Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / vorbis.c
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 }