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 "bitstream.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     unsigned long code_word;
  54 } VP56RangeCoder;
  55
  56 typedef struct {
  57     uint8_t not_null_dc;
  58     VP56Frame ref_frame;
  59     DCTELEM dc_coeff;
  60 } VP56RefDc;
  61
  62 struct vp56_mv {
  63     int x;
  64     int y;
  65 };
  66
  67 typedef struct {
  68     uint8_t type;
  69     VP56mv mv;
  70 } VP56Macroblock;
  71
  72 typedef 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
  89 struct 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
 171 void vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
 172 int vp56_free(AVCodecContext *avctx);
 173 void vp56_init_dequant(VP56Context *s, int quantizer);
 174 int 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
 182 static 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
 191 static 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
 216 static 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
 238 static 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
 249 static 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
 255 static 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 */