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Move the ALcomplex and FFT functions to a separate file

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This commit is contained in:
Chris Robinson
2018-05-15 18:31:41 -07:00
parent 197e88cdcc
commit 2b9064cb6e
4 changed files with 134 additions and 99 deletions
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Alc/effects/pshifter.c
+8 -99
View File
@@ -29,6 +29,8 @@
#include "alu.h"
#include "filters/defs.h"
#include "alcomplex.h"
#define STFT_SIZE 1024
#define STFT_HALF_SIZE (STFT_SIZE>>1)
@@ -37,10 +39,6 @@
#define STFT_STEP (STFT_SIZE / OVERSAMP)
#define FIFO_LATENCY (STFT_STEP * (OVERSAMP-1))
typedef struct ALcomplex {
ALdouble Real;
ALdouble Imag;
} ALcomplex;
typedef struct ALphasor {
ALdouble Amplitude;
@@ -52,6 +50,7 @@ typedef struct ALFrequencyDomain {
ALdouble Frequency;
} ALfrequencyDomain;
typedef struct ALpshifterState {
DERIVE_FROM_TYPE(ALeffectState);
@@ -149,7 +148,7 @@ static inline ALphasor rect2polar(ALcomplex number)
}
/* Converts ALphasor to ALcomplex */
static inline ALcomplex polar2rect(ALphasor number)
static inline ALcomplex polar2rect(ALphasor number)
{
ALcomplex cartesian;
@@ -159,96 +158,6 @@ static inline ALcomplex polar2rect(ALphasor number)
return cartesian;
}
/* Addition of two complex numbers (ALcomplex format) */
static inline ALcomplex complex_add(ALcomplex a, ALcomplex b)
{
ALcomplex result;
result.Real = a.Real + b.Real;
result.Imag = a.Imag + b.Imag;
return result;
}
/* Subtraction of two complex numbers (ALcomplex format) */
static inline ALcomplex complex_sub(ALcomplex a, ALcomplex b)
{
ALcomplex result;
result.Real = a.Real - b.Real;
result.Imag = a.Imag - b.Imag;
return result;
}
/* Multiplication of two complex numbers (ALcomplex format) */
static inline ALcomplex complex_mult(ALcomplex a, ALcomplex b)
{
ALcomplex result;
result.Real = a.Real*b.Real - a.Imag*b.Imag;
result.Imag = a.Imag*b.Real + a.Real*b.Imag;
return result;
}
/* Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
* FFT and 1 is iFFT (inverse). Fills FFTBuffer[0...FFTSize-1] with the
* Discrete Fourier Transform (DFT) of the time domain data stored in
* FFTBuffer[0...FFTSize-1]. FFTBuffer is an array of complex numbers
* (ALcomplex), FFTSize MUST BE power of two.
*/
static inline ALvoid FFT(ALcomplex *FFTBuffer, ALsizei FFTSize, ALdouble Sign)
{
ALsizei i, j, k, mask, step, step2;
ALcomplex temp, u, w;
ALdouble arg;
/* Bit-reversal permutation applied to a sequence of FFTSize items */
for(i = 1;i < FFTSize-1;i++)
{
for(mask = 0x1, j = 0;mask < FFTSize;mask <<= 1)
{
if((i&mask) != 0)
j++;
j <<= 1;
}
j >>= 1;
if(i < j)
{
temp = FFTBuffer[i];
FFTBuffer[i] = FFTBuffer[j];
FFTBuffer[j] = temp;
}
}
/* Iterative form of Danielson–Lanczos lemma */
for(i = 1, step = 2;i < FFTSize;i<<=1, step<<=1)
{
step2 = step >> 1;
arg = M_PI / step2;
w.Real = cos(arg);
w.Imag = sin(arg) * Sign;
u.Real = 1.0;
u.Imag = 0.0;
for(j = 0;j < step2;j++)
{
for(k = j;k < FFTSize;k+=step)
{
temp = complex_mult(FFTBuffer[k+step2], u);
FFTBuffer[k+step2] = complex_sub(FFTBuffer[k], temp);
FFTBuffer[k] = complex_add(FFTBuffer[k], temp);
}
u = complex_mult(u, w);
}
}
}
static void ALpshifterState_Construct(ALpshifterState *state)
{
@@ -295,8 +204,8 @@ static ALvoid ALpshifterState_update(ALpshifterState *state, const ALCcontext *c
pitch = powf(2.0f,
(ALfloat)(props->Pshifter.CoarseTune*100 + props->Pshifter.FineTune) / 1200.0f
);
state->PitchShiftI = (ALsizei)(pitch*FRACTIONONE + 0.5f);
state->PitchShift = state->PitchShiftI * (1.0f/FRACTIONONE);
state->PitchShiftI = fastf2i(pitch*FRACTIONONE);
state->PitchShift = state->PitchShiftI * (1.0f/FRACTIONONE);
CalcAngleCoeffs(0.0f, 0.0f, 0.0f, coeffs);
ComputeDryPanGains(&device->Dry, coeffs, slot->Params.Gain, state->TargetGains);
@@ -337,7 +246,7 @@ static ALvoid ALpshifterState_process(ALpshifterState *state, ALsizei SamplesToD
/* ANALYSIS */
/* Apply FFT to FFTbuffer data */
FFT(state->FFTbuffer, STFT_SIZE, -1.0);
complex_fft(state->FFTbuffer, STFT_SIZE, -1.0);
/* Analyze the obtained data. Since the real FFT is symmetric, only
* STFT_HALF_SIZE+1 samples are needed.
@@ -417,7 +326,7 @@ static ALvoid ALpshifterState_process(ALpshifterState *state, ALsizei SamplesToD
}
/* Apply iFFT to buffer data */
FFT(state->FFTbuffer, STFT_SIZE, 1.0);
complex_fft(state->FFTbuffer, STFT_SIZE, 1.0);
/* Windowing and add to output */
for(k = 0;k < STFT_SIZE;k++)
CMakeLists.txt
+2
View File
@@ -700,6 +700,8 @@ ENDIF()
SET(COMMON_OBJS
common/alcomplex.c
common/alcomplex.h
common/align.h
common/almalloc.c
common/almalloc.h
common/alcomplex.c
+62
View File
@@ -0,0 +1,62 @@
#include "config.h"
#include "alcomplex.h"
#include <math.h>
extern inline ALcomplex complex_add(ALcomplex a, ALcomplex b);
extern inline ALcomplex complex_sub(ALcomplex a, ALcomplex b);
extern inline ALcomplex complex_mult(ALcomplex a, ALcomplex b);
void complex_fft(ALcomplex *FFTBuffer, ALsizei FFTSize, ALdouble Sign)
{
ALsizei i, j, k, mask, step, step2;
ALcomplex temp, u, w;
ALdouble arg;
/* Bit-reversal permutation applied to a sequence of FFTSize items */
for(i = 1;i < FFTSize-1;i++)
{
for(mask = 0x1, j = 0;mask < FFTSize;mask <<= 1)
{
if((i&mask) != 0)
j++;
j <<= 1;
}
j >>= 1;
if(i < j)
{
temp = FFTBuffer[i];
FFTBuffer[i] = FFTBuffer[j];
FFTBuffer[j] = temp;
}
}
/* Iterative form of Danielson–Lanczos lemma */
for(i = 1, step = 2;i < FFTSize;i<<=1, step<<=1)
{
step2 = step >> 1;
arg = M_PI / step2;
w.Real = cos(arg);
w.Imag = sin(arg) * Sign;
u.Real = 1.0;
u.Imag = 0.0;
for(j = 0;j < step2;j++)
{
for(k = j;k < FFTSize;k+=step)
{
temp = complex_mult(FFTBuffer[k+step2], u);
FFTBuffer[k+step2] = complex_sub(FFTBuffer[k], temp);
FFTBuffer[k] = complex_add(FFTBuffer[k], temp);
}
u = complex_mult(u, w);
}
}
}
common/alcomplex.h
+62
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@@ -0,0 +1,62 @@
#ifndef ALCOMPLEX_H
#define ALCOMPLEX_H
#include "AL/al.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef struct ALcomplex {
ALdouble Real;
ALdouble Imag;
} ALcomplex;
/** Addition of two complex numbers. */
inline ALcomplex complex_add(ALcomplex a, ALcomplex b)
{
ALcomplex result;
result.Real = a.Real + b.Real;
result.Imag = a.Imag + b.Imag;
return result;
}
/** Subtraction of two complex numbers. */
inline ALcomplex complex_sub(ALcomplex a, ALcomplex b)
{
ALcomplex result;
result.Real = a.Real - b.Real;
result.Imag = a.Imag - b.Imag;
return result;
}
/** Multiplication of two complex numbers. */
inline ALcomplex complex_mult(ALcomplex a, ALcomplex b)
{
ALcomplex result;
result.Real = a.Real*b.Real - a.Imag*b.Imag;
result.Imag = a.Imag*b.Real + a.Real*b.Imag;
return result;
}
/**
* Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
* FFT and 1 is iFFT (inverse). Fills FFTBuffer[0...FFTSize-1] with the
* Discrete Fourier Transform (DFT) of the time domain data stored in
* FFTBuffer[0...FFTSize-1]. FFTBuffer is an array of complex numbers, FFTSize
* MUST BE power of two.
*/
void complex_fft(ALcomplex *FFTBuffer, ALsizei FFTSize, ALdouble Sign);
#ifdef __cplusplus
} // extern "C"
#endif
#endif /* ALCOMPLEX_H */