1/* 2 * various filters for ACELP-based codecs 3 * 4 * Copyright (c) 2008 Vladimir Voroshilov 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23#include <inttypes.h> 24 25#include "avcodec.h" 26#include "celp_filters.h" 27#include "libavutil/avassert.h" 28#include "libavutil/common.h" 29 30void ff_celp_convolve_circ(int16_t* fc_out, const int16_t* fc_in, 31 const int16_t* filter, int len) 32{ 33 int i, k; 34 35 memset(fc_out, 0, len * sizeof(int16_t)); 36 37 /* Since there are few pulses over an entire subframe (i.e. almost 38 all fc_in[i] are zero) it is faster to loop over fc_in first. */ 39 for (i = 0; i < len; i++) { 40 if (fc_in[i]) { 41 for (k = 0; k < i; k++) 42 fc_out[k] += (fc_in[i] * filter[len + k - i]) >> 15; 43 44 for (k = i; k < len; k++) 45 fc_out[k] += (fc_in[i] * filter[ k - i]) >> 15; 46 } 47 } 48} 49 50void ff_celp_circ_addf(float *out, const float *in, 51 const float *lagged, int lag, float fac, int n) 52{ 53 int k; 54 for (k = 0; k < lag; k++) 55 out[k] = in[k] + fac * lagged[n + k - lag]; 56 for (; k < n; k++) 57 out[k] = in[k] + fac * lagged[ k - lag]; 58} 59 60int ff_celp_lp_synthesis_filter(int16_t *out, const int16_t *filter_coeffs, 61 const int16_t *in, int buffer_length, 62 int filter_length, int stop_on_overflow, 63 int shift, int rounder) 64{ 65 int i,n; 66 67 for (n = 0; n < buffer_length; n++) { 68 int sum = -rounder, sum1; 69 for (i = 1; i <= filter_length; i++) 70 sum += filter_coeffs[i-1] * out[n-i]; 71 72 sum1 = ((-sum >> 12) + in[n]) >> shift; 73 sum = av_clip_int16(sum1); 74 75 if (stop_on_overflow && sum != sum1) 76 return 1; 77 78 out[n] = sum; 79 } 80 81 return 0; 82} 83 84void ff_celp_lp_synthesis_filterf(float *out, const float *filter_coeffs, 85 const float* in, int buffer_length, 86 int filter_length) 87{ 88 int i,n; 89 90#if 0 // Unoptimized code path for improved readability 91 for (n = 0; n < buffer_length; n++) { 92 out[n] = in[n]; 93 for (i = 1; i <= filter_length; i++) 94 out[n] -= filter_coeffs[i-1] * out[n-i]; 95 } 96#else 97 float out0, out1, out2, out3; 98 float old_out0, old_out1, old_out2, old_out3; 99 float a,b,c; 100 101 a = filter_coeffs[0]; 102 b = filter_coeffs[1]; 103 c = filter_coeffs[2]; 104 b -= filter_coeffs[0] * filter_coeffs[0]; 105 c -= filter_coeffs[1] * filter_coeffs[0]; 106 c -= filter_coeffs[0] * b; 107 108 av_assert2((filter_length&1)==0 && filter_length>=4); 109 110 old_out0 = out[-4]; 111 old_out1 = out[-3]; 112 old_out2 = out[-2]; 113 old_out3 = out[-1]; 114 for (n = 0; n <= buffer_length - 4; n+=4) { 115 float tmp0,tmp1,tmp2; 116 float val; 117 118 out0 = in[0]; 119 out1 = in[1]; 120 out2 = in[2]; 121 out3 = in[3]; 122 123 out0 -= filter_coeffs[2] * old_out1; 124 out1 -= filter_coeffs[2] * old_out2; 125 out2 -= filter_coeffs[2] * old_out3; 126 127 out0 -= filter_coeffs[1] * old_out2; 128 out1 -= filter_coeffs[1] * old_out3; 129 130 out0 -= filter_coeffs[0] * old_out3; 131 132 val = filter_coeffs[3]; 133 134 out0 -= val * old_out0; 135 out1 -= val * old_out1; 136 out2 -= val * old_out2; 137 out3 -= val * old_out3; 138 139 for (i = 5; i < filter_length; i += 2) { 140 old_out3 = out[-i]; 141 val = filter_coeffs[i-1]; 142 143 out0 -= val * old_out3; 144 out1 -= val * old_out0; 145 out2 -= val * old_out1; 146 out3 -= val * old_out2; 147 148 old_out2 = out[-i-1]; 149 150 val = filter_coeffs[i]; 151 152 out0 -= val * old_out2; 153 out1 -= val * old_out3; 154 out2 -= val * old_out0; 155 out3 -= val * old_out1; 156 157 FFSWAP(float, old_out0, old_out2); 158 old_out1 = old_out3; 159 } 160 161 tmp0 = out0; 162 tmp1 = out1; 163 tmp2 = out2; 164 165 out3 -= a * tmp2; 166 out2 -= a * tmp1; 167 out1 -= a * tmp0; 168 169 out3 -= b * tmp1; 170 out2 -= b * tmp0; 171 172 out3 -= c * tmp0; 173 174 175 out[0] = out0; 176 out[1] = out1; 177 out[2] = out2; 178 out[3] = out3; 179 180 old_out0 = out0; 181 old_out1 = out1; 182 old_out2 = out2; 183 old_out3 = out3; 184 185 out += 4; 186 in += 4; 187 } 188 189 out -= n; 190 in -= n; 191 for (; n < buffer_length; n++) { 192 out[n] = in[n]; 193 for (i = 1; i <= filter_length; i++) 194 out[n] -= filter_coeffs[i-1] * out[n-i]; 195 } 196#endif 197} 198 199void ff_celp_lp_zero_synthesis_filterf(float *out, const float *filter_coeffs, 200 const float *in, int buffer_length, 201 int filter_length) 202{ 203 int i,n; 204 205 for (n = 0; n < buffer_length; n++) { 206 out[n] = in[n]; 207 for (i = 1; i <= filter_length; i++) 208 out[n] += filter_coeffs[i-1] * in[n-i]; 209 } 210} 211 212void ff_celp_filter_init(CELPFContext *c) 213{ 214 c->celp_lp_synthesis_filterf = ff_celp_lp_synthesis_filterf; 215 c->celp_lp_zero_synthesis_filterf = ff_celp_lp_zero_synthesis_filterf; 216 217 if(HAVE_MIPSFPU) 218 ff_celp_filter_init_mips(c); 219} 220