FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
snowdec.c
Go to the documentation of this file.
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 "dsputil.h"
26 #include "snow_dwt.h"
27 #include "internal.h"
28 #include "snow.h"
29 
30 #include "rangecoder.h"
31 #include "mathops.h"
32 
33 #include "mpegvideo.h"
34 #include "h263.h"
35 
36 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
37  Plane *p= &s->plane[plane_index];
38  const int mb_w= s->b_width << s->block_max_depth;
39  const int mb_h= s->b_height << s->block_max_depth;
40  int x, y, mb_x;
41  int block_size = MB_SIZE >> s->block_max_depth;
42  int block_w = plane_index ? block_size>>s->chroma_h_shift : block_size;
43  int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;
44  const uint8_t *obmc = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
45  int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
46  int ref_stride= s->current_picture->linesize[plane_index];
47  uint8_t *dst8= s->current_picture->data[plane_index];
48  int w= p->width;
49  int h= p->height;
50 
51  if(s->keyframe || (s->avctx->debug&512)){
52  if(mb_y==mb_h)
53  return;
54 
55  if(add){
56  for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
57 // DWTELEM * line = slice_buffer_get_line(sb, y);
58  IDWTELEM * line = sb->line[y];
59  for(x=0; x<w; x++){
60 // int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
61  int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
62  v >>= FRAC_BITS;
63  if(v&(~255)) v= ~(v>>31);
64  dst8[x + y*ref_stride]= v;
65  }
66  }
67  }else{
68  for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
69 // DWTELEM * line = slice_buffer_get_line(sb, y);
70  IDWTELEM * line = sb->line[y];
71  for(x=0; x<w; x++){
72  line[x] -= 128 << FRAC_BITS;
73 // buf[x + y*w]-= 128<<FRAC_BITS;
74  }
75  }
76  }
77 
78  return;
79  }
80 
81  for(mb_x=0; mb_x<=mb_w; mb_x++){
82  add_yblock(s, 1, sb, old_buffer, dst8, obmc,
83  block_w*mb_x - block_w/2,
84  block_h*mb_y - block_h/2,
85  block_w, block_h,
86  w, h,
87  w, ref_stride, obmc_stride,
88  mb_x - 1, mb_y - 1,
89  add, 0, plane_index);
90  }
91 }
92 
93 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
94  const int w= b->width;
95  int y;
96  const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
97  int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
98  int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
99  int new_index = 0;
100 
101  if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
102  qadd= 0;
103  qmul= 1<<QEXPSHIFT;
104  }
105 
106  /* If we are on the second or later slice, restore our index. */
107  if (start_y != 0)
108  new_index = save_state[0];
109 
110 
111  for(y=start_y; y<h; y++){
112  int x = 0;
113  int v;
115  memset(line, 0, b->width*sizeof(IDWTELEM));
116  v = b->x_coeff[new_index].coeff;
117  x = b->x_coeff[new_index++].x;
118  while(x < w){
119  register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;
120  register int u= -(v&1);
121  line[x] = (t^u) - u;
122 
123  v = b->x_coeff[new_index].coeff;
124  x = b->x_coeff[new_index++].x;
125  }
126  }
127 
128  /* Save our variables for the next slice. */
129  save_state[0] = new_index;
130 
131  return;
132 }
133 
134 static int decode_q_branch(SnowContext *s, int level, int x, int y){
135  const int w= s->b_width << s->block_max_depth;
136  const int rem_depth= s->block_max_depth - level;
137  const int index= (x + y*w) << rem_depth;
138  int trx= (x+1)<<rem_depth;
139  const BlockNode *left = x ? &s->block[index-1] : &null_block;
140  const BlockNode *top = y ? &s->block[index-w] : &null_block;
141  const BlockNode *tl = y && x ? &s->block[index-w-1] : left;
142  const BlockNode *tr = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
143  int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
144  int res;
145 
146  if(s->keyframe){
148  return 0;
149  }
150 
151  if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
152  int type, mx, my;
153  int l = left->color[0];
154  int cb= left->color[1];
155  int cr= left->color[2];
156  int ref = 0;
157  int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
158  int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
159  int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
160 
161  type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
162 
163  if(type){
164  pred_mv(s, &mx, &my, 0, left, top, tr);
165  l += get_symbol(&s->c, &s->block_state[32], 1);
166  if (s->nb_planes > 2) {
167  cb+= get_symbol(&s->c, &s->block_state[64], 1);
168  cr+= get_symbol(&s->c, &s->block_state[96], 1);
169  }
170  }else{
171  if(s->ref_frames > 1)
172  ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
173  if (ref >= s->ref_frames) {
174  av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
175  return AVERROR_INVALIDDATA;
176  }
177  pred_mv(s, &mx, &my, ref, left, top, tr);
178  mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
179  my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
180  }
181  set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
182  }else{
183  if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
184  (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
185  (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
186  (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
187  return res;
188  }
189  return 0;
190 }
191 
192 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
193  const int w= b->width;
194  const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
195  const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
196  const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
197  int x,y;
198 
199  if(s->qlog == LOSSLESS_QLOG) return;
200 
201  for(y=start_y; y<end_y; y++){
202 // DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
204  for(x=0; x<w; x++){
205  int i= line[x];
206  if(i<0){
207  line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
208  }else if(i>0){
209  line[x]= (( i*qmul + qadd)>>(QEXPSHIFT));
210  }
211  }
212  }
213 }
214 
215 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){
216  const int w= b->width;
217  int x,y;
218 
219  IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
220  IDWTELEM * prev;
221 
222  if (start_y != 0)
223  line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
224 
225  for(y=start_y; y<end_y; y++){
226  prev = line;
227 // line = slice_buffer_get_line_from_address(sb, src + (y * stride));
228  line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
229  for(x=0; x<w; x++){
230  if(x){
231  if(use_median){
232  if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
233  else line[x] += line[x - 1];
234  }else{
235  if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
236  else line[x] += line[x - 1];
237  }
238  }else{
239  if(y) line[x] += prev[x];
240  }
241  }
242  }
243 }
244 
245 static void decode_qlogs(SnowContext *s){
246  int plane_index, level, orientation;
247 
248  for(plane_index=0; plane_index < s->nb_planes; plane_index++){
249  for(level=0; level<s->spatial_decomposition_count; level++){
250  for(orientation=level ? 1:0; orientation<4; orientation++){
251  int q;
252  if (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
253  else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
254  else q= get_symbol(&s->c, s->header_state, 1);
255  s->plane[plane_index].band[level][orientation].qlog= q;
256  }
257  }
258  }
259 }
260 
261 #define GET_S(dst, check) \
262  tmp= get_symbol(&s->c, s->header_state, 0);\
263  if(!(check)){\
264  av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
265  return -1;\
266  }\
267  dst= tmp;
268 
270  int plane_index, tmp;
271  uint8_t kstate[32];
272 
273  memset(kstate, MID_STATE, sizeof(kstate));
274 
275  s->keyframe= get_rac(&s->c, kstate);
276  if(s->keyframe || s->always_reset){
279  s->qlog=
280  s->qbias=
281  s->mv_scale=
282  s->block_max_depth= 0;
283  }
284  if(s->keyframe){
285  GET_S(s->version, tmp <= 0U)
286  s->always_reset= get_rac(&s->c, s->header_state);
290  s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
291  if (s->colorspace_type == 1) {
293  s->nb_planes = 1;
294  } else if(s->colorspace_type == 0) {
295  s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
296  s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
297 
298  if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
300  }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
302  }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
304  } else {
305  av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
306  s->chroma_h_shift = s->chroma_v_shift = 1;
308  return AVERROR_INVALIDDATA;
309  }
310  s->nb_planes = 3;
311  } else {
312  av_log(s, AV_LOG_ERROR, "unsupported color space\n");
313  s->chroma_h_shift = s->chroma_v_shift = 1;
315  return AVERROR_INVALIDDATA;
316  }
317 
318 
320 // s->rate_scalability= get_rac(&s->c, s->header_state);
321  GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
322  s->max_ref_frames++;
323 
324  decode_qlogs(s);
325  }
326 
327  if(!s->keyframe){
328  if(get_rac(&s->c, s->header_state)){
329  for(plane_index=0; plane_index<FFMIN(s->nb_planes, 2); plane_index++){
330  int htaps, i, sum=0;
331  Plane *p= &s->plane[plane_index];
332  p->diag_mc= get_rac(&s->c, s->header_state);
333  htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
334  if((unsigned)htaps > HTAPS_MAX || htaps==0)
335  return -1;
336  p->htaps= htaps;
337  for(i= htaps/2; i; i--){
338  p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
339  sum += p->hcoeff[i];
340  }
341  p->hcoeff[0]= 32-sum;
342  }
343  s->plane[2].diag_mc= s->plane[1].diag_mc;
344  s->plane[2].htaps = s->plane[1].htaps;
345  memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
346  }
347  if(get_rac(&s->c, s->header_state)){
349  decode_qlogs(s);
350  }
351  }
352 
354  if(s->spatial_decomposition_type > 1U){
355  av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
356  return -1;
357  }
358  if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
359  s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 1){
360  av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
361  return -1;
362  }
363 
364 
365  s->qlog += get_symbol(&s->c, s->header_state, 1);
366  s->mv_scale += get_symbol(&s->c, s->header_state, 1);
367  s->qbias += get_symbol(&s->c, s->header_state, 1);
368  s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
369  if(s->block_max_depth > 1 || s->block_max_depth < 0){
370  av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
371  s->block_max_depth= 0;
372  return -1;
373  }
374 
375  return 0;
376 }
377 
379 {
380  int ret;
381 
382  if ((ret = ff_snow_common_init(avctx)) < 0) {
384  return ret;
385  }
386 
387  return 0;
388 }
389 
391  int x, y;
392  int w= s->b_width;
393  int h= s->b_height;
394  int res;
395 
396  for(y=0; y<h; y++){
397  for(x=0; x<w; x++){
398  if ((res = decode_q_branch(s, 0, x, y)) < 0)
399  return res;
400  }
401  }
402  return 0;
403 }
404 
405 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
406  AVPacket *avpkt)
407 {
408  const uint8_t *buf = avpkt->data;
409  int buf_size = avpkt->size;
410  SnowContext *s = avctx->priv_data;
411  RangeCoder * const c= &s->c;
412  int bytes_read;
413  AVFrame *picture = data;
414  int level, orientation, plane_index;
415  int res;
416 
417  ff_init_range_decoder(c, buf, buf_size);
418  ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
419 
420  s->current_picture->pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
421  if(decode_header(s)<0)
422  return -1;
423  if ((res=ff_snow_common_init_after_header(avctx)) < 0)
424  return res;
425 
426  // realloc slice buffer for the case that spatial_decomposition_count changed
428  if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
429  (MB_SIZE >> s->block_max_depth) +
430  s->spatial_decomposition_count * 11 + 1,
431  s->plane[0].width,
432  s->spatial_idwt_buffer)) < 0)
433  return res;
434 
435  for(plane_index=0; plane_index < s->nb_planes; plane_index++){
436  Plane *p= &s->plane[plane_index];
437  p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
438  && p->hcoeff[1]==-10
439  && p->hcoeff[2]==2;
440  }
441 
443 
444  if(ff_snow_frame_start(s) < 0)
445  return -1;
446  //keyframe flag duplication mess FIXME
447  if(avctx->debug&FF_DEBUG_PICT_INFO)
448  av_log(avctx, AV_LOG_ERROR, "keyframe:%d qlog:%d\n", s->keyframe, s->qlog);
449 
450  if ((res = decode_blocks(s)) < 0)
451  return res;
452 
453  for(plane_index=0; plane_index < s->nb_planes; plane_index++){
454  Plane *p= &s->plane[plane_index];
455  int w= p->width;
456  int h= p->height;
457  int x, y;
458  int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
459 
460  if(s->avctx->debug&2048){
461  memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
462  predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
463 
464  for(y=0; y<h; y++){
465  for(x=0; x<w; x++){
466  int v= s->current_picture->data[plane_index][y*s->current_picture->linesize[plane_index] + x];
467  s->mconly_picture->data[plane_index][y*s->mconly_picture->linesize[plane_index] + x]= v;
468  }
469  }
470  }
471 
472  {
473  for(level=0; level<s->spatial_decomposition_count; level++){
474  for(orientation=level ? 1 : 0; orientation<4; orientation++){
475  SubBand *b= &p->band[level][orientation];
476  unpack_coeffs(s, b, b->parent, orientation);
477  }
478  }
479  }
480 
481  {
482  const int mb_h= s->b_height << s->block_max_depth;
483  const int block_size = MB_SIZE >> s->block_max_depth;
484  const int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;
485  int mb_y;
487  int yd=0, yq=0;
488  int y;
489  int end_y;
490 
492  for(mb_y=0; mb_y<=mb_h; mb_y++){
493 
494  int slice_starty = block_h*mb_y;
495  int slice_h = block_h*(mb_y+1);
496 
497  if (!(s->keyframe || s->avctx->debug&512)){
498  slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
499  slice_h -= (block_h >> 1);
500  }
501 
502  for(level=0; level<s->spatial_decomposition_count; level++){
503  for(orientation=level ? 1 : 0; orientation<4; orientation++){
504  SubBand *b= &p->band[level][orientation];
505  int start_y;
506  int end_y;
507  int our_mb_start = mb_y;
508  int our_mb_end = (mb_y + 1);
509  const int extra= 3;
510  start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
511  end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
512  if (!(s->keyframe || s->avctx->debug&512)){
513  start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
514  end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
515  }
516  start_y = FFMIN(b->height, start_y);
517  end_y = FFMIN(b->height, end_y);
518 
519  if (start_y != end_y){
520  if (orientation == 0){
521  SubBand * correlate_band = &p->band[0][0];
522  int correlate_end_y = FFMIN(b->height, end_y + 1);
523  int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
524  decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
525  correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
526  dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
527  }
528  else
529  decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
530  }
531  }
532  }
533 
534  for(; yd<slice_h; yd+=4){
536  }
537 
538  if(s->qlog == LOSSLESS_QLOG){
539  for(; yq<slice_h && yq<h; yq++){
540  IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
541  for(x=0; x<w; x++){
542  line[x] <<= FRAC_BITS;
543  }
544  }
545  }
546 
547  predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
548 
549  y = FFMIN(p->height, slice_starty);
550  end_y = FFMIN(p->height, slice_h);
551  while(y < end_y)
552  ff_slice_buffer_release(&s->sb, y++);
553  }
554 
556  }
557 
558  }
559 
560  emms_c();
561 
562  ff_snow_release_buffer(avctx);
563 
564  if(!(s->avctx->debug&2048))
565  res = av_frame_ref(picture, s->current_picture);
566  else
567  res = av_frame_ref(picture, s->mconly_picture);
568 
569  if (res < 0)
570  return res;
571 
572  *got_frame = 1;
573 
574  bytes_read= c->bytestream - c->bytestream_start;
575  if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
576 
577  return bytes_read;
578 }
579 
581 {
582  SnowContext *s = avctx->priv_data;
583 
585 
587 
588  return 0;
589 }
590 
592  .name = "snow",
593  .long_name = NULL_IF_CONFIG_SMALL("Snow"),
594  .type = AVMEDIA_TYPE_VIDEO,
595  .id = AV_CODEC_ID_SNOW,
596  .priv_data_size = sizeof(SnowContext),
597  .init = decode_init,
598  .close = decode_end,
599  .decode = decode_frame,
600  .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
601 };