ffmpeg/libavcodec/vp56.h

   1 /*
   2  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "get_bits.h"
  30 #include "hpeldsp.h"
  31 #include "bytestream.h"
  32 #include "h264chroma.h"
  33 #include "videodsp.h"
  34 #include "vp3dsp.h"
  35 #include "vp56dsp.h"
  36
  37 typedef struct vp56_context VP56Context;
  38
  39 typedef enum {
  40     VP56_FRAME_NONE     =-1,
  41     VP56_FRAME_CURRENT  = 0,
  42     VP56_FRAME_PREVIOUS = 1,
  43     VP56_FRAME_GOLDEN   = 2,
  44     VP56_FRAME_GOLDEN2  = 3,
  45 } VP56Frame;
  46
  47 typedef enum {
  48     VP56_MB_INTER_NOVEC_PF = 0,  /**< Inter MB, no vector, from previous frame */
  49     VP56_MB_INTRA          = 1,  /**< Intra MB */
  50     VP56_MB_INTER_DELTA_PF = 2,  /**< Inter MB, above/left vector + delta, from previous frame */
  51     VP56_MB_INTER_V1_PF    = 3,  /**< Inter MB, first vector, from previous frame */
  52     VP56_MB_INTER_V2_PF    = 4,  /**< Inter MB, second vector, from previous frame */
  53     VP56_MB_INTER_NOVEC_GF = 5,  /**< Inter MB, no vector, from golden frame */
  54     VP56_MB_INTER_DELTA_GF = 6,  /**< Inter MB, above/left vector + delta, from golden frame */
  55     VP56_MB_INTER_4V       = 7,  /**< Inter MB, 4 vectors, from previous frame */
  56     VP56_MB_INTER_V1_GF    = 8,  /**< Inter MB, first vector, from golden frame */
  57     VP56_MB_INTER_V2_GF    = 9,  /**< Inter MB, second vector, from golden frame */
  58 } VP56mb;
  59
  60 typedef struct VP56Tree {
  61   int8_t val;
  62   int8_t prob_idx;
  63 } VP56Tree;
  64
  65 typedef struct VP56mv {
  66     DECLARE_ALIGNED(4, int16_t, x);
  67     int16_t y;
  68 } VP56mv;
  69
  70 #define VP56_SIZE_CHANGE 1
  71
  72 typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
  73                                           VP56mv *vect);
  74 typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
  75                            int offset1, int offset2, int stride,
  76                            VP56mv mv, int mask, int select, int luma);
  77 typedef void (*VP56ParseCoeff)(VP56Context *s);
  78 typedef void (*VP56DefaultModelsInit)(VP56Context *s);
  79 typedef void (*VP56ParseVectorModels)(VP56Context *s);
  80 typedef int  (*VP56ParseCoeffModels)(VP56Context *s);
  81 typedef int  (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
  82                                 int buf_size);
  83
  84 typedef struct VP56RangeCoder {
  85     int high;
  86     int bits; /* stored negated (i.e. negative "bits" is a positive number of
  87                  bits left) in order to eliminate a negate in cache refilling */
  88     const uint8_t *buffer;
  89     const uint8_t *end;
  90     unsigned int code_word;
  91 } VP56RangeCoder;
  92
  93 typedef struct VP56RefDc {
  94     uint8_t not_null_dc;
  95     VP56Frame ref_frame;
  96     int16_t dc_coeff;
  97 } VP56RefDc;
  98
  99 typedef struct VP56Macroblock {
 100     uint8_t type;
 101     VP56mv mv;
 102 } VP56Macroblock;
 103
 104 typedef struct VP56Model {
 105     uint8_t coeff_reorder[64];       /* used in vp6 only */
 106     uint8_t coeff_index_to_pos[64];  /* used in vp6 only */
 107     uint8_t vector_sig[2];           /* delta sign */
 108     uint8_t vector_dct[2];           /* delta coding types */
 109     uint8_t vector_pdi[2][2];        /* predefined delta init */
 110     uint8_t vector_pdv[2][7];        /* predefined delta values */
 111     uint8_t vector_fdv[2][8];        /* 8 bit delta value definition */
 112     uint8_t coeff_dccv[2][11];       /* DC coeff value */
 113     uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
 114     uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
 115     uint8_t coeff_dcct[2][36][5];    /* DC coeff coding type */
 116     uint8_t coeff_runv[2][14];       /* run value (vp6 only) */
 117     uint8_t mb_type[3][10][10];      /* model for decoding MB type */
 118     uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
 119 } VP56Model;
 120
 121 struct vp56_context {
 122     AVCodecContext *avctx;
 123     H264ChromaContext h264chroma;
 124     HpelDSPContext hdsp;
 125     VideoDSPContext vdsp;
 126     VP3DSPContext vp3dsp;
 127     VP56DSPContext vp56dsp;
 128     uint8_t idct_scantable[64];
 129     AVFrame *frames[4];
 130     uint8_t *edge_emu_buffer_alloc;
 131     uint8_t *edge_emu_buffer;
 132     VP56RangeCoder c;
 133     VP56RangeCoder cc;
 134     VP56RangeCoder *ccp;
 135     int sub_version;
 136
 137     /* frame info */
 138     int golden_frame;
 139     int plane_width[4];
 140     int plane_height[4];
 141     int mb_width;   /* number of horizontal MB */
 142     int mb_height;  /* number of vertical MB */
 143     int block_offset[6];
 144
 145     int quantizer;
 146     uint16_t dequant_dc;
 147     uint16_t dequant_ac;
 148
 149     /* DC predictors management */
 150     VP56RefDc *above_blocks;
 151     VP56RefDc left_block[4];
 152     int above_block_idx[6];
 153     int16_t prev_dc[3][3];    /* [plan][ref_frame] */
 154
 155     /* blocks / macroblock */
 156     VP56mb mb_type;
 157     VP56Macroblock *macroblocks;
 158     DECLARE_ALIGNED(16, int16_t, block_coeff)[6][64];
 159
 160     /* motion vectors */
 161     VP56mv mv[6];  /* vectors for each block in MB */
 162     VP56mv vector_candidate[2];
 163     int vector_candidate_pos;
 164
 165     /* filtering hints */
 166     int filter_header;               /* used in vp6 only */
 167     int deblock_filtering;
 168     int filter_selection;
 169     int filter_mode;
 170     int max_vector_length;
 171     int sample_variance_threshold;
 172
 173     uint8_t coeff_ctx[4][64];              /* used in vp5 only */
 174     uint8_t coeff_ctx_last[4];             /* used in vp5 only */
 175
 176     int has_alpha;
 177
 178     /* upside-down flipping hints */
 179     int flip;  /* are we flipping ? */
 180     int frbi;  /* first row block index in MB */
 181     int srbi;  /* second row block index in MB */
 182     int stride[4];  /* stride for each plan */
 183
 184     const uint8_t *vp56_coord_div;
 185     VP56ParseVectorAdjustment parse_vector_adjustment;
 186     VP56Filter filter;
 187     VP56ParseCoeff parse_coeff;
 188     VP56DefaultModelsInit default_models_init;
 189     VP56ParseVectorModels parse_vector_models;
 190     VP56ParseCoeffModels parse_coeff_models;
 191     VP56ParseHeader parse_header;
 192
 193     /* for "slice" parallelism between YUV and A */
 194     VP56Context *alpha_context;
 195
 196     VP56Model *modelp;
 197     VP56Model model;
 198
 199     /* huffman decoding */
 200     int use_huffman;
 201     GetBitContext gb;
 202     VLC dccv_vlc[2];
 203     VLC runv_vlc[2];
 204     VLC ract_vlc[2][3][6];
 205     unsigned int nb_null[2][2];       /* number of consecutive NULL DC/AC */
 206 };
 207
 208
 209 int ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
 210 int ff_vp56_init_context(AVCodecContext *avctx, VP56Context *s,
 211                           int flip, int has_alpha);
 212 int ff_vp56_free(AVCodecContext *avctx);
 213 int ff_vp56_free_context(VP56Context *s);
 214 void ff_vp56_init_dequant(VP56Context *s, int quantizer);
 215 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 216                          AVPacket *avpkt);
 217
 218
 219 /**
 220  * vp56 specific range coder implementation
 221  */
 222
 223 extern const uint8_t ff_vp56_norm_shift[256];
 224 void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
 225
 226 static av_always_inline unsigned int vp56_rac_renorm(VP56RangeCoder *c)
 227 {
 228     int shift = ff_vp56_norm_shift[c->high];
 229     int bits = c->bits;
 230     unsigned int code_word = c->code_word;
 231
 232     c->high   <<= shift;
 233     code_word <<= shift;
 234     bits       += shift;
 235     if(bits >= 0 && c->buffer < c->end) {
 236         code_word |= bytestream_get_be16(&c->buffer) << bits;
 237         bits -= 16;
 238     }
 239     c->bits = bits;
 240     return code_word;
 241 }
 242
 243 #if   ARCH_ARM
 244 #include "arm/vp56_arith.h"
 245 #elif ARCH_X86
 246 #include "x86/vp56_arith.h"
 247 #endif
 248
 249 #ifndef vp56_rac_get_prob
 250 #define vp56_rac_get_prob vp56_rac_get_prob
 251 static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
 252 {
 253     unsigned int code_word = vp56_rac_renorm(c);
 254     unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
 255     unsigned int low_shift = low << 16;
 256     int bit = code_word >= low_shift;
 257
 258     c->high = bit ? c->high - low : low;
 259     c->code_word = bit ? code_word - low_shift : code_word;
 260
 261     return bit;
 262 }
 263 #endif
 264
 265 #ifndef vp56_rac_get_prob_branchy
 266 // branchy variant, to be used where there's a branch based on the bit decoded
 267 static av_always_inline int vp56_rac_get_prob_branchy(VP56RangeCoder *c, int prob)
 268 {
 269     unsigned long code_word = vp56_rac_renorm(c);
 270     unsigned low = 1 + (((c->high - 1) * prob) >> 8);
 271     unsigned low_shift = low << 16;
 272
 273     if (code_word >= low_shift) {
 274         c->high     -= low;
 275         c->code_word = code_word - low_shift;
 276         return 1;
 277     }
 278
 279     c->high = low;
 280     c->code_word = code_word;
 281     return 0;
 282 }
 283 #endif
 284
 285 static av_always_inline int vp56_rac_get(VP56RangeCoder *c)
 286 {
 287     unsigned int code_word = vp56_rac_renorm(c);
 288     /* equiprobable */
 289     int low = (c->high + 1) >> 1;
 290     unsigned int low_shift = low << 16;
 291     int bit = code_word >= low_shift;
 292     if (bit) {
 293         c->high   -= low;
 294         code_word -= low_shift;
 295     } else {
 296         c->high = low;
 297     }
 298
 299     c->code_word = code_word;
 300     return bit;
 301 }
 302
 303 // rounding is different than vp56_rac_get, is vp56_rac_get wrong?
 304 static av_always_inline int vp8_rac_get(VP56RangeCoder *c)
 305 {
 306     return vp56_rac_get_prob(c, 128);
 307 }
 308
 309 static int vp56_rac_gets(VP56RangeCoder *c, int bits)
 310 {
 311     int value = 0;
 312
 313     while (bits--) {
 314         value = (value << 1) | vp56_rac_get(c);
 315     }
 316
 317     return value;
 318 }
 319
 320 static int vp8_rac_get_uint(VP56RangeCoder *c, int bits)
 321 {
 322     int value = 0;
 323
 324     while (bits--) {
 325         value = (value << 1) | vp8_rac_get(c);
 326     }
 327
 328     return value;
 329 }
 330
 331 // fixme: add 1 bit to all the calls to this?
 332 static av_unused int vp8_rac_get_sint(VP56RangeCoder *c, int bits)
 333 {
 334     int v;
 335
 336     if (!vp8_rac_get(c))
 337         return 0;
 338
 339     v = vp8_rac_get_uint(c, bits);
 340
 341     if (vp8_rac_get(c))
 342         v = -v;
 343
 344     return v;
 345 }
 346
 347 // P(7)
 348 static av_unused int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
 349 {
 350     int v = vp56_rac_gets(c, 7) << 1;
 351     return v + !v;
 352 }
 353
 354 static av_unused int vp8_rac_get_nn(VP56RangeCoder *c)
 355 {
 356     int v = vp8_rac_get_uint(c, 7) << 1;
 357     return v + !v;
 358 }
 359
 360 static av_always_inline
 361 int vp56_rac_get_tree(VP56RangeCoder *c,
 362                       const VP56Tree *tree,
 363                       const uint8_t *probs)
 364 {
 365     while (tree->val > 0) {
 366         if (vp56_rac_get_prob_branchy(c, probs[tree->prob_idx]))
 367             tree += tree->val;
 368         else
 369             tree++;
 370     }
 371     return -tree->val;
 372 }
 373
 374 // how probabilities are associated with decisions is different I think
 375 // well, the new scheme fits in the old but this way has one fewer branches per decision
 376 static av_always_inline int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
 377                                    const uint8_t *probs)
 378 {
 379     int i = 0;
 380
 381     do {
 382         i = tree[i][vp56_rac_get_prob(c, probs[i])];
 383     } while (i > 0);
 384
 385     return -i;
 386 }
 387
 388 // DCTextra
 389 static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
 390 {
 391     int v = 0;
 392
 393     do {
 394         v = (v<<1) + vp56_rac_get_prob(c, *prob++);
 395     } while (*prob);
 396
 397     return v;
 398 }
 399
 400 #endif /* AVCODEC_VP56_H */