diff options
Diffstat (limited to 'lib/iir_cfs.c')
| -rw-r--r-- | lib/iir_cfs.c | 235 |
1 files changed, 0 insertions, 235 deletions
diff --git a/lib/iir_cfs.c b/lib/iir_cfs.c deleted file mode 100644 index 88ecbadc6..000000000 --- a/lib/iir_cfs.c +++ /dev/null @@ -1,235 +0,0 @@ -/* - * Copyright (C) 2002-2005 Felipe Rivera <liebremx at users.sourceforge.net> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program 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 General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - * - * - * Coefficient stuff - * - * $Id: iir_cfs.c,v 1.1 2005/10/17 01:57:59 liebremx Exp $ - */ - -#include "iir_cfs.h" -#include <stdio.h> -#include <math.h> - -/*************************** - * IIR filter coefficients * - ***************************/ -static sIIRCoefficients iir_cf10_11k_11025[10] __attribute__((aligned)); -static sIIRCoefficients iir_cf10_22k_22050[10] __attribute__((aligned)); -static sIIRCoefficients iir_cforiginal10_44100[10] __attribute__((aligned)); -static sIIRCoefficients iir_cforiginal10_48000[10] __attribute__((aligned)); -static sIIRCoefficients iir_cf10_44100[10] __attribute__((aligned)); -static sIIRCoefficients iir_cf10_48000[10] __attribute__((aligned)); -static sIIRCoefficients iir_cf15_44100[15] __attribute__((aligned)); -static sIIRCoefficients iir_cf15_48000[15] __attribute__((aligned)); -static sIIRCoefficients iir_cf25_44100[25] __attribute__((aligned)); -static sIIRCoefficients iir_cf25_48000[25] __attribute__((aligned)); -static sIIRCoefficients iir_cf31_44100[31] __attribute__((aligned)); -static sIIRCoefficients iir_cf31_48000[31] __attribute__((aligned)); - -/****************************************************************** - * Definitions and data structures to calculate the coefficients - ******************************************************************/ -static const double band_f011k[] = -{ 31, 62, 125, 250, 500, 1000, 2000, 3000, 4000, 5500 -}; -static const double band_f022k[] = -{ 31, 62, 125, 250, 500, 1000, 2000, 4000, 8000, 11000 -}; -static const double band_f010[] = -{ 31, 62, 125, 250, 500, 1000, 2000, 4000, 8000, 16000 -}; -static const double band_original_f010[] = -{ 60, 170, 310, 600, 1000, 3000, 6000, 12000, 14000, 16000 -}; -static const double band_f015[] = -{ 25,40,63,100,160,250,400,630,1000,1600,2500,4000,6300,10000,16000 -}; -static const double band_f025[] = -{ 20,31.5,40,50,80,100,125,160,250,315,400,500,800, - 1000,1250,1600,2500,3150,4000,5000,8000,10000,12500,16000,20000 -}; -static const double band_f031[] = -{ 20,25,31.5,40,50,63,80,100,125,160,200,250,315,400,500,630,800, - 1000,1250,1600,2000,2500,3150,4000,5000,6300,8000,10000,12500,16000,20000 -}; - -#define GAIN_F0 1.0 -#define GAIN_F1 GAIN_F0 / M_SQRT2 - -#define SAMPLING_FREQ 44100.0 -#define TETA(f) (2*M_PI*(double)f/bands[n].sfreq) -#define TWOPOWER(value) (value * value) - -#define BETA2(tf0, tf) \ -(TWOPOWER(GAIN_F1)*TWOPOWER(cos(tf0)) \ - - 2.0 * TWOPOWER(GAIN_F1) * cos(tf) * cos(tf0) \ - + TWOPOWER(GAIN_F1) \ - - TWOPOWER(GAIN_F0) * TWOPOWER(sin(tf))) -#define BETA1(tf0, tf) \ - (2.0 * TWOPOWER(GAIN_F1) * TWOPOWER(cos(tf)) \ - + TWOPOWER(GAIN_F1) * TWOPOWER(cos(tf0)) \ - - 2.0 * TWOPOWER(GAIN_F1) * cos(tf) * cos(tf0) \ - - TWOPOWER(GAIN_F1) + TWOPOWER(GAIN_F0) * TWOPOWER(sin(tf))) -#define BETA0(tf0, tf) \ - (0.25 * TWOPOWER(GAIN_F1) * TWOPOWER(cos(tf0)) \ - - 0.5 * TWOPOWER(GAIN_F1) * cos(tf) * cos(tf0) \ - + 0.25 * TWOPOWER(GAIN_F1) \ - - 0.25 * TWOPOWER(GAIN_F0) * TWOPOWER(sin(tf))) - -#define GAMMA(beta, tf0) ((0.5 + beta) * cos(tf0)) -#define ALPHA(beta) ((0.5 - beta)/2.0) - -struct { - sIIRCoefficients *coeffs; - const double *cfs; - double octave; - int band_count; - double sfreq; -} bands[] = { - { iir_cf10_11k_11025, band_f011k, 1.0, 10, 11025.0 }, - { iir_cf10_22k_22050, band_f022k, 1.0, 10, 22050.0 }, - { iir_cforiginal10_44100, band_original_f010, 1.0, 10, 44100.0 }, - { iir_cforiginal10_48000, band_original_f010, 1.0, 10, 48000.0 }, - { iir_cf10_44100, band_f010, 1.0, 10, 44100.0 }, - { iir_cf10_48000, band_f010, 1.0, 10, 48000.0 }, - { iir_cf15_44100, band_f015, 2.0/3.0, 15, 44100.0 }, - { iir_cf15_48000, band_f015, 2.0/3.0, 15, 48000.0 }, - { iir_cf25_44100, band_f025, 1.0/3.0, 25, 44100.0 }, - { iir_cf25_48000, band_f025, 1.0/3.0, 25, 48000.0 }, - { iir_cf31_44100, band_f031, 1.0/3.0, 31, 44100.0 }, - { iir_cf31_48000, band_f031, 1.0/3.0, 31, 48000.0 }, - { 0, 0, 0, 0, 0 } -}; - -/************* - * Functions * - *************/ - -/* Get the coeffs for a given number of bands and sampling frequency */ -sIIRCoefficients* get_coeffs(gint *bands, gint sfreq, gboolean use_xmms_original_freqs) -{ - sIIRCoefficients *iir_cf = 0; - switch(sfreq) - { - case 11025: iir_cf = iir_cf10_11k_11025; - *bands = 10; - break; - case 22050: iir_cf = iir_cf10_22k_22050; - *bands = 10; - break; - case 48000: - switch(*bands) - { - case 31: iir_cf = iir_cf31_48000; break; - case 25: iir_cf = iir_cf25_48000; break; - case 15: iir_cf = iir_cf15_48000; break; - default: - iir_cf = use_xmms_original_freqs ? - iir_cforiginal10_48000 : - iir_cf10_48000; - break; - } - break; - default: - switch(*bands) - { - case 31: iir_cf = iir_cf31_44100; break; - case 25: iir_cf = iir_cf25_44100; break; - case 15: iir_cf = iir_cf15_44100; break; - default: - iir_cf = use_xmms_original_freqs ? - iir_cforiginal10_44100 : - iir_cf10_44100; - break; - } - break; - } - return iir_cf; -} - -/* Get the freqs at both sides of F0. These will be cut at -3dB */ -static void find_f1_and_f2(double f0, double octave_percent, double *f1, double *f2) -{ - double octave_factor = pow(2.0, octave_percent/2.0); - *f1 = f0/octave_factor; - *f2 = f0*octave_factor; -} - -/* Find the quadratic root - * Always return the smallest root */ -static int find_root(double a, double b, double c, double *x0) { - double k = c-((b*b)/(4.*a)); - double h = -(b/(2.*a)); - double x1 = 0.; - if (-(k/a) < 0.) - return -1; - *x0 = h - sqrt(-(k/a)); - x1 = h + sqrt(-(k/a)); - if (x1 < *x0) - *x0 = x1; - return 0; -} - -/* Calculate all the coefficients as specified in the bands[] array */ -void calc_coeffs() -{ - int i, n; - double f1, f2; - double x0; - - n = 0; - for (; bands[n].cfs; n++) { - double *freqs = (double *)bands[n].cfs; - for (i=0; i<bands[n].band_count; i++) - { - - /* Find -3dB frequencies for the center freq */ - find_f1_and_f2(freqs[i], bands[n].octave, &f1, &f2); - /* Find Beta */ - if ( find_root( - BETA2(TETA(freqs[i]), TETA(f1)), - BETA1(TETA(freqs[i]), TETA(f1)), - BETA0(TETA(freqs[i]), TETA(f1)), - &x0) == 0) - { - /* Got a solution, now calculate the rest of the factors */ - /* Take the smallest root always (find_root returns the smallest one) - * - * NOTE: The IIR equation is - * y[n] = 2 * (alpha*(x[n]-x[n-2]) + gamma*y[n-1] - beta*y[n-2]) - * Now the 2 factor has been distributed in the coefficients - */ - /* Now store the coefficients */ - bands[n].coeffs[i].beta = 2.0 * x0; - bands[n].coeffs[i].alpha = 2.0 * ALPHA(x0); - bands[n].coeffs[i].gamma = 2.0 * GAMMA(x0, TETA(freqs[i])); -#ifdef DEBUG - printf("Freq[%d]: %f. Beta: %.10e Alpha: %.10e Gamma %.10e\n", - i, freqs[i], bands[n].coeffs[i].beta, - bands[n].coeffs[i].alpha, bands[n].coeffs[i].gamma); -#endif - } else { - /* Shouldn't happen */ - bands[n].coeffs[i].beta = 0.; - bands[n].coeffs[i].alpha = 0.; - bands[n].coeffs[i].gamma = 0.; - printf(" **** Where are the roots?\n"); - } - }// for i - }//for n -} |