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snowdec.c
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1 /*
2  * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
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 #include "libavutil/intmath.h"
22 #include "libavutil/log.h"
23 #include "libavutil/opt.h"
24 #include "avcodec.h"
25 #include "snow_dwt.h"
26 #include "internal.h"
27 #include "snow.h"
28 
29 #include "rangecoder.h"
30 #include "mathops.h"
31 
32 #include "mpegvideo.h"
33 #include "h263.h"
34 
35 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
36  Plane *p= &s->plane[plane_index];
37  const int mb_w= s->b_width << s->block_max_depth;
38  const int mb_h= s->b_height << s->block_max_depth;
39  int x, y, mb_x;
40  int block_size = MB_SIZE >> s->block_max_depth;
41  int block_w = plane_index ? block_size>>s->chroma_h_shift : block_size;
42  int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;
43  const uint8_t *obmc = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
44  int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
45  int ref_stride= s->current_picture->linesize[plane_index];
46  uint8_t *dst8= s->current_picture->data[plane_index];
47  int w= p->width;
48  int h= p->height;
49 
50  if(s->keyframe || (s->avctx->debug&512)){
51  if(mb_y==mb_h)
52  return;
53 
54  if(add){
55  for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
56 // DWTELEM * line = slice_buffer_get_line(sb, y);
57  IDWTELEM * line = sb->line[y];
58  for(x=0; x<w; x++){
59 // int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
60  int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
61  v >>= FRAC_BITS;
62  if(v&(~255)) v= ~(v>>31);
63  dst8[x + y*ref_stride]= v;
64  }
65  }
66  }else{
67  for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
68 // DWTELEM * line = slice_buffer_get_line(sb, y);
69  IDWTELEM * line = sb->line[y];
70  for(x=0; x<w; x++){
71  line[x] -= 128 << FRAC_BITS;
72 // buf[x + y*w]-= 128<<FRAC_BITS;
73  }
74  }
75  }
76 
77  return;
78  }
79 
80  for(mb_x=0; mb_x<=mb_w; mb_x++){
81  add_yblock(s, 1, sb, old_buffer, dst8, obmc,
82  block_w*mb_x - block_w/2,
83  block_h*mb_y - block_h/2,
84  block_w, block_h,
85  w, h,
86  w, ref_stride, obmc_stride,
87  mb_x - 1, mb_y - 1,
88  add, 0, plane_index);
89  }
90 
91  if(s->avmv && mb_y < mb_h && plane_index == 0)
92  for(mb_x=0; mb_x<mb_w; mb_x++){
93  AVMotionVector *avmv = s->avmv + (s->avmv_index++);
94  const int b_width = s->b_width << s->block_max_depth;
95  const int b_stride= b_width;
96  BlockNode *bn= &s->block[mb_x + mb_y*b_stride];
97 
98  if (bn->type)
99  continue;
100 
101  avmv->w = block_w;
102  avmv->h = block_h;
103  avmv->dst_x = block_w*mb_x - block_w/2;
104  avmv->dst_y = block_h*mb_y - block_h/2;
105  avmv->src_x = avmv->dst_x + (bn->mx * s->mv_scale)/8;
106  avmv->src_y = avmv->dst_y + (bn->my * s->mv_scale)/8;
107  avmv->source= -1 - bn->ref;
108  avmv->flags = 0;
109  }
110 }
111 
112 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
113  const int w= b->width;
114  int y;
115  const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
116  int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
117  int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
118  int new_index = 0;
119 
120  if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
121  qadd= 0;
122  qmul= 1<<QEXPSHIFT;
123  }
124 
125  /* If we are on the second or later slice, restore our index. */
126  if (start_y != 0)
127  new_index = save_state[0];
128 
129 
130  for(y=start_y; y<h; y++){
131  int x = 0;
132  int v;
134  memset(line, 0, b->width*sizeof(IDWTELEM));
135  v = b->x_coeff[new_index].coeff;
136  x = b->x_coeff[new_index++].x;
137  while(x < w){
138  register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;
139  register int u= -(v&1);
140  line[x] = (t^u) - u;
141 
142  v = b->x_coeff[new_index].coeff;
143  x = b->x_coeff[new_index++].x;
144  }
145  }
146 
147  /* Save our variables for the next slice. */
148  save_state[0] = new_index;
149 
150  return;
151 }
152 
153 static int decode_q_branch(SnowContext *s, int level, int x, int y){
154  const int w= s->b_width << s->block_max_depth;
155  const int rem_depth= s->block_max_depth - level;
156  const int index= (x + y*w) << rem_depth;
157  int trx= (x+1)<<rem_depth;
158  const BlockNode *left = x ? &s->block[index-1] : &null_block;
159  const BlockNode *top = y ? &s->block[index-w] : &null_block;
160  const BlockNode *tl = y && x ? &s->block[index-w-1] : left;
161  const BlockNode *tr = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
162  int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
163  int res;
164 
165  if(s->keyframe){
167  return 0;
168  }
169 
170  if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
171  int type, mx, my;
172  int l = left->color[0];
173  int cb= left->color[1];
174  int cr= left->color[2];
175  int ref = 0;
176  int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
177  int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
178  int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
179 
180  type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
181 
182  if(type){
183  pred_mv(s, &mx, &my, 0, left, top, tr);
184  l += get_symbol(&s->c, &s->block_state[32], 1);
185  if (s->nb_planes > 2) {
186  cb+= get_symbol(&s->c, &s->block_state[64], 1);
187  cr+= get_symbol(&s->c, &s->block_state[96], 1);
188  }
189  }else{
190  if(s->ref_frames > 1)
191  ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
192  if (ref >= s->ref_frames) {
193  av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
194  return AVERROR_INVALIDDATA;
195  }
196  pred_mv(s, &mx, &my, ref, left, top, tr);
197  mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
198  my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
199  }
200  set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
201  }else{
202  if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
203  (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
204  (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
205  (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
206  return res;
207  }
208  return 0;
209 }
210 
211 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
212  const int w= b->width;
213  const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
214  const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
215  const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
216  int x,y;
217 
218  if(s->qlog == LOSSLESS_QLOG) return;
219 
220  for(y=start_y; y<end_y; y++){
221 // DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
223  for(x=0; x<w; x++){
224  int i= line[x];
225  if(i<0){
226  line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
227  }else if(i>0){
228  line[x]= (( i*qmul + qadd)>>(QEXPSHIFT));
229  }
230  }
231  }
232 }
233 
234 static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int inverse, int use_median, int start_y, int end_y){
235  const int w= b->width;
236  int x,y;
237 
238  IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
239  IDWTELEM * prev;
240 
241  if (start_y != 0)
242  line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
243 
244  for(y=start_y; y<end_y; y++){
245  prev = line;
246 // line = slice_buffer_get_line_from_address(sb, src + (y * stride));
247  line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
248  for(x=0; x<w; x++){
249  if(x){
250  if(use_median){
251  if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
252  else line[x] += line[x - 1];
253  }else{
254  if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
255  else line[x] += line[x - 1];
256  }
257  }else{
258  if(y) line[x] += prev[x];
259  }
260  }
261  }
262 }
263 
264 static void decode_qlogs(SnowContext *s){
265  int plane_index, level, orientation;
266 
267  for(plane_index=0; plane_index < s->nb_planes; plane_index++){
268  for(level=0; level<s->spatial_decomposition_count; level++){
269  for(orientation=level ? 1:0; orientation<4; orientation++){
270  int q;
271  if (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
272  else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
273  else q= get_symbol(&s->c, s->header_state, 1);
274  s->plane[plane_index].band[level][orientation].qlog= q;
275  }
276  }
277  }
278 }
279 
280 #define GET_S(dst, check) \
281  tmp= get_symbol(&s->c, s->header_state, 0);\
282  if(!(check)){\
283  av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
284  return AVERROR_INVALIDDATA;\
285  }\
286  dst= tmp;
287 
289  int plane_index, tmp;
290  uint8_t kstate[32];
291 
292  memset(kstate, MID_STATE, sizeof(kstate));
293 
294  s->keyframe= get_rac(&s->c, kstate);
295  if(s->keyframe || s->always_reset){
298  s->qlog=
299  s->qbias=
300  s->mv_scale=
301  s->block_max_depth= 0;
302  }
303  if(s->keyframe){
304  GET_S(s->version, tmp <= 0U)
305  s->always_reset= get_rac(&s->c, s->header_state);
309  s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
310  if (s->colorspace_type == 1) {
312  s->nb_planes = 1;
313  } else if(s->colorspace_type == 0) {
314  s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
315  s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
316 
317  if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
319  }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
321  }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
323  } else {
324  av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
325  s->chroma_h_shift = s->chroma_v_shift = 1;
327  return AVERROR_INVALIDDATA;
328  }
329  s->nb_planes = 3;
330  } else {
331  av_log(s, AV_LOG_ERROR, "unsupported color space\n");
332  s->chroma_h_shift = s->chroma_v_shift = 1;
334  return AVERROR_INVALIDDATA;
335  }
336 
337 
339 // s->rate_scalability= get_rac(&s->c, s->header_state);
340  GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
341  s->max_ref_frames++;
342 
343  decode_qlogs(s);
344  }
345 
346  if(!s->keyframe){
347  if(get_rac(&s->c, s->header_state)){
348  for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
349  int htaps, i, sum=0;
350  Plane *p= &s->plane[plane_index];
351  p->diag_mc= get_rac(&s->c, s->header_state);
352  htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
353  if((unsigned)htaps > HTAPS_MAX || htaps==0)
354  return AVERROR_INVALIDDATA;
355  p->htaps= htaps;
356  for(i= htaps/2; i; i--){
357  p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
358  sum += p->hcoeff[i];
359  }
360  p->hcoeff[0]= 32-sum;
361  }
362  s->plane[2].diag_mc= s->plane[1].diag_mc;
363  s->plane[2].htaps = s->plane[1].htaps;
364  memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
365  }
366  if(get_rac(&s->c, s->header_state)){
368  decode_qlogs(s);
369  }
370  }
371 
373  if(s->spatial_decomposition_type > 1U){
374  av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
375  return AVERROR_INVALIDDATA;
376  }
377  if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
378  s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 1){
379  av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
380  return AVERROR_INVALIDDATA;
381  }
382 
383 
384  s->qlog += get_symbol(&s->c, s->header_state, 1);
385  s->mv_scale += get_symbol(&s->c, s->header_state, 1);
386  s->qbias += get_symbol(&s->c, s->header_state, 1);
387  s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
388  if(s->block_max_depth > 1 || s->block_max_depth < 0){
389  av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
390  s->block_max_depth= 0;
391  return AVERROR_INVALIDDATA;
392  }
393 
394  return 0;
395 }
396 
398 {
399  int ret;
400 
401  if ((ret = ff_snow_common_init(avctx)) < 0) {
403  return ret;
404  }
405 
406  return 0;
407 }
408 
410  int x, y;
411  int w= s->b_width;
412  int h= s->b_height;
413  int res;
414 
415  for(y=0; y<h; y++){
416  for(x=0; x<w; x++){
417  if ((res = decode_q_branch(s, 0, x, y)) < 0)
418  return res;
419  }
420  }
421  return 0;
422 }
423 
424 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
425  AVPacket *avpkt)
426 {
427  const uint8_t *buf = avpkt->data;
428  int buf_size = avpkt->size;
429  SnowContext *s = avctx->priv_data;
430  RangeCoder * const c= &s->c;
431  int bytes_read;
432  AVFrame *picture = data;
433  int level, orientation, plane_index;
434  int res;
435 
436  ff_init_range_decoder(c, buf, buf_size);
437  ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
438 
439  s->current_picture->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
440  if ((res = decode_header(s)) < 0)
441  return res;
442  if ((res=ff_snow_common_init_after_header(avctx)) < 0)
443  return res;
444 
445  // realloc slice buffer for the case that spatial_decomposition_count changed
447  if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
448  (MB_SIZE >> s->block_max_depth) +
449  s->spatial_decomposition_count * 11 + 1,
450  s->plane[0].width,
451  s->spatial_idwt_buffer)) < 0)
452  return res;
453 
454  for(plane_index=0; plane_index < s->nb_planes; plane_index++){
455  Plane *p= &s->plane[plane_index];
456  p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
457  && p->hcoeff[1]==-10
458  && p->hcoeff[2]==2;
459  }
460 
462 
463  if((res = ff_snow_frame_start(s)) < 0)
464  return res;
465 
467 
468  //keyframe flag duplication mess FIXME
469  if(avctx->debug&FF_DEBUG_PICT_INFO)
470  av_log(avctx, AV_LOG_ERROR,
471  "keyframe:%d qlog:%d qbias: %d mvscale: %d "
472  "decomposition_type:%d decomposition_count:%d\n",
473  s->keyframe, s->qlog, s->qbias, s->mv_scale,
476  );
477 
478  av_assert0(!s->avmv);
479  if (s->avctx->flags2 & CODEC_FLAG2_EXPORT_MVS) {
480  s->avmv = av_malloc_array(s->b_width * s->b_height, sizeof(AVMotionVector) << (s->block_max_depth*2));
481  }
482  s->avmv_index = 0;
483 
484  if ((res = decode_blocks(s)) < 0)
485  return res;
486 
487  for(plane_index=0; plane_index < s->nb_planes; plane_index++){
488  Plane *p= &s->plane[plane_index];
489  int w= p->width;
490  int h= p->height;
491  int x, y;
492  int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
493 
494  if(s->avctx->debug&2048){
495  memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
496  predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
497 
498  for(y=0; y<h; y++){
499  for(x=0; x<w; x++){
500  int v= s->current_picture->data[plane_index][y*s->current_picture->linesize[plane_index] + x];
501  s->mconly_picture->data[plane_index][y*s->mconly_picture->linesize[plane_index] + x]= v;
502  }
503  }
504  }
505 
506  {
507  for(level=0; level<s->spatial_decomposition_count; level++){
508  for(orientation=level ? 1 : 0; orientation<4; orientation++){
509  SubBand *b= &p->band[level][orientation];
510  unpack_coeffs(s, b, b->parent, orientation);
511  }
512  }
513  }
514 
515  {
516  const int mb_h= s->b_height << s->block_max_depth;
517  const int block_size = MB_SIZE >> s->block_max_depth;
518  const int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;
519  int mb_y;
521  int yd=0, yq=0;
522  int y;
523  int end_y;
524 
526  for(mb_y=0; mb_y<=mb_h; mb_y++){
527 
528  int slice_starty = block_h*mb_y;
529  int slice_h = block_h*(mb_y+1);
530 
531  if (!(s->keyframe || s->avctx->debug&512)){
532  slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
533  slice_h -= (block_h >> 1);
534  }
535 
536  for(level=0; level<s->spatial_decomposition_count; level++){
537  for(orientation=level ? 1 : 0; orientation<4; orientation++){
538  SubBand *b= &p->band[level][orientation];
539  int start_y;
540  int end_y;
541  int our_mb_start = mb_y;
542  int our_mb_end = (mb_y + 1);
543  const int extra= 3;
544  start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
545  end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
546  if (!(s->keyframe || s->avctx->debug&512)){
547  start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
548  end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
549  }
550  start_y = FFMIN(b->height, start_y);
551  end_y = FFMIN(b->height, end_y);
552 
553  if (start_y != end_y){
554  if (orientation == 0){
555  SubBand * correlate_band = &p->band[0][0];
556  int correlate_end_y = FFMIN(b->height, end_y + 1);
557  int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
558  decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
559  correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
560  dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
561  }
562  else
563  decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
564  }
565  }
566  }
567 
568  for(; yd<slice_h; yd+=4){
570  }
571 
572  if(s->qlog == LOSSLESS_QLOG){
573  for(; yq<slice_h && yq<h; yq++){
574  IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
575  for(x=0; x<w; x++){
576  line[x] <<= FRAC_BITS;
577  }
578  }
579  }
580 
581  predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
582 
583  y = FFMIN(p->height, slice_starty);
584  end_y = FFMIN(p->height, slice_h);
585  while(y < end_y)
586  ff_slice_buffer_release(&s->sb, y++);
587  }
588 
590  }
591 
592  }
593 
594  emms_c();
595 
596  ff_snow_release_buffer(avctx);
597 
598  if(!(s->avctx->debug&2048))
599  res = av_frame_ref(picture, s->current_picture);
600  else
601  res = av_frame_ref(picture, s->mconly_picture);
602  if (res >= 0 && s->avmv_index) {
603  AVFrameSideData *sd;
604 
606  if (!sd)
607  return AVERROR(ENOMEM);
608  memcpy(sd->data, s->avmv, s->avmv_index * sizeof(AVMotionVector));
609  }
610 
611  av_freep(&s->avmv);
612 
613  if (res < 0)
614  return res;
615 
616  *got_frame = 1;
617 
618  bytes_read= c->bytestream - c->bytestream_start;
619  if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
620 
621  return bytes_read;
622 }
623 
625 {
626  SnowContext *s = avctx->priv_data;
627 
629 
631 
632  return 0;
633 }
634 
636  .name = "snow",
637  .long_name = NULL_IF_CONFIG_SMALL("Snow"),
638  .type = AVMEDIA_TYPE_VIDEO,
639  .id = AV_CODEC_ID_SNOW,
640  .priv_data_size = sizeof(SnowContext),
641  .init = decode_init,
642  .close = decode_end,
643  .decode = decode_frame,
644  .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
645 };