1/**
2 * @file libavcodec/vp56.h
3 * VP5 and VP6 compatible video decoder (common features)
4 *
5 * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#ifndef AVCODEC_VP56_H
25#define AVCODEC_VP56_H
26
27#include "vp56data.h"
28#include "dsputil.h"
29#include "bitstream.h"
30#include "bytestream.h"
31
32
33typedef struct vp56_context VP56Context;
34typedef struct vp56_mv VP56mv;
35
36typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
37                                          VP56mv *vect);
38typedef int  (*VP56Adjust)(int v, int t);
39typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
40                           int offset1, int offset2, int stride,
41                           VP56mv mv, int mask, int select, int luma);
42typedef void (*VP56ParseCoeff)(VP56Context *s);
43typedef void (*VP56DefaultModelsInit)(VP56Context *s);
44typedef void (*VP56ParseVectorModels)(VP56Context *s);
45typedef void (*VP56ParseCoeffModels)(VP56Context *s);
46typedef int  (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
47                                int buf_size, int *golden_frame);
48
49typedef struct {
50    int high;
51    int bits;
52    const uint8_t *buffer;
53    unsigned long code_word;
54} VP56RangeCoder;
55
56typedef struct {
57    uint8_t not_null_dc;
58    VP56Frame ref_frame;
59    DCTELEM dc_coeff;
60} VP56RefDc;
61
62struct vp56_mv {
63    int x;
64    int y;
65};
66
67typedef struct {
68    uint8_t type;
69    VP56mv mv;
70} VP56Macroblock;
71
72typedef struct {
73    uint8_t coeff_reorder[64];       /* used in vp6 only */
74    uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
75    uint8_t vector_sig[2];           /* delta sign */
76    uint8_t vector_dct[2];           /* delta coding types */
77    uint8_t vector_pdi[2][2];        /* predefined delta init */
78    uint8_t vector_pdv[2][7];        /* predefined delta values */
79    uint8_t vector_fdv[2][8];        /* 8 bit delta value definition */
80    uint8_t coeff_dccv[2][11];       /* DC coeff value */
81    uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
82    uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
83    uint8_t coeff_dcct[2][36][5];    /* DC coeff coding type */
84    uint8_t coeff_runv[2][14];       /* run value (vp6 only) */
85    uint8_t mb_type[3][10][10];      /* model for decoding MB type */
86    uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
87} VP56Model;
88
89struct vp56_context {
90    AVCodecContext *avctx;
91    DSPContext dsp;
92    ScanTable scantable;
93    AVFrame frames[4];
94    AVFrame *framep[6];
95    uint8_t *edge_emu_buffer_alloc;
96    uint8_t *edge_emu_buffer;
97    VP56RangeCoder c;
98    VP56RangeCoder cc;
99    VP56RangeCoder *ccp;
100    int sub_version;
101
102    /* frame info */
103    int plane_width[4];
104    int plane_height[4];
105    int mb_width;   /* number of horizontal MB */
106    int mb_height;  /* number of vertical MB */
107    int block_offset[6];
108
109    int quantizer;
110    uint16_t dequant_dc;
111    uint16_t dequant_ac;
112
113    /* DC predictors management */
114    VP56RefDc *above_blocks;
115    VP56RefDc left_block[4];
116    int above_block_idx[6];
117    DCTELEM prev_dc[3][3];    /* [plan][ref_frame] */
118
119    /* blocks / macroblock */
120    VP56mb mb_type;
121    VP56Macroblock *macroblocks;
122    DECLARE_ALIGNED_16(DCTELEM, block_coeff[6][64]);
123
124    /* motion vectors */
125    VP56mv mv[6];  /* vectors for each block in MB */
126    VP56mv vector_candidate[2];
127    int vector_candidate_pos;
128
129    /* filtering hints */
130    int filter_header;               /* used in vp6 only */
131    int deblock_filtering;
132    int filter_selection;
133    int filter_mode;
134    int max_vector_length;
135    int sample_variance_threshold;
136
137    uint8_t coeff_ctx[4][64];              /* used in vp5 only */
138    uint8_t coeff_ctx_last[4];             /* used in vp5 only */
139
140    int has_alpha;
141
142    /* upside-down flipping hints */
143    int flip;  /* are we flipping ? */
144    int frbi;  /* first row block index in MB */
145    int srbi;  /* second row block index in MB */
146    int stride[4];  /* stride for each plan */
147
148    const uint8_t *vp56_coord_div;
149    VP56ParseVectorAdjustment parse_vector_adjustment;
150    VP56Adjust adjust;
151    VP56Filter filter;
152    VP56ParseCoeff parse_coeff;
153    VP56DefaultModelsInit default_models_init;
154    VP56ParseVectorModels parse_vector_models;
155    VP56ParseCoeffModels parse_coeff_models;
156    VP56ParseHeader parse_header;
157
158    VP56Model *modelp;
159    VP56Model models[2];
160
161    /* huffman decoding */
162    int use_huffman;
163    GetBitContext gb;
164    VLC dccv_vlc[2];
165    VLC runv_vlc[2];
166    VLC ract_vlc[2][3][6];
167    unsigned int nb_null[2][2];       /* number of consecutive NULL DC/AC */
168};
169
170
171void vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
172int vp56_free(AVCodecContext *avctx);
173void vp56_init_dequant(VP56Context *s, int quantizer);
174int vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
175                      const uint8_t *buf, int buf_size);
176
177
178/**
179 * vp56 specific range coder implementation
180 */
181
182static inline void vp56_init_range_decoder(VP56RangeCoder *c,
183                                           const uint8_t *buf, int buf_size)
184{
185    c->high = 255;
186    c->bits = 8;
187    c->buffer = buf;
188    c->code_word = bytestream_get_be16(&c->buffer);
189}
190
191static inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
192{
193    unsigned int low = 1 + (((c->high - 1) * prob) / 256);
194    unsigned int low_shift = low << 8;
195    int bit = c->code_word >= low_shift;
196
197    if (bit) {
198        c->high -= low;
199        c->code_word -= low_shift;
200    } else {
201        c->high = low;
202    }
203
204    /* normalize */
205    while (c->high < 128) {
206        c->high <<= 1;
207        c->code_word <<= 1;
208        if (--c->bits == 0) {
209            c->bits = 8;
210            c->code_word |= *c->buffer++;
211        }
212    }
213    return bit;
214}
215
216static inline int vp56_rac_get(VP56RangeCoder *c)
217{
218    /* equiprobable */
219    int low = (c->high + 1) >> 1;
220    unsigned int low_shift = low << 8;
221    int bit = c->code_word >= low_shift;
222    if (bit) {
223        c->high = (c->high - low) << 1;
224        c->code_word -= low_shift;
225    } else {
226        c->high = low << 1;
227    }
228
229    /* normalize */
230    c->code_word <<= 1;
231    if (--c->bits == 0) {
232        c->bits = 8;
233        c->code_word |= *c->buffer++;
234    }
235    return bit;
236}
237
238static inline int vp56_rac_gets(VP56RangeCoder *c, int bits)
239{
240    int value = 0;
241
242    while (bits--) {
243        value = (value << 1) | vp56_rac_get(c);
244    }
245
246    return value;
247}
248
249static inline int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
250{
251    int v = vp56_rac_gets(c, 7) << 1;
252    return v + !v;
253}
254
255static inline int vp56_rac_get_tree(VP56RangeCoder *c,
256                                    const VP56Tree *tree,
257                                    const uint8_t *probs)
258{
259    while (tree->val > 0) {
260        if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
261            tree += tree->val;
262        else
263            tree++;
264    }
265    return -tree->val;
266}
267
268#endif /* AVCODEC_VP56_H */
269