1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
/*
* JPEG-LS common code
* Copyright (c) 2003 Michael Niedermayer
* Copyright (c) 2006 Konstantin Shishkov
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* JPEG-LS common code.
*/
#ifndef AVCODEC_JPEGLS_H
#define AVCODEC_JPEGLS_H
#include "libavutil/common.h"
#include "avcodec.h"
typedef struct JpeglsContext {
AVCodecContext *avctx;
} JpeglsContext;
typedef struct JLSState {
int T1, T2, T3;
int A[367], B[367], C[365], N[367];
int limit, reset, bpp, qbpp, maxval, range;
int near, twonear;
int run_index[3];
} JLSState;
extern const uint8_t ff_log2_run[32];
/**
* Calculate initial JPEG-LS parameters
*/
void ff_jpegls_init_state(JLSState *state);
/**
* Calculate quantized gradient value, used for context determination
*/
static inline int ff_jpegls_quantize(JLSState *s, int v)
{
if (v == 0)
return 0;
if (v < 0) {
if (v <= -s->T3)
return -4;
if (v <= -s->T2)
return -3;
if (v <= -s->T1)
return -2;
if (v < -s->near)
return -1;
return 0;
} else {
if (v <= s->near)
return 0;
if (v < s->T1)
return 1;
if (v < s->T2)
return 2;
if (v < s->T3)
return 3;
return 4;
}
}
/**
* Calculate JPEG-LS codec values
*/
void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
static inline void ff_jpegls_downscale_state(JLSState *state, int Q)
{
if (state->N[Q] == state->reset) {
state->A[Q] >>= 1;
state->B[Q] >>= 1;
state->N[Q] >>= 1;
}
state->N[Q]++;
}
static inline int ff_jpegls_update_state_regular(JLSState *state,
int Q, int err)
{
state->A[Q] += FFABS(err);
err *= state->twonear;
state->B[Q] += err;
ff_jpegls_downscale_state(state, Q);
if (state->B[Q] <= -state->N[Q]) {
state->B[Q] = FFMAX(state->B[Q] + state->N[Q], 1 - state->N[Q]);
if (state->C[Q] > -128)
state->C[Q]--;
} else if (state->B[Q] > 0) {
state->B[Q] = FFMIN(state->B[Q] - state->N[Q], 0);
if (state->C[Q] < 127)
state->C[Q]++;
}
return err;
}
#define R(a, i) (bits == 8 ? ((uint8_t *)(a))[i] : ((uint16_t *)(a))[i])
#define W(a, i, v) (bits == 8 ? (((uint8_t *)(a))[i] = v) : (((uint16_t *)(a))[i] = v))
#endif /* AVCODEC_JPEGLS_H */
|
