CASpectralProcessor.cpp

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//#include "AudioFormulas.h"
#include "CASpectralProcessor.h"
#include "CABitOperations.h"


#include <vecLib/vectorOps.h>


#define OFFSETOF(class, field)((size_t)&((class*)0)->field)

CASpectralProcessor::CASpectralProcessor(UInt32 inFFTSize, UInt32 inHopSize, UInt32 inNumChannels, UInt32 inMaxFrames)
    : mFFTSize(inFFTSize), mHopSize(inHopSize), mNumChannels(inNumChannels), mMaxFrames(inMaxFrames),
    mLog2FFTSize(Log2Ceil(mFFTSize)), 
    mFFTMask(mFFTSize - 1),
    mFFTByteSize(mFFTSize * sizeof(Float32)),
    mIOBufSize(NextPowerOfTwo(mFFTSize + mMaxFrames)),
    mIOMask(mIOBufSize - 1),
    mInputSize(0),
    mInputPos(0), mOutputPos(-mFFTSize & mIOMask), 
    mInFFTPos(0), mOutFFTPos(0),
    mSpectralFunction(0), mUserData(0)
{
    mWindow.alloc(mFFTSize, false);
    SineWindow(); // set default window.
    
    mChannels.alloc(mNumChannels);
    mSpectralBufferList.allocBytes(OFFSETOF(SpectralBufferList, mDSPSplitComplex[mNumChannels]), true);
    mSpectralBufferList->mNumberSpectra = mNumChannels;
    for (UInt32 i = 0; i < mNumChannels; ++i) 
    {
        mChannels[i].mInputBuf.alloc(mIOBufSize, true);
        mChannels[i].mOutputBuf.alloc(mIOBufSize, true);
        mChannels[i].mFFTBuf.alloc(mFFTSize, true);
        mChannels[i].mSplitFFTBuf.alloc(mFFTSize, true);
        mSpectralBufferList->mDSPSplitComplex[i].realp = mChannels[i].mSplitFFTBuf();
        mSpectralBufferList->mDSPSplitComplex[i].imagp = mChannels[i].mSplitFFTBuf() + (mFFTSize >> 1);
    }

    mFFTSetup = vDSP_create_fftsetup (mLog2FFTSize, FFT_RADIX2);
    
}

CASpectralProcessor::~CASpectralProcessor()
{
    mWindow.free();
    mChannels.free();
    mSpectralBufferList.free();
    vDSP_destroy_fftsetup(mFFTSetup);
}

void CASpectralProcessor::Reset()
{
    mInputPos = 0;
    mOutputPos = -mFFTSize & mIOMask;
    mInFFTPos = 0;
    mOutFFTPos = 0;
    
    for (UInt32 i = 0; i < mNumChannels; ++i) 
    {
        memset(mChannels[i].mInputBuf(), 0, mIOBufSize * sizeof(Float32));
        memset(mChannels[i].mOutputBuf(), 0, mIOBufSize * sizeof(Float32));
        memset(mChannels[i].mFFTBuf(), 0, mFFTSize * sizeof(Float32));
    }
}

const double two_pi = 2. * M_PI;

void CASpectralProcessor::HanningWindow()
{ 
    // this is also vector optimized

    double w = two_pi / (double)(mFFTSize - 1);
    for (UInt32 i = 0; i < mFFTSize; ++i)
    {
        mWindow[i] = (0.5 - 0.5 * cos(w * (double)i));  
    }
}

void CASpectralProcessor::SineWindow()
{
    double w = M_PI / (double)(mFFTSize - 1);
    for (UInt32 i = 0; i < mFFTSize; ++i)
    {
        mWindow[i] = sin(w * (double)i);
    }
}

void CASpectralProcessor::Process(UInt32 inNumFrames, AudioBufferList* inInput, AudioBufferList* outOutput)
{
    // copy from buffer list to input buffer
    CopyInput(inNumFrames, inInput);
    
    // if enough input to process, then process.
    while (mInputSize >= mFFTSize) 
    {
        CopyInputToFFT(); // copy from input buffer to fft buffer
        DoWindowing();
        DoFwdFFT();
        ProcessSpectrum(mFFTSize, mSpectralBufferList());
        DoInvFFT();
        DoWindowing();
        OverlapAddOutput();
    }

    // copy from output buffer to buffer list
    CopyOutput(inNumFrames, outOutput);
}

void CASpectralProcessor::DoWindowing()
{
    Float32 *win = mWindow();
    if (!win) return;
    for (UInt32 i=0; i<mNumChannels; ++i) {
        Float32 *x = mChannels[i].mFFTBuf();
        vDSP_vmul(x, 1, win, 1, x, 1, mFFTSize);
    }
    //printf("DoWindowing %g %g\n", mChannels[0].mFFTBuf()[0], mChannels[0].mFFTBuf()[200]);
}



void CASpectralProcessor::CopyInput(UInt32 inNumFrames, AudioBufferList* inInput)
{
    UInt32 numBytes = inNumFrames * sizeof(Float32);
    UInt32 firstPart = mIOBufSize - mInputPos;
    

    if (firstPart < inNumFrames) {
        UInt32 firstPartBytes = firstPart * sizeof(Float32);
        UInt32 secondPartBytes = numBytes - firstPartBytes;
        for (UInt32 i=0; i<mNumChannels; ++i) {     
            memcpy(mChannels[i].mInputBuf + mInputPos, inInput->mBuffers[i].mData, firstPartBytes);
            memcpy(mChannels[i].mInputBuf, (UInt8*)inInput->mBuffers[i].mData + firstPartBytes, secondPartBytes);
        }
    } else {
        UInt32 numBytes = inNumFrames * sizeof(Float32);
        for (UInt32 i=0; i<mNumChannels; ++i) {     
            memcpy(mChannels[i].mInputBuf + mInputPos, inInput->mBuffers[i].mData, numBytes);
        }
    }
    //printf("CopyInput %g %g\n", mChannels[0].mInputBuf[mInputPos], mChannels[0].mInputBuf[(mInputPos + 200) & mIOMask]);
    //printf("CopyInput mInputPos %u   mIOBufSize %u\n", (unsigned)mInputPos, (unsigned)mIOBufSize);
    mInputSize += inNumFrames;
    mInputPos = (mInputPos + inNumFrames) & mIOMask;
}

void CASpectralProcessor::CopyOutput(UInt32 inNumFrames, AudioBufferList* outOutput)
{
    //printf("->CopyOutput %g %g\n", mChannels[0].mOutputBuf[mOutputPos], mChannels[0].mOutputBuf[(mOutputPos + 200) & mIOMask]);
    //printf("CopyOutput mOutputPos %u\n", (unsigned)mOutputPos);
    UInt32 numBytes = inNumFrames * sizeof(Float32);
    UInt32 firstPart = mIOBufSize - mOutputPos;
    if (firstPart < inNumFrames) {
        UInt32 firstPartBytes = firstPart * sizeof(Float32);
        UInt32 secondPartBytes = numBytes - firstPartBytes;
        for (UInt32 i=0; i<mNumChannels; ++i) {
            memcpy(outOutput->mBuffers[i].mData, mChannels[i].mOutputBuf + mOutputPos, firstPartBytes);
            memcpy((UInt8*)outOutput->mBuffers[i].mData + firstPartBytes, mChannels[i].mOutputBuf, secondPartBytes);
            memset(mChannels[i].mOutputBuf + mOutputPos, 0, firstPartBytes);
            memset(mChannels[i].mOutputBuf, 0, secondPartBytes);
        }
    } else {
        for (UInt32 i=0; i<mNumChannels; ++i) {
            memcpy(outOutput->mBuffers[i].mData, mChannels[i].mOutputBuf + mOutputPos, numBytes);
            memset(mChannels[i].mOutputBuf + mOutputPos, 0, numBytes);
        }
    }
    //printf("<-CopyOutput %g %g\n", ((Float32*)outOutput->mBuffers[0].mData)[0], ((Float32*)outOutput->mBuffers[0].mData)[200]);
    mOutputPos = (mOutputPos + inNumFrames) & mIOMask;
}

void CASpectralProcessor::PrintSpectralBufferList()
{
    UInt32 half = mFFTSize >> 1;
    for (UInt32 i=0; i<mNumChannels; ++i) {
        DSPSplitComplex &freqData = mSpectralBufferList->mDSPSplitComplex[i];
    
        for (UInt32 j=0; j<half; j++){
            printf(" bin[%d]: %lf + %lfi\n", (int) j, freqData.realp[j], freqData.imagp[j]);
        }
    }
}


void CASpectralProcessor::CopyInputToFFT()
{
    //printf("CopyInputToFFT mInFFTPos %u\n", (unsigned)mInFFTPos);
    UInt32 firstPart = mIOBufSize - mInFFTPos;
    UInt32 firstPartBytes = firstPart * sizeof(Float32);
    if (firstPartBytes < mFFTByteSize) {
        UInt32 secondPartBytes = mFFTByteSize - firstPartBytes;
        for (UInt32 i=0; i<mNumChannels; ++i) {
            memcpy(mChannels[i].mFFTBuf(), mChannels[i].mInputBuf() + mInFFTPos, firstPartBytes);
            memcpy((UInt8*)mChannels[i].mFFTBuf() + firstPartBytes, mChannels[i].mInputBuf(), secondPartBytes);
        }
    } else {
        for (UInt32 i=0; i<mNumChannels; ++i) {
            memcpy(mChannels[i].mFFTBuf(), mChannels[i].mInputBuf() + mInFFTPos, mFFTByteSize);
        }
    }
    mInputSize -= mHopSize;
    mInFFTPos = (mInFFTPos + mHopSize) & mIOMask;
    //printf("CopyInputToFFT %g %g\n", mChannels[0].mFFTBuf()[0], mChannels[0].mFFTBuf()[200]);
}

void CASpectralProcessor::OverlapAddOutput()
{
    //printf("OverlapAddOutput mOutFFTPos %u\n", (unsigned)mOutFFTPos);
    UInt32 firstPart = mIOBufSize - mOutFFTPos;
    if (firstPart < mFFTSize) {
        UInt32 secondPart = mFFTSize - firstPart;
        for (UInt32 i=0; i<mNumChannels; ++i) {
            float* out1 = mChannels[i].mOutputBuf() + mOutFFTPos;
            vDSP_vadd(out1, 1, mChannels[i].mFFTBuf(), 1, out1, 1, firstPart);
            float* out2 = mChannels[i].mOutputBuf();
            vDSP_vadd(out2, 1, mChannels[i].mFFTBuf() + firstPart, 1, out2, 1, secondPart);
        }
    } else {
        for (UInt32 i=0; i<mNumChannels; ++i) {
            float* out1 = mChannels[i].mOutputBuf() + mOutFFTPos;
            vDSP_vadd(out1, 1, mChannels[i].mFFTBuf(), 1, out1, 1, mFFTSize);
        }
    }
    //printf("OverlapAddOutput %g %g\n", mChannels[0].mOutputBuf[mOutFFTPos], mChannels[0].mOutputBuf[(mOutFFTPos + 200) & mIOMask]);
    mOutFFTPos = (mOutFFTPos + mHopSize) & mIOMask;
}


void CASpectralProcessor::DoFwdFFT()
{
    //printf("->DoFwdFFT %g %g\n", mChannels[0].mFFTBuf()[0], mChannels[0].mFFTBuf()[200]);
    UInt32 half = mFFTSize >> 1;
    for (UInt32 i=0; i<mNumChannels; ++i) 
    {
        vDSP_ctoz((DSPComplex*)mChannels[i].mFFTBuf(), 2, &mSpectralBufferList->mDSPSplitComplex[i], 1, half);
        vDSP_fft_zrip(mFFTSetup, &mSpectralBufferList->mDSPSplitComplex[i], 1, mLog2FFTSize, FFT_FORWARD);
    }
    //printf("<-DoFwdFFT %g %g\n", direction, mChannels[0].mFFTBuf()[0], mChannels[0].mFFTBuf()[200]);
}

void CASpectralProcessor::DoInvFFT()
{
    //printf("->DoInvFFT %g %g\n", mChannels[0].mFFTBuf()[0], mChannels[0].mFFTBuf()[200]);
    UInt32 half = mFFTSize >> 1;
    for (UInt32 i=0; i<mNumChannels; ++i) 
    {
        vDSP_fft_zrip(mFFTSetup, &mSpectralBufferList->mDSPSplitComplex[i], 1, mLog2FFTSize, FFT_INVERSE);
        vDSP_ztoc(&mSpectralBufferList->mDSPSplitComplex[i], 1, (DSPComplex*)mChannels[i].mFFTBuf(), 2, half);      
        float scale = 0.5 / mFFTSize;
        vDSP_vsmul(mChannels[i].mFFTBuf(), 1, &scale, mChannels[i].mFFTBuf(), 1, mFFTSize );
    }
    //printf("<-DoInvFFT %g %g\n", direction, mChannels[0].mFFTBuf()[0], mChannels[0].mFFTBuf()[200]);
}

void CASpectralProcessor::SetSpectralFunction(SpectralFunction inFunction, void* inUserData)
{
    mSpectralFunction = inFunction; 
    mUserData = inUserData;
}

void CASpectralProcessor::ProcessSpectrum(UInt32 inFFTSize, SpectralBufferList* inSpectra)
{
    if (mSpectralFunction)
        (mSpectralFunction)(inSpectra, mUserData);
}

#pragma mark ___Utility___

void CASpectralProcessor::GetMagnitude(AudioBufferList* list, Float32* min, Float32* max) 
{   
    UInt32 half = mFFTSize >> 1;    
    for (UInt32 i=0; i<mNumChannels; ++i) {
        DSPSplitComplex &freqData = mSpectralBufferList->mDSPSplitComplex[i];       
        
        Float32* b = (Float32*) list->mBuffers[i].mData;
        
        vDSP_zvabs(&freqData,1,b,1,half);       
   
        vDSP_maxmgv(b, 1, &max[i], half); 
        vDSP_minmgv(b, 1, &min[i], half); 
        
   } 
}


void CASpectralProcessor::GetFrequencies(Float32* freqs, Float32 sampleRate)
{
    UInt32 half = mFFTSize >> 1;    

    for (UInt32 i=0; i< half; i++){
        freqs[i] = ((Float32)(i))*sampleRate/((Float32)mFFTSize);   
    }
}


bool CASpectralProcessor::ProcessForwards(UInt32 inNumFrames, AudioBufferList* inInput)
{
    // copy from buffer list to input buffer
    CopyInput(inNumFrames, inInput);
        
    bool processed = false;
    // if enough input to process, then process.
    while (mInputSize >= mFFTSize) 
    {
        CopyInputToFFT(); // copy from input buffer to fft buffer
        DoWindowing();
        DoFwdFFT();
        ProcessSpectrum(mFFTSize, mSpectralBufferList()); // here you would copy the fft results out to a buffer indicated in mUserData, say for sonogram drawing
        processed = true;
    }
    
    return processed;
}

bool CASpectralProcessor::ProcessBackwards(UInt32 inNumFrames, AudioBufferList* outOutput)
{       
    
    ProcessSpectrum(mFFTSize, mSpectralBufferList());
    DoInvFFT();
    DoWindowing();
    OverlapAddOutput();     
    
    // copy from output buffer to buffer list
    CopyOutput(inNumFrames, outOutput);
    
    return true;
}