1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include <stdint.h>
20 #include <string.h>
21
22 #include "libavutil/attributes.h"
23 #include "libavutil/avassert.h"
24
25 #include "rl.h"
26
ff_rl_init(RLTable *rl, uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])27 av_cold void ff_rl_init(RLTable *rl,
28 uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])
29 {
30 int last, run, level, start, end, i;
31
32 /* compute max_level[], max_run[] and index_run[] */
33 for (last = 0; last < 2; last++) {
34 int8_t *max_level = static_store[last];
35 int8_t *max_run = static_store[last] + MAX_RUN + 1;
36 uint8_t *index_run = static_store[last] + MAX_RUN + 1 + MAX_LEVEL + 1;
37 if (last == 0) {
38 start = 0;
39 end = rl->last;
40 } else {
41 start = rl->last;
42 end = rl->n;
43 }
44
45 memset(index_run, rl->n, MAX_RUN + 1);
46 for (i = start; i < end; i++) {
47 run = rl->table_run[i];
48 level = rl->table_level[i];
49 if (index_run[run] == rl->n)
50 index_run[run] = i;
51 if (level > max_level[run])
52 max_level[run] = level;
53 if (run > max_run[level])
54 max_run[level] = run;
55 }
56 rl->max_level[last] = max_level;
57 rl->max_run[last] = max_run;
58 rl->index_run[last] = index_run;
59 }
60 }
61
ff_rl_init_vlc(RLTable *rl, unsigned static_size)62 av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
63 {
64 int i, q;
65 VLCElem table[1500] = { 0 };
66 VLC vlc = { .table = table, .table_allocated = static_size };
67 av_assert0(static_size <= FF_ARRAY_ELEMS(table));
68 init_vlc(&vlc, 9, rl->n + 1, &rl->table_vlc[0][1], 4, 2, &rl->table_vlc[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
69
70 for (q = 0; q < 32; q++) {
71 int qmul = q * 2;
72 int qadd = (q - 1) | 1;
73
74 if (!rl->rl_vlc[q])
75 return;
76
77 if (q == 0) {
78 qmul = 1;
79 qadd = 0;
80 }
81 for (i = 0; i < vlc.table_size; i++) {
82 int code = vlc.table[i].sym;
83 int len = vlc.table[i].len;
84 int level, run;
85
86 if (len == 0) { // illegal code
87 run = 66;
88 level = MAX_LEVEL;
89 } else if (len < 0) { // more bits needed
90 run = 0;
91 level = code;
92 } else {
93 if (code == rl->n) { // esc
94 run = 66;
95 level = 0;
96 } else {
97 run = rl->table_run[code] + 1;
98 level = rl->table_level[code] * qmul + qadd;
99 if (code >= rl->last) run += 192;
100 }
101 }
102 rl->rl_vlc[q][i].len = len;
103 rl->rl_vlc[q][i].level = level;
104 rl->rl_vlc[q][i].run = run;
105 }
106 }
107 }
108