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 73static 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 86static 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 126static 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 188