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_free(RLTable * rl)28 void ff_rl_free(RLTable *rl)
29 {
30 int i;
31
32 for (i = 0; i < 2; i++) {
33 av_freep(&rl->max_run[i]);
34 av_freep(&rl->max_level[i]);
35 av_freep(&rl->index_run[i]);
36 }
37 }
38
ff_rl_init(RLTable * rl,uint8_t static_store[2][2* MAX_RUN+MAX_LEVEL+3])39 av_cold int ff_rl_init(RLTable *rl,
40 uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])
41 {
42 int8_t max_level[MAX_RUN + 1], max_run[MAX_LEVEL + 1];
43 uint8_t index_run[MAX_RUN + 1];
44 int last, run, level, start, end, i;
45
46 /* If table is static, we can quit if rl->max_level[0] is not NULL */
47 if (static_store && rl->max_level[0])
48 return 0;
49
50 /* compute max_level[], max_run[] and index_run[] */
51 for (last = 0; last < 2; last++) {
52 if (last == 0) {
53 start = 0;
54 end = rl->last;
55 } else {
56 start = rl->last;
57 end = rl->n;
58 }
59
60 memset(max_level, 0, MAX_RUN + 1);
61 memset(max_run, 0, MAX_LEVEL + 1);
62 memset(index_run, rl->n, MAX_RUN + 1);
63 for (i = start; i < end; i++) {
64 run = rl->table_run[i];
65 level = rl->table_level[i];
66 if (index_run[run] == rl->n)
67 index_run[run] = i;
68 if (level > max_level[run])
69 max_level[run] = level;
70 if (run > max_run[level])
71 max_run[level] = run;
72 }
73 if (static_store)
74 rl->max_level[last] = static_store[last];
75 else {
76 rl->max_level[last] = av_malloc(MAX_RUN + 1);
77 if (!rl->max_level[last])
78 goto fail;
79 }
80 memcpy(rl->max_level[last], max_level, MAX_RUN + 1);
81 if (static_store)
82 rl->max_run[last] = static_store[last] + MAX_RUN + 1;
83 else {
84 rl->max_run[last] = av_malloc(MAX_LEVEL + 1);
85 if (!rl->max_run[last])
86 goto fail;
87 }
88 memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1);
89 if (static_store)
90 rl->index_run[last] = static_store[last] + MAX_RUN + MAX_LEVEL + 2;
91 else {
92 rl->index_run[last] = av_malloc(MAX_RUN + 1);
93 if (!rl->index_run[last])
94 goto fail;
95 }
96 memcpy(rl->index_run[last], index_run, MAX_RUN + 1);
97 }
98 return 0;
99
100 fail:
101 ff_rl_free(rl);
102 return AVERROR(ENOMEM);
103 }
104
ff_rl_init_vlc(RLTable * rl,unsigned static_size)105 av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
106 {
107 int i, q;
108 VLC_TYPE table[1500][2] = {{0}};
109 VLC vlc = { .table = table, .table_allocated = static_size };
110 av_assert0(static_size <= FF_ARRAY_ELEMS(table));
111 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);
112
113 for (q = 0; q < 32; q++) {
114 int qmul = q * 2;
115 int qadd = (q - 1) | 1;
116
117 if (q == 0) {
118 qmul = 1;
119 qadd = 0;
120 }
121 for (i = 0; i < vlc.table_size; i++) {
122 int code = vlc.table[i][0];
123 int len = vlc.table[i][1];
124 int level, run;
125
126 if (len == 0) { // illegal code
127 run = 66;
128 level = MAX_LEVEL;
129 } else if (len < 0) { // more bits needed
130 run = 0;
131 level = code;
132 } else {
133 if (code == rl->n) { // esc
134 run = 66;
135 level = 0;
136 } else {
137 run = rl->table_run[code] + 1;
138 level = rl->table_level[code] * qmul + qadd;
139 if (code >= rl->last) run += 192;
140 }
141 }
142 rl->rl_vlc[q][i].len = len;
143 rl->rl_vlc[q][i].level = level;
144 rl->rl_vlc[q][i].run = run;
145 }
146 }
147 }
148