libavcodec/vp56.h

   1 /**
   2  * @file 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 VP56_H
  25 #define VP56_H
  26
  27 #include "vp56data.h"
  28 #include "dsputil.h"
  29 #include "mpegvideo.h"
  30 #include "bytestream.h"
  31
  32
  33 typedef struct vp56_context vp56_context_t;
  34 typedef struct vp56_mv vp56_mv_t;
  35
  36 typedef void (*vp56_parse_vector_adjustment_t)(vp56_context_t *s,
  37                                                vp56_mv_t *vect);
  38 typedef int (*vp56_adjust_t)(int v, int t);
  39 typedef void (*vp56_filter_t)(vp56_context_t *s, uint8_t *dst, uint8_t *src,
  40                               int offset1, int offset2, int stride,
  41                               vp56_mv_t mv, int mask, int select, int luma);
  42 typedef void (*vp56_parse_coeff_t)(vp56_context_t *s);
  43 typedef void (*vp56_default_models_init_t)(vp56_context_t *s);
  44 typedef void (*vp56_parse_vector_models_t)(vp56_context_t *s);
  45 typedef void (*vp56_parse_coeff_models_t)(vp56_context_t *s);
  46 typedef int (*vp56_parse_header_t)(vp56_context_t *s, 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 } vp56_range_coder_t;
  55
  56 typedef struct {
  57     uint8_t not_null_dc;
  58     vp56_frame_t ref_frame;
  59     DCTELEM dc_coeff;
  60 } vp56_ref_dc_t;
  61
  62 struct vp56_mv {
  63     int x;
  64     int y;
  65 };
  66
  67 typedef struct {
  68     uint8_t type;
  69     vp56_mv_t mv;
  70 } vp56_macroblock_t;
  71
  72 struct vp56_context {
  73     AVCodecContext *avctx;
  74     DSPContext dsp;
  75     ScanTable scantable;
  76     AVFrame frames[3];
  77     AVFrame *framep[4];
  78     uint8_t *edge_emu_buffer_alloc;
  79     uint8_t *edge_emu_buffer;
  80     vp56_range_coder_t c;
  81     vp56_range_coder_t cc;
  82     vp56_range_coder_t *ccp;
  83     int sub_version;
  84
  85     /* frame info */
  86     int plane_width[3];
  87     int plane_height[3];
  88     int mb_width;   /* number of horizontal MB */
  89     int mb_height;  /* number of vertical MB */
  90     int block_offset[6];
  91
  92     int quantizer;
  93     uint16_t dequant_dc;
  94     uint16_t dequant_ac;
  95
  96     /* DC predictors management */
  97     vp56_ref_dc_t *above_blocks;
  98     vp56_ref_dc_t left_block[4];
  99     int above_block_idx[6];
 100     DCTELEM prev_dc[3][3];    /* [plan][ref_frame] */
 101
 102     /* blocks / macroblock */
 103     vp56_mb_t mb_type;
 104     vp56_macroblock_t *macroblocks;
 105     DECLARE_ALIGNED_16(DCTELEM, block_coeff[6][64]);
 106     uint8_t coeff_reorder[64];       /* used in vp6 only */
 107     uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
 108
 109     /* motion vectors */
 110     vp56_mv_t mv[6];  /* vectors for each block in MB */
 111     vp56_mv_t vector_candidate[2];
 112     int vector_candidate_pos;
 113
 114     /* filtering hints */
 115     int filter_header;               /* used in vp6 only */
 116     int deblock_filtering;
 117     int filter_selection;
 118     int filter_mode;
 119     int max_vector_length;
 120     int sample_variance_threshold;
 121
 122     /* AC models */
 123     uint8_t vector_model_sig[2];           /* delta sign */
 124     uint8_t vector_model_dct[2];           /* delta coding types */
 125     uint8_t vector_model_pdi[2][2];        /* predefined delta init */
 126     uint8_t vector_model_pdv[2][7];        /* predefined delta values */
 127     uint8_t vector_model_fdv[2][8];        /* 8 bit delta value definition */
 128     uint8_t mb_type_model[3][10][10];      /* model for decoding MB type */
 129     uint8_t coeff_model_dccv[2][11];       /* DC coeff value */
 130     uint8_t coeff_model_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
 131     uint8_t coeff_model_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
 132     uint8_t coeff_model_dcct[2][36][5];    /* DC coeff coding type */
 133     uint8_t coeff_model_runv[2][14];       /* run value (vp6 only) */
 134     uint8_t mb_types_stats[3][10][2];      /* contextual, next MB type stats */
 135     uint8_t coeff_ctx[4][64];              /* used in vp5 only */
 136     uint8_t coeff_ctx_last[4];             /* used in vp5 only */
 137
 138     /* upside-down flipping hints */
 139     int flip;  /* are we flipping ? */
 140     int frbi;  /* first row block index in MB */
 141     int srbi;  /* second row block index in MB */
 142     int stride[3];  /* stride for each plan */
 143
 144     const uint8_t *vp56_coord_div;
 145     vp56_parse_vector_adjustment_t parse_vector_adjustment;
 146     vp56_adjust_t adjust;
 147     vp56_filter_t filter;
 148     vp56_parse_coeff_t parse_coeff;
 149     vp56_default_models_init_t default_models_init;
 150     vp56_parse_vector_models_t parse_vector_models;
 151     vp56_parse_coeff_models_t parse_coeff_models;
 152     vp56_parse_header_t parse_header;
 153 };
 154
 155
 156 void vp56_init(vp56_context_t *s, AVCodecContext *avctx, int flip);
 157 int vp56_free(AVCodecContext *avctx);
 158 void vp56_init_dequant(vp56_context_t *s, int quantizer);
 159 int vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
 160                       uint8_t *buf, int buf_size);
 161
 162
 163 /**
 164  * vp56 specific range coder implementation
 165  */
 166
 167 static inline void vp56_init_range_decoder(vp56_range_coder_t *c,
 168                                            const uint8_t *buf, int buf_size)
 169 {
 170     c->high = 255;
 171     c->bits = 8;
 172     c->buffer = buf;
 173     c->code_word = bytestream_get_be16(&c->buffer);
 174 }
 175
 176 static inline int vp56_rac_get_prob(vp56_range_coder_t *c, uint8_t prob)
 177 {
 178     unsigned int low = 1 + (((c->high - 1) * prob) / 256);
 179     unsigned int low_shift = low << 8;
 180     int bit = c->code_word >= low_shift;
 181
 182     if (bit) {
 183         c->high -= low;
 184         c->code_word -= low_shift;
 185     } else {
 186         c->high = low;
 187     }
 188
 189     /* normalize */
 190     while (c->high < 128) {
 191         c->high <<= 1;
 192         c->code_word <<= 1;
 193         if (--c->bits == 0) {
 194             c->bits = 8;
 195             c->code_word |= *c->buffer++;
 196         }
 197     }
 198     return bit;
 199 }
 200
 201 static inline int vp56_rac_get(vp56_range_coder_t *c)
 202 {
 203     /* equiprobable */
 204     int low = (c->high + 1) >> 1;
 205     unsigned int low_shift = low << 8;
 206     int bit = c->code_word >= low_shift;
 207     if (bit) {
 208         c->high = (c->high - low) << 1;
 209         c->code_word -= low_shift;
 210     } else {
 211         c->high = low << 1;
 212     }
 213
 214     /* normalize */
 215     c->code_word <<= 1;
 216     if (--c->bits == 0) {
 217         c->bits = 8;
 218         c->code_word |= *c->buffer++;
 219     }
 220     return bit;
 221 }
 222
 223 static inline int vp56_rac_gets(vp56_range_coder_t *c, int bits)
 224 {
 225     int value = 0;
 226
 227     while (bits--) {
 228         value = (value << 1) | vp56_rac_get(c);
 229     }
 230
 231     return value;
 232 }
 233
 234 static inline int vp56_rac_gets_nn(vp56_range_coder_t *c, int bits)
 235 {
 236     int v = vp56_rac_gets(c, 7) << 1;
 237     return v + !v;
 238 }
 239
 240 static inline int vp56_rac_get_tree(vp56_range_coder_t *c,
 241                                     const vp56_tree_t *tree,
 242                                     const uint8_t *probs)
 243 {
 244     while (tree->val > 0) {
 245         if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
 246             tree += tree->val;
 247         else
 248             tree++;
 249     }
 250     return -tree->val;
 251 }
 252
 253 #endif /* VP56_H */