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#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "fft.h"
#define TRUE 1
#define FALSE 0
/*
band pass filter for the Eq. This is a modification of Kai Lassfolk's work, as
removed from the Sound Processing Kit:
Sound Processing Kit - A C++ Class Library for Audio Signal Processing
Copyright (C) 1995-1998 Kai Lassfolk
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1307 USA
*/
#define SAMPLERATE 44100
#ifndef M_PI
#define M_PI DDC_PI
#endif
void BandPassInit(struct BandPassInfo *ip, float center, float bw)
{
ip->center = center;
ip->bandwidth = bw;
ip->C = 1.0 / tan(M_PI * bw / SAMPLERATE);
ip->D = 2 * cos(2 * M_PI * center / SAMPLERATE);
ip->a[0] = 1.0 / (1.0 + ip->C);
ip->a[1] = 0.0;
ip->a[2] = -ip->a[0];
ip->b[0] = -ip->C * ip->D * ip->a[0];
ip->b[1] = (ip->C - 1.0) * ip->a[0];
ip->bufferX[0] = ip->bufferX[1] = 0.0;
ip->bufferY[0] = ip->bufferY[1] = 0.0;
}
void BandPassSSE(struct BandPassInfo *ip, float *inbuffer, float *outbuffer, unsigned long samples)
{
#ifdef HAVE_X86_SSE
__asm__(
"testl %0, %0 \n"
"jz .l5 \n" /* if (!samples) */
"movl %1, %%ecx \n"
"movups 0x10(%%ecx), %%xmm2 \n" /* ip->a[0] */
"shufps $0x00, %%xmm2, %%xmm2 \n" /* ip->a[0] all over xmm3 */
"movups 0x14(%%ecx), %%xmm4 \n" /* xmm4 = {ip->a[1], ip->a[2], ip->b} */
"movups 0x24(%%ecx), %%xmm5 \n" /* xmm5 = {ip->bufferX, ip->bufferY} */
"xorl %%ecx, %%ecx \n" /* i = 0 */
"movl $1, %%edx \n" /* j = 1 */
"prefetcht0 (%2) \n"
".l1: \n"
"decl %%edx \n" /* --j */
"jnz .l4 \n" /* if (j) */
/* only load single values if less than four remain in inbuffer */
"testl $0xfffffffc, %0 \n"
"jnz .l2 \n"
"movss (%2, %%ecx, 4), %%xmm3\n"
"movl $1, %%edx \n"
"jmp .l3 \n"
".l2: \n"
/* {inbuffer[i], inbuffer[i+1], inbuffer[i+2], inbuffer[i+3]} * ip->a[0] */
"movups (%2, %%ecx, 4), %%xmm3\n"
"movl $3, %%edx \n" /* j = 3 */
".l3: \n"
"movaps %%xmm3, %%xmm6 \n"
"mulps %%xmm2, %%xmm3 \n"
".l4: \n"
/* {ip->a[1], ip->a[2], ip->b} * {ip->bufferX, ip->bufferY} */
"movaps %%xmm4, %%xmm0 \n"
"mulps %%xmm5, %%xmm0 \n"
"movaps %%xmm0, %%xmm1 \n"
/* xmm0 = {xmm0[0] + xmm0[1], <unused>, xmm0[2] + xmm0[3], <unused>} */
"shufps $0xb1, %%xmm0, %%xmm1 \n"
"addps %%xmm1, %%xmm0 \n"
/* xmm0[0] -= xmm0[2] */
"movhlps %%xmm0, %%xmm1 \n"
"subss %%xmm1, %%xmm0 \n"
"addss %%xmm3, %%xmm0 \n" /* xmm0[0] += inbuffer[i] * ip->a[0] */
"movss %%xmm0, (%3, %%ecx, 4)\n" /* outbuffer[i] = xmm0[0] */
/* xmm5 = {inbuffer[i], xmm5[0], outbuffer[i], xmm5[2]} */
"shufps $0x24, %%xmm5, %%xmm0 \n"
"shufps $0x81, %%xmm0, %%xmm5 \n"
"movss %%xmm6, %%xmm5 \n"
/* right-shift xmm3 (inbuffer * ip->a[0]) and xmm6 (inbuffer) */
"shufps $0x39, %%xmm3, %%xmm3 \n"
"shufps $0x39, %%xmm6, %%xmm6 \n"
"incl %%ecx \n" /* ++i */
"decl %0 \n"
"jnz .l1 \n"
"movl %1,%%ecx \n"
"movups %%xmm5, 0x24(%%ecx) \n" /* {ip->bufferX, ip->bufferY} = xmm5 */
"emms \n"
".l5: \n"
:
: "r" (samples), /* %0 */
"m" (ip), /* %1 */
"r" (inbuffer), /* %2 */
"r" (outbuffer) /* %3 */
: "ecx", "edx");
#endif
}
void BandPass(struct BandPassInfo *ip, float *inbuffer, float *outbuffer, unsigned long samples)
{
unsigned long i;
for (i=0; i<samples; ++i)
{
outbuffer[i] = ip->a[0] * inbuffer[i] + ip->a[1] * ip->bufferX[0] + ip->a[2]
* ip->bufferX[1] - ip->b[0] * ip->bufferY[0] - ip->b[1]
* ip->bufferY[1];
ip->bufferX[1] = ip->bufferX[0];
ip->bufferX[0] = inbuffer[i];
ip->bufferY[1] = ip->bufferY[0];
ip->bufferY[0] = outbuffer[i];
}
}
/*============================================================================
fftmisc.c - Don Cross <dcross@intersrv.com>
http://www.intersrv.com/~dcross/fft.html
Helper routines for Fast Fourier Transform implementation.
Contains common code for fft_float() and fft_double().
See also:
fourierf.c
fourierd.c
..\include\fourier.h
Revision history:
1998 September 19 [Don Cross]
Improved the efficiency of IsPowerOfTwo().
Updated coding standards.
============================================================================*/
#define BITS_PER_WORD (sizeof(unsigned) * 8)
static int IsPowerOfTwo ( unsigned x )
{
if ( x < 2 )
return FALSE;
if ( x & (x-1) ) /* Thanks to 'byang' for this cute trick! */
return FALSE;
return TRUE;
}
static unsigned NumberOfBitsNeeded ( unsigned PowerOfTwo )
{
unsigned i;
if ( PowerOfTwo < 2 )
{
fprintf (
stderr,
">>> Error in fftmisc.c: argument %d to NumberOfBitsNeeded is too small.\n",
PowerOfTwo );
exit(1);
}
for ( i=0; ; i++ )
{
if ( PowerOfTwo & (1 << i) )
return i;
}
}
static unsigned ReverseBits ( unsigned ind, unsigned NumBits )
{
unsigned i, rev;
for ( i=rev=0; i < NumBits; i++ )
{
rev = (rev << 1) | (ind & 1);
ind >>= 1;
}
return rev;
}
/*
static double Index_to_frequency ( unsigned NumSamples, unsigned Index )
{
if ( Index >= NumSamples )
return 0.0;
else if ( Index <= NumSamples/2 )
return (double)Index / (double)NumSamples;
return -(double)(NumSamples-Index) / (double)NumSamples;
}
*/
#undef TRUE
#undef FALSE
#undef BITS_PER_WORD
/*============================================================================
fourierf.c - Don Cross <dcross@intersrv.com>
http://www.intersrv.com/~dcross/fft.html
Contains definitions for doing Fourier transforms
and inverse Fourier transforms.
This module performs operations on arrays of 'float'.
Revision history:
1998 September 19 [Don Cross]
Updated coding standards.
Improved efficiency of trig calculations.
============================================================================*/
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "fft.h"
#define CHECKPOINTER(p) CheckPointer(p,#p)
static void CheckPointer ( const void *p, const char *name )
{
if ( p == NULL )
{
fprintf ( stderr, "Error in fft_float(): %s == NULL\n", name );
exit(1);
}
}
void fft_float (
unsigned NumSamples,
int InverseTransform,
float *RealIn,
float *ImagIn,
float *RealOut,
float *ImagOut )
{
unsigned NumBits; /* Number of bits needed to store indices */
unsigned i, j, k, n;
unsigned BlockSize, BlockEnd;
double angle_numerator = 2.0 * DDC_PI;
double tr, ti; /* temp real, temp imaginary */
if ( !IsPowerOfTwo(NumSamples) )
{
fprintf (
stderr,
"Error in fft(): NumSamples=%u is not power of two\n",
NumSamples );
exit(1);
}
if ( InverseTransform )
angle_numerator = -angle_numerator;
CHECKPOINTER ( RealIn );
CHECKPOINTER ( RealOut );
CHECKPOINTER ( ImagOut );
NumBits = NumberOfBitsNeeded ( NumSamples );
/*
** Do simultaneous data copy and bit-reversal ordering into outputs...
*/
for ( i=0; i < NumSamples; i++ )
{
j = ReverseBits ( i, NumBits );
RealOut[j] = RealIn[i];
ImagOut[j] = (ImagIn == NULL) ? 0.0 : ImagIn[i];
}
/*
** Do the FFT itself...
*/
BlockEnd = 1;
for ( BlockSize = 2; BlockSize <= NumSamples; BlockSize <<= 1 )
{
double delta_angle = angle_numerator / (double)BlockSize;
double sm2 = sin ( -2 * delta_angle );
double sm1 = sin ( -delta_angle );
double cm2 = cos ( -2 * delta_angle );
double cm1 = cos ( -delta_angle );
double w = 2 * cm1;
double ar[3], ai[3];
for ( i=0; i < NumSamples; i += BlockSize )
{
ar[2] = cm2;
ar[1] = cm1;
ai[2] = sm2;
ai[1] = sm1;
for ( j=i, n=0; n < BlockEnd; j++, n++ )
{
ar[0] = w*ar[1] - ar[2];
ar[2] = ar[1];
ar[1] = ar[0];
ai[0] = w*ai[1] - ai[2];
ai[2] = ai[1];
ai[1] = ai[0];
k = j + BlockEnd;
tr = ar[0]*RealOut[k] - ai[0]*ImagOut[k];
ti = ar[0]*ImagOut[k] + ai[0]*RealOut[k];
RealOut[k] = RealOut[j] - tr;
ImagOut[k] = ImagOut[j] - ti;
RealOut[j] += tr;
ImagOut[j] += ti;
}
}
BlockEnd = BlockSize;
}
/*
** Need to normalize if inverse transform...
*/
if ( InverseTransform )
{
double denom = (double)NumSamples;
for ( i=0; i < NumSamples; i++ )
{
RealOut[i] /= denom;
ImagOut[i] /= denom;
}
}
}
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