libavcodec/vp56.h

   1 /*
   2  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * VP5 and VP6 compatible video decoder (common features)
  24  */
  25
  26 #ifndef AVCODEC_VP56_H
  27 #define AVCODEC_VP56_H
  28
  29 #include "vp56data.h"
  30 #include "dsputil.h"
  31 #include "get_bits.h"
  32 #include "bytestream.h"
  33 #include "h264chroma.h"
  34 #include "videodsp.h"
  35 #include "vp3dsp.h"
  36 #include "vp56dsp.h"
  37
  38 typedef struct vp56_context VP56Context;
  39
  40 typedef struct VP56mv {
  41     DECLARE_ALIGNED(4, int16_t, x);
  42     int16_t y;
  43 } VP56mv;
  44
  45 #define VP56_SIZE_CHANGE 1
  46
  47 typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
  48                                           VP56mv *vect);
  49 typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
  50                            int offset1, int offset2, int stride,
  51                            VP56mv mv, int mask, int select, int luma);
  52 typedef void (*VP56ParseCoeff)(VP56Context *s);
  53 typedef void (*VP56DefaultModelsInit)(VP56Context *s);
  54 typedef void (*VP56ParseVectorModels)(VP56Context *s);
  55 typedef int  (*VP56ParseCoeffModels)(VP56Context *s);
  56 typedef int  (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
  57                                 int buf_size, int *golden_frame);
  58
  59 typedef struct VP56RangeCoder {
  60     int high;
  61     int bits; /* stored negated (i.e. negative "bits" is a positive number of
  62                  bits left) in order to eliminate a negate in cache refilling */
  63     const uint8_t *buffer;
  64     const uint8_t *end;
  65     unsigned int code_word;
  66 } VP56RangeCoder;
  67
  68 typedef struct VP56RefDc {
  69     uint8_t not_null_dc;
  70     VP56Frame ref_frame;
  71     int16_t dc_coeff;
  72 } VP56RefDc;
  73
  74 typedef struct VP56Macroblock {
  75     uint8_t type;
  76     VP56mv mv;
  77 } VP56Macroblock;
  78
  79 typedef struct VP56Model {
  80     uint8_t coeff_reorder[64];       /* used in vp6 only */
  81     uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
  82     uint8_t vector_sig[2];           /* delta sign */
  83     uint8_t vector_dct[2];           /* delta coding types */
  84     uint8_t vector_pdi[2][2];        /* predefined delta init */
  85     uint8_t vector_pdv[2][7];        /* predefined delta values */
  86     uint8_t vector_fdv[2][8];        /* 8 bit delta value definition */
  87     uint8_t coeff_dccv[2][11];       /* DC coeff value */
  88     uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
  89     uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
  90     uint8_t coeff_dcct[2][36][5];    /* DC coeff coding type */
  91     uint8_t coeff_runv[2][14];       /* run value (vp6 only) */
  92     uint8_t mb_type[3][10][10];      /* model for decoding MB type */
  93     uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
  94 } VP56Model;
  95
  96 struct vp56_context {
  97     AVCodecContext *avctx;
  98     DSPContext dsp;
  99     H264ChromaContext h264chroma;
 100     VideoDSPContext vdsp;
 101     VP3DSPContext vp3dsp;
 102     VP56DSPContext vp56dsp;
 103     ScanTable scantable;
 104     AVFrame *frames[4];
 105     uint8_t *edge_emu_buffer_alloc;
 106     uint8_t *edge_emu_buffer;
 107     VP56RangeCoder c;
 108     VP56RangeCoder cc;
 109     VP56RangeCoder *ccp;
 110     int sub_version;
 111
 112     /* frame info */
 113     int plane_width[4];
 114     int plane_height[4];
 115     int mb_width;   /* number of horizontal MB */
 116     int mb_height;  /* number of vertical MB */
 117     int block_offset[6];
 118
 119     int quantizer;
 120     uint16_t dequant_dc;
 121     uint16_t dequant_ac;
 122
 123     /* DC predictors management */
 124     VP56RefDc *above_blocks;
 125     VP56RefDc left_block[4];
 126     int above_block_idx[6];
 127     int16_t prev_dc[3][3];    /* [plan][ref_frame] */
 128
 129     /* blocks / macroblock */
 130     VP56mb mb_type;
 131     VP56Macroblock *macroblocks;
 132     DECLARE_ALIGNED(16, int16_t, block_coeff)[6][64];
 133
 134     /* motion vectors */
 135     VP56mv mv[6];  /* vectors for each block in MB */
 136     VP56mv vector_candidate[2];
 137     int vector_candidate_pos;
 138
 139     /* filtering hints */
 140     int filter_header;               /* used in vp6 only */
 141     int deblock_filtering;
 142     int filter_selection;
 143     int filter_mode;
 144     int max_vector_length;
 145     int sample_variance_threshold;
 146
 147     uint8_t coeff_ctx[4][64];              /* used in vp5 only */
 148     uint8_t coeff_ctx_last[4];             /* used in vp5 only */
 149
 150     int has_alpha;
 151
 152     /* upside-down flipping hints */
 153     int flip;  /* are we flipping ? */
 154     int frbi;  /* first row block index in MB */
 155     int srbi;  /* second row block index in MB */
 156     int stride[4];  /* stride for each plan */
 157
 158     const uint8_t *vp56_coord_div;
 159     VP56ParseVectorAdjustment parse_vector_adjustment;
 160     VP56Filter filter;
 161     VP56ParseCoeff parse_coeff;
 162     VP56DefaultModelsInit default_models_init;
 163     VP56ParseVectorModels parse_vector_models;
 164     VP56ParseCoeffModels parse_coeff_models;
 165     VP56ParseHeader parse_header;
 166
 167     VP56Model *modelp;
 168     VP56Model models[2];
 169
 170     /* huffman decoding */
 171     int use_huffman;
 172     GetBitContext gb;
 173     VLC dccv_vlc[2];
 174     VLC runv_vlc[2];
 175     VLC ract_vlc[2][3][6];
 176     unsigned int nb_null[2][2];       /* number of consecutive NULL DC/AC */
 177 };
 178
 179
 180 int ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
 181 int ff_vp56_free(AVCodecContext *avctx);
 182 void ff_vp56_init_dequant(VP56Context *s, int quantizer);
 183 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 184                          AVPacket *avpkt);
 185
 186
 187 /**
 188  * vp56 specific range coder implementation
 189  */
 190
 191 extern const uint8_t ff_vp56_norm_shift[256];
 192 void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
 193
 194 static av_always_inline unsigned int vp56_rac_renorm(VP56RangeCoder *c)
 195 {
 196     int shift = ff_vp56_norm_shift[c->high];
 197     int bits = c->bits;
 198     unsigned int code_word = c->code_word;
 199
 200     c->high   <<= shift;
 201     code_word <<= shift;
 202     bits       += shift;
 203     if(bits >= 0 && c->buffer < c->end) {
 204         code_word |= bytestream_get_be16(&c->buffer) << bits;
 205         bits -= 16;
 206     }
 207     c->bits = bits;
 208     return code_word;
 209 }
 210
 211 #if   ARCH_ARM
 212 #include "arm/vp56_arith.h"
 213 #elif ARCH_X86
 214 #include "x86/vp56_arith.h"
 215 #endif
 216
 217 #ifndef vp56_rac_get_prob
 218 #define vp56_rac_get_prob vp56_rac_get_prob
 219 static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
 220 {
 221     unsigned int code_word = vp56_rac_renorm(c);
 222     unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
 223     unsigned int low_shift = low << 16;
 224     int bit = code_word >= low_shift;
 225
 226     c->high = bit ? c->high - low : low;
 227     c->code_word = bit ? code_word - low_shift : code_word;
 228
 229     return bit;
 230 }
 231 #endif
 232
 233 #ifndef vp56_rac_get_prob_branchy
 234 // branchy variant, to be used where there's a branch based on the bit decoded
 235 static av_always_inline int vp56_rac_get_prob_branchy(VP56RangeCoder *c, int prob)
 236 {
 237     unsigned long code_word = vp56_rac_renorm(c);
 238     unsigned low = 1 + (((c->high - 1) * prob) >> 8);
 239     unsigned low_shift = low << 16;
 240
 241     if (code_word >= low_shift) {
 242         c->high     -= low;
 243         c->code_word = code_word - low_shift;
 244         return 1;
 245     }
 246
 247     c->high = low;
 248     c->code_word = code_word;
 249     return 0;
 250 }
 251 #endif
 252
 253 static av_always_inline int vp56_rac_get(VP56RangeCoder *c)
 254 {
 255     unsigned int code_word = vp56_rac_renorm(c);
 256     /* equiprobable */
 257     int low = (c->high + 1) >> 1;
 258     unsigned int low_shift = low << 16;
 259     int bit = code_word >= low_shift;
 260     if (bit) {
 261         c->high   -= low;
 262         code_word -= low_shift;
 263     } else {
 264         c->high = low;
 265     }
 266
 267     c->code_word = code_word;
 268     return bit;
 269 }
 270
 271 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?
 272 static av_always_inline int vp8_rac_get(VP56RangeCoder *c)
 273 {
 274     return vp56_rac_get_prob(c, 128);
 275 }
 276
 277 static av_unused int vp56_rac_gets(VP56RangeCoder *c, int bits)
 278 {
 279     int value = 0;
 280
 281     while (bits--) {
 282         value = (value << 1) | vp56_rac_get(c);
 283     }
 284
 285     return value;
 286 }
 287
 288 static av_unused int vp8_rac_get_uint(VP56RangeCoder *c, int bits)
 289 {
 290     int value = 0;
 291
 292     while (bits--) {
 293         value = (value << 1) | vp8_rac_get(c);
 294     }
 295
 296     return value;
 297 }
 298
 299 // fixme: add 1 bit to all the calls to this?
 300 static av_unused int vp8_rac_get_sint(VP56RangeCoder *c, int bits)
 301 {
 302     int v;
 303
 304     if (!vp8_rac_get(c))
 305         return 0;
 306
 307     v = vp8_rac_get_uint(c, bits);
 308
 309     if (vp8_rac_get(c))
 310         v = -v;
 311
 312     return v;
 313 }
 314
 315 // P(7)
 316 static av_unused int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
 317 {
 318     int v = vp56_rac_gets(c, 7) << 1;
 319     return v + !v;
 320 }
 321
 322 static av_unused int vp8_rac_get_nn(VP56RangeCoder *c)
 323 {
 324     int v = vp8_rac_get_uint(c, 7) << 1;
 325     return v + !v;
 326 }
 327
 328 static av_always_inline
 329 int vp56_rac_get_tree(VP56RangeCoder *c,
 330                       const VP56Tree *tree,
 331                       const uint8_t *probs)
 332 {
 333     while (tree->val > 0) {
 334         if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
 335             tree += tree->val;
 336         else
 337             tree++;
 338     }
 339     return -tree->val;
 340 }
 341
 342 /**
 343  * This is identical to vp8_rac_get_tree except for the possibility of starting
 344  * on a node other than the root node, needed for coeff decode where this is
 345  * used to save a bit after a 0 token (by disallowing EOB to immediately follow.)
 346  */
 347 static av_always_inline
 348 int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
 349                                  const uint8_t *probs, int i)
 350 {
 351     do {
 352         i = tree[i][vp56_rac_get_prob(c, probs[i])];
 353     } while (i > 0);
 354
 355     return -i;
 356 }
 357
 358 // how probabilities are associated with decisions is different I think
 359 // well, the new scheme fits in the old but this way has one fewer branches per decision
 360 static av_always_inline
 361 int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
 362                      const uint8_t *probs)
 363 {
 364     return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
 365 }
 366
 367 // DCTextra
 368 static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
 369 {
 370     int v = 0;
 371
 372     do {
 373         v = (v<<1) + vp56_rac_get_prob(c, *prob++);
 374     } while (*prob);
 375
 376     return v;
 377 }
 378
 379 #endif /* AVCODEC_VP56_H */