| <!DOCTYPE html> |
| |
| <!-- |
| Tests that multiple audio-rate signals (AudioNode outputs) can be connected to an AudioParam |
| and that these signals are summed, along with the AudioParams intrinsic value. |
| --> |
| |
| <html> |
| <head> |
| <script src="resources/audio-testing.js"></script> |
| <script src="resources/mix-testing.js"></script> |
| <script src="../resources/js-test.js"></script> |
| |
| </head> |
| <body> |
| |
| <script> |
| |
| var sampleRate = 44100.0; |
| var lengthInSeconds = 1; |
| |
| var context = 0; |
| |
| // Buffers used by the two gain controlling sources. |
| var linearRampBuffer; |
| var toneBuffer; |
| var toneFrequency = 440; |
| |
| // Arbitrary non-zero value. |
| var baselineGain = 5; |
| |
| // Allow for a small round-off error. |
| var maxAllowedError = 1e-6; |
| |
| function checkResult(event) { |
| var renderedBuffer = event.renderedBuffer; |
| var renderedData = renderedBuffer.getChannelData(0); |
| |
| // Get buffer data from the two sources used to control gain. |
| var linearRampData = linearRampBuffer.getChannelData(0); |
| var toneData = toneBuffer.getChannelData(0); |
| |
| var n = renderedBuffer.length; |
| |
| if (n == linearRampBuffer.length) { |
| testPassed("Rendered signal is of correct length."); |
| } else { |
| testFailed("Rendered signal is not of correct length."); |
| } |
| |
| // Check that the rendered result exactly matches the sum of the intrinsic gain plus the two sources used to control gain. |
| // This is because we're changing the gain of a signal having constant value 1. |
| var success = true; |
| for (var i = 0; i < n; ++i) { |
| var expectedValue = baselineGain + linearRampData[i] + toneData[i]; |
| var error = Math.abs(expectedValue - renderedData[i]); |
| |
| if (error > maxAllowedError) { |
| success = false; |
| break; |
| } |
| } |
| |
| if (success) { |
| testPassed("Rendered signal matches sum of two audio-rate gain changing signals plus baseline gain."); |
| } else { |
| testFailed("Rendered signal differs from the sum of two audio-rate gain changing signals plus baseline gain."); |
| } |
| |
| finishJSTest(); |
| } |
| |
| function runTest() { |
| window.jsTestIsAsync = true; |
| |
| var sampleFrameLength = sampleRate * lengthInSeconds; |
| |
| // Create offline audio context. |
| context = new OfflineAudioContext(1, sampleFrameLength, sampleRate); |
| |
| // Create buffer used by the source which will have its gain controlled. |
| var constantOneBuffer = createConstantBuffer(context, sampleFrameLength, 1); |
| var constantSource = context.createBufferSource(); |
| constantSource.buffer = constantOneBuffer; |
| |
| // Create 1st buffer used to control gain (a linear ramp). |
| linearRampBuffer = createLinearRampBuffer(context, sampleFrameLength); |
| var gainSource1 = context.createBufferSource(); |
| gainSource1.buffer = linearRampBuffer; |
| |
| // Create 2st buffer used to control gain (a simple sine wave tone). |
| toneBuffer = createToneBuffer(context, toneFrequency, lengthInSeconds, 1); |
| var gainSource2 = context.createBufferSource(); |
| gainSource2.buffer = toneBuffer; |
| |
| // Create a gain node controlling the gain of constantSource and make the connections. |
| var gainNode = context.createGain(); |
| |
| // Intrinsic baseline gain. |
| // This gain value should be summed with gainSource1 and gainSource2. |
| gainNode.gain.value = baselineGain; |
| |
| constantSource.connect(gainNode); |
| gainNode.connect(context.destination); |
| |
| // Connect two audio-rate signals to control the .gain AudioParam. |
| gainSource1.connect(gainNode.gain); |
| gainSource2.connect(gainNode.gain); |
| |
| // Start all sources at time 0. |
| constantSource.start(0); |
| gainSource1.start(0); |
| gainSource2.start(0); |
| |
| context.oncomplete = checkResult; |
| context.startRendering(); |
| } |
| |
| runTest(); |
| |
| </script> |
| </body> |
| </html> |
