1/** 2 * @file 3 * Common code for Vorbis I encoder and decoder 4 * @author Denes Balatoni ( dbalatoni programozo hu ) 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/** 24 * @file 25 * Common code for Vorbis I encoder and decoder 26 * @author Denes Balatoni ( dbalatoni programozo hu ) 27 */ 28 29#define BITSTREAM_READER_LE 30#include "avcodec.h" 31#include "get_bits.h" 32 33#include "vorbis.h" 34 35 36/* Helper functions */ 37 38// x^(1/n) 39unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n) 40{ 41 unsigned int ret = 0, i, j; 42 43 do { 44 ++ret; 45 for (i = 0, j = ret; i < n - 1; i++) 46 j *= ret; 47 } while (j <= x); 48 49 return ret - 1; 50} 51 52// Generate vlc codes from vorbis huffman code lengths 53 54// the two bits[p] > 32 checks should be redundant, all calling code should 55// already ensure that, but since it allows overwriting the stack it seems 56// reasonable to check redundantly. 57int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num) 58{ 59 uint32_t exit_at_level[33] = { 404 }; 60 61 unsigned i, j, p, code; 62 63#ifdef DEBUG 64 GetBitContext gb; 65#endif 66 67 for (p = 0; (bits[p] == 0) && (p < num); ++p) 68 ; 69 if (p == num) 70 return 0; 71 72 codes[p] = 0; 73 if (bits[p] > 32) 74 return AVERROR_INVALIDDATA; 75 for (i = 0; i < bits[p]; ++i) 76 exit_at_level[i+1] = 1 << i; 77 78#ifdef DEBUG 79 av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]); 80 init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]); 81 for (i = 0; i < bits[p]; ++i) 82 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); 83 av_log(NULL, AV_LOG_INFO, "\n"); 84#endif 85 86 ++p; 87 88 for (i = p; (bits[i] == 0) && (i < num); ++i) 89 ; 90 if (i == num) 91 return 0; 92 93 for (; p < num; ++p) { 94 if (bits[p] > 32) 95 return AVERROR_INVALIDDATA; 96 if (bits[p] == 0) 97 continue; 98 // find corresponding exit(node which the tree can grow further from) 99 for (i = bits[p]; i > 0; --i) 100 if (exit_at_level[i]) 101 break; 102 if (!i) // overspecified tree 103 return AVERROR_INVALIDDATA; 104 code = exit_at_level[i]; 105 exit_at_level[i] = 0; 106 // construct code (append 0s to end) and introduce new exits 107 for (j = i + 1 ;j <= bits[p]; ++j) 108 exit_at_level[j] = code + (1 << (j - 1)); 109 codes[p] = code; 110 111#ifdef DEBUG 112 av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]); 113 init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]); 114 for (i = 0; i < bits[p]; ++i) 115 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); 116 av_log(NULL, AV_LOG_INFO, "\n"); 117#endif 118 119 } 120 121 //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC) 122 for (p = 1; p < 33; p++) 123 if (exit_at_level[p]) 124 return AVERROR_INVALIDDATA; 125 126 return 0; 127} 128 129int ff_vorbis_ready_floor1_list(AVCodecContext *avctx, 130 vorbis_floor1_entry *list, int values) 131{ 132 int i; 133 list[0].sort = 0; 134 list[1].sort = 1; 135 for (i = 2; i < values; i++) { 136 int j; 137 list[i].low = 0; 138 list[i].high = 1; 139 list[i].sort = i; 140 for (j = 2; j < i; j++) { 141 int tmp = list[j].x; 142 if (tmp < list[i].x) { 143 if (tmp > list[list[i].low].x) 144 list[i].low = j; 145 } else { 146 if (tmp < list[list[i].high].x) 147 list[i].high = j; 148 } 149 } 150 } 151 for (i = 0; i < values - 1; i++) { 152 int j; 153 for (j = i + 1; j < values; j++) { 154 if (list[i].x == list[j].x) { 155 av_log(avctx, AV_LOG_ERROR, 156 "Duplicate value found in floor 1 X coordinates\n"); 157 return AVERROR_INVALIDDATA; 158 } 159 if (list[list[i].sort].x > list[list[j].sort].x) { 160 int tmp = list[i].sort; 161 list[i].sort = list[j].sort; 162 list[j].sort = tmp; 163 } 164 } 165 } 166 return 0; 167} 168 169static inline void render_line_unrolled(intptr_t x, int y, int x1, 170 intptr_t sy, int ady, int adx, 171 float *buf) 172{ 173 int err = -adx; 174 x -= x1 - 1; 175 buf += x1 - 1; 176 while (++x < 0) { 177 err += ady; 178 if (err >= 0) { 179 err += ady - adx; 180 y += sy; 181 buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; 182 } 183 buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; 184 } 185 if (x <= 0) { 186 if (err + ady >= 0) 187 y += sy; 188 buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; 189 } 190} 191 192static void render_line(int x0, int y0, int x1, int y1, float *buf) 193{ 194 int dy = y1 - y0; 195 int adx = x1 - x0; 196 int ady = FFABS(dy); 197 int sy = dy < 0 ? -1 : 1; 198 buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)]; 199 if (ady*2 <= adx) { // optimized common case 200 render_line_unrolled(x0, y0, x1, sy, ady, adx, buf); 201 } else { 202 int base = dy / adx; 203 int x = x0; 204 int y = y0; 205 int err = -adx; 206 ady -= FFABS(base) * adx; 207 while (++x < x1) { 208 y += base; 209 err += ady; 210 if (err >= 0) { 211 err -= adx; 212 y += sy; 213 } 214 buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; 215 } 216 } 217} 218 219void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values, 220 uint16_t *y_list, int *flag, 221 int multiplier, float *out, int samples) 222{ 223 int lx, ly, i; 224 lx = 0; 225 ly = y_list[0] * multiplier; 226 for (i = 1; i < values; i++) { 227 int pos = list[i].sort; 228 if (flag[pos]) { 229 int x1 = list[pos].x; 230 int y1 = y_list[pos] * multiplier; 231 if (lx < samples) 232 render_line(lx, ly, FFMIN(x1,samples), y1, out); 233 lx = x1; 234 ly = y1; 235 } 236 if (lx >= samples) 237 break; 238 } 239 if (lx < samples) 240 render_line(lx, ly, samples, ly, out); 241} 242