FFmpeg
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  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 
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 (q == 0) {
84  qmul = 1;
85  qadd = 0;
86  }
87  for (i = 0; i < vlc.table_size; i++) {
88  int code = vlc.table[i][0];
89  int len = vlc.table[i][1];
90  int level, run;
91 
92  if (len == 0) { // illegal code
93  run = 66;
94  level = MAX_LEVEL;
95  } else if (len < 0) { // more bits needed
96  run = 0;
97  level = code;
98  } else {
99  if (code == rl->n) { // esc
100  run = 66;
101  level = 0;
102  } else {
103  run = rl->table_run[code] + 1;
104  level = rl->table_level[code] * qmul + qadd;
105  if (code >= rl->last) run += 192;
106  }
107  }
108  rl->rl_vlc[q][i].len = len;
109  rl->rl_vlc[q][i].level = level;
110  rl->rl_vlc[q][i].run = run;
111  }
112  }
113 }
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:205
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:88
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:92
int8_t * max_level[2]
encoding & decoding
Definition: rl.h:46
#define MAX_LEVEL
Definition: rl.h:36
static const uint16_t table[]
Definition: prosumer.c:206
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: vlc.h:38
simple assert() macros that are a bit more flexible than ISO C assert().
rl header.
int8_t len
Definition: vlc.h:34
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
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
av_cold void ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Definition: rl.c:28
#define FF_ARRAY_ELEMS(a)
uint8_t * index_run[2]
encoding only
Definition: rl.h:45
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
uint8_t level
Definition: svq3.c:206
uint8_t run
Definition: vlc.h:35
#define MAX_RUN
Definition: rl.h:35
#define INIT_VLC_USE_NEW_STATIC
Definition: vlc.h:95
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:71
#define VLC_TYPE
Definition: vlc.h:24
int i
Definition: input.c:407