Imported Debian version 2.5.0~trusty1.1
[deb_ffmpeg.git] / ffmpeg / libavcodec / jpegls.h
1 /*
2 * JPEG-LS common code
3 * Copyright (c) 2003 Michael Niedermayer
4 * Copyright (c) 2006 Konstantin Shishkov
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file
25 * JPEG-LS common code.
26 */
27
28 #ifndef AVCODEC_JPEGLS_H
29 #define AVCODEC_JPEGLS_H
30
31 #include "libavutil/common.h"
32 #include "avcodec.h"
33 #include "internal.h"
34
35 typedef struct JpeglsContext {
36 AVCodecContext *avctx;
37 } JpeglsContext;
38
39 typedef struct JLSState {
40 int T1, T2, T3;
41 int A[367], B[367], C[365], N[367];
42 int limit, reset, bpp, qbpp, maxval, range;
43 int near, twonear;
44 int run_index[4];
45 } JLSState;
46
47 /**
48 * Calculate initial JPEG-LS parameters
49 */
50 void ff_jpegls_init_state(JLSState *state);
51
52 /**
53 * Calculate quantized gradient value, used for context determination
54 */
55 static inline int ff_jpegls_quantize(JLSState *s, int v)
56 {
57 if (v == 0)
58 return 0;
59 if (v < 0) {
60 if (v <= -s->T3)
61 return -4;
62 if (v <= -s->T2)
63 return -3;
64 if (v <= -s->T1)
65 return -2;
66 if (v < -s->near)
67 return -1;
68 return 0;
69 } else {
70 if (v <= s->near)
71 return 0;
72 if (v < s->T1)
73 return 1;
74 if (v < s->T2)
75 return 2;
76 if (v < s->T3)
77 return 3;
78 return 4;
79 }
80 }
81
82 /**
83 * Calculate JPEG-LS codec values
84 */
85 void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
86
87 static inline void ff_jpegls_downscale_state(JLSState *state, int Q)
88 {
89 if (state->N[Q] == state->reset) {
90 state->A[Q] >>= 1;
91 state->B[Q] >>= 1;
92 state->N[Q] >>= 1;
93 }
94 state->N[Q]++;
95 }
96
97 static inline int ff_jpegls_update_state_regular(JLSState *state,
98 int Q, int err)
99 {
100 if(FFABS(err) > 0xFFFF)
101 return -0x10000;
102 state->A[Q] += FFABS(err);
103 err *= state->twonear;
104 state->B[Q] += err;
105
106 ff_jpegls_downscale_state(state, Q);
107
108 if (state->B[Q] <= -state->N[Q]) {
109 state->B[Q] = FFMAX(state->B[Q] + state->N[Q], 1 - state->N[Q]);
110 if (state->C[Q] > -128)
111 state->C[Q]--;
112 } else if (state->B[Q] > 0) {
113 state->B[Q] = FFMIN(state->B[Q] - state->N[Q], 0);
114 if (state->C[Q] < 127)
115 state->C[Q]++;
116 }
117
118 return err;
119 }
120
121 #define R(a, i) (bits == 8 ? ((uint8_t *)(a))[i] : ((uint16_t *)(a))[i])
122 #define W(a, i, v) (bits == 8 ? (((uint8_t *)(a))[i] = v) : (((uint16_t *)(a))[i] = v))
123
124 #endif /* AVCODEC_JPEGLS_H */