, 1.0, -2.0, 2.0];
	var expectedData=[1.0, 1.0, 1.0, 1.0, 1.0];
	executeTest(oneElementCurve, inputData, expectedData, "Testing single-element curve (boundary condition)");
	})();

	/*
	Testing null curve (should return input values)
	===============================================
	From the specification:
	Initially the curve attribute is null, which means that the WaveShaperNode will pass its input to its output
	without modification.
	*/
	(function() {
	var inputData=[-1.0, 0, 1.0, 2.0];
	var expectedData=[-1.0, 0.0, 1.0, 2.0];
	executeTest(null, inputData, expectedData, "Testing null curve (should return input values)");
	})();

	/*
	Testing zero-element curve (unspecified result)
	===============================================
	From the specification:
	Unspecified result (I assume it will be treated in the same way as a null curve).
	Note:
	Mozilla test_waveShaperNoCurve.html indicates they expect same results as a null curve.
	*/
	(function() {
	var zeroElementCurve=[];
	var inputData=[-1.0, 0, 1.0, 2.0];
	var expectedData=[-1.0, 0.0, 1.0, 2.0];
	executeTest(zeroElementCurve, inputData, expectedData, "Testing zero-element curve (unspecified result)");
	})();


	/**
	* Function that does the actual testing (using an asynchronous test).
	* @param {?Array.<number>} curveData - Array containing values for the WaveShaper curve.
	* @param {!Array.<number>} inputData - Array containing values for the input stream.
	* @param {!Array.<number>} expectedData - Array containing expected results for each of the corresponding inputs.
	* @param {!string} testName - Name of the test case.
	*/
	function executeTest(curveData, inputData, expectedData, testName) {
	var stTest=async_test("WaveShaperNode - "+testName);

	// Create offline audio context.
	var ac=new OfflineAudioContext(1, inputData.length, sampleRate);

	// Create the WaveShaper and its curve.
	var waveShaper=ac.createWaveShaper();
	if(curveData!=null) {
	var curve=new Float32Array(curveData.length);
	for(var i=0;i<curveData.length;i++) { curve[i]=curveData[i]; }
	waveShaper.curve=curve;
	}
	waveShaper.connect(ac.destination);

	// Create buffer containing the input values.
	var inputBuffer=ac.createBuffer(1, Math.max(inputData.length, 2), sampleRate);
	var d=inputBuffer.getChannelData(0);
	for(var i=0;i<inputData.length;i++) { d[i]=inputData[i]; }

	// Play the input buffer through the WaveShaper.
	var src=ac.createBufferSource();
	src.buffer=inputBuffer;
	src.connect(waveShaper);
	src.start();

	// Test the outputs match the expected values.
	ac.oncomplete=function(ev) {
	var d=ev.renderedBuffer.getChannelData(0);

	stTest.step(function() {
	for(var i=0;i<expectedData.length;i++) {
	var curveText="null";
	if(curve!=null) {
	if(curveData.length<20) {
	curveText=curveData.join(",");
	} else {
	curveText="TooBigToDisplay ("+(curveData.length-1)+" elements)";
	}
	}
	var comment="Input="+inputData[i]+", Curve=["+curveText+"] >>> ";
	assert_approx_equals(d[i], expectedData[i], tolerance, comment);
	}
	});

	stTest.done();
	};
	ac.startRendering();
	}
	</script>
	</body>
	</html>