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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 #include "internal.h"
36 
37 #include "vp56.h"
38 #include "vp56data.h"
39 #include "vp6data.h"
40 
41 #define VP6_MAX_HUFF_SIZE 12
42 
43 static void vp6_parse_coeff(VP56Context *s);
44 static void vp6_parse_coeff_huffman(VP56Context *s);
45 
46 static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size)
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->frames[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
58  ff_vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
59 
60  if (s->frames[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  avpriv_report_missing_feature(s->avctx, "Interlacing");
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  if (s->avctx->extradata_size == 0 &&
88  FFALIGN(s->avctx->width, 16) == 16 * cols &&
89  FFALIGN(s->avctx->height, 16) == 16 * rows) {
90  // We assume this is properly signalled container cropping,
91  // in an F4V file. Just set the coded_width/height, don't
92  // touch the cropped ones.
93  s->avctx->coded_width = 16 * cols;
94  s->avctx->coded_height = 16 * rows;
95  } else {
96  int ret = ff_set_dimensions(s->avctx, 16 * cols, 16 * rows);
97  if (ret < 0)
98  return ret;
99 
100  if (s->avctx->extradata_size == 1) {
101  s->avctx->width -= s->avctx->extradata[0] >> 4;
102  s->avctx->height -= s->avctx->extradata[0] & 0x0F;
103  }
104  }
105  res = VP56_SIZE_CHANGE;
106  }
107 
108  ff_vp56_init_range_decoder(c, buf+6, buf_size-6);
109  vp56_rac_gets(c, 2);
110 
111  parse_filter_info = s->filter_header;
112  if (sub_version < 8)
113  vrt_shift = 5;
114  s->sub_version = sub_version;
115  s->golden_frame = 0;
116  } else {
117  if (!s->sub_version || !s->avctx->coded_width || !s->avctx->coded_height)
118  return AVERROR_INVALIDDATA;
119 
120  if (separated_coeff || !s->filter_header) {
121  coeff_offset = AV_RB16(buf+1) - 2;
122  buf += 2;
123  buf_size -= 2;
124  }
125  ff_vp56_init_range_decoder(c, buf+1, buf_size-1);
126 
127  s->golden_frame = vp56_rac_get(c);
128  if (s->filter_header) {
129  s->deblock_filtering = vp56_rac_get(c);
130  if (s->deblock_filtering)
131  vp56_rac_get(c);
132  if (s->sub_version > 7)
133  parse_filter_info = vp56_rac_get(c);
134  }
135  }
136 
137  if (parse_filter_info) {
138  if (vp56_rac_get(c)) {
139  s->filter_mode = 2;
140  s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
141  s->max_vector_length = 2 << vp56_rac_gets(c, 3);
142  } else if (vp56_rac_get(c)) {
143  s->filter_mode = 1;
144  } else {
145  s->filter_mode = 0;
146  }
147  if (s->sub_version > 7)
148  s->filter_selection = vp56_rac_gets(c, 4);
149  else
150  s->filter_selection = 16;
151  }
152 
153  s->use_huffman = vp56_rac_get(c);
154 
155  s->parse_coeff = vp6_parse_coeff;
156  if (coeff_offset) {
157  buf += coeff_offset;
158  buf_size -= coeff_offset;
159  if (buf_size < 0) {
160  if (s->frames[VP56_FRAME_CURRENT]->key_frame)
161  ff_set_dimensions(s->avctx, 0, 0);
162  return AVERROR_INVALIDDATA;
163  }
164  if (s->use_huffman) {
165  s->parse_coeff = vp6_parse_coeff_huffman;
166  init_get_bits(&s->gb, buf, buf_size<<3);
167  } else {
168  ff_vp56_init_range_decoder(&s->cc, buf, buf_size);
169  s->ccp = &s->cc;
170  }
171  } else {
172  s->ccp = &s->c;
173  }
174 
175  return res;
176 }
177 
178 static void vp6_coeff_order_table_init(VP56Context *s)
179 {
180  int i, pos, idx = 1;
181 
182  s->modelp->coeff_index_to_pos[0] = 0;
183  for (i=0; i<16; i++)
184  for (pos=1; pos<64; pos++)
185  if (s->modelp->coeff_reorder[pos] == i)
186  s->modelp->coeff_index_to_pos[idx++] = pos;
187 }
188 
189 static void vp6_default_models_init(VP56Context *s)
190 {
191  VP56Model *model = s->modelp;
192 
193  model->vector_dct[0] = 0xA2;
194  model->vector_dct[1] = 0xA4;
195  model->vector_sig[0] = 0x80;
196  model->vector_sig[1] = 0x80;
197 
198  memcpy(model->mb_types_stats, ff_vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
199  memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
200  memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
201  memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
202  memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
203 
204  vp6_coeff_order_table_init(s);
205 }
206 
207 static void vp6_parse_vector_models(VP56Context *s)
208 {
209  VP56RangeCoder *c = &s->c;
210  VP56Model *model = s->modelp;
211  int comp, node;
212 
213  for (comp=0; comp<2; comp++) {
214  if (vp56_rac_get_prob_branchy(c, vp6_sig_dct_pct[comp][0]))
215  model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
216  if (vp56_rac_get_prob_branchy(c, vp6_sig_dct_pct[comp][1]))
217  model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
218  }
219 
220  for (comp=0; comp<2; comp++)
221  for (node=0; node<7; node++)
222  if (vp56_rac_get_prob_branchy(c, vp6_pdv_pct[comp][node]))
223  model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
224 
225  for (comp=0; comp<2; comp++)
226  for (node=0; node<8; node++)
227  if (vp56_rac_get_prob_branchy(c, vp6_fdv_pct[comp][node]))
228  model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
229 }
230 
231 /* nodes must ascend by count, but with descending symbol order */
232 static int vp6_huff_cmp(const void *va, const void *vb)
233 {
234  const Node *a = va, *b = vb;
235  return (a->count - b->count)*16 + (b->sym - a->sym);
236 }
237 
238 static int vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
239  const uint8_t *map, unsigned size, VLC *vlc)
240 {
241  Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
242  int a, b, i;
243 
244  /* first compute probabilities from model */
245  tmp[0].count = 256;
246  for (i=0; i<size-1; i++) {
247  a = tmp[i].count * coeff_model[i] >> 8;
248  b = tmp[i].count * (255 - coeff_model[i]) >> 8;
249  nodes[map[2*i ]].count = a + !a;
250  nodes[map[2*i+1]].count = b + !b;
251  }
252 
253  ff_free_vlc(vlc);
254  /* then build the huffman tree according to probabilities */
255  return ff_huff_build_tree(s->avctx, vlc, size, FF_HUFFMAN_BITS,
256  nodes, vp6_huff_cmp,
257  FF_HUFFMAN_FLAG_HNODE_FIRST);
258 }
259 
260 static int vp6_parse_coeff_models(VP56Context *s)
261 {
262  VP56RangeCoder *c = &s->c;
263  VP56Model *model = s->modelp;
264  int def_prob[11];
265  int node, cg, ctx, pos;
266  int ct; /* code type */
267  int pt; /* plane type (0 for Y, 1 for U or V) */
268 
269  memset(def_prob, 0x80, sizeof(def_prob));
270 
271  for (pt=0; pt<2; pt++)
272  for (node=0; node<11; node++)
273  if (vp56_rac_get_prob_branchy(c, vp6_dccv_pct[pt][node])) {
274  def_prob[node] = vp56_rac_gets_nn(c, 7);
275  model->coeff_dccv[pt][node] = def_prob[node];
276  } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
277  model->coeff_dccv[pt][node] = def_prob[node];
278  }
279 
280  if (vp56_rac_get(c)) {
281  for (pos=1; pos<64; pos++)
282  if (vp56_rac_get_prob_branchy(c, vp6_coeff_reorder_pct[pos]))
283  model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
284  vp6_coeff_order_table_init(s);
285  }
286 
287  for (cg=0; cg<2; cg++)
288  for (node=0; node<14; node++)
289  if (vp56_rac_get_prob_branchy(c, vp6_runv_pct[cg][node]))
290  model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
291 
292  for (ct=0; ct<3; ct++)
293  for (pt=0; pt<2; pt++)
294  for (cg=0; cg<6; cg++)
295  for (node=0; node<11; node++)
296  if (vp56_rac_get_prob_branchy(c, vp6_ract_pct[ct][pt][cg][node])) {
297  def_prob[node] = vp56_rac_gets_nn(c, 7);
298  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
299  } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
300  model->coeff_ract[pt][ct][cg][node] = def_prob[node];
301  }
302 
303  if (s->use_huffman) {
304  for (pt=0; pt<2; pt++) {
305  if (vp6_build_huff_tree(s, model->coeff_dccv[pt],
306  vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]))
307  return -1;
308  if (vp6_build_huff_tree(s, model->coeff_runv[pt],
309  vp6_huff_run_map, 9, &s->runv_vlc[pt]))
310  return -1;
311  for (ct=0; ct<3; ct++)
312  for (cg = 0; cg < 6; cg++)
313  if (vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
314  vp6_huff_coeff_map, 12,
315  &s->ract_vlc[pt][ct][cg]))
316  return -1;
317  }
318  memset(s->nb_null, 0, sizeof(s->nb_null));
319  } else {
320  /* coeff_dcct is a linear combination of coeff_dccv */
321  for (pt=0; pt<2; pt++)
322  for (ctx=0; ctx<3; ctx++)
323  for (node=0; node<5; node++)
324  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);
325  }
326  return 0;
327 }
328 
329 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
330 {
331  VP56RangeCoder *c = &s->c;
332  VP56Model *model = s->modelp;
333  int comp;
334 
335  *vect = (VP56mv) {0,0};
336  if (s->vector_candidate_pos < 2)
337  *vect = s->vector_candidate[0];
338 
339  for (comp=0; comp<2; comp++) {
340  int i, delta = 0;
341 
342  if (vp56_rac_get_prob_branchy(c, model->vector_dct[comp])) {
343  static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
344  for (i=0; i<sizeof(prob_order); i++) {
345  int j = prob_order[i];
346  delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
347  }
348  if (delta & 0xF0)
349  delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
350  else
351  delta |= 8;
352  } else {
353  delta = vp56_rac_get_tree(c, ff_vp56_pva_tree,
354  model->vector_pdv[comp]);
355  }
356 
357  if (delta && vp56_rac_get_prob_branchy(c, model->vector_sig[comp]))
358  delta = -delta;
359 
360  if (!comp)
361  vect->x += delta;
362  else
363  vect->y += delta;
364  }
365 }
366 
367 /**
368  * Read number of consecutive blocks with null DC or AC.
369  * This value is < 74.
370  */
371 static unsigned vp6_get_nb_null(VP56Context *s)
372 {
373  unsigned val = get_bits(&s->gb, 2);
374  if (val == 2)
375  val += get_bits(&s->gb, 2);
376  else if (val == 3) {
377  val = get_bits1(&s->gb) << 2;
378  val = 6+val + get_bits(&s->gb, 2+val);
379  }
380  return val;
381 }
382 
383 static void vp6_parse_coeff_huffman(VP56Context *s)
384 {
385  VP56Model *model = s->modelp;
386  uint8_t *permute = s->idct_scantable;
387  VLC *vlc_coeff;
388  int coeff, sign, coeff_idx;
389  int b, cg, idx;
390  int pt = 0; /* plane type (0 for Y, 1 for U or V) */
391 
392  for (b=0; b<6; b++) {
393  int ct = 0; /* code type */
394  if (b > 3) pt = 1;
395  vlc_coeff = &s->dccv_vlc[pt];
396 
397  for (coeff_idx = 0;;) {
398  int run = 1;
399  if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
400  s->nb_null[coeff_idx][pt]--;
401  if (coeff_idx)
402  break;
403  } else {
404  if (get_bits_left(&s->gb) <= 0)
405  return;
406  coeff = get_vlc2(&s->gb, vlc_coeff->table, FF_HUFFMAN_BITS, 3);
407  if (coeff == 0) {
408  if (coeff_idx) {
409  int pt = (coeff_idx >= 6);
410  run += get_vlc2(&s->gb, s->runv_vlc[pt].table, FF_HUFFMAN_BITS, 3);
411  if (run >= 9)
412  run += get_bits(&s->gb, 6);
413  } else
414  s->nb_null[0][pt] = vp6_get_nb_null(s);
415  ct = 0;
416  } else if (coeff == 11) { /* end of block */
417  if (coeff_idx == 1) /* first AC coeff ? */
418  s->nb_null[1][pt] = vp6_get_nb_null(s);
419  break;
420  } else {
421  int coeff2 = ff_vp56_coeff_bias[coeff];
422  if (coeff > 4)
423  coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
424  ct = 1 + (coeff2 > 1);
425  sign = get_bits1(&s->gb);
426  coeff2 = (coeff2 ^ -sign) + sign;
427  if (coeff_idx)
428  coeff2 *= s->dequant_ac;
429  idx = model->coeff_index_to_pos[coeff_idx];
430  s->block_coeff[b][permute[idx]] = coeff2;
431  }
432  }
433  coeff_idx+=run;
434  if (coeff_idx >= 64)
435  break;
436  cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
437  vlc_coeff = &s->ract_vlc[pt][ct][cg];
438  }
439  }
440 }
441 
442 static void vp6_parse_coeff(VP56Context *s)
443 {
444  VP56RangeCoder *c = s->ccp;
445  VP56Model *model = s->modelp;
446  uint8_t *permute = s->idct_scantable;
447  uint8_t *model1, *model2, *model3;
448  int coeff, sign, coeff_idx;
449  int b, i, cg, idx, ctx;
450  int pt = 0; /* plane type (0 for Y, 1 for U or V) */
451 
452  for (b=0; b<6; b++) {
453  int ct = 1; /* code type */
454  int run = 1;
455 
456  if (b > 3) pt = 1;
457 
458  ctx = s->left_block[ff_vp56_b6to4[b]].not_null_dc
459  + s->above_blocks[s->above_block_idx[b]].not_null_dc;
460  model1 = model->coeff_dccv[pt];
461  model2 = model->coeff_dcct[pt][ctx];
462 
463  coeff_idx = 0;
464  for (;;) {
465  if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob_branchy(c, model2[0])) {
466  /* parse a coeff */
467  if (vp56_rac_get_prob_branchy(c, model2[2])) {
468  if (vp56_rac_get_prob_branchy(c, model2[3])) {
469  idx = vp56_rac_get_tree(c, ff_vp56_pc_tree, model1);
470  coeff = ff_vp56_coeff_bias[idx+5];
471  for (i=ff_vp56_coeff_bit_length[idx]; i>=0; i--)
472  coeff += vp56_rac_get_prob(c, ff_vp56_coeff_parse_table[idx][i]) << i;
473  } else {
474  if (vp56_rac_get_prob_branchy(c, model2[4]))
475  coeff = 3 + vp56_rac_get_prob(c, model1[5]);
476  else
477  coeff = 2;
478  }
479  ct = 2;
480  } else {
481  ct = 1;
482  coeff = 1;
483  }
484  sign = vp56_rac_get(c);
485  coeff = (coeff ^ -sign) + sign;
486  if (coeff_idx)
487  coeff *= s->dequant_ac;
488  idx = model->coeff_index_to_pos[coeff_idx];
489  s->block_coeff[b][permute[idx]] = coeff;
490  run = 1;
491  } else {
492  /* parse a run */
493  ct = 0;
494  if (coeff_idx > 0) {
495  if (!vp56_rac_get_prob_branchy(c, model2[1]))
496  break;
497 
498  model3 = model->coeff_runv[coeff_idx >= 6];
499  run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
500  if (!run)
501  for (run=9, i=0; i<6; i++)
502  run += vp56_rac_get_prob(c, model3[i+8]) << i;
503  }
504  }
505  coeff_idx += run;
506  if (coeff_idx >= 64)
507  break;
508  cg = vp6_coeff_groups[coeff_idx];
509  model1 = model2 = model->coeff_ract[pt][ct][cg];
510  }
511 
512  s->left_block[ff_vp56_b6to4[b]].not_null_dc =
513  s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
514  }
515 }
516 
517 static int vp6_block_variance(uint8_t *src, int stride)
518 {
519  int sum = 0, square_sum = 0;
520  int y, x;
521 
522  for (y=0; y<8; y+=2) {
523  for (x=0; x<8; x+=2) {
524  sum += src[x];
525  square_sum += src[x]*src[x];
526  }
527  src += 2*stride;
528  }
529  return (16*square_sum - sum*sum) >> 8;
530 }
531 
532 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
533  int delta, const int16_t *weights)
534 {
535  int x, y;
536 
537  for (y=0; y<8; y++) {
538  for (x=0; x<8; x++) {
539  dst[x] = av_clip_uint8(( src[x-delta ] * weights[0]
540  + src[x ] * weights[1]
541  + src[x+delta ] * weights[2]
542  + src[x+2*delta] * weights[3] + 64) >> 7);
543  }
544  src += stride;
545  dst += stride;
546  }
547 }
548 
549 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
550  int stride, int h_weight, int v_weight)
551 {
552  uint8_t *tmp = s->edge_emu_buffer+16;
553  s->h264chroma.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
554  s->h264chroma.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
555 }
556 
557 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
558  int offset1, int offset2, int stride,
559  VP56mv mv, int mask, int select, int luma)
560 {
561  int filter4 = 0;
562  int x8 = mv.x & mask;
563  int y8 = mv.y & mask;
564 
565  if (luma) {
566  x8 *= 2;
567  y8 *= 2;
568  filter4 = s->filter_mode;
569  if (filter4 == 2) {
570  if (s->max_vector_length &&
571  (FFABS(mv.x) > s->max_vector_length ||
572  FFABS(mv.y) > s->max_vector_length)) {
573  filter4 = 0;
574  } else if (s->sample_variance_threshold
575  && (vp6_block_variance(src+offset1, stride)
576  < s->sample_variance_threshold)) {
577  filter4 = 0;
578  }
579  }
580  }
581 
582  if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
583  offset1 = offset2;
584  }
585 
586  if (filter4) {
587  if (!y8) { /* left or right combine */
588  vp6_filter_hv4(dst, src+offset1, stride, 1,
589  vp6_block_copy_filter[select][x8]);
590  } else if (!x8) { /* above or below combine */
591  vp6_filter_hv4(dst, src+offset1, stride, stride,
592  vp6_block_copy_filter[select][y8]);
593  } else {
594  s->vp56dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
595  vp6_block_copy_filter[select][x8],
596  vp6_block_copy_filter[select][y8]);
597  }
598  } else {
599  if (!x8 || !y8) {
600  s->h264chroma.put_h264_chroma_pixels_tab[0](dst, src + offset1, stride, 8, x8, y8);
601  } else {
602  vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
603  }
604  }
605 }
606 
607 static av_cold void vp6_decode_init_context(VP56Context *s);
608 
609 static av_cold int vp6_decode_init(AVCodecContext *avctx)
610 {
611  VP56Context *s = avctx->priv_data;
612  int ret;
613 
614  if ((ret = ff_vp56_init(avctx, avctx->codec->id == AV_CODEC_ID_VP6,
615  avctx->codec->id == AV_CODEC_ID_VP6A)) < 0)
616  return ret;
617 
618  vp6_decode_init_context(s);
619 
620  if (s->has_alpha) {
621  s->alpha_context = av_mallocz(sizeof(VP56Context));
622  ff_vp56_init_context(avctx, s->alpha_context,
623  s->flip == -1, s->has_alpha);
624  vp6_decode_init_context(s->alpha_context);
625  }
626 
627  return 0;
628 }
629 
630 static av_cold void vp6_decode_init_context(VP56Context *s)
631 {
632  s->deblock_filtering = 0;
633  s->vp56_coord_div = vp6_coord_div;
634  s->parse_vector_adjustment = vp6_parse_vector_adjustment;
635  s->filter = vp6_filter;
636  s->default_models_init = vp6_default_models_init;
637  s->parse_vector_models = vp6_parse_vector_models;
638  s->parse_coeff_models = vp6_parse_coeff_models;
639  s->parse_header = vp6_parse_header;
640 }
641 
642 static av_cold void vp6_decode_free_context(VP56Context *s);
643 
644 static av_cold int vp6_decode_free(AVCodecContext *avctx)
645 {
646  VP56Context *s = avctx->priv_data;
647 
648  ff_vp56_free(avctx);
649  vp6_decode_free_context(s);
650 
651  if (s->alpha_context) {
652  ff_vp56_free_context(s->alpha_context);
653  vp6_decode_free_context(s->alpha_context);
654  av_freep(&s->alpha_context);
655  }
656 
657  return 0;
658 }
659 
660 static av_cold void vp6_decode_free_context(VP56Context *s)
661 {
662  int pt, ct, cg;
663 
664  for (pt=0; pt<2; pt++) {
665  ff_free_vlc(&s->dccv_vlc[pt]);
666  ff_free_vlc(&s->runv_vlc[pt]);
667  for (ct=0; ct<3; ct++)
668  for (cg=0; cg<6; cg++)
669  ff_free_vlc(&s->ract_vlc[pt][ct][cg]);
670  }
671 }
672 
673 AVCodec ff_vp6_decoder = {
674  .name = "vp6",
675  .long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),
676  .type = AVMEDIA_TYPE_VIDEO,
677  .id = AV_CODEC_ID_VP6,
678  .priv_data_size = sizeof(VP56Context),
679  .init = vp6_decode_init,
680  .close = vp6_decode_free,
681  .decode = ff_vp56_decode_frame,
682  .capabilities = CODEC_CAP_DR1,
683 };
684 
685 /* flash version, not flipped upside-down */
686 AVCodec ff_vp6f_decoder = {
687  .name = "vp6f",
688  .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
689  .type = AVMEDIA_TYPE_VIDEO,
690  .id = AV_CODEC_ID_VP6F,
691  .priv_data_size = sizeof(VP56Context),
692  .init = vp6_decode_init,
693  .close = vp6_decode_free,
694  .decode = ff_vp56_decode_frame,
695  .capabilities = CODEC_CAP_DR1,
696 };
697 
698 /* flash version, not flipped upside-down, with alpha channel */
699 AVCodec ff_vp6a_decoder = {
700  .name = "vp6a",
701  .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),
702  .type = AVMEDIA_TYPE_VIDEO,
703  .id = AV_CODEC_ID_VP6A,
704  .priv_data_size = sizeof(VP56Context),
705  .init = vp6_decode_init,
706  .close = vp6_decode_free,
707  .decode = ff_vp56_decode_frame,
708  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,
709 };
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