libavcodec/vp6.c

   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  * VP6 compatible video decoder
  24  *
  25  * The VP6F decoder accepts an optional 1 byte extradata. It is composed of:
  26  *  - upper 4 bits: difference between encoded width and visible width
  27  *  - lower 4 bits: difference between encoded height and visible height
  28  */
  29
  30 #include <stdlib.h>
  31
  32 #include "avcodec.h"
  33 #include "get_bits.h"
  34 #include "huffman.h"
  35
  36 #include "vp56.h"
  37 #include "vp56data.h"
  38 #include "vp6data.h"
  39
  40 #define VP6_MAX_HUFF_SIZE 12
  41
  42 static void vp6_parse_coeff(VP56Context *s);
  43 static void vp6_parse_coeff_huffman(VP56Context *s);
  44
  45 static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
  46                             int *golden_frame)
  47 {
  48     VP56RangeCoder *c = &s->c;
  49     int parse_filter_info = 0;
  50     int coeff_offset = 0;
  51     int vrt_shift = 0;
  52     int sub_version;
  53     int rows, cols;
  54     int res = 0;
  55     int separated_coeff = buf[0] & 1;
  56
  57     s->framep[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
  58     ff_vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
  59
  60     if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
  61         sub_version = buf[1] >> 3;
  62         if (sub_version > 8)
  63             return AVERROR_INVALIDDATA;
  64         s->filter_header = buf[1] & 0x06;
  65         if (buf[1] & 1) {
  66             av_log_missing_feature(s->avctx, "Interlacing", 0);
  67             return AVERROR_PATCHWELCOME;
  68         }
  69         if (separated_coeff || !s->filter_header) {
  70             coeff_offset = AV_RB16(buf+2) - 2;
  71             buf += 2;
  72             buf_size -= 2;
  73         }
  74
  75         rows = buf[2];  /* number of stored macroblock rows */
  76         cols = buf[3];  /* number of stored macroblock cols */
  77         /* buf[4] is number of displayed macroblock rows */
  78         /* buf[5] is number of displayed macroblock cols */
  79         if (!rows || !cols) {
  80             av_log(s->avctx, AV_LOG_ERROR, "Invalid size %dx%d\n", cols << 4, rows << 4);
  81             return AVERROR_INVALIDDATA;
  82         }
  83
  84         if (!s->macroblocks || /* first frame */
  85             16*cols != s->avctx->coded_width ||
  86             16*rows != s->avctx->coded_height) {
  87             avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
  88             if (s->avctx->extradata_size == 1) {
  89                 s->avctx->width  -= s->avctx->extradata[0] >> 4;
  90                 s->avctx->height -= s->avctx->extradata[0] & 0x0F;
  91             }
  92             res = VP56_SIZE_CHANGE;
  93         }
  94
  95         ff_vp56_init_range_decoder(c, buf+6, buf_size-6);
  96         vp56_rac_gets(c, 2);
  97
  98         parse_filter_info = s->filter_header;
  99         if (sub_version < 8)
 100             vrt_shift = 5;
 101         s->sub_version = sub_version;
 102     } else {
 103         if (!s->sub_version || !s->avctx->coded_width || !s->avctx->coded_height)
 104             return AVERROR_INVALIDDATA;
 105
 106         if (separated_coeff || !s->filter_header) {
 107             coeff_offset = AV_RB16(buf+1) - 2;
 108             buf += 2;
 109             buf_size -= 2;
 110         }
 111         ff_vp56_init_range_decoder(c, buf+1, buf_size-1);
 112
 113         *golden_frame = vp56_rac_get(c);
 114         if (s->filter_header) {
 115             s->deblock_filtering = vp56_rac_get(c);
 116             if (s->deblock_filtering)
 117                 vp56_rac_get(c);
 118             if (s->sub_version > 7)
 119                 parse_filter_info = vp56_rac_get(c);
 120         }
 121     }
 122
 123     if (parse_filter_info) {
 124         if (vp56_rac_get(c)) {
 125             s->filter_mode = 2;
 126             s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
 127             s->max_vector_length = 2 << vp56_rac_gets(c, 3);
 128         } else if (vp56_rac_get(c)) {
 129             s->filter_mode = 1;
 130         } else {
 131             s->filter_mode = 0;
 132         }
 133         if (s->sub_version > 7)
 134             s->filter_selection = vp56_rac_gets(c, 4);
 135         else
 136             s->filter_selection = 16;
 137     }
 138
 139     s->use_huffman = vp56_rac_get(c);
 140
 141     s->parse_coeff = vp6_parse_coeff;
 142     if (coeff_offset) {
 143         buf      += coeff_offset;
 144         buf_size -= coeff_offset;
 145         if (buf_size < 0) {
 146             if (s->framep[VP56_FRAME_CURRENT]->key_frame)
 147                 avcodec_set_dimensions(s->avctx, 0, 0);
 148             return AVERROR_INVALIDDATA;
 149         }
 150         if (s->use_huffman) {
 151             s->parse_coeff = vp6_parse_coeff_huffman;
 152             init_get_bits(&s->gb, buf, buf_size<<3);
 153         } else {
 154             ff_vp56_init_range_decoder(&s->cc, buf, buf_size);
 155             s->ccp = &s->cc;
 156         }
 157     } else {
 158         s->ccp = &s->c;
 159     }
 160
 161     return res;
 162 }
 163
 164 static void vp6_coeff_order_table_init(VP56Context *s)
 165 {
 166     int i, pos, idx = 1;
 167
 168     s->modelp->coeff_index_to_pos[0] = 0;
 169     for (i=0; i<16; i++)
 170         for (pos=1; pos<64; pos++)
 171             if (s->modelp->coeff_reorder[pos] == i)
 172                 s->modelp->coeff_index_to_pos[idx++] = pos;
 173 }
 174
 175 static void vp6_default_models_init(VP56Context *s)
 176 {
 177     VP56Model *model = s->modelp;
 178
 179     model->vector_dct[0] = 0xA2;
 180     model->vector_dct[1] = 0xA4;
 181     model->vector_sig[0] = 0x80;
 182     model->vector_sig[1] = 0x80;
 183
 184     memcpy(model->mb_types_stats, ff_vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
 185     memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
 186     memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
 187     memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
 188     memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
 189
 190     vp6_coeff_order_table_init(s);
 191 }
 192
 193 static void vp6_parse_vector_models(VP56Context *s)
 194 {
 195     VP56RangeCoder *c = &s->c;
 196     VP56Model *model = s->modelp;
 197     int comp, node;
 198
 199     for (comp=0; comp<2; comp++) {
 200         if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))
 201             model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
 202         if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))
 203             model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
 204     }
 205
 206     for (comp=0; comp<2; comp++)
 207         for (node=0; node<7; node++)
 208             if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))
 209                 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
 210
 211     for (comp=0; comp<2; comp++)
 212         for (node=0; node<8; node++)
 213             if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
 214                 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
 215 }
 216
 217 /* nodes must ascend by count, but with descending symbol order */
 218 static int vp6_huff_cmp(const void *va, const void *vb)
 219 {
 220     const Node *a = va, *b = vb;
 221     return (a->count - b->count)*16 + (b->sym - a->sym);
 222 }
 223
 224 static int vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
 225                                const uint8_t *map, unsigned size, VLC *vlc)
 226 {
 227     Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
 228     int a, b, i;
 229
 230     /* first compute probabilities from model */
 231     tmp[0].count = 256;
 232     for (i=0; i<size-1; i++) {
 233         a = tmp[i].count *        coeff_model[i]  >> 8;
 234         b = tmp[i].count * (255 - coeff_model[i]) >> 8;
 235         nodes[map[2*i  ]].count = a + !a;
 236         nodes[map[2*i+1]].count = b + !b;
 237     }
 238
 239     ff_free_vlc(vlc);
 240     /* then build the huffman tree according to probabilities */
 241     return ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
 242                               FF_HUFFMAN_FLAG_HNODE_FIRST);
 243 }
 244
 245 static int vp6_parse_coeff_models(VP56Context *s)
 246 {
 247     VP56RangeCoder *c = &s->c;
 248     VP56Model *model = s->modelp;
 249     int def_prob[11];
 250     int node, cg, ctx, pos;
 251     int ct;    /* code type */
 252     int pt;    /* plane type (0 for Y, 1 for U or V) */
 253
 254     memset(def_prob, 0x80, sizeof(def_prob));
 255
 256     for (pt=0; pt<2; pt++)
 257         for (node=0; node<11; node++)
 258             if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {
 259                 def_prob[node] = vp56_rac_gets_nn(c, 7);
 260                 model->coeff_dccv[pt][node] = def_prob[node];
 261             } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
 262                 model->coeff_dccv[pt][node] = def_prob[node];
 263             }
 264
 265     if (vp56_rac_get(c)) {
 266         for (pos=1; pos<64; pos++)
 267             if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
 268                 model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
 269         vp6_coeff_order_table_init(s);
 270     }
 271
 272     for (cg=0; cg<2; cg++)
 273         for (node=0; node<14; node++)
 274             if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
 275                 model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
 276
 277     for (ct=0; ct<3; ct++)
 278         for (pt=0; pt<2; pt++)
 279             for (cg=0; cg<6; cg++)
 280                 for (node=0; node<11; node++)
 281                     if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
 282                         def_prob[node] = vp56_rac_gets_nn(c, 7);
 283                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
 284                     } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
 285                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
 286                     }
 287
 288     if (s->use_huffman) {
 289         for (pt=0; pt<2; pt++) {
 290             if (vp6_build_huff_tree(s, model->coeff_dccv[pt],
 291                                     vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]))
 292                 return -1;
 293             if (vp6_build_huff_tree(s, model->coeff_runv[pt],
 294                                     vp6_huff_run_map, 9, &s->runv_vlc[pt]))
 295                 return -1;
 296             for (ct=0; ct<3; ct++)
 297                 for (cg = 0; cg < 6; cg++)
 298                     if (vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
 299                                             vp6_huff_coeff_map, 12,
 300                                             &s->ract_vlc[pt][ct][cg]))
 301                         return -1;
 302         }
 303         memset(s->nb_null, 0, sizeof(s->nb_null));
 304     } else {
 305     /* coeff_dcct is a linear combination of coeff_dccv */
 306     for (pt=0; pt<2; pt++)
 307         for (ctx=0; ctx<3; ctx++)
 308             for (node=0; node<5; node++)
 309                 model->coeff_dcct[pt][ctx][node] = av_clip(((model->coeff_dccv[pt][node] * vp6_dccv_lc[ctx][node][0] + 128) >> 8) + vp6_dccv_lc[ctx][node][1], 1, 255);
 310     }
 311     return 0;
 312 }
 313
 314 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
 315 {
 316     VP56RangeCoder *c = &s->c;
 317     VP56Model *model = s->modelp;
 318     int comp;
 319
 320     *vect = (VP56mv) {0,0};
 321     if (s->vector_candidate_pos < 2)
 322         *vect = s->vector_candidate[0];
 323
 324     for (comp=0; comp<2; comp++) {
 325         int i, delta = 0;
 326
 327         if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
 328             static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
 329             for (i=0; i<sizeof(prob_order); i++) {
 330                 int j = prob_order[i];
 331                 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
 332             }
 333             if (delta & 0xF0)
 334                 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
 335             else
 336                 delta |= 8;
 337         } else {
 338             delta = vp56_rac_get_tree(c, ff_vp56_pva_tree,
 339                                       model->vector_pdv[comp]);
 340         }
 341
 342         if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))
 343             delta = -delta;
 344
 345         if (!comp)
 346             vect->x += delta;
 347         else
 348             vect->y += delta;
 349     }
 350 }
 351
 352 /**
 353  * Read number of consecutive blocks with null DC or AC.
 354  * This value is < 74.
 355  */
 356 static unsigned vp6_get_nb_null(VP56Context *s)
 357 {
 358     unsigned val = get_bits(&s->gb, 2);
 359     if (val == 2)
 360         val += get_bits(&s->gb, 2);
 361     else if (val == 3) {
 362         val = get_bits1(&s->gb) << 2;
 363         val = 6+val + get_bits(&s->gb, 2+val);
 364     }
 365     return val;
 366 }
 367
 368 static void vp6_parse_coeff_huffman(VP56Context *s)
 369 {
 370     VP56Model *model = s->modelp;
 371     uint8_t *permute = s->scantable.permutated;
 372     VLC *vlc_coeff;
 373     int coeff, sign, coeff_idx;
 374     int b, cg, idx;
 375     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
 376
 377     for (b=0; b<6; b++) {
 378         int ct = 0;    /* code type */
 379         if (b > 3) pt = 1;
 380         vlc_coeff = &s->dccv_vlc[pt];
 381
 382         for (coeff_idx = 0;;) {
 383             int run = 1;
 384             if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
 385                 s->nb_null[coeff_idx][pt]--;
 386                 if (coeff_idx)
 387                     break;
 388             } else {
 389                 if (get_bits_left(&s->gb) <= 0)
 390                     return;
 391                 coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);
 392                 if (coeff == 0) {
 393                     if (coeff_idx) {
 394                         int pt = (coeff_idx >= 6);
 395                         run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);
 396                         if (run >= 9)
 397                             run += get_bits(&s->gb, 6);
 398                     } else
 399                         s->nb_null[0][pt] = vp6_get_nb_null(s);
 400                     ct = 0;
 401                 } else if (coeff == 11) {  /* end of block */
 402                     if (coeff_idx == 1)    /* first AC coeff ? */
 403                         s->nb_null[1][pt] = vp6_get_nb_null(s);
 404                     break;
 405                 } else {
 406                     int coeff2 = ff_vp56_coeff_bias[coeff];
 407                     if (coeff > 4)
 408                         coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
 409                     ct = 1 + (coeff2 > 1);
 410                     sign = get_bits1(&s->gb);
 411                     coeff2 = (coeff2 ^ -sign) + sign;
 412                     if (coeff_idx)
 413                         coeff2 *= s->dequant_ac;
 414                     idx = model->coeff_index_to_pos[coeff_idx];
 415                     s->block_coeff[b][permute[idx]] = coeff2;
 416                 }
 417             }
 418             coeff_idx+=run;
 419             if (coeff_idx >= 64)
 420                 break;
 421             cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
 422             vlc_coeff = &s->ract_vlc[pt][ct][cg];
 423         }
 424     }
 425 }
 426
 427 static void vp6_parse_coeff(VP56Context *s)
 428 {
 429     VP56RangeCoder *c = s->ccp;
 430     VP56Model *model = s->modelp;
 431     uint8_t *permute = s->scantable.permutated;
 432     uint8_t *model1, *model2, *model3;
 433     int coeff, sign, coeff_idx;
 434     int b, i, cg, idx, ctx;
 435     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
 436
 437     for (b=0; b<6; b++) {
 438         int ct = 1;    /* code type */
 439         int run = 1;
 440
 441         if (b > 3) pt = 1;
 442
 443         ctx = s->left_block[ff_vp56_b6to4[b]].not_null_dc
 444               + s->above_blocks[s->above_block_idx[b]].not_null_dc;
 445         model1 = model->coeff_dccv[pt];
 446         model2 = model->coeff_dcct[pt][ctx];
 447
 448         coeff_idx = 0;
 449         for (;;) {
 450             if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
 451                 /* parse a coeff */
 452                 if (vp56_rac_get_prob(c, model2[2])) {
 453                     if (vp56_rac_get_prob(c, model2[3])) {
 454                         idx = vp56_rac_get_tree(c, ff_vp56_pc_tree, model1);
 455                         coeff = ff_vp56_coeff_bias[idx+5];
 456                         for (i=ff_vp56_coeff_bit_length[idx]; i>=0; i--)
 457                             coeff += vp56_rac_get_prob(c, ff_vp56_coeff_parse_table[idx][i]) << i;
 458                     } else {
 459                         if (vp56_rac_get_prob(c, model2[4]))
 460                             coeff = 3 + vp56_rac_get_prob(c, model1[5]);
 461                         else
 462                             coeff = 2;
 463                     }
 464                     ct = 2;
 465                 } else {
 466                     ct = 1;
 467                     coeff = 1;
 468                 }
 469                 sign = vp56_rac_get(c);
 470                 coeff = (coeff ^ -sign) + sign;
 471                 if (coeff_idx)
 472                     coeff *= s->dequant_ac;
 473                 idx = model->coeff_index_to_pos[coeff_idx];
 474                 s->block_coeff[b][permute[idx]] = coeff;
 475                 run = 1;
 476             } else {
 477                 /* parse a run */
 478                 ct = 0;
 479                 if (coeff_idx > 0) {
 480                     if (!vp56_rac_get_prob(c, model2[1]))
 481                         break;
 482
 483                     model3 = model->coeff_runv[coeff_idx >= 6];
 484                     run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
 485                     if (!run)
 486                         for (run=9, i=0; i<6; i++)
 487                             run += vp56_rac_get_prob(c, model3[i+8]) << i;
 488                 }
 489             }
 490             coeff_idx += run;
 491             if (coeff_idx >= 64)
 492                 break;
 493             cg = vp6_coeff_groups[coeff_idx];
 494             model1 = model2 = model->coeff_ract[pt][ct][cg];
 495         }
 496
 497         s->left_block[ff_vp56_b6to4[b]].not_null_dc =
 498         s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
 499     }
 500 }
 501
 502 static int vp6_block_variance(uint8_t *src, int stride)
 503 {
 504     int sum = 0, square_sum = 0;
 505     int y, x;
 506
 507     for (y=0; y<8; y+=2) {
 508         for (x=0; x<8; x+=2) {
 509             sum += src[x];
 510             square_sum += src[x]*src[x];
 511         }
 512         src += 2*stride;
 513     }
 514     return (16*square_sum - sum*sum) >> 8;
 515 }
 516
 517 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
 518                            int delta, const int16_t *weights)
 519 {
 520     int x, y;
 521
 522     for (y=0; y<8; y++) {
 523         for (x=0; x<8; x++) {
 524             dst[x] = av_clip_uint8((  src[x-delta  ] * weights[0]
 525                                  + src[x        ] * weights[1]
 526                                  + src[x+delta  ] * weights[2]
 527                                  + src[x+2*delta] * weights[3] + 64) >> 7);
 528         }
 529         src += stride;
 530         dst += stride;
 531     }
 532 }
 533
 534 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
 535                              int stride, int h_weight, int v_weight)
 536 {
 537     uint8_t *tmp = s->edge_emu_buffer+16;
 538     s->h264chroma.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
 539     s->h264chroma.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
 540 }
 541
 542 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
 543                        int offset1, int offset2, int stride,
 544                        VP56mv mv, int mask, int select, int luma)
 545 {
 546     int filter4 = 0;
 547     int x8 = mv.x & mask;
 548     int y8 = mv.y & mask;
 549
 550     if (luma) {
 551         x8 *= 2;
 552         y8 *= 2;
 553         filter4 = s->filter_mode;
 554         if (filter4 == 2) {
 555             if (s->max_vector_length &&
 556                 (FFABS(mv.x) > s->max_vector_length ||
 557                  FFABS(mv.y) > s->max_vector_length)) {
 558                 filter4 = 0;
 559             } else if (s->sample_variance_threshold
 560                        && (vp6_block_variance(src+offset1, stride)
 561                            < s->sample_variance_threshold)) {
 562                 filter4 = 0;
 563             }
 564         }
 565     }
 566
 567     if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
 568         offset1 = offset2;
 569     }
 570
 571     if (filter4) {
 572         if (!y8) {                      /* left or right combine */
 573             vp6_filter_hv4(dst, src+offset1, stride, 1,
 574                            vp6_block_copy_filter[select][x8]);
 575         } else if (!x8) {               /* above or below combine */
 576             vp6_filter_hv4(dst, src+offset1, stride, stride,
 577                            vp6_block_copy_filter[select][y8]);
 578         } else {
 579             s->vp56dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
 580                              vp6_block_copy_filter[select][x8],
 581                              vp6_block_copy_filter[select][y8]);
 582         }
 583     } else {
 584         if (!x8 || !y8) {
 585             s->h264chroma.put_h264_chroma_pixels_tab[0](dst, src + offset1, stride, 8, x8, y8);
 586         } else {
 587             vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
 588         }
 589     }
 590 }
 591
 592 static av_cold int vp6_decode_init(AVCodecContext *avctx)
 593 {
 594     VP56Context *s = avctx->priv_data;
 595
 596     ff_vp56_init(avctx, avctx->codec->id == AV_CODEC_ID_VP6,
 597                         avctx->codec->id == AV_CODEC_ID_VP6A);
 598     s->vp56_coord_div = vp6_coord_div;
 599     s->parse_vector_adjustment = vp6_parse_vector_adjustment;
 600     s->filter = vp6_filter;
 601     s->default_models_init = vp6_default_models_init;
 602     s->parse_vector_models = vp6_parse_vector_models;
 603     s->parse_coeff_models = vp6_parse_coeff_models;
 604     s->parse_header = vp6_parse_header;
 605
 606     return 0;
 607 }
 608
 609 static av_cold int vp6_decode_free(AVCodecContext *avctx)
 610 {
 611     VP56Context *s = avctx->priv_data;
 612     int pt, ct, cg;
 613
 614     ff_vp56_free(avctx);
 615
 616     for (pt=0; pt<2; pt++) {
 617         ff_free_vlc(&s->dccv_vlc[pt]);
 618         ff_free_vlc(&s->runv_vlc[pt]);
 619         for (ct=0; ct<3; ct++)
 620             for (cg=0; cg<6; cg++)
 621                 ff_free_vlc(&s->ract_vlc[pt][ct][cg]);
 622     }
 623     return 0;
 624 }
 625
 626 AVCodec ff_vp6_decoder = {
 627     .name           = "vp6",
 628     .type           = AVMEDIA_TYPE_VIDEO,
 629     .id             = AV_CODEC_ID_VP6,
 630     .priv_data_size = sizeof(VP56Context),
 631     .init           = vp6_decode_init,
 632     .close          = vp6_decode_free,
 633     .decode         = ff_vp56_decode_frame,
 634     .capabilities   = CODEC_CAP_DR1,
 635     .long_name      = NULL_IF_CONFIG_SMALL("On2 VP6"),
 636 };
 637
 638 /* flash version, not flipped upside-down */
 639 AVCodec ff_vp6f_decoder = {
 640     .name           = "vp6f",
 641     .type           = AVMEDIA_TYPE_VIDEO,
 642     .id             = AV_CODEC_ID_VP6F,
 643     .priv_data_size = sizeof(VP56Context),
 644     .init           = vp6_decode_init,
 645     .close          = vp6_decode_free,
 646     .decode         = ff_vp56_decode_frame,
 647     .capabilities   = CODEC_CAP_DR1,
 648     .long_name      = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
 649 };
 650
 651 /* flash version, not flipped upside-down, with alpha channel */
 652 AVCodec ff_vp6a_decoder = {
 653     .name           = "vp6a",
 654     .type           = AVMEDIA_TYPE_VIDEO,
 655     .id             = AV_CODEC_ID_VP6A,
 656     .priv_data_size = sizeof(VP56Context),
 657     .init           = vp6_decode_init,
 658     .close          = vp6_decode_free,
 659     .decode         = ff_vp56_decode_frame,
 660     .capabilities   = CODEC_CAP_DR1,
 661     .long_name      = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),
 662 };