aic: Fix slice size computation for widths multiples of 32 macroblocks
[ffmpeg.git] / libavcodec / mss12.h
1 /*
2  * Copyright (c) 2012 Konstantin Shishkov
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20
21 /**
22  * @file
23  * Common header for Microsoft Screen 1 and 2
24  */
25
26 #ifndef AVCODEC_MSS12_H
27 #define AVCODEC_MSS12_H
28
29 #include "libavutil/intreadwrite.h"
30 #include "avcodec.h"
31 #include "get_bits.h"
32 #include "bytestream.h"
33
34 #define MODEL_MIN_SYMS    2
35 #define MODEL_MAX_SYMS  256
36 #define THRESH_ADAPTIVE  -1
37 #define THRESH_LOW       15
38 #define THRESH_HIGH      50
39
40 typedef struct Model {
41     int16_t cum_prob[MODEL_MAX_SYMS + 1];
42     int16_t weights[MODEL_MAX_SYMS + 1];
43     uint8_t idx2sym[MODEL_MAX_SYMS + 1];
44     int num_syms;
45     int thr_weight, threshold;
46 } Model;
47
48 typedef struct ArithCoder {
49     int low, high, value;
50     union {
51         GetBitContext *gb;
52         GetByteContext *gB;
53     } gbc;
54     int (*get_model_sym)(struct ArithCoder *c, Model *m);
55     int (*get_number)   (struct ArithCoder *c, int n);
56 } ArithCoder;
57
58 typedef struct PixContext {
59     int cache_size, num_syms;
60     uint8_t cache[12];
61     Model cache_model, full_model;
62     Model sec_models[15][4];
63     int special_initial_cache;
64 } PixContext;
65
66 struct MSS12Context;
67
68 typedef struct SliceContext {
69     struct MSS12Context *c;
70     Model      intra_region, inter_region;
71     Model      pivot, edge_mode, split_mode;
72     PixContext intra_pix_ctx, inter_pix_ctx;
73 } SliceContext;
74
75 typedef struct MSS12Context {
76     AVCodecContext *avctx;
77     uint32_t       pal[256];
78     uint8_t        *pal_pic;
79     uint8_t        *last_pal_pic;
80     int            pal_stride;
81     uint8_t        *mask;
82     int            mask_stride;
83     uint8_t        *rgb_pic;
84     uint8_t        *last_rgb_pic;
85     int            rgb_stride;
86     int            free_colours;
87     int            keyframe;
88     int            mvX, mvY;
89     int            corrupted;
90     int            slice_split;
91     int            full_model_syms;
92 } MSS12Context;
93
94 int ff_mss12_decode_rect(SliceContext *ctx, ArithCoder *acoder,
95                          int x, int y, int width, int height);
96 void ff_mss12_model_update(Model *m, int val);
97 void ff_mss12_slicecontext_reset(SliceContext *sc);
98 int ff_mss12_decode_init(MSS12Context *c, int version,
99                          SliceContext *sc1, SliceContext *sc2);
100 int ff_mss12_decode_end(MSS12Context *ctx);
101
102 #define ARITH_GET_BIT(VERSION)                                          \
103 static int arith ## VERSION ## _get_bit(ArithCoder *c)                  \
104 {                                                                       \
105     int range = c->high - c->low + 1;                                   \
106     int bit   = 2 * c->value - c->low >= c->high;                       \
107                                                                         \
108     if (bit)                                                            \
109         c->low += range >> 1;                                           \
110     else                                                                \
111         c->high = c->low + (range >> 1) - 1;                            \
112                                                                         \
113     arith ## VERSION ## _normalise(c);                                  \
114                                                                         \
115     return bit;                                                         \
116 }
117
118 #define ARITH_GET_MODEL_SYM(VERSION)                                    \
119 static int arith ## VERSION ## _get_model_sym(ArithCoder *c, Model *m)  \
120 {                                                                       \
121     int idx, val;                                                       \
122                                                                         \
123     idx = arith ## VERSION ## _get_prob(c, m->cum_prob);                \
124                                                                         \
125     val = m->idx2sym[idx];                                              \
126     ff_mss12_model_update(m, idx);                                      \
127                                                                         \
128     arith ## VERSION ## _normalise(c);                                  \
129                                                                         \
130     return val;                                                         \
131 }
132
133 #endif /* AVCODEC_MSS12_H */