792d2be3b54cebfff6d82e7e4d1a0a02a8d112ff
[libav.git] / 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 jpegls.h
25 * JPEG-LS common code.
26 */
27
28 #ifndef FFMPEG_JPEGLS_H
29 #define FFMPEG_JPEGLS_H
30
31 #include "avcodec.h"
32
33 typedef struct JpeglsContext{
34 AVCodecContext *avctx;
35 AVFrame picture;
36 }JpeglsContext;
37
38 typedef struct JLSState{
39 int T1, T2, T3;
40 int A[367], B[367], C[365], N[367];
41 int limit, reset, bpp, qbpp, maxval, range;
42 int near, twonear;
43 int run_index[3];
44 }JLSState;
45
46 extern const uint8_t ff_log2_run[32];
47
48 /**
49 * Calculate initial JPEG-LS parameters
50 */
51 void ff_jpegls_init_state(JLSState *state);
52
53 /**
54 * Calculate quantized gradient value, used for context determination
55 */
56 static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
57 if(v==0) return 0;
58 if(v < 0){
59 if(v <= -s->T3) return -4;
60 if(v <= -s->T2) return -3;
61 if(v <= -s->T1) return -2;
62 if(v < -s->near) return -1;
63 return 0;
64 }else{
65 if(v <= s->near) return 0;
66 if(v < s->T1) return 1;
67 if(v < s->T2) return 2;
68 if(v < s->T3) return 3;
69 return 4;
70 }
71 }
72
73 /**
74 * Calculate JPEG-LS codec values
75 */
76 void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
77
78
79 static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
80 if(state->N[Q] == state->reset){
81 state->A[Q] >>=1;
82 state->B[Q] >>=1;
83 state->N[Q] >>=1;
84 }
85 state->N[Q]++;
86 }
87
88 static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
89 state->A[Q] += FFABS(err);
90 err *= state->twonear;
91 state->B[Q] += err;
92
93 ff_jpegls_downscale_state(state, Q);
94
95 if(state->B[Q] <= -state->N[Q]) {
96 state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
97 if(state->C[Q] > -128)
98 state->C[Q]--;
99 }else if(state->B[Q] > 0){
100 state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
101 if(state->C[Q] < 127)
102 state->C[Q]++;
103 }
104
105 return err;
106 }
107
108 #define R(a, i ) (bits == 8 ? ((uint8_t*)(a))[i] : ((uint16_t*)(a))[i] )
109 #define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
110
111 #endif /* FFMPEG_JPEGLS_H */