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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 | } |