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-rw-r--r--noatun/library/noatunarts/fft.c384
1 files changed, 384 insertions, 0 deletions
diff --git a/noatun/library/noatunarts/fft.c b/noatun/library/noatunarts/fft.c
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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., 59 Temple Place, Suite 330, 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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