FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vp56.c
Go to the documentation of this file.
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 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "internal.h"
29 #include "h264chroma.h"
30 #include "vp56.h"
31 #include "vp56data.h"
32 
33 
34 void ff_vp56_init_dequant(VP56Context *s, int quantizer)
35 {
36  s->quantizer = quantizer;
37  s->dequant_dc = ff_vp56_dc_dequant[quantizer] << 2;
38  s->dequant_ac = ff_vp56_ac_dequant[quantizer] << 2;
39 }
40 
41 static int vp56_get_vectors_predictors(VP56Context *s, int row, int col,
43 {
44  int nb_pred = 0;
45  VP56mv vect[2] = {{0,0}, {0,0}};
46  int pos, offset;
47  VP56mv mvp;
48 
49  for (pos=0; pos<12; pos++) {
50  mvp.x = col + ff_vp56_candidate_predictor_pos[pos][0];
51  mvp.y = row + ff_vp56_candidate_predictor_pos[pos][1];
52  if (mvp.x < 0 || mvp.x >= s->mb_width ||
53  mvp.y < 0 || mvp.y >= s->mb_height)
54  continue;
55  offset = mvp.x + s->mb_width*mvp.y;
56 
57  if (ff_vp56_reference_frame[s->macroblocks[offset].type] != ref_frame)
58  continue;
59  if ((s->macroblocks[offset].mv.x == vect[0].x &&
60  s->macroblocks[offset].mv.y == vect[0].y) ||
61  (s->macroblocks[offset].mv.x == 0 &&
62  s->macroblocks[offset].mv.y == 0))
63  continue;
64 
65  vect[nb_pred++] = s->macroblocks[offset].mv;
66  if (nb_pred > 1) {
67  nb_pred = -1;
68  break;
69  }
70  s->vector_candidate_pos = pos;
71  }
72 
73  s->vector_candidate[0] = vect[0];
74  s->vector_candidate[1] = vect[1];
75 
76  return nb_pred+1;
77 }
78 
79 static void vp56_parse_mb_type_models(VP56Context *s)
80 {
81  VP56RangeCoder *c = &s->c;
82  VP56Model *model = s->modelp;
83  int i, ctx, type;
84 
85  for (ctx=0; ctx<3; ctx++) {
86  if (vp56_rac_get_prob(c, 174)) {
87  int idx = vp56_rac_gets(c, 4);
88  memcpy(model->mb_types_stats[ctx],
90  sizeof(model->mb_types_stats[ctx]));
91  }
92  if (vp56_rac_get_prob(c, 254)) {
93  for (type=0; type<10; type++) {
94  for(i=0; i<2; i++) {
95  if (vp56_rac_get_prob(c, 205)) {
96  int delta, sign = vp56_rac_get(c);
97 
100  if (!delta)
101  delta = 4 * vp56_rac_gets(c, 7);
102  model->mb_types_stats[ctx][type][i] += (delta ^ -sign) + sign;
103  }
104  }
105  }
106  }
107  }
108 
109  /* compute MB type probability tables based on previous MB type */
110  for (ctx=0; ctx<3; ctx++) {
111  int p[10];
112 
113  for (type=0; type<10; type++)
114  p[type] = 100 * model->mb_types_stats[ctx][type][1];
115 
116  for (type=0; type<10; type++) {
117  int p02, p34, p0234, p17, p56, p89, p5689, p156789;
118 
119  /* conservative MB type probability */
120  model->mb_type[ctx][type][0] = 255 - (255 * model->mb_types_stats[ctx][type][0]) / (1 + model->mb_types_stats[ctx][type][0] + model->mb_types_stats[ctx][type][1]);
121 
122  p[type] = 0; /* same MB type => weight is null */
123 
124  /* binary tree parsing probabilities */
125  p02 = p[0] + p[2];
126  p34 = p[3] + p[4];
127  p0234 = p02 + p34;
128  p17 = p[1] + p[7];
129  p56 = p[5] + p[6];
130  p89 = p[8] + p[9];
131  p5689 = p56 + p89;
132  p156789 = p17 + p5689;
133 
134  model->mb_type[ctx][type][1] = 1 + 255 * p0234/(1+p0234+p156789);
135  model->mb_type[ctx][type][2] = 1 + 255 * p02 / (1+p0234);
136  model->mb_type[ctx][type][3] = 1 + 255 * p17 / (1+p156789);
137  model->mb_type[ctx][type][4] = 1 + 255 * p[0] / (1+p02);
138  model->mb_type[ctx][type][5] = 1 + 255 * p[3] / (1+p34);
139  model->mb_type[ctx][type][6] = 1 + 255 * p[1] / (1+p17);
140  model->mb_type[ctx][type][7] = 1 + 255 * p56 / (1+p5689);
141  model->mb_type[ctx][type][8] = 1 + 255 * p[5] / (1+p56);
142  model->mb_type[ctx][type][9] = 1 + 255 * p[8] / (1+p89);
143 
144  /* restore initial value */
145  p[type] = 100 * model->mb_types_stats[ctx][type][1];
146  }
147  }
148 }
149 
150 static VP56mb vp56_parse_mb_type(VP56Context *s,
151  VP56mb prev_type, int ctx)
152 {
153  uint8_t *mb_type_model = s->modelp->mb_type[ctx][prev_type];
154  VP56RangeCoder *c = &s->c;
155 
156  if (vp56_rac_get_prob(c, mb_type_model[0]))
157  return prev_type;
158  else
159  return vp56_rac_get_tree(c, ff_vp56_pmbt_tree, mb_type_model);
160 }
161 
162 static void vp56_decode_4mv(VP56Context *s, int row, int col)
163 {
164  VP56mv mv = {0,0};
165  int type[4];
166  int b;
167 
168  /* parse each block type */
169  for (b=0; b<4; b++) {
170  type[b] = vp56_rac_gets(&s->c, 2);
171  if (type[b])
172  type[b]++; /* only returns 0, 2, 3 or 4 (all INTER_PF) */
173  }
174 
175  /* get vectors */
176  for (b=0; b<4; b++) {
177  switch (type[b]) {
179  s->mv[b] = (VP56mv) {0,0};
180  break;
182  s->parse_vector_adjustment(s, &s->mv[b]);
183  break;
184  case VP56_MB_INTER_V1_PF:
185  s->mv[b] = s->vector_candidate[0];
186  break;
187  case VP56_MB_INTER_V2_PF:
188  s->mv[b] = s->vector_candidate[1];
189  break;
190  }
191  mv.x += s->mv[b].x;
192  mv.y += s->mv[b].y;
193  }
194 
195  /* this is the one selected for the whole MB for prediction */
196  s->macroblocks[row * s->mb_width + col].mv = s->mv[3];
197 
198  /* chroma vectors are average luma vectors */
199  if (s->avctx->codec->id == AV_CODEC_ID_VP5) {
200  s->mv[4].x = s->mv[5].x = RSHIFT(mv.x,2);
201  s->mv[4].y = s->mv[5].y = RSHIFT(mv.y,2);
202  } else {
203  s->mv[4] = s->mv[5] = (VP56mv) {mv.x/4, mv.y/4};
204  }
205 }
206 
207 static VP56mb vp56_decode_mv(VP56Context *s, int row, int col)
208 {
209  VP56mv *mv, vect = {0,0};
210  int ctx, b;
211 
213  s->mb_type = vp56_parse_mb_type(s, s->mb_type, ctx);
214  s->macroblocks[row * s->mb_width + col].type = s->mb_type;
215 
216  switch (s->mb_type) {
217  case VP56_MB_INTER_V1_PF:
218  mv = &s->vector_candidate[0];
219  break;
220 
221  case VP56_MB_INTER_V2_PF:
222  mv = &s->vector_candidate[1];
223  break;
224 
225  case VP56_MB_INTER_V1_GF:
227  mv = &s->vector_candidate[0];
228  break;
229 
230  case VP56_MB_INTER_V2_GF:
232  mv = &s->vector_candidate[1];
233  break;
234 
236  s->parse_vector_adjustment(s, &vect);
237  mv = &vect;
238  break;
239 
242  s->parse_vector_adjustment(s, &vect);
243  mv = &vect;
244  break;
245 
246  case VP56_MB_INTER_4V:
247  vp56_decode_4mv(s, row, col);
248  return s->mb_type;
249 
250  default:
251  mv = &vect;
252  break;
253  }
254 
255  s->macroblocks[row*s->mb_width + col].mv = *mv;
256 
257  /* same vector for all blocks */
258  for (b=0; b<6; b++)
259  s->mv[b] = *mv;
260 
261  return s->mb_type;
262 }
263 
264 static void vp56_add_predictors_dc(VP56Context *s, VP56Frame ref_frame)
265 {
266  int idx = s->idct_scantable[0];
267  int b;
268 
269  for (b=0; b<6; b++) {
270  VP56RefDc *ab = &s->above_blocks[s->above_block_idx[b]];
271  VP56RefDc *lb = &s->left_block[ff_vp56_b6to4[b]];
272  int count = 0;
273  int dc = 0;
274  int i;
275 
276  if (ref_frame == lb->ref_frame) {
277  dc += lb->dc_coeff;
278  count++;
279  }
280  if (ref_frame == ab->ref_frame) {
281  dc += ab->dc_coeff;
282  count++;
283  }
284  if (s->avctx->codec->id == AV_CODEC_ID_VP5)
285  for (i=0; i<2; i++)
286  if (count < 2 && ref_frame == ab[-1+2*i].ref_frame) {
287  dc += ab[-1+2*i].dc_coeff;
288  count++;
289  }
290  if (count == 0)
291  dc = s->prev_dc[ff_vp56_b2p[b]][ref_frame];
292  else if (count == 2)
293  dc /= 2;
294 
295  s->block_coeff[b][idx] += dc;
296  s->prev_dc[ff_vp56_b2p[b]][ref_frame] = s->block_coeff[b][idx];
297  ab->dc_coeff = s->block_coeff[b][idx];
298  ab->ref_frame = ref_frame;
299  lb->dc_coeff = s->block_coeff[b][idx];
300  lb->ref_frame = ref_frame;
301  s->block_coeff[b][idx] *= s->dequant_dc;
302  }
303 }
304 
305 static void vp56_deblock_filter(VP56Context *s, uint8_t *yuv,
306  ptrdiff_t stride, int dx, int dy)
307 {
308  int t = ff_vp56_filter_threshold[s->quantizer];
309  if (dx) s->vp56dsp.edge_filter_hor(yuv + 10-dx , stride, t);
310  if (dy) s->vp56dsp.edge_filter_ver(yuv + stride*(10-dy), stride, t);
311 }
312 
313 static void vp56_mc(VP56Context *s, int b, int plane, uint8_t *src,
314  ptrdiff_t stride, int x, int y)
315 {
316  uint8_t *dst = s->frames[VP56_FRAME_CURRENT]->data[plane] + s->block_offset[b];
317  uint8_t *src_block;
318  int src_offset;
319  int overlap_offset = 0;
320  int mask = s->vp56_coord_div[b] - 1;
321  int deblock_filtering = s->deblock_filtering;
322  int dx;
323  int dy;
324 
325  if (s->avctx->skip_loop_filter >= AVDISCARD_ALL ||
326  (s->avctx->skip_loop_filter >= AVDISCARD_NONKEY
327  && !s->frames[VP56_FRAME_CURRENT]->key_frame))
328  deblock_filtering = 0;
329 
330  dx = s->mv[b].x / s->vp56_coord_div[b];
331  dy = s->mv[b].y / s->vp56_coord_div[b];
332 
333  if (b >= 4) {
334  x /= 2;
335  y /= 2;
336  }
337  x += dx - 2;
338  y += dy - 2;
339 
340  if (x<0 || x+12>=s->plane_width[plane] ||
341  y<0 || y+12>=s->plane_height[plane]) {
342  s->vdsp.emulated_edge_mc(s->edge_emu_buffer, stride,
343  src + s->block_offset[b] + (dy-2)*stride + (dx-2),
344  stride, 12, 12, x, y,
345  s->plane_width[plane],
346  s->plane_height[plane]);
347  src_block = s->edge_emu_buffer;
348  src_offset = 2 + 2*stride;
349  } else if (deblock_filtering) {
350  /* only need a 12x12 block, but there is no such dsp function, */
351  /* so copy a 16x12 block */
352  s->hdsp.put_pixels_tab[0][0](s->edge_emu_buffer,
353  src + s->block_offset[b] + (dy-2)*stride + (dx-2),
354  stride, 12);
355  src_block = s->edge_emu_buffer;
356  src_offset = 2 + 2*stride;
357  } else {
358  src_block = src;
359  src_offset = s->block_offset[b] + dy*stride + dx;
360  }
361 
362  if (deblock_filtering)
363  vp56_deblock_filter(s, src_block, stride, dx&7, dy&7);
364 
365  if (s->mv[b].x & mask)
366  overlap_offset += (s->mv[b].x > 0) ? 1 : -1;
367  if (s->mv[b].y & mask)
368  overlap_offset += (s->mv[b].y > 0) ? stride : -stride;
369 
370  if (overlap_offset) {
371  if (s->filter)
372  s->filter(s, dst, src_block, src_offset, src_offset+overlap_offset,
373  stride, s->mv[b], mask, s->filter_selection, b<4);
374  else
375  s->vp3dsp.put_no_rnd_pixels_l2(dst, src_block+src_offset,
376  src_block+src_offset+overlap_offset,
377  stride, 8);
378  } else {
379  s->hdsp.put_pixels_tab[1][0](dst, src_block+src_offset, stride, 8);
380  }
381 }
382 
383 static void vp56_decode_mb(VP56Context *s, int row, int col, int is_alpha)
384 {
385  AVFrame *frame_current, *frame_ref;
386  VP56mb mb_type;
388  int b, ab, b_max, plane, off;
389 
390  if (s->frames[VP56_FRAME_CURRENT]->key_frame)
391  mb_type = VP56_MB_INTRA;
392  else
393  mb_type = vp56_decode_mv(s, row, col);
394  ref_frame = ff_vp56_reference_frame[mb_type];
395 
396  s->parse_coeff(s);
397 
398  vp56_add_predictors_dc(s, ref_frame);
399 
400  frame_current = s->frames[VP56_FRAME_CURRENT];
401  frame_ref = s->frames[ref_frame];
402  if (mb_type != VP56_MB_INTRA && !frame_ref->data[0])
403  return;
404 
405  ab = 6*is_alpha;
406  b_max = 6 - 2*is_alpha;
407 
408  switch (mb_type) {
409  case VP56_MB_INTRA:
410  for (b=0; b<b_max; b++) {
411  plane = ff_vp56_b2p[b+ab];
412  s->vp3dsp.idct_put(frame_current->data[plane] + s->block_offset[b],
413  s->stride[plane], s->block_coeff[b]);
414  }
415  break;
416 
419  for (b=0; b<b_max; b++) {
420  plane = ff_vp56_b2p[b+ab];
421  off = s->block_offset[b];
422  s->hdsp.put_pixels_tab[1][0](frame_current->data[plane] + off,
423  frame_ref->data[plane] + off,
424  s->stride[plane], 8);
425  s->vp3dsp.idct_add(frame_current->data[plane] + off,
426  s->stride[plane], s->block_coeff[b]);
427  }
428  break;
429 
431  case VP56_MB_INTER_V1_PF:
432  case VP56_MB_INTER_V2_PF:
434  case VP56_MB_INTER_4V:
435  case VP56_MB_INTER_V1_GF:
436  case VP56_MB_INTER_V2_GF:
437  for (b=0; b<b_max; b++) {
438  int x_off = b==1 || b==3 ? 8 : 0;
439  int y_off = b==2 || b==3 ? 8 : 0;
440  plane = ff_vp56_b2p[b+ab];
441  vp56_mc(s, b, plane, frame_ref->data[plane], s->stride[plane],
442  16*col+x_off, 16*row+y_off);
443  s->vp3dsp.idct_add(frame_current->data[plane] + s->block_offset[b],
444  s->stride[plane], s->block_coeff[b]);
445  }
446  break;
447  }
448 
449  if (is_alpha) {
450  s->block_coeff[4][0] = 0;
451  s->block_coeff[5][0] = 0;
452  }
453 }
454 
455 static int vp56_size_changed(VP56Context *s)
456 {
457  AVCodecContext *avctx = s->avctx;
458  int stride = s->frames[VP56_FRAME_CURRENT]->linesize[0];
459  int i;
460 
461  s->plane_width[0] = s->plane_width[3] = avctx->coded_width;
462  s->plane_width[1] = s->plane_width[2] = avctx->coded_width/2;
463  s->plane_height[0] = s->plane_height[3] = avctx->coded_height;
464  s->plane_height[1] = s->plane_height[2] = avctx->coded_height/2;
465 
466  for (i=0; i<4; i++)
467  s->stride[i] = s->flip * s->frames[VP56_FRAME_CURRENT]->linesize[i];
468 
469  s->mb_width = (avctx->coded_width +15) / 16;
470  s->mb_height = (avctx->coded_height+15) / 16;
471 
472  if (s->mb_width > 1000 || s->mb_height > 1000) {
473  avcodec_set_dimensions(avctx, 0, 0);
474  av_log(avctx, AV_LOG_ERROR, "picture too big\n");
475  return -1;
476  }
477 
478  av_reallocp_array(&s->above_blocks, 4*s->mb_width+6,
479  sizeof(*s->above_blocks));
480  av_reallocp_array(&s->macroblocks, s->mb_width*s->mb_height,
481  sizeof(*s->macroblocks));
482  av_free(s->edge_emu_buffer_alloc);
483  s->edge_emu_buffer_alloc = av_malloc(16*stride);
484  s->edge_emu_buffer = s->edge_emu_buffer_alloc;
485  if (!s->above_blocks || !s->macroblocks || !s->edge_emu_buffer_alloc)
486  return AVERROR(ENOMEM);
487  if (s->flip < 0)
488  s->edge_emu_buffer += 15 * stride;
489 
490  if (s->alpha_context)
491  return vp56_size_changed(s->alpha_context);
492 
493  return 0;
494 }
495 
496 static int ff_vp56_decode_mbs(AVCodecContext *avctx, void *, int, int);
497 
498 int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
499  AVPacket *avpkt)
500 {
501  const uint8_t *buf = avpkt->data;
502  VP56Context *s = avctx->priv_data;
503  AVFrame *const p = s->frames[VP56_FRAME_CURRENT];
504  int remaining_buf_size = avpkt->size;
505  int av_uninit(alpha_offset);
506  int i, res;
507  int ret;
508 
509  if (s->has_alpha) {
510  if (remaining_buf_size < 3)
511  return -1;
512  alpha_offset = bytestream_get_be24(&buf);
513  remaining_buf_size -= 3;
514  if (remaining_buf_size < alpha_offset)
515  return -1;
516  }
517 
518  res = s->parse_header(s, buf, remaining_buf_size);
519  if (res < 0)
520  return res;
521 
522  if (res == VP56_SIZE_CHANGE) {
523  for (i = 0; i < 4; i++) {
524  av_frame_unref(s->frames[i]);
525  if (s->alpha_context)
526  av_frame_unref(s->alpha_context->frames[i]);
527  }
528  }
529 
530  if (ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF) < 0)
531  return -1;
532 
533  if (avctx->pix_fmt == AV_PIX_FMT_YUVA420P) {
534  av_frame_unref(s->alpha_context->frames[VP56_FRAME_CURRENT]);
535  if ((ret = av_frame_ref(s->alpha_context->frames[VP56_FRAME_CURRENT], p)) < 0) {
536  av_frame_unref(p);
537  return ret;
538  }
539  }
540 
541  if (res == VP56_SIZE_CHANGE) {
542  if (vp56_size_changed(s)) {
543  av_frame_unref(p);
544  return -1;
545  }
546  }
547 
548  if (avctx->pix_fmt == AV_PIX_FMT_YUVA420P) {
549  int bak_w = avctx->width;
550  int bak_h = avctx->height;
551  int bak_cw = avctx->coded_width;
552  int bak_ch = avctx->coded_height;
553  buf += alpha_offset;
554  remaining_buf_size -= alpha_offset;
555 
556  res = s->alpha_context->parse_header(s->alpha_context, buf, remaining_buf_size);
557  if (res != 0) {
558  if(res==VP56_SIZE_CHANGE) {
559  av_log(avctx, AV_LOG_ERROR, "Alpha reconfiguration\n");
560  avctx->width = bak_w;
561  avctx->height = bak_h;
562  avctx->coded_width = bak_cw;
563  avctx->coded_height = bak_ch;
564  }
565  av_frame_unref(p);
566  return -1;
567  }
568  }
569 
570  avctx->execute2(avctx, ff_vp56_decode_mbs, 0, 0, (avctx->pix_fmt == AV_PIX_FMT_YUVA420P) + 1);
571 
572  if ((res = av_frame_ref(data, p)) < 0)
573  return res;
574  *got_frame = 1;
575 
576  return avpkt->size;
577 }
578 
579 static int ff_vp56_decode_mbs(AVCodecContext *avctx, void *data,
580  int jobnr, int threadnr)
581 {
582  VP56Context *s0 = avctx->priv_data;
583  int is_alpha = (jobnr == 1);
584  VP56Context *s = is_alpha ? s0->alpha_context : s0;
585  AVFrame *const p = s->frames[VP56_FRAME_CURRENT];
586  int mb_row, mb_col, mb_row_flip, mb_offset = 0;
587  int block, y, uv;
588  ptrdiff_t stride_y, stride_uv;
589  int res;
590 
591  if (p->key_frame) {
593  s->default_models_init(s);
594  for (block=0; block<s->mb_height*s->mb_width; block++)
595  s->macroblocks[block].type = VP56_MB_INTRA;
596  } else {
599  s->parse_vector_models(s);
600  s->mb_type = VP56_MB_INTER_NOVEC_PF;
601  }
602 
603  if (s->parse_coeff_models(s))
604  goto next;
605 
606  memset(s->prev_dc, 0, sizeof(s->prev_dc));
607  s->prev_dc[1][VP56_FRAME_CURRENT] = 128;
608  s->prev_dc[2][VP56_FRAME_CURRENT] = 128;
609 
610  for (block=0; block < 4*s->mb_width+6; block++) {
611  s->above_blocks[block].ref_frame = VP56_FRAME_NONE;
612  s->above_blocks[block].dc_coeff = 0;
613  s->above_blocks[block].not_null_dc = 0;
614  }
615  s->above_blocks[2*s->mb_width + 2].ref_frame = VP56_FRAME_CURRENT;
616  s->above_blocks[3*s->mb_width + 4].ref_frame = VP56_FRAME_CURRENT;
617 
618  stride_y = p->linesize[0];
619  stride_uv = p->linesize[1];
620 
621  if (s->flip < 0)
622  mb_offset = 7;
623 
624  /* main macroblocks loop */
625  for (mb_row=0; mb_row<s->mb_height; mb_row++) {
626  if (s->flip < 0)
627  mb_row_flip = s->mb_height - mb_row - 1;
628  else
629  mb_row_flip = mb_row;
630 
631  for (block=0; block<4; block++) {
632  s->left_block[block].ref_frame = VP56_FRAME_NONE;
633  s->left_block[block].dc_coeff = 0;
634  s->left_block[block].not_null_dc = 0;
635  }
636  memset(s->coeff_ctx, 0, sizeof(s->coeff_ctx));
637  memset(s->coeff_ctx_last, 24, sizeof(s->coeff_ctx_last));
638 
639  s->above_block_idx[0] = 1;
640  s->above_block_idx[1] = 2;
641  s->above_block_idx[2] = 1;
642  s->above_block_idx[3] = 2;
643  s->above_block_idx[4] = 2*s->mb_width + 2 + 1;
644  s->above_block_idx[5] = 3*s->mb_width + 4 + 1;
645 
646  s->block_offset[s->frbi] = (mb_row_flip*16 + mb_offset) * stride_y;
647  s->block_offset[s->srbi] = s->block_offset[s->frbi] + 8*stride_y;
648  s->block_offset[1] = s->block_offset[0] + 8;
649  s->block_offset[3] = s->block_offset[2] + 8;
650  s->block_offset[4] = (mb_row_flip*8 + mb_offset) * stride_uv;
651  s->block_offset[5] = s->block_offset[4];
652 
653  for (mb_col=0; mb_col<s->mb_width; mb_col++) {
654  vp56_decode_mb(s, mb_row, mb_col, is_alpha);
655 
656  for (y=0; y<4; y++) {
657  s->above_block_idx[y] += 2;
658  s->block_offset[y] += 16;
659  }
660 
661  for (uv=4; uv<6; uv++) {
662  s->above_block_idx[uv] += 1;
663  s->block_offset[uv] += 8;
664  }
665  }
666  }
667 
668 next:
669  if (p->key_frame || s->golden_frame) {
670  av_frame_unref(s->frames[VP56_FRAME_GOLDEN]);
671  if ((res = av_frame_ref(s->frames[VP56_FRAME_GOLDEN], p)) < 0)
672  return res;
673  }
674 
676  FFSWAP(AVFrame *, s->frames[VP56_FRAME_CURRENT],
677  s->frames[VP56_FRAME_PREVIOUS]);
678  return 0;
679 }
680 
681 av_cold int ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha)
682 {
683  VP56Context *s = avctx->priv_data;
684  return ff_vp56_init_context(avctx, s, flip, has_alpha);
685 }
686 
687 av_cold int ff_vp56_init_context(AVCodecContext *avctx, VP56Context *s,
688  int flip, int has_alpha)
689 {
690  int i;
691 
692  s->avctx = avctx;
693  avctx->pix_fmt = has_alpha ? AV_PIX_FMT_YUVA420P : AV_PIX_FMT_YUV420P;
694  if (avctx->skip_alpha) avctx->pix_fmt = AV_PIX_FMT_YUV420P;
695 
696  ff_h264chroma_init(&s->h264chroma, 8);
697  ff_hpeldsp_init(&s->hdsp, avctx->flags);
698  ff_videodsp_init(&s->vdsp, 8);
699  ff_vp3dsp_init(&s->vp3dsp, avctx->flags);
700  ff_vp56dsp_init(&s->vp56dsp, avctx->codec->id);
701  for (i = 0; i < 64; i++) {
702 #define T(x) (x >> 3) | ((x & 7) << 3)
703  s->idct_scantable[i] = T(ff_zigzag_direct[i]);
704 #undef T
705  }
706 
707  for (i = 0; i < FF_ARRAY_ELEMS(s->frames); i++) {
708  s->frames[i] = av_frame_alloc();
709  if (!s->frames[i]) {
710  ff_vp56_free(avctx);
711  return AVERROR(ENOMEM);
712  }
713  }
714  s->edge_emu_buffer_alloc = NULL;
715 
716  s->above_blocks = NULL;
717  s->macroblocks = NULL;
718  s->quantizer = -1;
719  s->deblock_filtering = 1;
720  s->golden_frame = 0;
721 
722  s->filter = NULL;
723 
724  s->has_alpha = has_alpha;
725 
726  s->modelp = &s->model;
727 
728  if (flip) {
729  s->flip = -1;
730  s->frbi = 2;
731  s->srbi = 0;
732  } else {
733  s->flip = 1;
734  s->frbi = 0;
735  s->srbi = 2;
736  }
737 
738  return 0;
739 }
740 
742 {
743  VP56Context *s = avctx->priv_data;
744  return ff_vp56_free_context(s);
745 }
746 
747 av_cold int ff_vp56_free_context(VP56Context *s)
748 {
749  int i;
750 
751  av_freep(&s->above_blocks);
752  av_freep(&s->macroblocks);
753  av_freep(&s->edge_emu_buffer_alloc);
754 
755  for (i = 0; i < FF_ARRAY_ELEMS(s->frames); i++)
756  av_frame_free(&s->frames[i]);
757 
758  return 0;
759 }