| 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) |
| 39 | unsigned 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. |
| 57 | int 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 | |
| 129 | int 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 | |
| 169 | static 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 | |
| 192 | static 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 | |
| 219 | void 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 | } |