libavcodec/vp56.h

   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 "get_bits.h"
  30 #include "bytestream.h"
  31
  32
  33 typedef struct vp56_context VP56Context;
  34 typedef struct vp56_mv VP56mv;
  35
  36 typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
  37                                           VP56mv *vect);
  38 typedef int  (*VP56Adjust)(int v, int t);
  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);
  48
  49 typedef struct {
  50     int high;
  51     int bits;
  52     const uint8_t *buffer;
  53     const uint8_t *end;
  54     unsigned long code_word;
  55 } VP56RangeCoder;
  56
  57 typedef struct {
  58     uint8_t not_null_dc;
  59     VP56Frame ref_frame;
  60     DCTELEM dc_coeff;
  61 } VP56RefDc;
  62
  63 struct vp56_mv {
  64     int x;
  65     int y;
  66 };
  67
  68 typedef struct {
  69     uint8_t type;
  70     VP56mv mv;
  71 } VP56Macroblock;
  72
  73 typedef struct {
  74     uint8_t coeff_reorder[64];       /* used in vp6 only */
  75     uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
  76     uint8_t vector_sig[2];           /* delta sign */
  77     uint8_t vector_dct[2];           /* delta coding types */
  78     uint8_t vector_pdi[2][2];        /* predefined delta init */
  79     uint8_t vector_pdv[2][7];        /* predefined delta values */
  80     uint8_t vector_fdv[2][8];        /* 8 bit delta value definition */
  81     uint8_t coeff_dccv[2][11];       /* DC coeff value */
  82     uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
  83     uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
  84     uint8_t coeff_dcct[2][36][5];    /* DC coeff coding type */
  85     uint8_t coeff_runv[2][14];       /* run value (vp6 only) */
  86     uint8_t mb_type[3][10][10];      /* model for decoding MB type */
  87     uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
  88 } VP56Model;
  89
  90 struct vp56_context {
  91     AVCodecContext *avctx;
  92     DSPContext dsp;
  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
 114     /* DC predictors management */
 115     VP56RefDc *above_blocks;
 116     VP56RefDc left_block[4];
 117     int above_block_idx[6];
 118     DCTELEM prev_dc[3][3];    /* [plan][ref_frame] */
 119
 120     /* blocks / macroblock */
 121     VP56mb mb_type;
 122     VP56Macroblock *macroblocks;
 123     DECLARE_ALIGNED_16(DCTELEM, block_coeff[6][64]);
 124
 125     /* motion vectors */
 126     VP56mv mv[6];  /* vectors for each block in MB */
 127     VP56mv vector_candidate[2];
 128     int vector_candidate_pos;
 129
 130     /* filtering hints */
 131     int filter_header;               /* used in vp6 only */
 132     int deblock_filtering;
 133     int filter_selection;
 134     int filter_mode;
 135     int max_vector_length;
 136     int sample_variance_threshold;
 137
 138     uint8_t coeff_ctx[4][64];              /* used in vp5 only */
 139     uint8_t coeff_ctx_last[4];             /* used in vp5 only */
 140
 141     int has_alpha;
 142
 143     /* upside-down flipping hints */
 144     int flip;  /* are we flipping ? */
 145     int frbi;  /* first row block index in MB */
 146     int srbi;  /* second row block index in MB */
 147     int stride[4];  /* stride for each plan */
 148
 149     const uint8_t *vp56_coord_div;
 150     VP56ParseVectorAdjustment parse_vector_adjustment;
 151     VP56Adjust adjust;
 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
 172 void vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
 173 int vp56_free(AVCodecContext *avctx);
 174 void vp56_init_dequant(VP56Context *s, int quantizer);
 175 int vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
 176                       AVPacket *avpkt);
 177
 178
 179 /**
 180  * vp56 specific range coder implementation
 181  */
 182
 183 static 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
 193 static 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
 218 static 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
 240 static 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
 251 static 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
 257 static 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 */