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vp6.c
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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  * 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 {
47  VP56RangeCoder *c = &s->c;
48  int parse_filter_info = 0;
49  int coeff_offset = 0;
50  int vrt_shift = 0;
51  int sub_version;
52  int rows, cols;
53  int res = 0;
54  int separated_coeff = buf[0] & 1;
55 
56  s->frames[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
57  ff_vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
58 
59  if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
60  sub_version = buf[1] >> 3;
61  if (sub_version > 8)
62  return AVERROR_INVALIDDATA;
63  s->filter_header = buf[1] & 0x06;
64  if (buf[1] & 1) {
65  avpriv_report_missing_feature(s->avctx, "Interlacing");
66  return AVERROR_PATCHWELCOME;
67  }
68  if (separated_coeff || !s->filter_header) {
69  coeff_offset = AV_RB16(buf+2) - 2;
70  buf += 2;
71  buf_size -= 2;
72  }
73 
74  rows = buf[2]; /* number of stored macroblock rows */
75  cols = buf[3]; /* number of stored macroblock cols */
76  /* buf[4] is number of displayed macroblock rows */
77  /* buf[5] is number of displayed macroblock cols */
78  if (!rows || !cols) {
79  av_log(s->avctx, AV_LOG_ERROR, "Invalid size %dx%d\n", cols << 4, rows << 4);
80  return AVERROR_INVALIDDATA;
81  }
82 
83  if (!s->macroblocks || /* first frame */
84  16*cols != s->avctx->coded_width ||
85  16*rows != s->avctx->coded_height) {
86  if (s->avctx->extradata_size == 0 &&
87  FFALIGN(s->avctx->width, 16) == 16 * cols &&
88  FFALIGN(s->avctx->height, 16) == 16 * rows) {
89  // We assume this is properly signalled container cropping,
90  // in an F4V file. Just set the coded_width/height, don't
91  // touch the cropped ones.
92  s->avctx->coded_width = 16 * cols;
93  s->avctx->coded_height = 16 * rows;
94  } else {
95  avcodec_set_dimensions(s->avctx, 16 * cols, 16 * rows);
96  if (s->avctx->extradata_size == 1) {
97  s->avctx->width -= s->avctx->extradata[0] >> 4;
98  s->avctx->height -= s->avctx->extradata[0] & 0x0F;
99  }
100  }
101  res = VP56_SIZE_CHANGE;
102  }
103 
104  ff_vp56_init_range_decoder(c, buf+6, buf_size-6);
105  vp56_rac_gets(c, 2);
106 
107  parse_filter_info = s->filter_header;
108  if (sub_version < 8)
109  vrt_shift = 5;
110  s->sub_version = sub_version;
111  s->golden_frame = 0;
112  } else {
113  if (!s->sub_version || !s->avctx->coded_width || !s->avctx->coded_height)
114  return AVERROR_INVALIDDATA;
115 
116  if (separated_coeff || !s->filter_header) {
117  coeff_offset = AV_RB16(buf+1) - 2;
118  buf += 2;
119  buf_size -= 2;
120  }
121  ff_vp56_init_range_decoder(c, buf+1, buf_size-1);
122 
123  s->golden_frame = vp56_rac_get(c);
124  if (s->filter_header) {
125  s->deblock_filtering = vp56_rac_get(c);
126  if (s->deblock_filtering)
127  vp56_rac_get(c);
128  if (s->sub_version > 7)
129  parse_filter_info = vp56_rac_get(c);
130  }
131  }
132 
133  if (parse_filter_info) {
134  if (vp56_rac_get(c)) {
135  s->filter_mode = 2;
136  s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
137  s->max_vector_length = 2 << vp56_rac_gets(c, 3);
138  } else if (vp56_rac_get(c)) {
139  s->filter_mode = 1;
140  } else {
141  s->filter_mode = 0;
142  }
143  if (s->sub_version > 7)
144  s->filter_selection = vp56_rac_gets(c, 4);
145  else
146  s->filter_selection = 16;
147  }
148 
149  s->use_huffman = vp56_rac_get(c);
150 
151  s->parse_coeff = vp6_parse_coeff;
152  if (coeff_offset) {
153  buf += coeff_offset;
154  buf_size -= coeff_offset;
155  if (buf_size < 0) {
156  if (s->frames[VP56_FRAME_CURRENT]->key_frame)
157  avcodec_set_dimensions(s->avctx, 0, 0);
158  return AVERROR_INVALIDDATA;
159  }
160  if (s->use_huffman) {
161  s->parse_coeff = vp6_parse_coeff_huffman;
162  init_get_bits(&s->gb, buf, buf_size<<3);
163  } else {
164  ff_vp56_init_range_decoder(&s->cc, buf, buf_size);
165  s->ccp = &s->cc;
166  }
167  } else {
168  s->ccp = &s->c;
169  }
170 
171  return res;
172 }
173 
174 static void vp6_coeff_order_table_init(VP56Context *s)
175 {
176  int i, pos, idx = 1;
177 
178  s->modelp->coeff_index_to_pos[0] = 0;
179  for (i=0; i<16; i++)
180  for (pos=1; pos<64; pos++)
181  if (s->modelp->coeff_reorder[pos] == i)
182  s->modelp->coeff_index_to_pos[idx++] = pos;
183 }
184 
185 static void vp6_default_models_init(VP56Context *s)
186 {
187  VP56Model *model = s->modelp;
188 
189  model->vector_dct[0] = 0xA2;
190  model->vector_dct[1] = 0xA4;
191  model->vector_sig[0] = 0x80;
192  model->vector_sig[1] = 0x80;
193 
194  memcpy(model->mb_types_stats, ff_vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
195  memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
196  memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
197  memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
198  memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
199 
200  vp6_coeff_order_table_init(s);
201 }
202 
203 static void vp6_parse_vector_models(VP56Context *s)
204 {
205  VP56RangeCoder *c = &s->c;
206  VP56Model *model = s->modelp;
207  int comp, node;
208 
209  for (comp=0; comp<2; comp++) {
210  if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))
211  model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
212  if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))
213  model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
214  }
215 
216  for (comp=0; comp<2; comp++)
217  for (node=0; node<7; node++)
218  if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))
219  model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
220 
221  for (comp=0; comp<2; comp++)
222  for (node=0; node<8; node++)
223  if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
224  model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
225 }
226 
227 /* nodes must ascend by count, but with descending symbol order */
228 static int vp6_huff_cmp(const void *va, const void *vb)
229 {
230  const Node *a = va, *b = vb;
231  return (a->count - b->count)*16 + (b->sym - a->sym);
232 }
233 
234 static int vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
235  const uint8_t *map, unsigned size, VLC *vlc)
236 {
237  Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
238  int a, b, i;
239 
240  /* first compute probabilities from model */
241  tmp[0].count = 256;
242  for (i=0; i<size-1; i++) {
243  a = tmp[i].count * coeff_model[i] >> 8;
244  b = tmp[i].count * (255 - coeff_model[i]) >> 8;
245  nodes[map[2*i ]].count = a + !a;
246  nodes[map[2*i+1]].count = b + !b;
247  }
248 
249  ff_free_vlc(vlc);
250  /* then build the huffman tree according to probabilities */
251  return ff_huff_build_tree(s->avctx, vlc, size, FF_HUFFMAN_BITS,
252  nodes, vp6_huff_cmp,
253  FF_HUFFMAN_FLAG_HNODE_FIRST);
254 }
255 
256 static int vp6_parse_coeff_models(VP56Context *s)
257 {
258  VP56RangeCoder *c = &s->c;
259  VP56Model *model = s->modelp;
260  int def_prob[11];
261  int node, cg, ctx, pos;
262  int ct; /* code type */
263  int pt; /* plane type (0 for Y, 1 for U or V) */
264 
265  memset(def_prob, 0x80, sizeof(def_prob));
266 
267  for (pt=0; pt<2; pt++)
268  for (node=0; node<11; node++)
269  if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {
270  def_prob[node] = vp56_rac_gets_nn(c, 7);
271  model->coeff_dccv[pt][node] = def_prob[node];
272  } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
273  model->coeff_dccv[pt][node] = def_prob[node];
274  }
275 
276  if (vp56_rac_get(c)) {
277  for (pos=1; pos<64; pos++)
278  if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
279  model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
280  vp6_coeff_order_table_init(s);
281  }
282 
283  for (cg=0; cg<2; cg++)
284  for (node=0; node<14; node++)
285  if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
286  model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
287 
288  for (ct=0; ct<3; ct++)
289  for (pt=0; pt<2; pt++)
290  for (cg=0; cg<6; cg++)
291  for (node=0; node<11; node++)
292  if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
293  def_prob[node] = vp56_rac_gets_nn(c, 7);
294  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
295  } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
296  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
297  }
298 
299  if (s->use_huffman) {
300  for (pt=0; pt<2; pt++) {
301  if (vp6_build_huff_tree(s, model->coeff_dccv[pt],
302  vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]))
303  return -1;
304  if (vp6_build_huff_tree(s, model->coeff_runv[pt],
305  vp6_huff_run_map, 9, &s->runv_vlc[pt]))
306  return -1;
307  for (ct=0; ct<3; ct++)
308  for (cg = 0; cg < 6; cg++)
309  if (vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
310  vp6_huff_coeff_map, 12,
311  &s->ract_vlc[pt][ct][cg]))
312  return -1;
313  }
314  memset(s->nb_null, 0, sizeof(s->nb_null));
315  } else {
316  /* coeff_dcct is a linear combination of coeff_dccv */
317  for (pt=0; pt<2; pt++)
318  for (ctx=0; ctx<3; ctx++)
319  for (node=0; node<5; node++)
320  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);
321  }
322  return 0;
323 }
324 
325 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
326 {
327  VP56RangeCoder *c = &s->c;
328  VP56Model *model = s->modelp;
329  int comp;
330 
331  *vect = (VP56mv) {0,0};
332  if (s->vector_candidate_pos < 2)
333  *vect = s->vector_candidate[0];
334 
335  for (comp=0; comp<2; comp++) {
336  int i, delta = 0;
337 
338  if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
339  static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
340  for (i=0; i<sizeof(prob_order); i++) {
341  int j = prob_order[i];
342  delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
343  }
344  if (delta & 0xF0)
345  delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
346  else
347  delta |= 8;
348  } else {
349  delta = vp56_rac_get_tree(c, ff_vp56_pva_tree,
350  model->vector_pdv[comp]);
351  }
352 
353  if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))
354  delta = -delta;
355 
356  if (!comp)
357  vect->x += delta;
358  else
359  vect->y += delta;
360  }
361 }
362 
363 /**
364  * Read number of consecutive blocks with null DC or AC.
365  * This value is < 74.
366  */
367 static unsigned vp6_get_nb_null(VP56Context *s)
368 {
369  unsigned val = get_bits(&s->gb, 2);
370  if (val == 2)
371  val += get_bits(&s->gb, 2);
372  else if (val == 3) {
373  val = get_bits1(&s->gb) << 2;
374  val = 6+val + get_bits(&s->gb, 2+val);
375  }
376  return val;
377 }
378 
379 static void vp6_parse_coeff_huffman(VP56Context *s)
380 {
381  VP56Model *model = s->modelp;
382  uint8_t *permute = s->idct_scantable;
383  VLC *vlc_coeff;
384  int coeff, sign, coeff_idx;
385  int b, cg, idx;
386  int pt = 0; /* plane type (0 for Y, 1 for U or V) */
387 
388  for (b=0; b<6; b++) {
389  int ct = 0; /* code type */
390  if (b > 3) pt = 1;
391  vlc_coeff = &s->dccv_vlc[pt];
392 
393  for (coeff_idx = 0;;) {
394  int run = 1;
395  if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
396  s->nb_null[coeff_idx][pt]--;
397  if (coeff_idx)
398  break;
399  } else {
400  if (get_bits_left(&s->gb) <= 0)
401  return;
402  coeff = get_vlc2(&s->gb, vlc_coeff->table, FF_HUFFMAN_BITS, 3);
403  if (coeff == 0) {
404  if (coeff_idx) {
405  int pt = (coeff_idx >= 6);
406  run += get_vlc2(&s->gb, s->runv_vlc[pt].table, FF_HUFFMAN_BITS, 3);
407  if (run >= 9)
408  run += get_bits(&s->gb, 6);
409  } else
410  s->nb_null[0][pt] = vp6_get_nb_null(s);
411  ct = 0;
412  } else if (coeff == 11) { /* end of block */
413  if (coeff_idx == 1) /* first AC coeff ? */
414  s->nb_null[1][pt] = vp6_get_nb_null(s);
415  break;
416  } else {
417  int coeff2 = ff_vp56_coeff_bias[coeff];
418  if (coeff > 4)
419  coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
420  ct = 1 + (coeff2 > 1);
421  sign = get_bits1(&s->gb);
422  coeff2 = (coeff2 ^ -sign) + sign;
423  if (coeff_idx)
424  coeff2 *= s->dequant_ac;
425  idx = model->coeff_index_to_pos[coeff_idx];
426  s->block_coeff[b][permute[idx]] = coeff2;
427  }
428  }
429  coeff_idx+=run;
430  if (coeff_idx >= 64)
431  break;
432  cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
433  vlc_coeff = &s->ract_vlc[pt][ct][cg];
434  }
435  }
436 }
437 
438 static void vp6_parse_coeff(VP56Context *s)
439 {
440  VP56RangeCoder *c = s->ccp;
441  VP56Model *model = s->modelp;
442  uint8_t *permute = s->idct_scantable;
443  uint8_t *model1, *model2, *model3;
444  int coeff, sign, coeff_idx;
445  int b, i, cg, idx, ctx;
446  int pt = 0; /* plane type (0 for Y, 1 for U or V) */
447 
448  for (b=0; b<6; b++) {
449  int ct = 1; /* code type */
450  int run = 1;
451 
452  if (b > 3) pt = 1;
453 
454  ctx = s->left_block[ff_vp56_b6to4[b]].not_null_dc
455  + s->above_blocks[s->above_block_idx[b]].not_null_dc;
456  model1 = model->coeff_dccv[pt];
457  model2 = model->coeff_dcct[pt][ctx];
458 
459  coeff_idx = 0;
460  for (;;) {
461  if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
462  /* parse a coeff */
463  if (vp56_rac_get_prob(c, model2[2])) {
464  if (vp56_rac_get_prob(c, model2[3])) {
465  idx = vp56_rac_get_tree(c, ff_vp56_pc_tree, model1);
466  coeff = ff_vp56_coeff_bias[idx+5];
467  for (i=ff_vp56_coeff_bit_length[idx]; i>=0; i--)
468  coeff += vp56_rac_get_prob(c, ff_vp56_coeff_parse_table[idx][i]) << i;
469  } else {
470  if (vp56_rac_get_prob(c, model2[4]))
471  coeff = 3 + vp56_rac_get_prob(c, model1[5]);
472  else
473  coeff = 2;
474  }
475  ct = 2;
476  } else {
477  ct = 1;
478  coeff = 1;
479  }
480  sign = vp56_rac_get(c);
481  coeff = (coeff ^ -sign) + sign;
482  if (coeff_idx)
483  coeff *= s->dequant_ac;
484  idx = model->coeff_index_to_pos[coeff_idx];
485  s->block_coeff[b][permute[idx]] = coeff;
486  run = 1;
487  } else {
488  /* parse a run */
489  ct = 0;
490  if (coeff_idx > 0) {
491  if (!vp56_rac_get_prob(c, model2[1]))
492  break;
493 
494  model3 = model->coeff_runv[coeff_idx >= 6];
495  run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
496  if (!run)
497  for (run=9, i=0; i<6; i++)
498  run += vp56_rac_get_prob(c, model3[i+8]) << i;
499  }
500  }
501  coeff_idx += run;
502  if (coeff_idx >= 64)
503  break;
504  cg = vp6_coeff_groups[coeff_idx];
505  model1 = model2 = model->coeff_ract[pt][ct][cg];
506  }
507 
508  s->left_block[ff_vp56_b6to4[b]].not_null_dc =
509  s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
510  }
511 }
512 
513 static int vp6_block_variance(uint8_t *src, int stride)
514 {
515  int sum = 0, square_sum = 0;
516  int y, x;
517 
518  for (y=0; y<8; y+=2) {
519  for (x=0; x<8; x+=2) {
520  sum += src[x];
521  square_sum += src[x]*src[x];
522  }
523  src += 2*stride;
524  }
525  return (16*square_sum - sum*sum) >> 8;
526 }
527 
528 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
529  int delta, const int16_t *weights)
530 {
531  int x, y;
532 
533  for (y=0; y<8; y++) {
534  for (x=0; x<8; x++) {
535  dst[x] = av_clip_uint8(( src[x-delta ] * weights[0]
536  + src[x ] * weights[1]
537  + src[x+delta ] * weights[2]
538  + src[x+2*delta] * weights[3] + 64) >> 7);
539  }
540  src += stride;
541  dst += stride;
542  }
543 }
544 
545 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
546  int stride, int h_weight, int v_weight)
547 {
548  uint8_t *tmp = s->edge_emu_buffer+16;
549  s->h264chroma.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
550  s->h264chroma.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
551 }
552 
553 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
554  int offset1, int offset2, int stride,
555  VP56mv mv, int mask, int select, int luma)
556 {
557  int filter4 = 0;
558  int x8 = mv.x & mask;
559  int y8 = mv.y & mask;
560 
561  if (luma) {
562  x8 *= 2;
563  y8 *= 2;
564  filter4 = s->filter_mode;
565  if (filter4 == 2) {
566  if (s->max_vector_length &&
567  (FFABS(mv.x) > s->max_vector_length ||
568  FFABS(mv.y) > s->max_vector_length)) {
569  filter4 = 0;
570  } else if (s->sample_variance_threshold
571  && (vp6_block_variance(src+offset1, stride)
572  < s->sample_variance_threshold)) {
573  filter4 = 0;
574  }
575  }
576  }
577 
578  if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
579  offset1 = offset2;
580  }
581 
582  if (filter4) {
583  if (!y8) { /* left or right combine */
584  vp6_filter_hv4(dst, src+offset1, stride, 1,
585  vp6_block_copy_filter[select][x8]);
586  } else if (!x8) { /* above or below combine */
587  vp6_filter_hv4(dst, src+offset1, stride, stride,
588  vp6_block_copy_filter[select][y8]);
589  } else {
590  s->vp56dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
591  vp6_block_copy_filter[select][x8],
592  vp6_block_copy_filter[select][y8]);
593  }
594  } else {
595  if (!x8 || !y8) {
596  s->h264chroma.put_h264_chroma_pixels_tab[0](dst, src + offset1, stride, 8, x8, y8);
597  } else {
598  vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
599  }
600  }
601 }
602 
603 static av_cold void vp6_decode_init_context(VP56Context *s);
604 
605 static av_cold int vp6_decode_init(AVCodecContext *avctx)
606 {
607  VP56Context *s = avctx->priv_data;
608  int ret;
609 
610  if ((ret = ff_vp56_init(avctx, avctx->codec->id == AV_CODEC_ID_VP6,
611  avctx->codec->id == AV_CODEC_ID_VP6A)) < 0)
612  return ret;
613 
614  vp6_decode_init_context(s);
615 
616  if (s->has_alpha) {
617  s->alpha_context = av_mallocz(sizeof(VP56Context));
618  ff_vp56_init_context(avctx, s->alpha_context,
619  s->flip == -1, s->has_alpha);
620  vp6_decode_init_context(s->alpha_context);
621  }
622 
623  return 0;
624 }
625 
626 static av_cold void vp6_decode_init_context(VP56Context *s)
627 {
628  s->deblock_filtering = 0;
629  s->vp56_coord_div = vp6_coord_div;
630  s->parse_vector_adjustment = vp6_parse_vector_adjustment;
631  s->filter = vp6_filter;
632  s->default_models_init = vp6_default_models_init;
633  s->parse_vector_models = vp6_parse_vector_models;
634  s->parse_coeff_models = vp6_parse_coeff_models;
635  s->parse_header = vp6_parse_header;
636 }
637 
638 static av_cold void vp6_decode_free_context(VP56Context *s);
639 
640 static av_cold int vp6_decode_free(AVCodecContext *avctx)
641 {
642  VP56Context *s = avctx->priv_data;
643 
644  ff_vp56_free(avctx);
645  vp6_decode_free_context(s);
646 
647  if (s->alpha_context) {
648  ff_vp56_free_context(s->alpha_context);
649  vp6_decode_free_context(s->alpha_context);
650  av_free(s->alpha_context);
651  }
652 
653  return 0;
654 }
655 
656 static av_cold void vp6_decode_free_context(VP56Context *s)
657 {
658  int pt, ct, cg;
659 
660  for (pt=0; pt<2; pt++) {
661  ff_free_vlc(&s->dccv_vlc[pt]);
662  ff_free_vlc(&s->runv_vlc[pt]);
663  for (ct=0; ct<3; ct++)
664  for (cg=0; cg<6; cg++)
665  ff_free_vlc(&s->ract_vlc[pt][ct][cg]);
666  }
667 }
668 
669 AVCodec ff_vp6_decoder = {
670  .name = "vp6",
671  .long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),
672  .type = AVMEDIA_TYPE_VIDEO,
673  .id = AV_CODEC_ID_VP6,
674  .priv_data_size = sizeof(VP56Context),
675  .init = vp6_decode_init,
676  .close = vp6_decode_free,
677  .decode = ff_vp56_decode_frame,
678  .capabilities = CODEC_CAP_DR1,
679 };
680 
681 /* flash version, not flipped upside-down */
682 AVCodec ff_vp6f_decoder = {
683  .name = "vp6f",
684  .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
685  .type = AVMEDIA_TYPE_VIDEO,
686  .id = AV_CODEC_ID_VP6F,
687  .priv_data_size = sizeof(VP56Context),
688  .init = vp6_decode_init,
689  .close = vp6_decode_free,
690  .decode = ff_vp56_decode_frame,
691  .capabilities = CODEC_CAP_DR1,
692 };
693 
694 /* flash version, not flipped upside-down, with alpha channel */
695 AVCodec ff_vp6a_decoder = {
696  .name = "vp6a",
697  .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),
698  .type = AVMEDIA_TYPE_VIDEO,
699  .id = AV_CODEC_ID_VP6A,
700  .priv_data_size = sizeof(VP56Context),
701  .init = vp6_decode_init,
702  .close = vp6_decode_free,
703  .decode = ff_vp56_decode_frame,
704  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,
705 };
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