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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 "dsputil.h"
26 #include "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 #undef NDEBUG
37 #include <assert.h>
38 
39 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
40  Plane *p= &s->plane[plane_index];
41  const int mb_w= s->b_width << s->block_max_depth;
42  const int mb_h= s->b_height << s->block_max_depth;
43  int x, y, mb_x;
44  int block_size = MB_SIZE >> s->block_max_depth;
45  int block_w = plane_index ? block_size>>s->chroma_h_shift : block_size;
46  int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;
47  const uint8_t *obmc = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];
48  int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;
49  int ref_stride= s->current_picture.linesize[plane_index];
50  uint8_t *dst8= s->current_picture.data[plane_index];
51  int w= p->width;
52  int h= p->height;
53 
54  if(s->keyframe || (s->avctx->debug&512)){
55  if(mb_y==mb_h)
56  return;
57 
58  if(add){
59  for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
60 // DWTELEM * line = slice_buffer_get_line(sb, y);
61  IDWTELEM * line = sb->line[y];
62  for(x=0; x<w; x++){
63 // int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
64  int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
65  v >>= FRAC_BITS;
66  if(v&(~255)) v= ~(v>>31);
67  dst8[x + y*ref_stride]= v;
68  }
69  }
70  }else{
71  for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){
72 // DWTELEM * line = slice_buffer_get_line(sb, y);
73  IDWTELEM * line = sb->line[y];
74  for(x=0; x<w; x++){
75  line[x] -= 128 << FRAC_BITS;
76 // buf[x + y*w]-= 128<<FRAC_BITS;
77  }
78  }
79  }
80 
81  return;
82  }
83 
84  for(mb_x=0; mb_x<=mb_w; mb_x++){
85  add_yblock(s, 1, sb, old_buffer, dst8, obmc,
86  block_w*mb_x - block_w/2,
87  block_h*mb_y - block_h/2,
88  block_w, block_h,
89  w, h,
90  w, ref_stride, obmc_stride,
91  mb_x - 1, mb_y - 1,
92  add, 0, plane_index);
93  }
94 }
95 
96 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
97  const int w= b->width;
98  int y;
99  const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
100  int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
101  int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
102  int new_index = 0;
103 
104  if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
105  qadd= 0;
106  qmul= 1<<QEXPSHIFT;
107  }
108 
109  /* If we are on the second or later slice, restore our index. */
110  if (start_y != 0)
111  new_index = save_state[0];
112 
113 
114  for(y=start_y; y<h; y++){
115  int x = 0;
116  int v;
118  memset(line, 0, b->width*sizeof(IDWTELEM));
119  v = b->x_coeff[new_index].coeff;
120  x = b->x_coeff[new_index++].x;
121  while(x < w){
122  register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;
123  register int u= -(v&1);
124  line[x] = (t^u) - u;
125 
126  v = b->x_coeff[new_index].coeff;
127  x = b->x_coeff[new_index++].x;
128  }
129  }
130 
131  /* Save our variables for the next slice. */
132  save_state[0] = new_index;
133 
134  return;
135 }
136 
137 static int decode_q_branch(SnowContext *s, int level, int x, int y){
138  const int w= s->b_width << s->block_max_depth;
139  const int rem_depth= s->block_max_depth - level;
140  const int index= (x + y*w) << rem_depth;
141  int trx= (x+1)<<rem_depth;
142  const BlockNode *left = x ? &s->block[index-1] : &null_block;
143  const BlockNode *top = y ? &s->block[index-w] : &null_block;
144  const BlockNode *tl = y && x ? &s->block[index-w-1] : left;
145  const BlockNode *tr = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
146  int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
147  int res;
148 
149  if(s->keyframe){
151  return 0;
152  }
153 
154  if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
155  int type, mx, my;
156  int l = left->color[0];
157  int cb= left->color[1];
158  int cr= left->color[2];
159  int ref = 0;
160  int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
161  int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
162  int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
163 
164  type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
165 
166  if(type){
167  pred_mv(s, &mx, &my, 0, left, top, tr);
168  l += get_symbol(&s->c, &s->block_state[32], 1);
169  cb+= get_symbol(&s->c, &s->block_state[64], 1);
170  cr+= get_symbol(&s->c, &s->block_state[96], 1);
171  }else{
172  if(s->ref_frames > 1)
173  ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
174  if (ref >= s->ref_frames) {
175  av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");
176  return AVERROR_INVALIDDATA;
177  }
178  pred_mv(s, &mx, &my, ref, left, top, tr);
179  mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
180  my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
181  }
182  set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
183  }else{
184  if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||
185  (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||
186  (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||
187  (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)
188  return res;
189  }
190  return 0;
191 }
192 
193 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
194  const int w= b->width;
195  const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
196  const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
197  const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
198  int x,y;
199 
200  if(s->qlog == LOSSLESS_QLOG) return;
201 
202  for(y=start_y; y<end_y; y++){
203 // DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
205  for(x=0; x<w; x++){
206  int i= line[x];
207  if(i<0){
208  line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
209  }else if(i>0){
210  line[x]= (( i*qmul + qadd)>>(QEXPSHIFT));
211  }
212  }
213  }
214 }
215 
216 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){
217  const int w= b->width;
218  int x,y;
219 
220  IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
221  IDWTELEM * prev;
222 
223  if (start_y != 0)
224  line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
225 
226  for(y=start_y; y<end_y; y++){
227  prev = line;
228 // line = slice_buffer_get_line_from_address(sb, src + (y * stride));
229  line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
230  for(x=0; x<w; x++){
231  if(x){
232  if(use_median){
233  if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
234  else line[x] += line[x - 1];
235  }else{
236  if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
237  else line[x] += line[x - 1];
238  }
239  }else{
240  if(y) line[x] += prev[x];
241  }
242  }
243  }
244 }
245 
246 static void decode_qlogs(SnowContext *s){
247  int plane_index, level, orientation;
248 
249  for(plane_index=0; plane_index<3; plane_index++){
250  for(level=0; level<s->spatial_decomposition_count; level++){
251  for(orientation=level ? 1:0; orientation<4; orientation++){
252  int q;
253  if (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
254  else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
255  else q= get_symbol(&s->c, s->header_state, 1);
256  s->plane[plane_index].band[level][orientation].qlog= q;
257  }
258  }
259  }
260 }
261 
262 #define GET_S(dst, check) \
263  tmp= get_symbol(&s->c, s->header_state, 0);\
264  if(!(check)){\
265  av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
266  return -1;\
267  }\
268  dst= tmp;
269 
270 static int decode_header(SnowContext *s){
271  int plane_index, tmp;
272  uint8_t kstate[32];
273 
274  memset(kstate, MID_STATE, sizeof(kstate));
275 
276  s->keyframe= get_rac(&s->c, kstate);
277  if(s->keyframe || s->always_reset){
280  s->qlog=
281  s->qbias=
282  s->mv_scale=
283  s->block_max_depth= 0;
284  }
285  if(s->keyframe){
286  GET_S(s->version, tmp <= 0U)
287  s->always_reset= get_rac(&s->c, s->header_state);
291  s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
292  s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
293  s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
294 
295  if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){
297  }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){
299  }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){
301  } else {
302  av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);
303  s->chroma_h_shift = s->chroma_v_shift = 1;
305  return AVERROR_INVALIDDATA;
306  }
307 
309 // s->rate_scalability= get_rac(&s->c, s->header_state);
310  GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
311  s->max_ref_frames++;
312 
313  decode_qlogs(s);
314  }
315 
316  if(!s->keyframe){
317  if(get_rac(&s->c, s->header_state)){
318  for(plane_index=0; plane_index<2; plane_index++){
319  int htaps, i, sum=0;
320  Plane *p= &s->plane[plane_index];
321  p->diag_mc= get_rac(&s->c, s->header_state);
322  htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
323  if((unsigned)htaps > HTAPS_MAX || htaps==0)
324  return -1;
325  p->htaps= htaps;
326  for(i= htaps/2; i; i--){
327  p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
328  sum += p->hcoeff[i];
329  }
330  p->hcoeff[0]= 32-sum;
331  }
332  s->plane[2].diag_mc= s->plane[1].diag_mc;
333  s->plane[2].htaps = s->plane[1].htaps;
334  memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
335  }
336  if(get_rac(&s->c, s->header_state)){
338  decode_qlogs(s);
339  }
340  }
341 
343  if(s->spatial_decomposition_type > 1U){
344  av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);
345  return -1;
346  }
347  if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
348  s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 0){
349  av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);
350  return -1;
351  }
352 
353 
354  s->qlog += get_symbol(&s->c, s->header_state, 1);
355  s->mv_scale += get_symbol(&s->c, s->header_state, 1);
356  s->qbias += get_symbol(&s->c, s->header_state, 1);
357  s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
358  if(s->block_max_depth > 1 || s->block_max_depth < 0){
359  av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);
360  s->block_max_depth= 0;
361  return -1;
362  }
363 
364  return 0;
365 }
366 
368 {
369  int ret;
370 
371  if ((ret = ff_snow_common_init(avctx)) < 0) {
373  return ret;
374  }
375 
376  return 0;
377 }
378 
379 static int decode_blocks(SnowContext *s){
380  int x, y;
381  int w= s->b_width;
382  int h= s->b_height;
383  int res;
384 
385  for(y=0; y<h; y++){
386  for(x=0; x<w; x++){
387  if ((res = decode_q_branch(s, 0, x, y)) < 0)
388  return res;
389  }
390  }
391  return 0;
392 }
393 
394 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
395  AVPacket *avpkt)
396 {
397  const uint8_t *buf = avpkt->data;
398  int buf_size = avpkt->size;
399  SnowContext *s = avctx->priv_data;
400  RangeCoder * const c= &s->c;
401  int bytes_read;
402  AVFrame *picture = data;
403  int level, orientation, plane_index;
404  int res;
405 
406  ff_init_range_decoder(c, buf, buf_size);
407  ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
408 
409  s->current_picture.pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
410  if(decode_header(s)<0)
411  return -1;
412  if ((res=ff_snow_common_init_after_header(avctx)) < 0)
413  return res;
414 
415  // realloc slice buffer for the case that spatial_decomposition_count changed
417  if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,
418  (MB_SIZE >> s->block_max_depth) +
419  s->spatial_decomposition_count * 11 + 1,
420  s->plane[0].width,
421  s->spatial_idwt_buffer)) < 0)
422  return res;
423 
424  for(plane_index=0; plane_index<3; plane_index++){
425  Plane *p= &s->plane[plane_index];
426  p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
427  && p->hcoeff[1]==-10
428  && p->hcoeff[2]==2;
429  }
430 
432 
433  if(ff_snow_frame_start(s) < 0)
434  return -1;
435  //keyframe flag duplication mess FIXME
436  if(avctx->debug&FF_DEBUG_PICT_INFO)
437  av_log(avctx, AV_LOG_ERROR, "keyframe:%d qlog:%d\n", s->keyframe, s->qlog);
438 
439  if ((res = decode_blocks(s)) < 0)
440  return res;
441 
442  for(plane_index=0; plane_index<3; plane_index++){
443  Plane *p= &s->plane[plane_index];
444  int w= p->width;
445  int h= p->height;
446  int x, y;
447  int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
448 
449  if(s->avctx->debug&2048){
450  memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
451  predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
452 
453  for(y=0; y<h; y++){
454  for(x=0; x<w; x++){
455  int v= s->current_picture.data[plane_index][y*s->current_picture.linesize[plane_index] + x];
456  s->mconly_picture.data[plane_index][y*s->mconly_picture.linesize[plane_index] + x]= v;
457  }
458  }
459  }
460 
461  {
462  for(level=0; level<s->spatial_decomposition_count; level++){
463  for(orientation=level ? 1 : 0; orientation<4; orientation++){
464  SubBand *b= &p->band[level][orientation];
465  unpack_coeffs(s, b, b->parent, orientation);
466  }
467  }
468  }
469 
470  {
471  const int mb_h= s->b_height << s->block_max_depth;
472  const int block_size = MB_SIZE >> s->block_max_depth;
473  const int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;
474  int mb_y;
476  int yd=0, yq=0;
477  int y;
478  int end_y;
479 
481  for(mb_y=0; mb_y<=mb_h; mb_y++){
482 
483  int slice_starty = block_h*mb_y;
484  int slice_h = block_h*(mb_y+1);
485 
486  if (!(s->keyframe || s->avctx->debug&512)){
487  slice_starty = FFMAX(0, slice_starty - (block_h >> 1));
488  slice_h -= (block_h >> 1);
489  }
490 
491  for(level=0; level<s->spatial_decomposition_count; level++){
492  for(orientation=level ? 1 : 0; orientation<4; orientation++){
493  SubBand *b= &p->band[level][orientation];
494  int start_y;
495  int end_y;
496  int our_mb_start = mb_y;
497  int our_mb_end = (mb_y + 1);
498  const int extra= 3;
499  start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
500  end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
501  if (!(s->keyframe || s->avctx->debug&512)){
502  start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));
503  end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));
504  }
505  start_y = FFMIN(b->height, start_y);
506  end_y = FFMIN(b->height, end_y);
507 
508  if (start_y != end_y){
509  if (orientation == 0){
510  SubBand * correlate_band = &p->band[0][0];
511  int correlate_end_y = FFMIN(b->height, end_y + 1);
512  int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
513  decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
514  correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
515  dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
516  }
517  else
518  decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
519  }
520  }
521  }
522 
523  for(; yd<slice_h; yd+=4){
525  }
526 
527  if(s->qlog == LOSSLESS_QLOG){
528  for(; yq<slice_h && yq<h; yq++){
529  IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
530  for(x=0; x<w; x++){
531  line[x] <<= FRAC_BITS;
532  }
533  }
534  }
535 
536  predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
537 
538  y = FFMIN(p->height, slice_starty);
539  end_y = FFMIN(p->height, slice_h);
540  while(y < end_y)
541  ff_slice_buffer_release(&s->sb, y++);
542  }
543 
545  }
546 
547  }
548 
549  emms_c();
550 
551  ff_snow_release_buffer(avctx);
552 
553  if(!(s->avctx->debug&2048))
554  *picture= s->current_picture;
555  else
556  *picture= s->mconly_picture;
557 
558  *got_frame = 1;
559 
560  bytes_read= c->bytestream - c->bytestream_start;
561  if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
562 
563  return bytes_read;
564 }
565 
567 {
568  SnowContext *s = avctx->priv_data;
569 
571 
573 
574  return 0;
575 }
576 
578  .name = "snow",
579  .type = AVMEDIA_TYPE_VIDEO,
580  .id = AV_CODEC_ID_SNOW,
581  .priv_data_size = sizeof(SnowContext),
582  .init = decode_init,
583  .close = decode_end,
584  .decode = decode_frame,
585  .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
586  .long_name = NULL_IF_CONFIG_SMALL("Snow"),
587 };