| 1 | /* |
| 2 | * audio resampling |
| 3 | * Copyright (c) 2004-2012 Michael Niedermayer <michaelni@gmx.at> |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * audio resampling |
| 25 | * @author Michael Niedermayer <michaelni@gmx.at> |
| 26 | */ |
| 27 | |
| 28 | #if defined(TEMPLATE_RESAMPLE_DBL) |
| 29 | |
| 30 | # define RENAME(N) N ## _double |
| 31 | # define FILTER_SHIFT 0 |
| 32 | # define DELEM double |
| 33 | # define FELEM double |
| 34 | # define FELEM2 double |
| 35 | # define OUT(d, v) d = v |
| 36 | |
| 37 | #elif defined(TEMPLATE_RESAMPLE_FLT) |
| 38 | |
| 39 | # define RENAME(N) N ## _float |
| 40 | # define FILTER_SHIFT 0 |
| 41 | # define DELEM float |
| 42 | # define FELEM float |
| 43 | # define FELEM2 float |
| 44 | # define OUT(d, v) d = v |
| 45 | |
| 46 | #elif defined(TEMPLATE_RESAMPLE_S32) |
| 47 | |
| 48 | # define RENAME(N) N ## _int32 |
| 49 | # define FILTER_SHIFT 30 |
| 50 | # define DELEM int32_t |
| 51 | # define FELEM int32_t |
| 52 | # define FELEM2 int64_t |
| 53 | # define FELEM_MAX INT32_MAX |
| 54 | # define FELEM_MIN INT32_MIN |
| 55 | # define OUT(d, v) v = (v + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\ |
| 56 | d = (uint64_t)(v + 0x80000000) > 0xFFFFFFFF ? (v>>63) ^ 0x7FFFFFFF : v |
| 57 | |
| 58 | #elif defined(TEMPLATE_RESAMPLE_S16) |
| 59 | |
| 60 | # define RENAME(N) N ## _int16 |
| 61 | # define FILTER_SHIFT 15 |
| 62 | # define DELEM int16_t |
| 63 | # define FELEM int16_t |
| 64 | # define FELEM2 int32_t |
| 65 | # define FELEML int64_t |
| 66 | # define FELEM_MAX INT16_MAX |
| 67 | # define FELEM_MIN INT16_MIN |
| 68 | # define OUT(d, v) v = (v + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\ |
| 69 | d = (unsigned)(v + 32768) > 65535 ? (v>>31) ^ 32767 : v |
| 70 | |
| 71 | #endif |
| 72 | |
| 73 | static void RENAME(resample_one)(void *dest, const void *source, |
| 74 | int dst_size, int64_t index2, int64_t incr) |
| 75 | { |
| 76 | DELEM *dst = dest; |
| 77 | const DELEM *src = source; |
| 78 | int dst_index; |
| 79 | |
| 80 | for (dst_index = 0; dst_index < dst_size; dst_index++) { |
| 81 | dst[dst_index] = src[index2 >> 32]; |
| 82 | index2 += incr; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | static int RENAME(resample_common)(ResampleContext *c, |
| 87 | void *dest, const void *source, |
| 88 | int n, int update_ctx) |
| 89 | { |
| 90 | DELEM *dst = dest; |
| 91 | const DELEM *src = source; |
| 92 | int dst_index; |
| 93 | int index= c->index; |
| 94 | int frac= c->frac; |
| 95 | int sample_index = index >> c->phase_shift; |
| 96 | |
| 97 | index &= c->phase_mask; |
| 98 | for (dst_index = 0; dst_index < n; dst_index++) { |
| 99 | FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index; |
| 100 | |
| 101 | FELEM2 val=0; |
| 102 | int i; |
| 103 | for (i = 0; i < c->filter_length; i++) { |
| 104 | val += src[sample_index + i] * (FELEM2)filter[i]; |
| 105 | } |
| 106 | OUT(dst[dst_index], val); |
| 107 | |
| 108 | frac += c->dst_incr_mod; |
| 109 | index += c->dst_incr_div; |
| 110 | if (frac >= c->src_incr) { |
| 111 | frac -= c->src_incr; |
| 112 | index++; |
| 113 | } |
| 114 | sample_index += index >> c->phase_shift; |
| 115 | index &= c->phase_mask; |
| 116 | } |
| 117 | |
| 118 | if(update_ctx){ |
| 119 | c->frac= frac; |
| 120 | c->index= index; |
| 121 | } |
| 122 | |
| 123 | return sample_index; |
| 124 | } |
| 125 | |
| 126 | static int RENAME(resample_linear)(ResampleContext *c, |
| 127 | void *dest, const void *source, |
| 128 | int n, int update_ctx) |
| 129 | { |
| 130 | DELEM *dst = dest; |
| 131 | const DELEM *src = source; |
| 132 | int dst_index; |
| 133 | int index= c->index; |
| 134 | int frac= c->frac; |
| 135 | int sample_index = index >> c->phase_shift; |
| 136 | #if FILTER_SHIFT == 0 |
| 137 | double inv_src_incr = 1.0 / c->src_incr; |
| 138 | #endif |
| 139 | |
| 140 | index &= c->phase_mask; |
| 141 | for (dst_index = 0; dst_index < n; dst_index++) { |
| 142 | FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index; |
| 143 | FELEM2 val=0, v2 = 0; |
| 144 | |
| 145 | int i; |
| 146 | for (i = 0; i < c->filter_length; i++) { |
| 147 | val += src[sample_index + i] * (FELEM2)filter[i]; |
| 148 | v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_alloc]; |
| 149 | } |
| 150 | #ifdef FELEML |
| 151 | val += (v2 - val) * (FELEML) frac / c->src_incr; |
| 152 | #else |
| 153 | # if FILTER_SHIFT == 0 |
| 154 | val += (v2 - val) * inv_src_incr * frac; |
| 155 | # else |
| 156 | val += (v2 - val) / c->src_incr * frac; |
| 157 | # endif |
| 158 | #endif |
| 159 | OUT(dst[dst_index], val); |
| 160 | |
| 161 | frac += c->dst_incr_mod; |
| 162 | index += c->dst_incr_div; |
| 163 | if (frac >= c->src_incr) { |
| 164 | frac -= c->src_incr; |
| 165 | index++; |
| 166 | } |
| 167 | sample_index += index >> c->phase_shift; |
| 168 | index &= c->phase_mask; |
| 169 | } |
| 170 | |
| 171 | if(update_ctx){ |
| 172 | c->frac= frac; |
| 173 | c->index= index; |
| 174 | } |
| 175 | |
| 176 | return sample_index; |
| 177 | } |
| 178 | |
| 179 | #undef RENAME |
| 180 | #undef FILTER_SHIFT |
| 181 | #undef DELEM |
| 182 | #undef FELEM |
| 183 | #undef FELEM2 |
| 184 | #undef FELEML |
| 185 | #undef FELEM_MAX |
| 186 | #undef FELEM_MIN |
| 187 | #undef OUT |