| 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 | |
| 30 | void 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 | |
| 50 | void 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 | |
| 60 | int 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 | |
| 84 | void 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 | |
| 199 | void 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 | |
| 212 | void 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 | } |