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rl.c
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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 
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 
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 
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 }
int last
number of values for last = 0
Definition: rl.h:41
int table_size
Definition: vlc.h:29
Memory handling functions.
const int8_t * table_level
Definition: rl.h:44
uint8_t run
Definition: svq3.c:206
RLTable.
Definition: rl.h:39
Macro definitions for various function/variable attributes.
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
int8_t * max_run[2]
encoding & decoding
Definition: rl.h:47
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int8_t * max_level[2]
encoding & decoding
Definition: rl.h:46
#define MAX_LEVEL
Definition: rl.h:36
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: vlc.h:38
#define AVERROR(e)
Definition: error.h:43
static const struct endianess table[]
simple assert() macros that are a bit more flexible than ISO C assert().
rl header.
int8_t len
Definition: vlc.h:34
#define fail()
Definition: checkasm.h:113
Definition: vlc.h:26
int n
number of entries of table_vlc minus 1
Definition: rl.h:40
const uint16_t(* table_vlc)[2]
Definition: rl.h:42
const int8_t * table_run
Definition: rl.h:43
void ff_rl_free(RLTable *rl)
Free the contents of a dynamically allocated table.
Definition: rl.c:28
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
#define FF_ARRAY_ELEMS(a)
av_cold int ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Definition: rl.c:39
uint8_t * index_run[2]
encoding only
Definition: rl.h:45
uint8_t level
Definition: svq3.c:207
uint8_t run
Definition: vlc.h:35
#define MAX_RUN
Definition: rl.h:35
#define INIT_VLC_USE_NEW_STATIC
Definition: vlc.h:55
int len
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
int16_t level
Definition: vlc.h:33
av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
Definition: rl.c:105
#define av_freep(p)
void INT64 start
Definition: avisynth_c.h:690
#define VLC_TYPE
Definition: vlc.h:24