jpegls.h
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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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
28 #ifndef AVCODEC_JPEGLS_H
29 #define AVCODEC_JPEGLS_H
30 
31 #include "avcodec.h"
32 #include "libavutil/common.h"
33 
34 typedef struct JpeglsContext{
38 
39 typedef struct JLSState{
40  int T1, T2, T3;
41  int A[367], B[367], C[365], N[367];
43  int near, twonear;
44  int run_index[3];
45 }JLSState;
46 
47 extern const uint8_t ff_log2_run[32];
48 
53 
57 static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
58  if(v==0) return 0;
59  if(v < 0){
60  if(v <= -s->T3) return -4;
61  if(v <= -s->T2) return -3;
62  if(v <= -s->T1) return -2;
63  if(v < -s->near) return -1;
64  return 0;
65  }else{
66  if(v <= s->near) return 0;
67  if(v < s->T1) return 1;
68  if(v < s->T2) return 2;
69  if(v < s->T3) return 3;
70  return 4;
71  }
72 }
73 
77 void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
78 
79 
80 static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
81  if(state->N[Q] == state->reset){
82  state->A[Q] >>=1;
83  state->B[Q] >>=1;
84  state->N[Q] >>=1;
85  }
86  state->N[Q]++;
87 }
88 
89 static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
90  state->A[Q] += FFABS(err);
91  err *= state->twonear;
92  state->B[Q] += err;
93 
94  ff_jpegls_downscale_state(state, Q);
95 
96  if(state->B[Q] <= -state->N[Q]) {
97  state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
98  if(state->C[Q] > -128)
99  state->C[Q]--;
100  }else if(state->B[Q] > 0){
101  state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
102  if(state->C[Q] < 127)
103  state->C[Q]++;
104  }
105 
106  return err;
107 }
108 
109 #define R(a, i ) (bits == 8 ? ((uint8_t*)(a))[i] : ((uint16_t*)(a))[i] )
110 #define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
111 
112 #endif /* AVCODEC_JPEGLS_H */
int reset
Definition: jpegls.h:42
int T2
Definition: jpegls.h:40
This structure describes decoded (raw) audio or video data.
Definition: avcodec.h:989
int C[365]
Definition: jpegls.h:41
int twonear
Definition: jpegls.h:43
AVFrame picture
Definition: jpegls.h:36
int limit
Definition: jpegls.h:42
void ff_jpegls_init_state(JLSState *state)
Calculate initial JPEG-LS parameters.
Definition: jpegls.c:30
int bpp
Definition: jpegls.h:42
int maxval
Definition: jpegls.h:42
uint8_t
int run_index[3]
Definition: jpegls.h:44
static int ff_jpegls_update_state_regular(JLSState *state, int Q, int err)
Definition: jpegls.h:89
int B[367]
Definition: jpegls.h:41
int near
Definition: jpegls.h:43
const uint8_t ff_log2_run[32]
Definition: bitstream.c:36
int qbpp
Definition: jpegls.h:42
external API header
AVCodecContext * avctx
Definition: jpegls.h:35
void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all)
Calculate JPEG-LS codec values.
Definition: jpegls.c:59
main external API structure.
Definition: avcodec.h:1339
int A[367]
Definition: jpegls.h:41
int T1
Definition: jpegls.h:40
int range
Definition: jpegls.h:42
int N[367]
Definition: jpegls.h:41
static uint32_t state
Definition: trasher.c:27
common internal and external API header
static int ff_jpegls_quantize(JLSState *s, int v)
Calculate quantized gradient value, used for context determination.
Definition: jpegls.h:57
struct JLSState JLSState
int T3
Definition: jpegls.h:40
static void ff_jpegls_downscale_state(JLSState *state, int Q)
Definition: jpegls.h:80
struct JpeglsContext JpeglsContext