3 * VP5 and VP6 compatible video decoder (common features)
5 * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
7 * This file is part of FFmpeg.
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.
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.
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
24 #ifndef AVCODEC_VP56_H
25 #define AVCODEC_VP56_H
30 #include "bytestream.h"
34 typedef struct vp56_context VP56Context;
35 typedef struct vp56_mv VP56mv;
37 typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
39 typedef 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);
42 typedef void (*VP56ParseCoeff)(VP56Context *s);
43 typedef void (*VP56DefaultModelsInit)(VP56Context *s);
44 typedef void (*VP56ParseVectorModels)(VP56Context *s);
45 typedef void (*VP56ParseCoeffModels)(VP56Context *s);
46 typedef int (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
47 int buf_size, int *golden_frame);
51 int bits; /* stored negated (i.e. negative "bits" is a positive number of
52 bits left) in order to eliminate a negate in cache refilling */
53 const uint8_t *buffer;
55 unsigned long code_word;
75 uint8_t coeff_reorder[64]; /* used in vp6 only */
76 uint8_t coeff_index_to_pos[64]; /* used in vp6 only */
77 uint8_t vector_sig[2]; /* delta sign */
78 uint8_t vector_dct[2]; /* delta coding types */
79 uint8_t vector_pdi[2][2]; /* predefined delta init */
80 uint8_t vector_pdv[2][7]; /* predefined delta values */
81 uint8_t vector_fdv[2][8]; /* 8 bit delta value definition */
82 uint8_t coeff_dccv[2][11]; /* DC coeff value */
83 uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
84 uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
85 uint8_t coeff_dcct[2][36][5]; /* DC coeff coding type */
86 uint8_t coeff_runv[2][14]; /* run value (vp6 only) */
87 uint8_t mb_type[3][10][10]; /* model for decoding MB type */
88 uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
92 AVCodecContext *avctx;
94 VP56DSPContext vp56dsp;
98 uint8_t *edge_emu_buffer_alloc;
99 uint8_t *edge_emu_buffer;
108 int mb_width; /* number of horizontal MB */
109 int mb_height; /* number of vertical MB */
115 int8_t *qscale_table;
117 /* DC predictors management */
118 VP56RefDc *above_blocks;
119 VP56RefDc left_block[4];
120 int above_block_idx[6];
121 DCTELEM prev_dc[3][3]; /* [plan][ref_frame] */
123 /* blocks / macroblock */
125 VP56Macroblock *macroblocks;
126 DECLARE_ALIGNED(16, DCTELEM, block_coeff)[6][64];
129 VP56mv mv[6]; /* vectors for each block in MB */
130 VP56mv vector_candidate[2];
131 int vector_candidate_pos;
133 /* filtering hints */
134 int filter_header; /* used in vp6 only */
135 int deblock_filtering;
136 int filter_selection;
138 int max_vector_length;
139 int sample_variance_threshold;
141 uint8_t coeff_ctx[4][64]; /* used in vp5 only */
142 uint8_t coeff_ctx_last[4]; /* used in vp5 only */
146 /* upside-down flipping hints */
147 int flip; /* are we flipping ? */
148 int frbi; /* first row block index in MB */
149 int srbi; /* second row block index in MB */
150 int stride[4]; /* stride for each plan */
152 const uint8_t *vp56_coord_div;
153 VP56ParseVectorAdjustment parse_vector_adjustment;
155 VP56ParseCoeff parse_coeff;
156 VP56DefaultModelsInit default_models_init;
157 VP56ParseVectorModels parse_vector_models;
158 VP56ParseCoeffModels parse_coeff_models;
159 VP56ParseHeader parse_header;
164 /* huffman decoding */
169 VLC ract_vlc[2][3][6];
170 unsigned int nb_null[2][2]; /* number of consecutive NULL DC/AC */
174 void vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
175 int vp56_free(AVCodecContext *avctx);
176 void vp56_init_dequant(VP56Context *s, int quantizer);
177 int vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
182 * vp56 specific range coder implementation
185 static inline void vp56_init_range_decoder(VP56RangeCoder *c,
186 const uint8_t *buf, int buf_size)
191 c->end = buf + buf_size;
192 c->code_word = bytestream_get_be16(&c->buffer);
195 static inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
197 /* Don't put c->high in a local variable; if we do that, gcc gets
198 * the stupids and turns the code below into a branch again. */
200 unsigned long code_word = c->code_word;
201 unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
202 unsigned int low_shift = low << 8;
203 int bit = code_word >= low_shift;
206 /* Incantation to convince GCC to turn these into conditional moves
207 * instead of branches -- faster, as this branch is basically
209 c->high = bit ? c->high - low : low;
210 code_word = bit ? code_word - low_shift : code_word;
213 shift = ff_h264_norm_shift[c->high] - 1;
217 if(bits >= 0 && c->buffer < c->end) {
218 code_word |= *c->buffer++ << bits;
222 c->code_word = code_word;
226 static inline int vp56_rac_get(VP56RangeCoder *c)
229 int low = (c->high + 1) >> 1;
230 unsigned int low_shift = low << 8;
231 int bit = c->code_word >= low_shift;
233 c->high = (c->high - low) << 1;
234 c->code_word -= low_shift;
241 if (++c->bits == 0 && c->buffer < c->end) {
243 c->code_word |= *c->buffer++;
248 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?
249 static inline int vp8_rac_get(VP56RangeCoder *c)
251 return vp56_rac_get_prob(c, 128);
254 static inline int vp56_rac_gets(VP56RangeCoder *c, int bits)
259 value = (value << 1) | vp56_rac_get(c);
265 static inline int vp8_rac_get_uint(VP56RangeCoder *c, int bits)
270 value = (value << 1) | vp8_rac_get(c);
276 // fixme: add 1 bit to all the calls to this?
277 static inline int vp8_rac_get_sint(VP56RangeCoder *c, int bits)
284 v = vp8_rac_get_uint(c, bits);
293 static inline int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
295 int v = vp56_rac_gets(c, 7) << 1;
299 static inline int vp8_rac_get_nn(VP56RangeCoder *c)
301 int v = vp8_rac_get_uint(c, 7) << 1;
305 static inline int vp56_rac_get_tree(VP56RangeCoder *c,
306 const VP56Tree *tree,
307 const uint8_t *probs)
309 while (tree->val > 0) {
310 if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
319 * This is identical to vp8_rac_get_tree except for the possibility of starting
320 * on a node other than the root node, needed for coeff decode where this is
321 * used to save a bit after a 0 token (by disallowing EOB to immediately follow.)
323 static inline int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
324 const uint8_t *probs, int i)
327 i = tree[i][vp56_rac_get_prob(c, probs[i])];
333 // how probabilities are associated with decisions is different I think
334 // well, the new scheme fits in the old but this way has one fewer branches per decision
335 static inline int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
336 const uint8_t *probs)
338 return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
342 static inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
347 v = (v<<1) + vp56_rac_get_prob(c, *prob++);
353 #endif /* AVCODEC_VP56_H */