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 
25 #include "rl.h"
26 
28  uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])
29 {
30  int8_t max_level[MAX_RUN + 1], max_run[MAX_LEVEL + 1];
31  uint8_t index_run[MAX_RUN + 1];
32  int last, run, level, start, end, i;
33 
34  /* If rl->max_level[0] is set, this RLTable has already been initialized */
35  if (rl->max_level[0])
36  return;
37 
38  /* compute max_level[], max_run[] and index_run[] */
39  for (last = 0; last < 2; last++) {
40  if (last == 0) {
41  start = 0;
42  end = rl->last;
43  } else {
44  start = rl->last;
45  end = rl->n;
46  }
47 
48  memset(max_level, 0, MAX_RUN + 1);
49  memset(max_run, 0, MAX_LEVEL + 1);
50  memset(index_run, rl->n, MAX_RUN + 1);
51  for (i = start; i < end; i++) {
52  run = rl->table_run[i];
53  level = rl->table_level[i];
54  if (index_run[run] == rl->n)
55  index_run[run] = i;
56  if (level > max_level[run])
57  max_level[run] = level;
58  if (run > max_run[level])
59  max_run[level] = run;
60  }
61  rl->max_level[last] = static_store[last];
62  memcpy(rl->max_level[last], max_level, MAX_RUN + 1);
63  rl->max_run[last] = static_store[last] + MAX_RUN + 1;
64  memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1);
65  rl->index_run[last] = static_store[last] + MAX_RUN + MAX_LEVEL + 2;
66  memcpy(rl->index_run[last], index_run, MAX_RUN + 1);
67  }
68 }
69 
70 av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
71 {
72  int i, q;
73  VLC_TYPE table[1500][2] = {{0}};
74  VLC vlc = { .table = table, .table_allocated = static_size };
75  av_assert0(static_size <= FF_ARRAY_ELEMS(table));
76  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);
77 
78  for (q = 0; q < 32; q++) {
79  int qmul = q * 2;
80  int qadd = (q - 1) | 1;
81 
82  if (!rl->rl_vlc[q])
83  return;
84 
85  if (q == 0) {
86  qmul = 1;
87  qadd = 0;
88  }
89  for (i = 0; i < vlc.table_size; i++) {
90  int code = vlc.table[i][0];
91  int len = vlc.table[i][1];
92  int level, run;
93 
94  if (len == 0) { // illegal code
95  run = 66;
96  level = MAX_LEVEL;
97  } else if (len < 0) { // more bits needed
98  run = 0;
99  level = code;
100  } else {
101  if (code == rl->n) { // esc
102  run = 66;
103  level = 0;
104  } else {
105  run = rl->table_run[code] + 1;
106  level = rl->table_level[code] * qmul + qadd;
107  if (code >= rl->last) run += 192;
108  }
109  }
110  rl->rl_vlc[q][i].len = len;
111  rl->rl_vlc[q][i].level = level;
112  rl->rl_vlc[q][i].run = run;
113  }
114  }
115 }
level
uint8_t level
Definition: svq3.c:204
RLTable::index_run
uint8_t * index_run[2]
encoding only
Definition: rl.h:45
MAX_RUN
#define MAX_RUN
Definition: rl.h:35
init_vlc
#define init_vlc(vlc, nb_bits, nb_codes, bits, bits_wrap, bits_size, codes, codes_wrap, codes_size, flags)
Definition: vlc.h:38
table
static const uint16_t table[]
Definition: prosumer.c:206
RL_VLC_ELEM::run
uint8_t run
Definition: vlc.h:35
VLC_TYPE
#define VLC_TYPE
Definition: vlc.h:24
ff_rl_init_vlc
av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size)
Initialize rl_vlc from n, last, table_vlc, table_run and table_level.
Definition: rl.c:70
RLTable
RLTable.
Definition: rl.h:39
avassert.h
RLTable::n
int n
number of entries of table_vlc minus 1
Definition: rl.h:40
FF_ARRAY_ELEMS
#define FF_ARRAY_ELEMS(a)
Definition: sinewin_tablegen.c:29
av_cold
#define av_cold
Definition: attributes.h:90
RLTable::max_level
int8_t * max_level[2]
encoding & decoding
Definition: rl.h:46
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
ff_rl_init
av_cold void ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Initialize index_run, max_level and max_run from n, last, table_vlc, table_run and table_level.
Definition: rl.c:27
run
uint8_t run
Definition: svq3.c:203
RLTable::table_vlc
const uint16_t(* table_vlc)[2]
Definition: rl.h:42
INIT_VLC_USE_NEW_STATIC
#define INIT_VLC_USE_NEW_STATIC
Definition: vlc.h:95
RL_VLC_ELEM::len
int8_t len
Definition: vlc.h:34
MAX_LEVEL
#define MAX_LEVEL
Definition: rl.h:36
RLTable::table_level
const int8_t * table_level
Definition: rl.h:44
attributes.h
i
int i
Definition: input.c:406
code
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
Definition: filter_design.txt:178
RLTable::max_run
int8_t * max_run[2]
encoding & decoding
Definition: rl.h:47
len
int len
Definition: vorbis_enc_data.h:426
VLC
Definition: vlc.h:26
RLTable::last
int last
number of values for last = 0
Definition: rl.h:41
VLC::table_size
int table_size
Definition: vlc.h:29
rl.h
VLC::table
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
RLTable::table_run
const int8_t * table_run
Definition: rl.h:43
RLTable::rl_vlc
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
RL_VLC_ELEM::level
int16_t level
Definition: vlc.h:33