Frequency Domain implementation of Dynamics Processing Effect

Ported the frequency domain implementation of the effect from the
development sandbox.

Bug: 64161702
Bug: 38266419

Test: manual with Triton app. Cts tests. Listening tests.
Change-Id: I9417beba2f98f2a677f0857c7976bf76a0e0d8e0
diff --git a/media/libeffects/dynamicsproc/dsp/DPFrequency.cpp b/media/libeffects/dynamicsproc/dsp/DPFrequency.cpp
new file mode 100644
index 0000000..59195fc
--- /dev/null
+++ b/media/libeffects/dynamicsproc/dsp/DPFrequency.cpp
@@ -0,0 +1,518 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "DPFrequency"
+//#define LOG_NDEBUG 0
+
+#include <log/log.h>
+#include "DPFrequency.h"
+#include <algorithm>
+
+namespace dp_fx {
+
+using Eigen::MatrixXd;
+#define MAX_BLOCKSIZE 16384 //For this implementation
+#define MIN_BLOCKSIZE 8
+
+#define CIRCULAR_BUFFER_UPSAMPLE 4  //4 times buffer size
+
+static constexpr float MIN_ENVELOPE = 0.000001f;
+//helper functionS
+static inline bool isPowerOf2(unsigned long n) {
+    return (n & (n - 1)) == 0;
+}
+static constexpr float EPSILON = 0.0000001f;
+
+static inline bool isZero(float f) {
+    return fabs(f) <= EPSILON;
+}
+
+template <class T>
+bool compareEquality(T a, T b) {
+    return (a == b);
+}
+
+template <> bool compareEquality<float>(float a, float b) {
+    return isZero(a - b);
+}
+
+//TODO: avoid using macro for estimating change and assignment.
+#define IS_CHANGED(c, a, b) { c |= !compareEquality(a,b); \
+    (a) = (b); }
+
+float dBtoLinear(float valueDb) {
+    return  pow (10, valueDb / 20.0);
+}
+
+float linearToDb(float value) {
+    return 20 * log10(value);
+}
+
+//ChannelBuffers helper
+void ChannelBuffer::initBuffers(unsigned int blockSize, unsigned int overlapSize,
+        unsigned int halfFftSize, unsigned int samplingRate, DPBase &dpBase) {
+    ALOGV("ChannelBuffer::initBuffers blockSize %d, overlap %d, halfFft %d",
+            blockSize, overlapSize, halfFftSize);
+
+    mSamplingRate = samplingRate;
+    mBlockSize = blockSize;
+
+    cBInput.resize(mBlockSize * CIRCULAR_BUFFER_UPSAMPLE);
+    cBOutput.resize(mBlockSize * CIRCULAR_BUFFER_UPSAMPLE);
+
+    //fill input with half block size...
+    for (unsigned int k = 0;  k < mBlockSize/2; k++) {
+        cBInput.write(0);
+    }
+
+    //temp vectors
+    input.resize(mBlockSize);
+    output.resize(mBlockSize);
+    outTail.resize(overlapSize);
+
+    //module vectors
+    mPreEqFactorVector.resize(halfFftSize, 1.0);
+    mPostEqFactorVector.resize(halfFftSize, 1.0);
+
+    mPreEqBands.resize(dpBase.getPreEqBandCount());
+    mMbcBands.resize(dpBase.getMbcBandCount());
+    mPostEqBands.resize(dpBase.getPostEqBandCount());
+    ALOGV("mPreEqBands %zu, mMbcBands %zu, mPostEqBands %zu",mPreEqBands.size(),
+            mMbcBands.size(), mPostEqBands.size());
+
+    DPChannel *pChannel = dpBase.getChannel(0);
+    if (pChannel != NULL) {
+        mPreEqInUse = pChannel->getPreEq()->isInUse();
+        mMbcInUse = pChannel->getMbc()->isInUse();
+        mPostEqInUse = pChannel->getPostEq()->isInUse();
+        mLimiterInUse = pChannel->getLimiter()->isInUse();
+    }
+}
+
+void ChannelBuffer::computeBinStartStop(BandParams &bp, size_t binStart) {
+
+    bp.binStart = binStart;
+    bp.binStop = (int)(0.5 + bp.freqCutoffHz * mBlockSize / mSamplingRate);
+}
+
+//== DPFrequency
+
+void DPFrequency::reset() {
+}
+
+size_t DPFrequency::getMinBockSize() {
+    return MIN_BLOCKSIZE;
+}
+
+size_t DPFrequency::getMaxBockSize() {
+    return MAX_BLOCKSIZE;
+}
+
+void DPFrequency::configure(size_t blockSize, size_t overlapSize,
+        size_t samplingRate) {
+    ALOGV("configure");
+    mBlockSize = blockSize;
+    if (mBlockSize > MAX_BLOCKSIZE) {
+        mBlockSize = MAX_BLOCKSIZE;
+    } else if (mBlockSize < MIN_BLOCKSIZE) {
+        mBlockSize = MIN_BLOCKSIZE;
+    } else {
+        if (!isPowerOf2(blockSize)) {
+            //find next highest power of 2.
+            mBlockSize = 1 << (32 - __builtin_clz(blockSize));
+        }
+    }
+
+    mHalfFFTSize = 1 + mBlockSize / 2; //including Nyquist bin
+    mOverlapSize = std::min(overlapSize, mBlockSize/2);
+
+    int channelcount = getChannelCount();
+    mSamplingRate = samplingRate;
+    mChannelBuffers.resize(channelcount);
+    for (int ch = 0; ch < channelcount; ch++) {
+        mChannelBuffers[ch].initBuffers(mBlockSize, mOverlapSize, mHalfFFTSize,
+                mSamplingRate, *this);
+    }
+
+    //dsp
+    fill_window(mVWindow, RDSP_WINDOW_HANNING_FLAT_TOP, mBlockSize, mOverlapSize);
+}
+
+void DPFrequency::updateParameters(ChannelBuffer &cb, int channelIndex) {
+    DPChannel *pChannel = getChannel(channelIndex);
+
+    if (pChannel == NULL) {
+        ALOGE("Error: updateParameters null DPChannel %d", channelIndex);
+        return;
+    }
+
+    //===Input Gain and preEq
+    {
+        bool changed = false;
+        IS_CHANGED(changed, cb.inputGainDb, pChannel->getInputGain());
+        //===EqPre
+        if (cb.mPreEqInUse) {
+            DPEq *pPreEq = pChannel->getPreEq();
+            if (pPreEq == NULL) {
+                ALOGE("Error: updateParameters null PreEq for channel: %d", channelIndex);
+                return;
+            }
+            IS_CHANGED(changed, cb.mPreEqEnabled, pPreEq->isEnabled());
+            if (cb.mPreEqEnabled) {
+                for (unsigned int b = 0; b < getPreEqBandCount(); b++) {
+                    DPEqBand *pEqBand = pPreEq->getBand(b);
+                    if (pEqBand == NULL) {
+                        ALOGE("Error: updateParameters null PreEqBand for band %d", b);
+                        return; //failed.
+                    }
+                    ChannelBuffer::EqBandParams *pEqBandParams = &cb.mPreEqBands[b];
+                    IS_CHANGED(changed, pEqBandParams->enabled, pEqBand->isEnabled());
+                    IS_CHANGED(changed, pEqBandParams->freqCutoffHz,
+                            pEqBand->getCutoffFrequency());
+                    IS_CHANGED(changed, pEqBandParams->gainDb, pEqBand->getGain());
+                }
+            }
+        }
+
+        if (changed) {
+            float inputGainFactor = dBtoLinear(cb.inputGainDb);
+            if (cb.mPreEqInUse && cb.mPreEqEnabled) {
+                ALOGV("preEq changed, recomputing! channel %d", channelIndex);
+                size_t binNext = 0;
+                for (unsigned int b = 0; b < getPreEqBandCount(); b++) {
+                    ChannelBuffer::EqBandParams *pEqBandParams = &cb.mPreEqBands[b];
+
+                    //frequency translation
+                    cb.computeBinStartStop(*pEqBandParams, binNext);
+                    binNext = pEqBandParams->binStop + 1;
+                    float factor = dBtoLinear(pEqBandParams->gainDb);
+                    if (!pEqBandParams->enabled) {
+                        factor = inputGainFactor;
+                    }
+                    for (size_t k = pEqBandParams->binStart;
+                            k <= pEqBandParams->binStop && k < mHalfFFTSize; k++) {
+                        cb.mPreEqFactorVector[k] = factor * inputGainFactor;
+                    }
+                }
+            } else {
+                ALOGV("only input gain changed, recomputing!");
+                //populate PreEq factor with input gain factor.
+                for (size_t k = 0; k < mHalfFFTSize; k++) {
+                    cb.mPreEqFactorVector[k] = inputGainFactor;
+                }
+            }
+        }
+    } //inputGain and preEq
+
+    //===EqPost
+    if (cb.mPostEqInUse) {
+        bool changed = false;
+
+        DPEq *pPostEq = pChannel->getPostEq();
+        if (pPostEq == NULL) {
+            ALOGE("Error: updateParameters null postEq for channel: %d", channelIndex);
+            return; //failed.
+        }
+        IS_CHANGED(changed, cb.mPostEqEnabled, pPostEq->isEnabled());
+        if (cb.mPostEqEnabled) {
+            for (unsigned int b = 0; b < getPostEqBandCount(); b++) {
+                DPEqBand *pEqBand = pPostEq->getBand(b);
+                if (pEqBand == NULL) {
+                    ALOGE("Error: updateParameters PostEqBand NULL for band %d", b);
+                    return; //failed.
+                }
+                ChannelBuffer::EqBandParams *pEqBandParams = &cb.mPostEqBands[b];
+                IS_CHANGED(changed, pEqBandParams->enabled, pEqBand->isEnabled());
+                IS_CHANGED(changed, pEqBandParams->freqCutoffHz,
+                        pEqBand->getCutoffFrequency());
+                IS_CHANGED(changed, pEqBandParams->gainDb, pEqBand->getGain());
+            }
+            if (changed) {
+                ALOGV("postEq changed, recomputing! channel %d", channelIndex);
+                size_t binNext = 0;
+                for (unsigned int b = 0; b < getPostEqBandCount(); b++) {
+                    ChannelBuffer::EqBandParams *pEqBandParams = &cb.mPostEqBands[b];
+
+                    //frequency translation
+                    cb.computeBinStartStop(*pEqBandParams, binNext);
+                    binNext = pEqBandParams->binStop + 1;
+                    float factor = dBtoLinear(pEqBandParams->gainDb);
+                    if (!pEqBandParams->enabled) {
+                        factor = 1.0;
+                    }
+                    for (size_t k = pEqBandParams->binStart;
+                            k <= pEqBandParams->binStop && k < mHalfFFTSize; k++) {
+                        cb.mPostEqFactorVector[k] = factor;
+                    }
+                }
+            }
+        } //enabled
+    }
+
+    //===MBC
+    if (cb.mMbcInUse) {
+        DPMbc *pMbc = pChannel->getMbc();
+        if (pMbc == NULL) {
+            ALOGE("Error: updateParameters Mbc NULL for channel: %d", channelIndex);
+            return;
+        }
+        cb.mMbcEnabled = pMbc->isEnabled();
+        if (cb.mMbcEnabled) {
+            bool changed = false;
+            for (unsigned int b = 0; b < getMbcBandCount(); b++) {
+                DPMbcBand *pMbcBand = pMbc->getBand(b);
+                if (pMbcBand == NULL) {
+                    ALOGE("Error: updateParameters MbcBand NULL for band %d", b);
+                    return; //failed.
+                }
+                ChannelBuffer::MbcBandParams *pMbcBandParams = &cb.mMbcBands[b];
+                pMbcBandParams->enabled = pMbcBand->isEnabled();
+                IS_CHANGED(changed, pMbcBandParams->freqCutoffHz,
+                        pMbcBand->getCutoffFrequency());
+
+                pMbcBandParams->gainPreDb = pMbcBand->getPreGain();
+                pMbcBandParams->gainPostDb = pMbcBand->getPostGain();
+                pMbcBandParams->attackTimeMs = pMbcBand->getAttackTime();
+                pMbcBandParams->releaseTimeMs = pMbcBand->getReleaseTime();
+                pMbcBandParams->ratio = pMbcBand->getRatio();
+                pMbcBandParams->thresholdDb = pMbcBand->getThreshold();
+                pMbcBandParams->kneeWidthDb = pMbcBand->getKneeWidth();
+                pMbcBandParams->noiseGateThresholdDb = pMbcBand->getNoiseGateThreshold();
+                pMbcBandParams->expanderRatio = pMbcBand->getExpanderRatio();
+
+            }
+
+            if (changed) {
+                ALOGV("mbc changed, recomputing! channel %d", channelIndex);
+                size_t binNext= 0;
+                for (unsigned int b = 0; b < getMbcBandCount(); b++) {
+                    ChannelBuffer::MbcBandParams *pMbcBandParams = &cb.mMbcBands[b];
+
+                    pMbcBandParams->previousEnvelope = 0;
+
+                    //frequency translation
+                    cb.computeBinStartStop(*pMbcBandParams, binNext);
+                    binNext = pMbcBandParams->binStop + 1;
+                }
+
+            }
+
+        }
+    }
+}
+
+size_t DPFrequency::processSamples(const float *in, float *out, size_t samples) {
+       const float *pIn = in;
+       float *pOut = out;
+
+       int channelCount = mChannelBuffers.size();
+       if (channelCount < 1) {
+           ALOGW("warning: no Channels ready for processing");
+           return 0;
+       }
+
+       //**Check if parameters have changed and update
+       for (int ch = 0; ch < channelCount; ch++) {
+           updateParameters(mChannelBuffers[ch], ch);
+       }
+
+       //**separate into channels
+       for (size_t k = 0; k < samples; k += channelCount) {
+           for (int ch = 0; ch < channelCount; ch++) {
+               mChannelBuffers[ch].cBInput.write(*pIn++);
+           }
+       }
+
+       //TODO: lookahead limiters
+       //TODO: apply linked limiters to all channels.
+       //**Process each Channel
+       for (int ch = 0; ch < channelCount; ch++) {
+           processMono(mChannelBuffers[ch]);
+       }
+
+       //** estimate how much data is available in ALL channels
+       size_t available = mChannelBuffers[0].cBOutput.availableToRead();
+       for (int ch = 1; ch < channelCount; ch++) {
+           available = std::min(available, mChannelBuffers[ch].cBOutput.availableToRead());
+       }
+
+       //** make sure to output just what the buffer can handle
+       if (available > samples/channelCount) {
+           available = samples/channelCount;
+       }
+
+       //**Prepend zeroes if necessary
+       size_t fill = samples - (channelCount * available);
+       for (size_t k = 0; k < fill; k++) {
+           *pOut++ = 0;
+       }
+
+       //**interleave channels
+       for (size_t k = 0; k < available; k++) {
+           for (int ch = 0; ch < channelCount; ch++) {
+               *pOut++ = mChannelBuffers[ch].cBOutput.read();
+           }
+       }
+
+       return samples;
+}
+
+size_t DPFrequency::processMono(ChannelBuffer &cb) {
+
+    size_t processedSamples = 0;
+
+    size_t available = cb.cBInput.availableToRead();
+    while (available >= mBlockSize - mOverlapSize) {
+
+        //move tail of previous
+        for (unsigned int k = 0; k < mOverlapSize; ++k) {
+            cb.input[k] = cb.input[mBlockSize - mOverlapSize + k];
+        }
+
+        //read new available data
+        for (unsigned int k = 0; k < mBlockSize - mOverlapSize; k++) {
+            cb.input[mOverlapSize + k] = cb.cBInput.read();
+        }
+
+        //## Actual process
+        processOneVector(cb.output, cb.input, cb);
+        //##End of Process
+
+        //mix tail (and capture new tail
+        for (unsigned int k = 0; k < mOverlapSize; k++) {
+            cb.output[k] += cb.outTail[k];
+            cb.outTail[k] = cb.output[mBlockSize - mOverlapSize + k]; //new tail
+        }
+
+        //output data
+        for (unsigned int k = 0; k < mBlockSize - mOverlapSize; k++) {
+            cb.cBOutput.write(cb.output[k]);
+        }
+
+        available = cb.cBInput.availableToRead();
+    }
+
+    return processedSamples;
+}
+
+size_t DPFrequency::processOneVector(FloatVec & output, FloatVec & input,
+        ChannelBuffer &cb) {
+
+    //##apply window
+    Eigen::Map<Eigen::VectorXf> eWindow(&mVWindow[0], mVWindow.size());
+    Eigen::Map<Eigen::VectorXf> eInput(&input[0], input.size());
+
+    Eigen::VectorXf eWin = eInput.cwiseProduct(eWindow); //apply window
+
+    //##fft //TODO: refactor frequency transformations away from other stages.
+    mFftServer.fwd(mComplexTemp, eWin);
+
+    size_t cSize = mComplexTemp.size();
+    size_t maxBin = std::min(cSize/2, mHalfFFTSize);
+
+    //== EqPre (always runs)
+    for (size_t k = 0; k < maxBin; k++) {
+        mComplexTemp[k] *= cb.mPreEqFactorVector[k];
+    }
+
+    //== MBC
+    if (cb.mMbcInUse && cb.mMbcEnabled) {
+        for (size_t band = 0; band < cb.mMbcBands.size(); band++) {
+            ChannelBuffer::MbcBandParams *pMbcBandParams = &cb.mMbcBands[band];
+            float fEnergySum = 0;
+
+            //apply pre gain.
+            float preGainFactor = dBtoLinear(pMbcBandParams->gainPreDb);
+            float preGainSquared = preGainFactor * preGainFactor;
+
+            for (size_t k = pMbcBandParams->binStart; k <= pMbcBandParams->binStop; k++) {
+                float fReal = mComplexTemp[k].real();
+                float fImag = mComplexTemp[k].imag();
+                float fSquare = (fReal * fReal + fImag * fImag) * preGainSquared;
+
+                fEnergySum += fSquare;
+            }
+
+            fEnergySum = sqrt(fEnergySum /2.0);
+            float fTheta = 0.0;
+            float fFAtt = pMbcBandParams->attackTimeMs;
+            float fFRel = pMbcBandParams->releaseTimeMs;
+
+            float fUpdatesPerSecond = 10; //TODO: compute from framerate
+
+
+            if (fEnergySum > pMbcBandParams->previousEnvelope) {
+                fTheta = exp(-1.0 / (fFAtt * fUpdatesPerSecond));
+            } else {
+                fTheta = exp(-1.0 / (fFRel * fUpdatesPerSecond));
+            }
+
+            float fEnv = (1.0 - fTheta) * fEnergySum + fTheta * pMbcBandParams->previousEnvelope;
+
+            //preserve for next iteration
+            pMbcBandParams->previousEnvelope = fEnv;
+
+            float fThreshold = dBtoLinear(pMbcBandParams->thresholdDb);
+            float fNoiseGateThreshold = dBtoLinear(pMbcBandParams->noiseGateThresholdDb);
+
+            float fNewFactor = 1.0;
+
+            if (fEnv > fThreshold) {
+                float fDbAbove = linearToDb(fThreshold / fEnv);
+                float fDbTarget = fDbAbove / pMbcBandParams->ratio;
+                float fDbChange = fDbAbove - fDbTarget;
+                fNewFactor = dBtoLinear(fDbChange);
+            } else if (fEnv < fNoiseGateThreshold) {
+                if (fEnv < MIN_ENVELOPE) {
+                    fEnv = MIN_ENVELOPE;
+                }
+                float fDbBelow = linearToDb(fNoiseGateThreshold / fEnv);
+                float fDbTarget = fDbBelow / pMbcBandParams->expanderRatio;
+                float fDbChange = fDbBelow - fDbTarget;
+                fNewFactor = dBtoLinear(fDbChange);
+            }
+
+            //apply post gain.
+            fNewFactor *= dBtoLinear(pMbcBandParams->gainPostDb);
+
+            if (fNewFactor < 0) {
+                fNewFactor = 0;
+            }
+
+            //apply to this band
+            for (size_t k = pMbcBandParams->binStart; k <= pMbcBandParams->binStop; k++) {
+                mComplexTemp[k] *= fNewFactor;
+            }
+
+        } //end per band process
+
+    } //end MBC
+
+    //== EqPost
+    if (cb.mPostEqInUse && cb.mPostEqEnabled) {
+        for (size_t k = 0; k < maxBin; k++) {
+            mComplexTemp[k] *= cb.mPostEqFactorVector[k];
+        }
+    }
+
+    //##ifft directly to output.
+    Eigen::Map<Eigen::VectorXf> eOutput(&output[0], output.size());
+    mFftServer.inv(eOutput, mComplexTemp);
+
+    return mBlockSize;
+}
+
+} //namespace dp_fx