diff options
| author | Tim Redfern <tim@eclectronics.org> | 2014-02-17 13:36:38 +0000 |
|---|---|---|
| committer | Tim Redfern <tim@eclectronics.org> | 2014-02-17 13:36:38 +0000 |
| commit | 22e28216336da876e1fd17f380ce42eaf1446769 (patch) | |
| tree | 444dad3dc7e2656992d29f34f7bce31970c122a5 /ffmpeg/libavcodec/iirfilter.c | |
| parent | ae5e8541f6e06e64c28719467cdf366ac57aff31 (diff) | |
chasing indexing error
Diffstat (limited to 'ffmpeg/libavcodec/iirfilter.c')
| -rw-r--r-- | ffmpeg/libavcodec/iirfilter.c | 354 |
1 files changed, 0 insertions, 354 deletions
diff --git a/ffmpeg/libavcodec/iirfilter.c b/ffmpeg/libavcodec/iirfilter.c deleted file mode 100644 index a2d9d11..0000000 --- a/ffmpeg/libavcodec/iirfilter.c +++ /dev/null @@ -1,354 +0,0 @@ -/* - * IIR filter - * Copyright (c) 2008 Konstantin Shishkov - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -/** - * @file - * different IIR filters implementation - */ - -#include "iirfilter.h" -#include <math.h> -#include "libavutil/attributes.h" -#include "libavutil/common.h" - -/** - * IIR filter global parameters - */ -typedef struct FFIIRFilterCoeffs{ - int order; - float gain; - int *cx; - float *cy; -}FFIIRFilterCoeffs; - -/** - * IIR filter state - */ -typedef struct FFIIRFilterState{ - float x[1]; -}FFIIRFilterState; - -/// maximum supported filter order -#define MAXORDER 30 - -static av_cold int butterworth_init_coeffs(void *avc, - struct FFIIRFilterCoeffs *c, - enum IIRFilterMode filt_mode, - int order, float cutoff_ratio, - float stopband) -{ - int i, j; - double wa; - double p[MAXORDER + 1][2]; - - if (filt_mode != FF_FILTER_MODE_LOWPASS) { - av_log(avc, AV_LOG_ERROR, "Butterworth filter currently only supports " - "low-pass filter mode\n"); - return -1; - } - if (order & 1) { - av_log(avc, AV_LOG_ERROR, "Butterworth filter currently only supports " - "even filter orders\n"); - return -1; - } - - wa = 2 * tan(M_PI * 0.5 * cutoff_ratio); - - c->cx[0] = 1; - for(i = 1; i < (order >> 1) + 1; i++) - c->cx[i] = c->cx[i - 1] * (order - i + 1LL) / i; - - p[0][0] = 1.0; - p[0][1] = 0.0; - for(i = 1; i <= order; i++) - p[i][0] = p[i][1] = 0.0; - for(i = 0; i < order; i++){ - double zp[2]; - double th = (i + (order >> 1) + 0.5) * M_PI / order; - double a_re, a_im, c_re, c_im; - zp[0] = cos(th) * wa; - zp[1] = sin(th) * wa; - a_re = zp[0] + 2.0; - c_re = zp[0] - 2.0; - a_im = - c_im = zp[1]; - zp[0] = (a_re * c_re + a_im * c_im) / (c_re * c_re + c_im * c_im); - zp[1] = (a_im * c_re - a_re * c_im) / (c_re * c_re + c_im * c_im); - - for(j = order; j >= 1; j--) - { - a_re = p[j][0]; - a_im = p[j][1]; - p[j][0] = a_re*zp[0] - a_im*zp[1] + p[j-1][0]; - p[j][1] = a_re*zp[1] + a_im*zp[0] + p[j-1][1]; - } - a_re = p[0][0]*zp[0] - p[0][1]*zp[1]; - p[0][1] = p[0][0]*zp[1] + p[0][1]*zp[0]; - p[0][0] = a_re; - } - c->gain = p[order][0]; - for(i = 0; i < order; i++){ - c->gain += p[i][0]; - c->cy[i] = (-p[i][0] * p[order][0] + -p[i][1] * p[order][1]) / - (p[order][0] * p[order][0] + p[order][1] * p[order][1]); - } - c->gain /= 1 << order; - - return 0; -} - -static av_cold int biquad_init_coeffs(void *avc, struct FFIIRFilterCoeffs *c, - enum IIRFilterMode filt_mode, int order, - float cutoff_ratio, float stopband) -{ - double cos_w0, sin_w0; - double a0, x0, x1; - - if (filt_mode != FF_FILTER_MODE_HIGHPASS && - filt_mode != FF_FILTER_MODE_LOWPASS) { - av_log(avc, AV_LOG_ERROR, "Biquad filter currently only supports " - "high-pass and low-pass filter modes\n"); - return -1; - } - if (order != 2) { - av_log(avc, AV_LOG_ERROR, "Biquad filter must have order of 2\n"); - return -1; - } - - cos_w0 = cos(M_PI * cutoff_ratio); - sin_w0 = sin(M_PI * cutoff_ratio); - - a0 = 1.0 + (sin_w0 / 2.0); - - if (filt_mode == FF_FILTER_MODE_HIGHPASS) { - c->gain = ((1.0 + cos_w0) / 2.0) / a0; - x0 = ((1.0 + cos_w0) / 2.0) / a0; - x1 = (-(1.0 + cos_w0)) / a0; - } else { // FF_FILTER_MODE_LOWPASS - c->gain = ((1.0 - cos_w0) / 2.0) / a0; - x0 = ((1.0 - cos_w0) / 2.0) / a0; - x1 = (1.0 - cos_w0) / a0; - } - c->cy[0] = (-1.0 + (sin_w0 / 2.0)) / a0; - c->cy[1] = (2.0 * cos_w0) / a0; - - // divide by gain to make the x coeffs integers. - // during filtering, the delay state will include the gain multiplication - c->cx[0] = lrintf(x0 / c->gain); - c->cx[1] = lrintf(x1 / c->gain); - - return 0; -} - -av_cold struct FFIIRFilterCoeffs* ff_iir_filter_init_coeffs(void *avc, - enum IIRFilterType filt_type, - enum IIRFilterMode filt_mode, - int order, float cutoff_ratio, - float stopband, float ripple) -{ - FFIIRFilterCoeffs *c; - int ret = 0; - - if (order <= 0 || order > MAXORDER || cutoff_ratio >= 1.0) - return NULL; - - FF_ALLOCZ_OR_GOTO(avc, c, sizeof(FFIIRFilterCoeffs), - init_fail); - FF_ALLOC_OR_GOTO (avc, c->cx, sizeof(c->cx[0]) * ((order >> 1) + 1), - init_fail); - FF_ALLOC_OR_GOTO (avc, c->cy, sizeof(c->cy[0]) * order, - init_fail); - c->order = order; - - switch (filt_type) { - case FF_FILTER_TYPE_BUTTERWORTH: - ret = butterworth_init_coeffs(avc, c, filt_mode, order, cutoff_ratio, - stopband); - break; - case FF_FILTER_TYPE_BIQUAD: - ret = biquad_init_coeffs(avc, c, filt_mode, order, cutoff_ratio, - stopband); - break; - default: - av_log(avc, AV_LOG_ERROR, "filter type is not currently implemented\n"); - goto init_fail; - } - - if (!ret) - return c; - -init_fail: - ff_iir_filter_free_coeffs(c); - return NULL; -} - -av_cold struct FFIIRFilterState* ff_iir_filter_init_state(int order) -{ - FFIIRFilterState* s = av_mallocz(sizeof(FFIIRFilterState) + sizeof(s->x[0]) * (order - 1)); - return s; -} - -#define CONV_S16(dest, source) dest = av_clip_int16(lrintf(source)); - -#define CONV_FLT(dest, source) dest = source; - -#define FILTER_BW_O4_1(i0, i1, i2, i3, fmt) \ - in = *src0 * c->gain \ - + c->cy[0]*s->x[i0] + c->cy[1]*s->x[i1] \ - + c->cy[2]*s->x[i2] + c->cy[3]*s->x[i3]; \ - res = (s->x[i0] + in )*1 \ - + (s->x[i1] + s->x[i3])*4 \ - + s->x[i2] *6; \ - CONV_##fmt(*dst0, res) \ - s->x[i0] = in; \ - src0 += sstep; \ - dst0 += dstep; - -#define FILTER_BW_O4(type, fmt) { \ - int i; \ - const type *src0 = src; \ - type *dst0 = dst; \ - for (i = 0; i < size; i += 4) { \ - float in, res; \ - FILTER_BW_O4_1(0, 1, 2, 3, fmt); \ - FILTER_BW_O4_1(1, 2, 3, 0, fmt); \ - FILTER_BW_O4_1(2, 3, 0, 1, fmt); \ - FILTER_BW_O4_1(3, 0, 1, 2, fmt); \ - } \ -} - -#define FILTER_DIRECT_FORM_II(type, fmt) { \ - int i; \ - const type *src0 = src; \ - type *dst0 = dst; \ - for (i = 0; i < size; i++) { \ - int j; \ - float in, res; \ - in = *src0 * c->gain; \ - for(j = 0; j < c->order; j++) \ - in += c->cy[j] * s->x[j]; \ - res = s->x[0] + in + s->x[c->order >> 1] * c->cx[c->order >> 1]; \ - for(j = 1; j < c->order >> 1; j++) \ - res += (s->x[j] + s->x[c->order - j]) * c->cx[j]; \ - for(j = 0; j < c->order - 1; j++) \ - s->x[j] = s->x[j + 1]; \ - CONV_##fmt(*dst0, res) \ - s->x[c->order - 1] = in; \ - src0 += sstep; \ - dst0 += dstep; \ - } \ -} - -#define FILTER_O2(type, fmt) { \ - int i; \ - const type *src0 = src; \ - type *dst0 = dst; \ - for (i = 0; i < size; i++) { \ - float in = *src0 * c->gain + \ - s->x[0] * c->cy[0] + \ - s->x[1] * c->cy[1]; \ - CONV_##fmt(*dst0, s->x[0] + in + s->x[1] * c->cx[1]) \ - s->x[0] = s->x[1]; \ - s->x[1] = in; \ - src0 += sstep; \ - dst0 += dstep; \ - } \ -} - -void ff_iir_filter(const struct FFIIRFilterCoeffs *c, - struct FFIIRFilterState *s, int size, - const int16_t *src, int sstep, int16_t *dst, int dstep) -{ - if (c->order == 2) { - FILTER_O2(int16_t, S16) - } else if (c->order == 4) { - FILTER_BW_O4(int16_t, S16) - } else { - FILTER_DIRECT_FORM_II(int16_t, S16) - } -} - -void ff_iir_filter_flt(const struct FFIIRFilterCoeffs *c, - struct FFIIRFilterState *s, int size, - const float *src, int sstep, float *dst, int dstep) -{ - if (c->order == 2) { - FILTER_O2(float, FLT) - } else if (c->order == 4) { - FILTER_BW_O4(float, FLT) - } else { - FILTER_DIRECT_FORM_II(float, FLT) - } -} - -av_cold void ff_iir_filter_free_state(struct FFIIRFilterState *state) -{ - av_free(state); -} - -av_cold void ff_iir_filter_free_coeffs(struct FFIIRFilterCoeffs *coeffs) -{ - if(coeffs){ - av_free(coeffs->cx); - av_free(coeffs->cy); - } - av_free(coeffs); -} - -void ff_iir_filter_init(FFIIRFilterContext *f) { - f->filter_flt = ff_iir_filter_flt; - - if (HAVE_MIPSFPU) - ff_iir_filter_init_mips(f); -} - -#ifdef TEST -#include <stdio.h> - -#define FILT_ORDER 4 -#define SIZE 1024 -int main(void) -{ - struct FFIIRFilterCoeffs *fcoeffs = NULL; - struct FFIIRFilterState *fstate = NULL; - float cutoff_coeff = 0.4; - int16_t x[SIZE], y[SIZE]; - int i; - - fcoeffs = ff_iir_filter_init_coeffs(NULL, FF_FILTER_TYPE_BUTTERWORTH, - FF_FILTER_MODE_LOWPASS, FILT_ORDER, - cutoff_coeff, 0.0, 0.0); - fstate = ff_iir_filter_init_state(FILT_ORDER); - - for (i = 0; i < SIZE; i++) { - x[i] = lrint(0.75 * INT16_MAX * sin(0.5*M_PI*i*i/SIZE)); - } - - ff_iir_filter(fcoeffs, fstate, SIZE, x, 1, y, 1); - - for (i = 0; i < SIZE; i++) - printf("%6d %6d\n", x[i], y[i]); - - ff_iir_filter_free_coeffs(fcoeffs); - ff_iir_filter_free_state(fstate); - return 0; -} -#endif /* TEST */ |
