1/**
2 * @file
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 "get_bits.h"
30#include "bytestream.h"
31#include "vp56dsp.h"
32
33typedef struct vp56_context VP56Context;
34typedef struct vp56_mv VP56mv;
35
36typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
37                                          VP56mv *vect);
38typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
39                           int offset1, int offset2, int stride,
40                           VP56mv mv, int mask, int select, int luma);
41typedef void (*VP56ParseCoeff)(VP56Context *s);
42typedef void (*VP56DefaultModelsInit)(VP56Context *s);
43typedef void (*VP56ParseVectorModels)(VP56Context *s);
44typedef void (*VP56ParseCoeffModels)(VP56Context *s);
45typedef int  (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
46                                int buf_size, int *golden_frame);
47
48typedef struct {
49    int high;
50    int bits;
51    const uint8_t *buffer;
52    const uint8_t *end;
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    VP56DSPContext vp56dsp;
93    ScanTable scantable;
94    AVFrame frames[4];
95    AVFrame *framep[6];
96    uint8_t *edge_emu_buffer_alloc;
97    uint8_t *edge_emu_buffer;
98    VP56RangeCoder c;
99    VP56RangeCoder cc;
100    VP56RangeCoder *ccp;
101    int sub_version;
102
103    /* frame info */
104    int plane_width[4];
105    int plane_height[4];
106    int mb_width;   /* number of horizontal MB */
107    int mb_height;  /* number of vertical MB */
108    int block_offset[6];
109
110    int quantizer;
111    uint16_t dequant_dc;
112    uint16_t dequant_ac;
113    int8_t *qscale_table;
114
115    /* DC predictors management */
116    VP56RefDc *above_blocks;
117    VP56RefDc left_block[4];
118    int above_block_idx[6];
119    DCTELEM prev_dc[3][3];    /* [plan][ref_frame] */
120
121    /* blocks / macroblock */
122    VP56mb mb_type;
123    VP56Macroblock *macroblocks;
124    DECLARE_ALIGNED(16, DCTELEM, block_coeff)[6][64];
125
126    /* motion vectors */
127    VP56mv mv[6];  /* vectors for each block in MB */
128    VP56mv vector_candidate[2];
129    int vector_candidate_pos;
130
131    /* filtering hints */
132    int filter_header;               /* used in vp6 only */
133    int deblock_filtering;
134    int filter_selection;
135    int filter_mode;
136    int max_vector_length;
137    int sample_variance_threshold;
138
139    uint8_t coeff_ctx[4][64];              /* used in vp5 only */
140    uint8_t coeff_ctx_last[4];             /* used in vp5 only */
141
142    int has_alpha;
143
144    /* upside-down flipping hints */
145    int flip;  /* are we flipping ? */
146    int frbi;  /* first row block index in MB */
147    int srbi;  /* second row block index in MB */
148    int stride[4];  /* stride for each plan */
149
150    const uint8_t *vp56_coord_div;
151    VP56ParseVectorAdjustment parse_vector_adjustment;
152    VP56Filter filter;
153    VP56ParseCoeff parse_coeff;
154    VP56DefaultModelsInit default_models_init;
155    VP56ParseVectorModels parse_vector_models;
156    VP56ParseCoeffModels parse_coeff_models;
157    VP56ParseHeader parse_header;
158
159    VP56Model *modelp;
160    VP56Model models[2];
161
162    /* huffman decoding */
163    int use_huffman;
164    GetBitContext gb;
165    VLC dccv_vlc[2];
166    VLC runv_vlc[2];
167    VLC ract_vlc[2][3][6];
168    unsigned int nb_null[2][2];       /* number of consecutive NULL DC/AC */
169};
170
171
172void vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
173int vp56_free(AVCodecContext *avctx);
174void vp56_init_dequant(VP56Context *s, int quantizer);
175int vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
176                      AVPacket *avpkt);
177
178
179/**
180 * vp56 specific range coder implementation
181 */
182
183static inline void vp56_init_range_decoder(VP56RangeCoder *c,
184                                           const uint8_t *buf, int buf_size)
185{
186    c->high = 255;
187    c->bits = 8;
188    c->buffer = buf;
189    c->end = buf + buf_size;
190    c->code_word = bytestream_get_be16(&c->buffer);
191}
192
193static inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
194{
195    unsigned int low = 1 + (((c->high - 1) * prob) / 256);
196    unsigned int low_shift = low << 8;
197    int bit = c->code_word >= low_shift;
198
199    if (bit) {
200        c->high -= low;
201        c->code_word -= low_shift;
202    } else {
203        c->high = low;
204    }
205
206    /* normalize */
207    while (c->high < 128) {
208        c->high <<= 1;
209        c->code_word <<= 1;
210        if (--c->bits == 0 && c->buffer < c->end) {
211            c->bits = 8;
212            c->code_word |= *c->buffer++;
213        }
214    }
215    return bit;
216}
217
218static inline int vp56_rac_get(VP56RangeCoder *c)
219{
220    /* equiprobable */
221    int low = (c->high + 1) >> 1;
222    unsigned int low_shift = low << 8;
223    int bit = c->code_word >= low_shift;
224    if (bit) {
225        c->high = (c->high - low) << 1;
226        c->code_word -= low_shift;
227    } else {
228        c->high = low << 1;
229    }
230
231    /* normalize */
232    c->code_word <<= 1;
233    if (--c->bits == 0 && c->buffer < c->end) {
234        c->bits = 8;
235        c->code_word |= *c->buffer++;
236    }
237    return bit;
238}
239
240static inline int vp56_rac_gets(VP56RangeCoder *c, int bits)
241{
242    int value = 0;
243
244    while (bits--) {
245        value = (value << 1) | vp56_rac_get(c);
246    }
247
248    return value;
249}
250
251static inline int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
252{
253    int v = vp56_rac_gets(c, 7) << 1;
254    return v + !v;
255}
256
257static inline int vp56_rac_get_tree(VP56RangeCoder *c,
258                                    const VP56Tree *tree,
259                                    const uint8_t *probs)
260{
261    while (tree->val > 0) {
262        if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
263            tree += tree->val;
264        else
265            tree++;
266    }
267    return -tree->val;
268}
269
270#endif /* AVCODEC_VP56_H */
271