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 #include "libavutil/mem.h"
25
26 #include "rl.h"
27
ff_rl_init(RLTable * rl,uint8_t static_store[2][2* MAX_RUN+MAX_LEVEL+3])28 av_cold void ff_rl_init(RLTable *rl,
29 uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])
30 {
31 int8_t max_level[MAX_RUN + 1], max_run[MAX_LEVEL + 1];
32 uint8_t index_run[MAX_RUN + 1];
33 int last, run, level, start, end, i;
34
35 /* If rl->max_level[0] is set, this RLTable has already been initialized */
36 if (rl->max_level[0])
37 return;
38
39 /* compute max_level[], max_run[] and index_run[] */
40 for (last = 0; last < 2; last++) {
41 if (last == 0) {
42 start = 0;
43 end = rl->last;
44 } else {
45 start = rl->last;
46 end = rl->n;
47 }
48
49 memset(max_level, 0, MAX_RUN + 1);
50 memset(max_run, 0, MAX_LEVEL + 1);
51 memset(index_run, rl->n, MAX_RUN + 1);
52 for (i = start; i < end; i++) {
53 run = rl->table_run[i];
54 level = rl->table_level[i];
55 if (index_run[run] == rl->n)
56 index_run[run] = i;
57 if (level > max_level[run])
58 max_level[run] = level;
59 if (run > max_run[level])
60 max_run[level] = run;
61 }
62 rl->max_level[last] = static_store[last];
63 memcpy(rl->max_level[last], max_level, MAX_RUN + 1);
64 rl->max_run[last] = static_store[last] + MAX_RUN + 1;
65 memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1);
66 rl->index_run[last] = static_store[last] + MAX_RUN + MAX_LEVEL + 2;
67 memcpy(rl->index_run[last], index_run, MAX_RUN + 1);
68 }
69 }
70
ff_rl_init_vlc(RLTable * rl,unsigned static_size)71 av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
72 {
73 int i, q;
74 VLC_TYPE table[1500][2] = {{0}};
75 VLC vlc = { .table = table, .table_allocated = static_size };
76 av_assert0(static_size <= FF_ARRAY_ELEMS(table));
77 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);
78
79 for (q = 0; q < 32; q++) {
80 int qmul = q * 2;
81 int qadd = (q - 1) | 1;
82
83 if (!rl->rl_vlc[q])
84 return;
85
86 if (q == 0) {
87 qmul = 1;
88 qadd = 0;
89 }
90 for (i = 0; i < vlc.table_size; i++) {
91 int code = vlc.table[i][0];
92 int len = vlc.table[i][1];
93 int level, run;
94
95 if (len == 0) { // illegal code
96 run = 66;
97 level = MAX_LEVEL;
98 } else if (len < 0) { // more bits needed
99 run = 0;
100 level = code;
101 } else {
102 if (code == rl->n) { // esc
103 run = 66;
104 level = 0;
105 } else {
106 run = rl->table_run[code] + 1;
107 level = rl->table_level[code] * qmul + qadd;
108 if (code >= rl->last) run += 192;
109 }
110 }
111 rl->rl_vlc[q][i].len = len;
112 rl->rl_vlc[q][i].level = level;
113 rl->rl_vlc[q][i].run = run;
114 }
115 }
116 }
117