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AudioFFT.cpp
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AudioFFT.cpp
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// ==================================================================================
// Copyright (c) 2017 HiFi-LoFi
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is furnished
// to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// ==================================================================================
#include "AudioFFT.h"
#include <cassert>
#include <cmath>
#include <cstring>
#if defined(AUDIOFFT_INTEL_IPP)
#define AUDIOFFT_INTEL_IPP_USED
#include <ipp.h>
#elif defined(AUDIOFFT_APPLE_ACCELERATE)
#define AUDIOFFT_APPLE_ACCELERATE_USED
#include <Accelerate/Accelerate.h>
#include <vector>
#elif defined (AUDIOFFT_FFTW3)
#define AUDIOFFT_FFTW3_USED
#include <fftw3.h>
#else
#if !defined(AUDIOFFT_OOURA)
#define AUDIOFFT_OOURA
#endif
#define AUDIOFFT_OOURA_USED
#include <vector>
#endif
namespace audiofft
{
namespace detail
{
class AudioFFTImpl
{
public:
AudioFFTImpl() = default;
AudioFFTImpl(const AudioFFTImpl&) = delete;
AudioFFTImpl& operator=(const AudioFFTImpl&) = delete;
virtual ~AudioFFTImpl() = default;
virtual void init(size_t size) = 0;
virtual void fft(const float* data, float* re, float* im) = 0;
virtual void ifft(float* data, const float* re, const float* im) = 0;
};
constexpr bool IsPowerOf2(size_t val)
{
return (val == 1 || (val & (val-1)) == 0);
}
template<typename TypeDest, typename TypeSrc>
void ConvertBuffer(TypeDest* dest, const TypeSrc* src, size_t len)
{
for (size_t i=0; i<len; ++i)
{
dest[i] = static_cast<TypeDest>(src[i]);
}
}
template<typename TypeDest, typename TypeSrc, typename TypeFactor>
void ScaleBuffer(TypeDest* dest, const TypeSrc* src, const TypeFactor factor, size_t len)
{
for (size_t i=0; i<len; ++i)
{
dest[i] = static_cast<TypeDest>(static_cast<TypeFactor>(src[i]) * factor);
}
}
} // End of namespace detail
// ================================================================
#ifdef AUDIOFFT_OOURA_USED
/**
* @internal
* @class OouraFFT
* @brief FFT implementation based on the great radix-4 routines by Takuya Ooura
*/
class OouraFFT : public detail::AudioFFTImpl
{
public:
OouraFFT() :
detail::AudioFFTImpl(),
_size(0),
_ip(),
_w(),
_buffer()
{
}
OouraFFT(const OouraFFT&) = delete;
OouraFFT& operator=(const OouraFFT&) = delete;
virtual void init(size_t size) override
{
if (_size != size)
{
_ip.resize(2 + static_cast<int>(std::sqrt(static_cast<double>(size))));
_w.resize(size / 2);
_buffer.resize(size);
_size = size;
const int size4 = static_cast<int>(_size) / 4;
makewt(size4, _ip.data(), _w.data());
makect(size4, _ip.data(), _w.data() + size4);
}
}
virtual void fft(const float* data, float* re, float* im) override
{
// Convert into the format as required by the Ooura FFT
detail::ConvertBuffer(_buffer.data(), data, _size);
rdft(static_cast<int>(_size), +1, _buffer.data(), _ip.data(), _w.data());
// Convert back to split-complex
{
double* b = _buffer.data();
double* bEnd = b + _size;
float *r = re;
float *i = im;
while (b != bEnd)
{
*(r++) = static_cast<float>(*(b++));
*(i++) = static_cast<float>(-(*(b++)));
}
}
const size_t size2 = _size / 2;
re[size2] = -im[0];
im[0] = 0.0;
im[size2] = 0.0;
}
virtual void ifft(float* data, const float* re, const float* im) override
{
// Convert into the format as required by the Ooura FFT
{
double* b = _buffer.data();
double* bEnd = b + _size;
const float *r = re;
const float *i = im;
while (b != bEnd)
{
*(b++) = static_cast<double>(*(r++));
*(b++) = -static_cast<double>(*(i++));
}
_buffer[1] = re[_size / 2];
}
rdft(static_cast<int>(_size), -1, _buffer.data(), _ip.data(), _w.data());
// Convert back to split-complex
detail::ScaleBuffer(data, _buffer.data(), 2.0 / static_cast<double>(_size), _size);
}
private:
size_t _size;
std::vector<int> _ip;
std::vector<double> _w;
std::vector<double> _buffer;
void rdft(int n, int isgn, double *a, int *ip, double *w)
{
int nw = ip[0];
int nc = ip[1];
if (isgn >= 0)
{
if (n > 4)
{
bitrv2(n, ip + 2, a);
cftfsub(n, a, w);
rftfsub(n, a, nc, w + nw);
}
else if (n == 4)
{
cftfsub(n, a, w);
}
double xi = a[0] - a[1];
a[0] += a[1];
a[1] = xi;
}
else
{
a[1] = 0.5 * (a[0] - a[1]);
a[0] -= a[1];
if (n > 4)
{
rftbsub(n, a, nc, w + nw);
bitrv2(n, ip + 2, a);
cftbsub(n, a, w);
}
else if (n == 4)
{
cftfsub(n, a, w);
}
}
}
/* -------- initializing routines -------- */
void makewt(int nw, int *ip, double *w)
{
int j, nwh;
double delta, x, y;
ip[0] = nw;
ip[1] = 1;
if (nw > 2) {
nwh = nw >> 1;
delta = atan(1.0) / nwh;
w[0] = 1;
w[1] = 0;
w[nwh] = cos(delta * nwh);
w[nwh + 1] = w[nwh];
if (nwh > 2) {
for (j = 2; j < nwh; j += 2) {
x = cos(delta * j);
y = sin(delta * j);
w[j] = x;
w[j + 1] = y;
w[nw - j] = y;
w[nw - j + 1] = x;
}
bitrv2(nw, ip + 2, w);
}
}
}
void makect(int nc, int *ip, double *c)
{
int j, nch;
double delta;
ip[1] = nc;
if (nc > 1) {
nch = nc >> 1;
delta = atan(1.0) / nch;
c[0] = cos(delta * nch);
c[nch] = 0.5 * c[0];
for (j = 1; j < nch; j++) {
c[j] = 0.5 * cos(delta * j);
c[nc - j] = 0.5 * sin(delta * j);
}
}
}
/* -------- child routines -------- */
void bitrv2(int n, int *ip, double *a)
{
int j, j1, k, k1, l, m, m2;
double xr, xi, yr, yi;
ip[0] = 0;
l = n;
m = 1;
while ((m << 3) < l) {
l >>= 1;
for (j = 0; j < m; j++) {
ip[m + j] = ip[j] + l;
}
m <<= 1;
}
m2 = 2 * m;
if ((m << 3) == l) {
for (k = 0; k < m; k++) {
for (j = 0; j < k; j++) {
j1 = 2 * j + ip[k];
k1 = 2 * k + ip[j];
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
j1 += m2;
k1 += 2 * m2;
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
j1 += m2;
k1 -= m2;
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
j1 += m2;
k1 += 2 * m2;
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
}
j1 = 2 * k + m2 + ip[k];
k1 = j1 + m2;
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
}
} else {
for (k = 1; k < m; k++) {
for (j = 0; j < k; j++) {
j1 = 2 * j + ip[k];
k1 = 2 * k + ip[j];
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
j1 += m2;
k1 += m2;
xr = a[j1];
xi = a[j1 + 1];
yr = a[k1];
yi = a[k1 + 1];
a[j1] = yr;
a[j1 + 1] = yi;
a[k1] = xr;
a[k1 + 1] = xi;
}
}
}
}
void cftfsub(int n, double *a, double *w)
{
int j, j1, j2, j3, l;
double x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
l = 2;
if (n > 8) {
cft1st(n, a, w);
l = 8;
while ((l << 2) < n) {
cftmdl(n, l, a, w);
l <<= 2;
}
}
if ((l << 2) == n) {
for (j = 0; j < l; j += 2) {
j1 = j + l;
j2 = j1 + l;
j3 = j2 + l;
x0r = a[j] + a[j1];
x0i = a[j + 1] + a[j1 + 1];
x1r = a[j] - a[j1];
x1i = a[j + 1] - a[j1 + 1];
x2r = a[j2] + a[j3];
x2i = a[j2 + 1] + a[j3 + 1];
x3r = a[j2] - a[j3];
x3i = a[j2 + 1] - a[j3 + 1];
a[j] = x0r + x2r;
a[j + 1] = x0i + x2i;
a[j2] = x0r - x2r;
a[j2 + 1] = x0i - x2i;
a[j1] = x1r - x3i;
a[j1 + 1] = x1i + x3r;
a[j3] = x1r + x3i;
a[j3 + 1] = x1i - x3r;
}
} else {
for (j = 0; j < l; j += 2) {
j1 = j + l;
x0r = a[j] - a[j1];
x0i = a[j + 1] - a[j1 + 1];
a[j] += a[j1];
a[j + 1] += a[j1 + 1];
a[j1] = x0r;
a[j1 + 1] = x0i;
}
}
}
void cftbsub(int n, double *a, double *w)
{
int j, j1, j2, j3, l;
double x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
l = 2;
if (n > 8) {
cft1st(n, a, w);
l = 8;
while ((l << 2) < n) {
cftmdl(n, l, a, w);
l <<= 2;
}
}
if ((l << 2) == n) {
for (j = 0; j < l; j += 2) {
j1 = j + l;
j2 = j1 + l;
j3 = j2 + l;
x0r = a[j] + a[j1];
x0i = -a[j + 1] - a[j1 + 1];
x1r = a[j] - a[j1];
x1i = -a[j + 1] + a[j1 + 1];
x2r = a[j2] + a[j3];
x2i = a[j2 + 1] + a[j3 + 1];
x3r = a[j2] - a[j3];
x3i = a[j2 + 1] - a[j3 + 1];
a[j] = x0r + x2r;
a[j + 1] = x0i - x2i;
a[j2] = x0r - x2r;
a[j2 + 1] = x0i + x2i;
a[j1] = x1r - x3i;
a[j1 + 1] = x1i - x3r;
a[j3] = x1r + x3i;
a[j3 + 1] = x1i + x3r;
}
} else {
for (j = 0; j < l; j += 2) {
j1 = j + l;
x0r = a[j] - a[j1];
x0i = -a[j + 1] + a[j1 + 1];
a[j] += a[j1];
a[j + 1] = -a[j + 1] - a[j1 + 1];
a[j1] = x0r;
a[j1 + 1] = x0i;
}
}
}
void cft1st(int n, double *a, double *w)
{
int j, k1, k2;
double wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
double x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
x0r = a[0] + a[2];
x0i = a[1] + a[3];
x1r = a[0] - a[2];
x1i = a[1] - a[3];
x2r = a[4] + a[6];
x2i = a[5] + a[7];
x3r = a[4] - a[6];
x3i = a[5] - a[7];
a[0] = x0r + x2r;
a[1] = x0i + x2i;
a[4] = x0r - x2r;
a[5] = x0i - x2i;
a[2] = x1r - x3i;
a[3] = x1i + x3r;
a[6] = x1r + x3i;
a[7] = x1i - x3r;
wk1r = w[2];
x0r = a[8] + a[10];
x0i = a[9] + a[11];
x1r = a[8] - a[10];
x1i = a[9] - a[11];
x2r = a[12] + a[14];
x2i = a[13] + a[15];
x3r = a[12] - a[14];
x3i = a[13] - a[15];
a[8] = x0r + x2r;
a[9] = x0i + x2i;
a[12] = x2i - x0i;
a[13] = x0r - x2r;
x0r = x1r - x3i;
x0i = x1i + x3r;
a[10] = wk1r * (x0r - x0i);
a[11] = wk1r * (x0r + x0i);
x0r = x3i + x1r;
x0i = x3r - x1i;
a[14] = wk1r * (x0i - x0r);
a[15] = wk1r * (x0i + x0r);
k1 = 0;
for (j = 16; j < n; j += 16) {
k1 += 2;
k2 = 2 * k1;
wk2r = w[k1];
wk2i = w[k1 + 1];
wk1r = w[k2];
wk1i = w[k2 + 1];
wk3r = wk1r - 2 * wk2i * wk1i;
wk3i = 2 * wk2i * wk1r - wk1i;
x0r = a[j] + a[j + 2];
x0i = a[j + 1] + a[j + 3];
x1r = a[j] - a[j + 2];
x1i = a[j + 1] - a[j + 3];
x2r = a[j + 4] + a[j + 6];
x2i = a[j + 5] + a[j + 7];
x3r = a[j + 4] - a[j + 6];
x3i = a[j + 5] - a[j + 7];
a[j] = x0r + x2r;
a[j + 1] = x0i + x2i;
x0r -= x2r;
x0i -= x2i;
a[j + 4] = wk2r * x0r - wk2i * x0i;
a[j + 5] = wk2r * x0i + wk2i * x0r;
x0r = x1r - x3i;
x0i = x1i + x3r;
a[j + 2] = wk1r * x0r - wk1i * x0i;
a[j + 3] = wk1r * x0i + wk1i * x0r;
x0r = x1r + x3i;
x0i = x1i - x3r;
a[j + 6] = wk3r * x0r - wk3i * x0i;
a[j + 7] = wk3r * x0i + wk3i * x0r;
wk1r = w[k2 + 2];
wk1i = w[k2 + 3];
wk3r = wk1r - 2 * wk2r * wk1i;
wk3i = 2 * wk2r * wk1r - wk1i;
x0r = a[j + 8] + a[j + 10];
x0i = a[j + 9] + a[j + 11];
x1r = a[j + 8] - a[j + 10];
x1i = a[j + 9] - a[j + 11];
x2r = a[j + 12] + a[j + 14];
x2i = a[j + 13] + a[j + 15];
x3r = a[j + 12] - a[j + 14];
x3i = a[j + 13] - a[j + 15];
a[j + 8] = x0r + x2r;
a[j + 9] = x0i + x2i;
x0r -= x2r;
x0i -= x2i;
a[j + 12] = -wk2i * x0r - wk2r * x0i;
a[j + 13] = -wk2i * x0i + wk2r * x0r;
x0r = x1r - x3i;
x0i = x1i + x3r;
a[j + 10] = wk1r * x0r - wk1i * x0i;
a[j + 11] = wk1r * x0i + wk1i * x0r;
x0r = x1r + x3i;
x0i = x1i - x3r;
a[j + 14] = wk3r * x0r - wk3i * x0i;
a[j + 15] = wk3r * x0i + wk3i * x0r;
}
}
void cftmdl(int n, int l, double *a, double *w)
{
int j, j1, j2, j3, k, k1, k2, m, m2;
double wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
double x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
m = l << 2;
for (j = 0; j < l; j += 2) {
j1 = j + l;
j2 = j1 + l;
j3 = j2 + l;
x0r = a[j] + a[j1];
x0i = a[j + 1] + a[j1 + 1];
x1r = a[j] - a[j1];
x1i = a[j + 1] - a[j1 + 1];
x2r = a[j2] + a[j3];
x2i = a[j2 + 1] + a[j3 + 1];
x3r = a[j2] - a[j3];
x3i = a[j2 + 1] - a[j3 + 1];
a[j] = x0r + x2r;
a[j + 1] = x0i + x2i;
a[j2] = x0r - x2r;
a[j2 + 1] = x0i - x2i;
a[j1] = x1r - x3i;
a[j1 + 1] = x1i + x3r;
a[j3] = x1r + x3i;
a[j3 + 1] = x1i - x3r;
}
wk1r = w[2];
for (j = m; j < l + m; j += 2) {
j1 = j + l;
j2 = j1 + l;
j3 = j2 + l;
x0r = a[j] + a[j1];
x0i = a[j + 1] + a[j1 + 1];
x1r = a[j] - a[j1];
x1i = a[j + 1] - a[j1 + 1];
x2r = a[j2] + a[j3];
x2i = a[j2 + 1] + a[j3 + 1];
x3r = a[j2] - a[j3];
x3i = a[j2 + 1] - a[j3 + 1];
a[j] = x0r + x2r;
a[j + 1] = x0i + x2i;
a[j2] = x2i - x0i;
a[j2 + 1] = x0r - x2r;
x0r = x1r - x3i;
x0i = x1i + x3r;
a[j1] = wk1r * (x0r - x0i);
a[j1 + 1] = wk1r * (x0r + x0i);
x0r = x3i + x1r;
x0i = x3r - x1i;
a[j3] = wk1r * (x0i - x0r);
a[j3 + 1] = wk1r * (x0i + x0r);
}
k1 = 0;
m2 = 2 * m;
for (k = m2; k < n; k += m2) {
k1 += 2;
k2 = 2 * k1;
wk2r = w[k1];
wk2i = w[k1 + 1];
wk1r = w[k2];
wk1i = w[k2 + 1];
wk3r = wk1r - 2 * wk2i * wk1i;
wk3i = 2 * wk2i * wk1r - wk1i;
for (j = k; j < l + k; j += 2) {
j1 = j + l;
j2 = j1 + l;
j3 = j2 + l;
x0r = a[j] + a[j1];
x0i = a[j + 1] + a[j1 + 1];
x1r = a[j] - a[j1];
x1i = a[j + 1] - a[j1 + 1];
x2r = a[j2] + a[j3];
x2i = a[j2 + 1] + a[j3 + 1];
x3r = a[j2] - a[j3];
x3i = a[j2 + 1] - a[j3 + 1];
a[j] = x0r + x2r;
a[j + 1] = x0i + x2i;
x0r -= x2r;
x0i -= x2i;
a[j2] = wk2r * x0r - wk2i * x0i;
a[j2 + 1] = wk2r * x0i + wk2i * x0r;
x0r = x1r - x3i;
x0i = x1i + x3r;
a[j1] = wk1r * x0r - wk1i * x0i;
a[j1 + 1] = wk1r * x0i + wk1i * x0r;
x0r = x1r + x3i;
x0i = x1i - x3r;
a[j3] = wk3r * x0r - wk3i * x0i;
a[j3 + 1] = wk3r * x0i + wk3i * x0r;
}
wk1r = w[k2 + 2];
wk1i = w[k2 + 3];
wk3r = wk1r - 2 * wk2r * wk1i;
wk3i = 2 * wk2r * wk1r - wk1i;
for (j = k + m; j < l + (k + m); j += 2) {
j1 = j + l;
j2 = j1 + l;
j3 = j2 + l;
x0r = a[j] + a[j1];
x0i = a[j + 1] + a[j1 + 1];
x1r = a[j] - a[j1];
x1i = a[j + 1] - a[j1 + 1];
x2r = a[j2] + a[j3];
x2i = a[j2 + 1] + a[j3 + 1];
x3r = a[j2] - a[j3];
x3i = a[j2 + 1] - a[j3 + 1];
a[j] = x0r + x2r;
a[j + 1] = x0i + x2i;
x0r -= x2r;
x0i -= x2i;
a[j2] = -wk2i * x0r - wk2r * x0i;
a[j2 + 1] = -wk2i * x0i + wk2r * x0r;
x0r = x1r - x3i;
x0i = x1i + x3r;
a[j1] = wk1r * x0r - wk1i * x0i;
a[j1 + 1] = wk1r * x0i + wk1i * x0r;
x0r = x1r + x3i;
x0i = x1i - x3r;
a[j3] = wk3r * x0r - wk3i * x0i;
a[j3 + 1] = wk3r * x0i + wk3i * x0r;
}
}
}
void rftfsub(int n, double *a, int nc, double *c)
{
int j, k, kk, ks, m;
double wkr, wki, xr, xi, yr, yi;
m = n >> 1;
ks = 2 * nc / m;
kk = 0;
for (j = 2; j < m; j += 2) {
k = n - j;
kk += ks;
wkr = 0.5 - c[nc - kk];
wki = c[kk];
xr = a[j] - a[k];
xi = a[j + 1] + a[k + 1];
yr = wkr * xr - wki * xi;
yi = wkr * xi + wki * xr;
a[j] -= yr;
a[j + 1] -= yi;
a[k] += yr;
a[k + 1] -= yi;
}
}
void rftbsub(int n, double *a, int nc, double *c)
{
int j, k, kk, ks, m;
double wkr, wki, xr, xi, yr, yi;
a[1] = -a[1];
m = n >> 1;
ks = 2 * nc / m;
kk = 0;
for (j = 2; j < m; j += 2) {
k = n - j;
kk += ks;
wkr = 0.5 - c[nc - kk];
wki = c[kk];
xr = a[j] - a[k];
xi = a[j + 1] + a[k + 1];
yr = wkr * xr + wki * xi;
yi = wkr * xi - wki * xr;
a[j] -= yr;
a[j + 1] = yi - a[j + 1];
a[k] += yr;
a[k + 1] = yi - a[k + 1];
}
a[m + 1] = -a[m + 1];
}
};
/**
* @internal
* @brief Concrete FFT implementation
*/
typedef OouraFFT AudioFFTImplementation;
#endif // AUDIOFFT_OOURA_USED
// ================================================================
#ifdef AUDIOFFT_INTEL_IPP_USED
/**
* @internal
* @class IntelIppFFT
* @brief FFT implementation using the Intel Integrated Performance Primitives
*/
class IntelIppFFT : public detail::AudioFFTImpl
{
public:
IntelIppFFT() :
detail::AudioFFTImpl(),
_size(0),
_operationalBufferSize(0),
_powerOf2(0),
_fftSpec(nullptr),
_fftSpecBuf(0),
_fftWorkBuf(0),
_operationalBuffer(nullptr)
{
ippInit();
}
IntelIppFFT(const IntelIppFFT&) = delete;
IntelIppFFT& operator=(const IntelIppFFT&) = delete;
virtual ~IntelIppFFT()
{
init(0);
}
virtual void init(size_t size) override
{
if (_fftSpec)
{
if (_fftWorkBuf) ippFree(_fftWorkBuf);
if (_fftSpecBuf) ippFree(_fftSpecBuf);
ippFree(_operationalBuffer);
_size = 0;
_operationalBufferSize = 0;
_powerOf2 = 0;
_fftSpec = 0;
}
if (size > 0)
{
_size = size;
_operationalBufferSize = _size + 2;
_powerOf2 = (int)(log((double)_size)/log(2.0));
// Query to get buffer sizes
int sizeFFTSpec,
sizeFFTInitBuf,
sizeFFTWorkBuf;
ippsFFTGetSize_R_32f(
_powerOf2,
IPP_FFT_NODIV_BY_ANY,
ippAlgHintAccurate,
&sizeFFTSpec,
&sizeFFTInitBuf,
&sizeFFTWorkBuf
);
Ipp8u* fftInitBuf;
// init buffers
_fftSpecBuf = ippsMalloc_8u(sizeFFTSpec);
_fftWorkBuf = ippsMalloc_8u(sizeFFTWorkBuf);
fftInitBuf = ippsMalloc_8u(sizeFFTInitBuf);
// Initialize FFT
ippsFFTInit_R_32f(
&_fftSpec,
_powerOf2,
IPP_FFT_NODIV_BY_ANY,
ippAlgHintAccurate,
_fftSpecBuf,
fftInitBuf
);
if (fftInitBuf) ippFree(fftInitBuf);
// init operational buffer
_operationalBuffer = ippsMalloc_32f(
_operationalBufferSize
);
}
}
virtual void fft(const float* data, float* re, float* im) override
{
size_t complexNumbersCount = _operationalBufferSize / 2;
ippsFFTFwd_RToCCS_32f(
data,
_operationalBuffer,
_fftSpec,
_fftWorkBuf
);
// no need to scale
size_t complexCounter = 0;
for (int i = 0; i < complexNumbersCount; ++i)
{
re[i] = _operationalBuffer[complexCounter++];
im[i] = _operationalBuffer[complexCounter++];
}
}
virtual void ifft(float* data, const float* re, const float* im) override
{
size_t complexNumbersCount = _operationalBufferSize / 2;
size_t complexCounter = 0;
for (int i = 0; i < complexNumbersCount; ++i)
{
_operationalBuffer[complexCounter++] = re[i];
_operationalBuffer[complexCounter++] = im[i];
}
ippsFFTInv_CCSToR_32f(
_operationalBuffer,
data,
_fftSpec,
_fftWorkBuf
);
// scaling
const float factor = 1.0f / static_cast<float>(_size);
ippsMulC_32f_I(factor, data, _size);
}
private:
size_t _size;
size_t _operationalBufferSize;
size_t _powerOf2;
IppsFFTSpec_R_32f* _fftSpec;
Ipp8u* _fftSpecBuf;
Ipp8u* _fftWorkBuf;
Ipp32f* _operationalBuffer;
};
/**
* @internal
* @brief Concrete FFT implementation
*/
typedef IntelIppFFT AudioFFTImplementation;
#endif // AUDIOFFT_INTEL_IPP_USED
// ================================================================
#ifdef AUDIOFFT_APPLE_ACCELERATE_USED
/**
* @internal
* @class AppleAccelerateFFT
* @brief FFT implementation using the Apple Accelerate framework internally
*/
class AppleAccelerateFFT : public detail::AudioFFTImpl
{
public:
AppleAccelerateFFT() :
detail::AudioFFTImpl(),
_size(0),
_powerOf2(0),
_fftSetup(0),
_re(),
_im()
{
}
AppleAccelerateFFT(const AppleAccelerateFFT&) = delete;
AppleAccelerateFFT& operator=(const AppleAccelerateFFT&) = delete;
virtual ~AppleAccelerateFFT()
{
init(0);
}
virtual void init(size_t size) override
{
if (_fftSetup)
{
vDSP_destroy_fftsetup(_fftSetup);
_size = 0;
_powerOf2 = 0;
_fftSetup = 0;
_re.clear();
_im.clear();
}
if (size > 0)
{
_size = size;
_powerOf2 = 0;
while ((1 << _powerOf2) < _size)
{
++_powerOf2;
}
_fftSetup = vDSP_create_fftsetup(_powerOf2, FFT_RADIX2);
_re.resize(_size / 2);
_im.resize(_size / 2);
}
}
virtual void fft(const float* data, float* re, float* im) override
{
const size_t size2 = _size / 2;
DSPSplitComplex splitComplex;
splitComplex.realp = re;
splitComplex.imagp = im;
vDSP_ctoz(reinterpret_cast<const COMPLEX*>(data), 2, &splitComplex, 1, size2);
vDSP_fft_zrip(_fftSetup, &splitComplex, 1, _powerOf2, FFT_FORWARD);
const float factor = 0.5f;
vDSP_vsmul(re, 1, &factor, re, 1, size2);
vDSP_vsmul(im, 1, &factor, im, 1, size2);