1 /* 2 * Copyright (C) 2010 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "config.h" 27 28 #if ENABLE(WEB_AUDIO) 29 30 #include "modules/webaudio/AudioParam.h" 31 32 #include "platform/audio/AudioUtilities.h" 33 #include "modules/webaudio/AudioNode.h" 34 #include "modules/webaudio/AudioNodeOutput.h" 35 #include "platform/FloatConversion.h" 36 #include "wtf/MathExtras.h" 37 38 namespace WebCore { 39 40 const double AudioParam::DefaultSmoothingConstant = 0.05; 41 const double AudioParam::SnapThreshold = 0.001; 42 43 float AudioParam::value() 44 { 45 // Update value for timeline. 46 if (context() && context()->isAudioThread()) { 47 bool hasValue; 48 float timelineValue = m_timeline.valueForContextTime(context(), narrowPrecisionToFloat(m_value), hasValue); 49 50 if (hasValue) 51 m_value = timelineValue; 52 } 53 54 return narrowPrecisionToFloat(m_value); 55 } 56 57 void AudioParam::setValue(float value) 58 { 59 // Check against JavaScript giving us bogus floating-point values. 60 // Don't ASSERT, since this can happen if somebody writes bad JS. 61 if (!std::isnan(value) && !std::isinf(value)) 62 m_value = value; 63 } 64 65 float AudioParam::smoothedValue() 66 { 67 return narrowPrecisionToFloat(m_smoothedValue); 68 } 69 70 bool AudioParam::smooth() 71 { 72 // If values have been explicitly scheduled on the timeline, then use the exact value. 73 // Smoothing effectively is performed by the timeline. 74 bool useTimelineValue = false; 75 if (context()) 76 m_value = m_timeline.valueForContextTime(context(), narrowPrecisionToFloat(m_value), useTimelineValue); 77 78 if (m_smoothedValue == m_value) { 79 // Smoothed value has already approached and snapped to value. 80 return true; 81 } 82 83 if (useTimelineValue) 84 m_smoothedValue = m_value; 85 else { 86 // Dezipper - exponential approach. 87 m_smoothedValue += (m_value - m_smoothedValue) * m_smoothingConstant; 88 89 // If we get close enough then snap to actual value. 90 if (fabs(m_smoothedValue - m_value) < SnapThreshold) // FIXME: the threshold needs to be adjustable depending on range - but this is OK general purpose value. 91 m_smoothedValue = m_value; 92 } 93 94 return false; 95 } 96 97 float AudioParam::finalValue() 98 { 99 float value; 100 calculateFinalValues(&value, 1, false); 101 return value; 102 } 103 104 void AudioParam::calculateSampleAccurateValues(float* values, unsigned numberOfValues) 105 { 106 bool isSafe = context() && context()->isAudioThread() && values && numberOfValues; 107 ASSERT(isSafe); 108 if (!isSafe) 109 return; 110 111 calculateFinalValues(values, numberOfValues, true); 112 } 113 114 void AudioParam::calculateFinalValues(float* values, unsigned numberOfValues, bool sampleAccurate) 115 { 116 bool isGood = context() && context()->isAudioThread() && values && numberOfValues; 117 ASSERT(isGood); 118 if (!isGood) 119 return; 120 121 // The calculated result will be the "intrinsic" value summed with all audio-rate connections. 122 123 if (sampleAccurate) { 124 // Calculate sample-accurate (a-rate) intrinsic values. 125 calculateTimelineValues(values, numberOfValues); 126 } else { 127 // Calculate control-rate (k-rate) intrinsic value. 128 bool hasValue; 129 float timelineValue = m_timeline.valueForContextTime(context(), narrowPrecisionToFloat(m_value), hasValue); 130 131 if (hasValue) 132 m_value = timelineValue; 133 134 values[0] = narrowPrecisionToFloat(m_value); 135 } 136 137 // Now sum all of the audio-rate connections together (unity-gain summing junction). 138 // Note that connections would normally be mono, but we mix down to mono if necessary. 139 RefPtr<AudioBus> summingBus = AudioBus::create(1, numberOfValues, false); 140 summingBus->setChannelMemory(0, values, numberOfValues); 141 142 for (unsigned i = 0; i < numberOfRenderingConnections(); ++i) { 143 AudioNodeOutput* output = renderingOutput(i); 144 ASSERT(output); 145 146 // Render audio from this output. 147 AudioBus* connectionBus = output->pull(0, AudioNode::ProcessingSizeInFrames); 148 149 // Sum, with unity-gain. 150 summingBus->sumFrom(*connectionBus); 151 } 152 } 153 154 void AudioParam::calculateTimelineValues(float* values, unsigned numberOfValues) 155 { 156 // Calculate values for this render quantum. 157 // Normally numberOfValues will equal AudioNode::ProcessingSizeInFrames (the render quantum size). 158 double sampleRate = context()->sampleRate(); 159 double startTime = context()->currentTime(); 160 double endTime = startTime + numberOfValues / sampleRate; 161 162 // Note we're running control rate at the sample-rate. 163 // Pass in the current value as default value. 164 m_value = m_timeline.valuesForTimeRange(startTime, endTime, narrowPrecisionToFloat(m_value), values, numberOfValues, sampleRate, sampleRate); 165 } 166 167 void AudioParam::connect(AudioNodeOutput* output) 168 { 169 ASSERT(context()->isGraphOwner()); 170 171 ASSERT(output); 172 if (!output) 173 return; 174 175 if (m_outputs.contains(output)) 176 return; 177 178 output->addParam(this); 179 m_outputs.add(output); 180 changedOutputs(); 181 } 182 183 void AudioParam::disconnect(AudioNodeOutput* output) 184 { 185 ASSERT(context()->isGraphOwner()); 186 187 ASSERT(output); 188 if (!output) 189 return; 190 191 if (m_outputs.contains(output)) { 192 m_outputs.remove(output); 193 changedOutputs(); 194 output->removeParam(this); 195 } 196 } 197 198 } // namespace WebCore 199 200 #endif // ENABLE(WEB_AUDIO) 201
