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/*############################################################################*/
/*# #*/
/*# Ambisonic C++ Library #*/
/*# CAmbisonicBinauralizer - Ambisonic Binauralizer #*/
/*# Copyright © 2007 Aristotel Digenis #*/
/*# #*/
/*# Filename: AmbisonicBinauralizer.cpp #*/
/*# Version: 0.1 #*/
/*# Date: 19/05/2007 #*/
/*# Author(s): Aristotel Digenis #*/
/*# Licence: MIT #*/
/*# #*/
/*############################################################################*/
#include "SpeakersBinauralizer.h"
SpeakersBinauralizer::SpeakersBinauralizer()
: m_nSpeakers(0)
{
}
bool SpeakersBinauralizer::Configure(unsigned nSampleRate,
unsigned nBlockSize,
CAmbisonicSpeaker *speakers,
unsigned nSpeakers,
unsigned& tailLength,
std::string HRTFPath)
{
//Iterators
unsigned niEar = 0;
unsigned niTap = 0;
HRTF *p_hrtf = getHRTF(nSampleRate, HRTFPath);
if (p_hrtf == nullptr)
return false;
m_nTaps = tailLength = p_hrtf->getHRTFLen();
m_nBlockSize = nBlockSize;
//What will the overlap size be?
m_nOverlapLength = m_nBlockSize < m_nTaps ? m_nBlockSize - 1 : m_nTaps - 1;
//How large does the FFT need to be
m_nFFTSize = 1;
while(m_nFFTSize < (m_nBlockSize + m_nTaps + m_nOverlapLength))
m_nFFTSize <<= 1;
//How many bins is that
m_nFFTBins = m_nFFTSize / 2 + 1;
//What do we need to scale the result of the iFFT by
m_fFFTScaler = 1.f / m_nFFTSize;
m_nSpeakers = nSpeakers;
//Allocate buffers with new settings
AllocateBuffers();
//Allocate temporary buffers for retrieving taps from mit_hrtf_lib
float* pfHRTF[2];
for(niEar = 0; niEar < 2; niEar++)
pfHRTF[niEar] = new float[m_nTaps];
//Allocate buffers for HRTF accumulators
float** ppfAccumulator[2];
for(niEar = 0; niEar < 2; niEar++)
{
ppfAccumulator[niEar] = new float*[nSpeakers];
for (unsigned niChannel = 0; niChannel < nSpeakers; niChannel++)
{
ppfAccumulator[niEar][niChannel] = new float[m_nTaps];
memset(ppfAccumulator[niEar][niChannel], 0, m_nTaps * sizeof(float));
}
}
for(unsigned niChannel = 0; niChannel < nSpeakers; niChannel++)
{
PolarPoint position = speakers[niChannel].GetPosition();
bool b_found = p_hrtf->get(position.fAzimuth, position.fElevation, pfHRTF);
if (!b_found)
return false;
//Accumulate channel/component HRTF
for(niTap = 0; niTap < m_nTaps; niTap++)
{
ppfAccumulator[0][niChannel][niTap] += pfHRTF[0][niTap];
ppfAccumulator[1][niChannel][niTap] += pfHRTF[1][niTap];
}
}
delete p_hrtf;
//Find the maximum tap
float fMax = 0;
for(niEar = 0; niEar < 2; niEar++)
{
for (unsigned niChannel = 0; niChannel < nSpeakers; niChannel++)
{
for(niTap = 0; niTap < m_nTaps; niTap++)
{
fMax = fabs(ppfAccumulator[niEar][niChannel][niTap]) > fMax ?
fabs(ppfAccumulator[niEar][niChannel][niTap]) : fMax;
}
}
}
//Normalize to pre-defined value
float fUpperSample = 1.f;
float fScaler = fUpperSample / fMax;
fScaler *= 0.35f;
for(niEar = 0; niEar < 2; niEar++)
{
for (unsigned niChannel = 0; niChannel < nSpeakers; niChannel++)
{
for(niTap = 0; niTap < m_nTaps; niTap++)
{
ppfAccumulator[niEar][niChannel][niTap] *= fScaler;
}
}
}
//Convert frequency domain filters
for(niEar = 0; niEar < 2; niEar++)
{
for (unsigned niChannel = 0; niChannel < nSpeakers; niChannel++)
{
memcpy(m_pfScratchBufferA.data(), ppfAccumulator[niEar][niChannel], m_nTaps * sizeof(float));
memset(&m_pfScratchBufferA[m_nTaps], 0, (m_nFFTSize - m_nTaps) * sizeof(float));
kiss_fftr(m_pFFT_cfg.get(), m_pfScratchBufferA.data(), m_ppcpFilters[niEar][niChannel].get());
}
}
for(niEar = 0; niEar < 2; niEar++)
delete [] pfHRTF[niEar];
for(niEar = 0; niEar < 2; niEar++)
{
for(unsigned niChannel = 0; niChannel < nSpeakers; niChannel++)
delete [] ppfAccumulator[niEar][niChannel];
delete [] ppfAccumulator[niEar];
}
return true;
}
void SpeakersBinauralizer::Process(float** pBFSrc, float** ppfDst)
{
kiss_fft_cpx cpTemp;
for (unsigned niEar = 0; niEar < 2; niEar++)
{
memset(m_pfScratchBufferA.data(), 0, m_nFFTSize * sizeof(float));
for (unsigned niChannel = 0; niChannel < m_nSpeakers; niChannel++)
{
memcpy(m_pfScratchBufferB.data(), pBFSrc[niChannel], m_nBlockSize * sizeof(float));
memset(&m_pfScratchBufferB[m_nBlockSize], 0, (m_nFFTSize - m_nBlockSize) * sizeof(float));
kiss_fftr(m_pFFT_cfg.get(), m_pfScratchBufferB.data(), m_pcpScratch.get());
for(unsigned ni = 0; ni < m_nFFTBins; ni++)
{
cpTemp.r = m_pcpScratch[ni].r * m_ppcpFilters[niEar][niChannel][ni].r
- m_pcpScratch[ni].i * m_ppcpFilters[niEar][niChannel][ni].i;
cpTemp.i = m_pcpScratch[ni].r * m_ppcpFilters[niEar][niChannel][ni].i
+ m_pcpScratch[ni].i * m_ppcpFilters[niEar][niChannel][ni].r;
m_pcpScratch[ni] = cpTemp;
}
kiss_fftri(m_pIFFT_cfg.get(), m_pcpScratch.get(), m_pfScratchBufferB.data());
for (unsigned ni = 0; ni < m_nFFTSize; ni++)
m_pfScratchBufferA[ni] += m_pfScratchBufferB[ni];
}
for (unsigned ni = 0; ni < m_nFFTSize; ni++)
m_pfScratchBufferA[ni] *= m_fFFTScaler;
memcpy(ppfDst[niEar], m_pfScratchBufferA.data(), m_nBlockSize * sizeof(float));
for (unsigned ni = 0; ni < m_nOverlapLength; ni++)
ppfDst[niEar][ni] += m_pfOverlap[niEar][ni];
memcpy(m_pfOverlap[niEar].data(), &m_pfScratchBufferA[m_nBlockSize], m_nOverlapLength * sizeof(float));
}
}
void SpeakersBinauralizer::AllocateBuffers()
{
CAmbisonicBinauralizer::AllocateBuffers();
//Allocate the FFTBins for each channel, for each ear
for(unsigned niEar = 0; niEar < 2; niEar++)
{
m_ppcpFilters[niEar].resize(m_nSpeakers);
for(unsigned niChannel = 0; niChannel < m_nSpeakers; niChannel++)
m_ppcpFilters[niEar][niChannel].reset(new kiss_fft_cpx[m_nFFTBins]);
}
}
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