/*

     File: CASpectralProcessor.cpp

 Abstract: CASpectralProcessor.h

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*/

//#include "AudioFormulas.h"

#include "CASpectralProcessor.h"

#include "CABitOperations.h"

#include <Accelerate/Accelerate.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;

}