/* * Copyright (C) 2011 Google Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of * its contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef DynamicsCompressorKernel_h #define DynamicsCompressorKernel_h #include "AudioArray.h" namespace WebCore { class DynamicsCompressorKernel { public: DynamicsCompressorKernel(double sampleRate); // Performs stereo-linked compression. void process(float *sourceL, float *destinationL, float *sourceR, float *destinationR, unsigned framesToProcess, float dbThreshold, float dbHeadroom, float attackTime, float releaseTime, float preDelayTime, float dbPostGain, float effectBlend, float releaseZone1, float releaseZone2, float releaseZone3, float releaseZone4 ); void reset(); unsigned latencyFrames() const { return m_lastPreDelayFrames; } float sampleRate() const { return m_sampleRate; } protected: float m_sampleRate; float m_detectorAverage; float m_compressorGain; // Metering float m_meteringReleaseK; float m_meteringGain; // Lookahead section. enum { MaxPreDelayFrames = 1024 }; enum { MaxPreDelayFramesMask = MaxPreDelayFrames - 1 }; enum { DefaultPreDelayFrames = 256 }; // setPreDelayTime() will override this initial value unsigned m_lastPreDelayFrames; void setPreDelayTime(float); AudioFloatArray m_preDelayBufferL; AudioFloatArray m_preDelayBufferR; int m_preDelayReadIndex; int m_preDelayWriteIndex; float m_maxAttackCompressionDiffDb; }; } // namespace WebCore #endif // DynamicsCompressorKernel_h