michael@0: /*
michael@0:  * Copyright (C) 2011 Google Inc. All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  * 1.  Redistributions of source code must retain the above copyright
michael@0:  *     notice, this list of conditions and the following disclaimer.
michael@0:  * 2.  Redistributions in binary form must reproduce the above copyright
michael@0:  *     notice, this list of conditions and the following disclaimer in the
michael@0:  *     documentation and/or other materials provided with the distribution.
michael@0:  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
michael@0:  *     its contributors may be used to endorse or promote products derived
michael@0:  *     from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
michael@0:  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
michael@0:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
michael@0:  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
michael@0:  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
michael@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
michael@0:  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
michael@0:  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: 
michael@0: #ifndef DynamicsCompressorKernel_h
michael@0: #define DynamicsCompressorKernel_h
michael@0: 
michael@0: #include "nsTArray.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: 
michael@0: namespace WebCore {
michael@0: 
michael@0: class DynamicsCompressorKernel {
michael@0: public:
michael@0:     DynamicsCompressorKernel(float sampleRate, unsigned numberOfChannels);
michael@0: 
michael@0:     void setNumberOfChannels(unsigned);
michael@0: 
michael@0:     // Performs stereo-linked compression.
michael@0:     void process(float* sourceChannels[],
michael@0:                  float* destinationChannels[],
michael@0:                  unsigned numberOfChannels,
michael@0:                  unsigned framesToProcess,
michael@0: 
michael@0:                  float dbThreshold,
michael@0:                  float dbKnee,
michael@0:                  float ratio,
michael@0:                  float attackTime,
michael@0:                  float releaseTime,
michael@0:                  float preDelayTime,
michael@0:                  float dbPostGain,
michael@0:                  float effectBlend,
michael@0: 
michael@0:                  float releaseZone1,
michael@0:                  float releaseZone2,
michael@0:                  float releaseZone3,
michael@0:                  float releaseZone4
michael@0:                  );
michael@0: 
michael@0:     void reset();
michael@0: 
michael@0:     unsigned latencyFrames() const { return m_lastPreDelayFrames; }
michael@0: 
michael@0:     float sampleRate() const { return m_sampleRate; }
michael@0: 
michael@0:     float meteringGain() const { return m_meteringGain; }
michael@0: 
michael@0:     size_t sizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
michael@0: 
michael@0: protected:
michael@0:     float m_sampleRate;
michael@0: 
michael@0:     float m_detectorAverage;
michael@0:     float m_compressorGain;
michael@0: 
michael@0:     // Metering
michael@0:     float m_meteringReleaseK;
michael@0:     float m_meteringGain;
michael@0: 
michael@0:     // Lookahead section.
michael@0:     enum { MaxPreDelayFrames = 1024 };
michael@0:     enum { MaxPreDelayFramesMask = MaxPreDelayFrames - 1 };
michael@0:     enum { DefaultPreDelayFrames = 256 }; // setPreDelayTime() will override this initial value
michael@0:     unsigned m_lastPreDelayFrames;
michael@0:     void setPreDelayTime(float);
michael@0: 
michael@0:     nsTArray<nsAutoArrayPtr<float> > m_preDelayBuffers;
michael@0:     int m_preDelayReadIndex;
michael@0:     int m_preDelayWriteIndex;
michael@0: 
michael@0:     float m_maxAttackCompressionDiffDb;
michael@0: 
michael@0:     // Static compression curve.
michael@0:     float kneeCurve(float x, float k);
michael@0:     float saturate(float x, float k);
michael@0:     float slopeAt(float x, float k);
michael@0:     float kAtSlope(float desiredSlope);
michael@0: 
michael@0:     float updateStaticCurveParameters(float dbThreshold, float dbKnee, float ratio);
michael@0: 
michael@0:     // Amount of input change in dB required for 1 dB of output change.
michael@0:     // This applies to the portion of the curve above m_kneeThresholdDb (see below).
michael@0:     float m_ratio;
michael@0:     float m_slope; // Inverse ratio.
michael@0: 
michael@0:     // The input to output change below the threshold is linear 1:1.
michael@0:     float m_linearThreshold;
michael@0:     float m_dbThreshold;
michael@0: 
michael@0:     // m_dbKnee is the number of dB above the threshold before we enter the "ratio" portion of the curve.
michael@0:     // m_kneeThresholdDb = m_dbThreshold + m_dbKnee
michael@0:     // The portion between m_dbThreshold and m_kneeThresholdDb is the "soft knee" portion of the curve
michael@0:     // which transitions smoothly from the linear portion to the ratio portion.
michael@0:     float m_dbKnee;
michael@0:     float m_kneeThreshold;
michael@0:     float m_kneeThresholdDb;
michael@0:     float m_ykneeThresholdDb;
michael@0: 
michael@0:     // Internal parameter for the knee portion of the curve.
michael@0:     float m_K;
michael@0: };
michael@0: 
michael@0: } // namespace WebCore
michael@0: 
michael@0: #endif // DynamicsCompressorKernel_h