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mss12.c
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1 /*
2  * Copyright (c) 2012 Konstantin Shishkov
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  * Common functions for Microsoft Screen 1 and 2
24  */
25 
26 #include "libavutil/intfloat.h"
27 #include "libavutil/intreadwrite.h"
28 #include "avcodec.h"
29 #include "mss12.h"
30 
31 enum SplitMode {
35 };
36 
37 static const int sec_order_sizes[4] = { 1, 7, 6, 1 };
38 
40  TOP_LEFT = 0,
41  TOP,
44 };
45 
47 {
48  int thr;
49 
50  thr = 2 * m->weights[m->num_syms] - 1;
51  thr = ((thr >> 1) + 4 * m->cum_prob[0]) / thr;
52 
53  return FFMIN(thr, 0x3FFF);
54 }
55 
56 static void model_reset(Model *m)
57 {
58  int i;
59 
60  for (i = 0; i <= m->num_syms; i++) {
61  m->weights[i] = 1;
62  m->cum_prob[i] = m->num_syms - i;
63  }
64  m->weights[0] = 0;
65  for (i = 0; i < m->num_syms; i++)
66  m->idx2sym[i + 1] = i;
67 }
68 
69 static av_cold void model_init(Model *m, int num_syms, int thr_weight)
70 {
71  m->num_syms = num_syms;
72  m->thr_weight = thr_weight;
73  m->threshold = num_syms * thr_weight;
74 }
75 
77 {
78  int i;
79  int cum_prob;
80 
81  if (m->thr_weight == THRESH_ADAPTIVE)
83  while (m->cum_prob[0] > m->threshold) {
84  cum_prob = 0;
85  for (i = m->num_syms; i >= 0; i--) {
86  m->cum_prob[i] = cum_prob;
87  m->weights[i] = (m->weights[i] + 1) >> 1;
88  cum_prob += m->weights[i];
89  }
90  }
91 }
92 
93 void ff_mss12_model_update(Model *m, int val)
94 {
95  int i;
96 
97  if (m->weights[val] == m->weights[val - 1]) {
98  for (i = val; m->weights[i - 1] == m->weights[val]; i--);
99  if (i != val) {
100  int sym1, sym2;
101 
102  sym1 = m->idx2sym[val];
103  sym2 = m->idx2sym[i];
104 
105  m->idx2sym[val] = sym2;
106  m->idx2sym[i] = sym1;
107 
108  val = i;
109  }
110  }
111  m->weights[val]++;
112  for (i = val - 1; i >= 0; i--)
113  m->cum_prob[i]++;
115 }
116 
117 static void pixctx_reset(PixContext *ctx)
118 {
119  int i, j;
120 
121  if (!ctx->special_initial_cache)
122  for (i = 0; i < ctx->cache_size; i++)
123  ctx->cache[i] = i;
124  else {
125  ctx->cache[0] = 1;
126  ctx->cache[1] = 2;
127  ctx->cache[2] = 4;
128  }
129 
130  model_reset(&ctx->cache_model);
131  model_reset(&ctx->full_model);
132 
133  for (i = 0; i < 15; i++)
134  for (j = 0; j < 4; j++)
135  model_reset(&ctx->sec_models[i][j]);
136 }
137 
138 static av_cold void pixctx_init(PixContext *ctx, int cache_size,
139  int full_model_syms, int special_initial_cache)
140 {
141  int i, j, k, idx;
142 
143  ctx->cache_size = cache_size + 4;
144  ctx->num_syms = cache_size;
145  ctx->special_initial_cache = special_initial_cache;
146 
147  model_init(&ctx->cache_model, ctx->num_syms + 1, THRESH_LOW);
148  model_init(&ctx->full_model, full_model_syms, THRESH_HIGH);
149 
150  for (i = 0, idx = 0; i < 4; i++)
151  for (j = 0; j < sec_order_sizes[i]; j++, idx++)
152  for (k = 0; k < 4; k++)
153  model_init(&ctx->sec_models[idx][k], 2 + i,
155 }
156 
158  uint8_t *ngb, int num_ngb, int any_ngb)
159 {
160  int i, val, pix;
161 
162  val = acoder->get_model_sym(acoder, &pctx->cache_model);
163  if (val < pctx->num_syms) {
164  if (any_ngb) {
165  int idx, j;
166 
167  idx = 0;
168  for (i = 0; i < pctx->cache_size; i++) {
169  for (j = 0; j < num_ngb; j++)
170  if (pctx->cache[i] == ngb[j])
171  break;
172  if (j == num_ngb) {
173  if (idx == val)
174  break;
175  idx++;
176  }
177  }
178  val = FFMIN(i, pctx->cache_size - 1);
179  }
180  pix = pctx->cache[val];
181  } else {
182  pix = acoder->get_model_sym(acoder, &pctx->full_model);
183  for (i = 0; i < pctx->cache_size - 1; i++)
184  if (pctx->cache[i] == pix)
185  break;
186  val = i;
187  }
188  if (val) {
189  for (i = val; i > 0; i--)
190  pctx->cache[i] = pctx->cache[i - 1];
191  pctx->cache[0] = pix;
192  }
193 
194  return pix;
195 }
196 
198  uint8_t *src, int stride, int x, int y,
199  int has_right)
200 {
201  uint8_t neighbours[4];
202  uint8_t ref_pix[4];
203  int nlen;
204  int layer = 0, sub;
205  int pix;
206  int i, j;
207 
208  if (!y) {
209  memset(neighbours, src[-1], 4);
210  } else {
211  neighbours[TOP] = src[-stride];
212  if (!x) {
213  neighbours[TOP_LEFT] = neighbours[LEFT] = neighbours[TOP];
214  } else {
215  neighbours[TOP_LEFT] = src[-stride - 1];
216  neighbours[ LEFT] = src[-1];
217  }
218  if (has_right)
219  neighbours[TOP_RIGHT] = src[-stride + 1];
220  else
221  neighbours[TOP_RIGHT] = neighbours[TOP];
222  }
223 
224  sub = 0;
225  if (x >= 2 && src[-2] == neighbours[LEFT])
226  sub = 1;
227  if (y >= 2 && src[-2 * stride] == neighbours[TOP])
228  sub |= 2;
229 
230  nlen = 1;
231  ref_pix[0] = neighbours[0];
232  for (i = 1; i < 4; i++) {
233  for (j = 0; j < nlen; j++)
234  if (ref_pix[j] == neighbours[i])
235  break;
236  if (j == nlen)
237  ref_pix[nlen++] = neighbours[i];
238  }
239 
240  switch (nlen) {
241  case 1:
242  layer = 0;
243  break;
244  case 2:
245  if (neighbours[TOP] == neighbours[TOP_LEFT]) {
246  if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT])
247  layer = 1;
248  else if (neighbours[LEFT] == neighbours[TOP_LEFT])
249  layer = 2;
250  else
251  layer = 3;
252  } else if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT]) {
253  if (neighbours[LEFT] == neighbours[TOP_LEFT])
254  layer = 4;
255  else
256  layer = 5;
257  } else if (neighbours[LEFT] == neighbours[TOP_LEFT]) {
258  layer = 6;
259  } else {
260  layer = 7;
261  }
262  break;
263  case 3:
264  if (neighbours[TOP] == neighbours[TOP_LEFT])
265  layer = 8;
266  else if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT])
267  layer = 9;
268  else if (neighbours[LEFT] == neighbours[TOP_LEFT])
269  layer = 10;
270  else if (neighbours[TOP_RIGHT] == neighbours[TOP])
271  layer = 11;
272  else if (neighbours[TOP] == neighbours[LEFT])
273  layer = 12;
274  else
275  layer = 13;
276  break;
277  case 4:
278  layer = 14;
279  break;
280  }
281 
282  pix = acoder->get_model_sym(acoder,
283  &pctx->sec_models[layer][sub]);
284  if (pix < nlen)
285  return ref_pix[pix];
286  else
287  return decode_pixel(acoder, pctx, ref_pix, nlen, 1);
288 }
289 
290 static int decode_region(ArithCoder *acoder, uint8_t *dst, uint8_t *rgb_pic,
291  int x, int y, int width, int height, int stride,
292  int rgb_stride, PixContext *pctx, const uint32_t *pal)
293 {
294  int i, j, p;
295  uint8_t *rgb_dst = rgb_pic + x * 3 + y * rgb_stride;
296 
297  dst += x + y * stride;
298 
299  for (j = 0; j < height; j++) {
300  for (i = 0; i < width; i++) {
301  if (!i && !j)
302  p = decode_pixel(acoder, pctx, NULL, 0, 0);
303  else
304  p = decode_pixel_in_context(acoder, pctx, dst + i, stride,
305  i, j, width - i - 1);
306  dst[i] = p;
307 
308  if (rgb_pic)
309  AV_WB24(rgb_dst + i * 3, pal[p]);
310  }
311  dst += stride;
312  rgb_dst += rgb_stride;
313  }
314 
315  return 0;
316 }
317 
318 static void copy_rectangles(MSS12Context const *c,
319  int x, int y, int width, int height)
320 {
321  int j;
322 
323  if (c->last_rgb_pic)
324  for (j = y; j < y + height; j++) {
325  memcpy(c->rgb_pic + j * c->rgb_stride + x * 3,
326  c->last_rgb_pic + j * c->rgb_stride + x * 3,
327  width * 3);
328  memcpy(c->pal_pic + j * c->pal_stride + x,
329  c->last_pal_pic + j * c->pal_stride + x,
330  width);
331  }
332 }
333 
335  int x, int y, int width, int height)
336 {
337  if (x + c->mvX < 0 || x + c->mvX + width > c->avctx->width ||
338  y + c->mvY < 0 || y + c->mvY + height > c->avctx->height ||
339  !c->rgb_pic)
340  return -1;
341  else {
342  uint8_t *dst = c->pal_pic + x + y * c->pal_stride;
343  uint8_t *rgb_dst = c->rgb_pic + x * 3 + y * c->rgb_stride;
344  uint8_t *src;
345  uint8_t *rgb_src;
346  int j;
347  x += c->mvX;
348  y += c->mvY;
349  if (c->last_rgb_pic) {
350  src = c->last_pal_pic + x + y * c->pal_stride;
351  rgb_src = c->last_rgb_pic + x * 3 + y * c->rgb_stride;
352  } else {
353  src = c->pal_pic + x + y * c->pal_stride;
354  rgb_src = c->rgb_pic + x * 3 + y * c->rgb_stride;
355  }
356  for (j = 0; j < height; j++) {
357  memmove(dst, src, width);
358  memmove(rgb_dst, rgb_src, width * 3);
359  dst += c->pal_stride;
360  src += c->pal_stride;
361  rgb_dst += c->rgb_stride;
362  rgb_src += c->rgb_stride;
363  }
364  }
365  return 0;
366 }
367 
368 static int decode_region_masked(MSS12Context const *c, ArithCoder *acoder,
369  uint8_t *dst, int stride, uint8_t *mask,
370  int mask_stride, int x, int y,
371  int width, int height,
372  PixContext *pctx)
373 {
374  int i, j, p;
375  uint8_t *rgb_dst = c->rgb_pic + x * 3 + y * c->rgb_stride;
376 
377  dst += x + y * stride;
378  mask += x + y * mask_stride;
379 
380  for (j = 0; j < height; j++) {
381  for (i = 0; i < width; i++) {
382  if (c->avctx->err_recognition & AV_EF_EXPLODE &&
383  ( c->rgb_pic && mask[i] != 0x01 && mask[i] != 0x02 && mask[i] != 0x04 ||
384  !c->rgb_pic && mask[i] != 0x80 && mask[i] != 0xFF))
385  return -1;
386 
387  if (mask[i] == 0x02) {
388  copy_rectangles(c, x + i, y + j, 1, 1);
389  } else if (mask[i] == 0x04) {
390  if (motion_compensation(c, x + i, y + j, 1, 1))
391  return -1;
392  } else if (mask[i] != 0x80) {
393  if (!i && !j)
394  p = decode_pixel(acoder, pctx, NULL, 0, 0);
395  else
396  p = decode_pixel_in_context(acoder, pctx, dst + i, stride,
397  i, j, width - i - 1);
398  dst[i] = p;
399  if (c->rgb_pic)
400  AV_WB24(rgb_dst + i * 3, c->pal[p]);
401  }
402  }
403  dst += stride;
404  mask += mask_stride;
405  rgb_dst += c->rgb_stride;
406  }
407 
408  return 0;
409 }
410 
412  int version, int full_model_syms)
413 {
417  model_init(&sc->edge_mode, 2, THRESH_HIGH);
418  model_init(&sc->pivot, 3, THRESH_LOW);
419 
420  pixctx_init(&sc->intra_pix_ctx, 8, full_model_syms, 0);
421 
422  pixctx_init(&sc->inter_pix_ctx, version ? 3 : 2,
423  full_model_syms, version ? 1 : 0);
424 }
425 
427 {
430  model_reset(&sc->split_mode);
431  model_reset(&sc->edge_mode);
432  model_reset(&sc->pivot);
435 }
436 
437 static int decode_pivot(SliceContext *sc, ArithCoder *acoder, int base)
438 {
439  int val, inv;
440 
441  inv = acoder->get_model_sym(acoder, &sc->edge_mode);
442  val = acoder->get_model_sym(acoder, &sc->pivot) + 1;
443 
444  if (val > 2) {
445  if ((base + 1) / 2 - 2 <= 0)
446  return -1;
447 
448  val = acoder->get_number(acoder, (base + 1) / 2 - 2) + 3;
449  }
450 
451  if ((unsigned)val >= base)
452  return -1;
453 
454  return inv ? base - val : val;
455 }
456 
458  int x, int y, int width, int height)
459 {
460  MSS12Context const *c = sc->c;
461  int mode;
462 
463  mode = acoder->get_model_sym(acoder, &sc->intra_region);
464 
465  if (!mode) {
466  int i, j, pix, rgb_pix;
467  int stride = c->pal_stride;
468  int rgb_stride = c->rgb_stride;
469  uint8_t *dst = c->pal_pic + x + y * stride;
470  uint8_t *rgb_dst = c->rgb_pic + x * 3 + y * rgb_stride;
471 
472  pix = decode_pixel(acoder, &sc->intra_pix_ctx, NULL, 0, 0);
473  rgb_pix = c->pal[pix];
474  for (i = 0; i < height; i++, dst += stride, rgb_dst += rgb_stride) {
475  memset(dst, pix, width);
476  if (c->rgb_pic)
477  for (j = 0; j < width * 3; j += 3)
478  AV_WB24(rgb_dst + j, rgb_pix);
479  }
480  } else {
481  return decode_region(acoder, c->pal_pic, c->rgb_pic,
482  x, y, width, height, c->pal_stride, c->rgb_stride,
483  &sc->intra_pix_ctx, &c->pal[0]);
484  }
485 
486  return 0;
487 }
488 
490  int x, int y, int width, int height)
491 {
492  MSS12Context const *c = sc->c;
493  int mode;
494 
495  mode = acoder->get_model_sym(acoder, &sc->inter_region);
496 
497  if (!mode) {
498  mode = decode_pixel(acoder, &sc->inter_pix_ctx, NULL, 0, 0);
499 
500  if (c->avctx->err_recognition & AV_EF_EXPLODE &&
501  ( c->rgb_pic && mode != 0x01 && mode != 0x02 && mode != 0x04 ||
502  !c->rgb_pic && mode != 0x80 && mode != 0xFF))
503  return -1;
504 
505  if (mode == 0x02)
506  copy_rectangles(c, x, y, width, height);
507  else if (mode == 0x04)
508  return motion_compensation(c, x, y, width, height);
509  else if (mode != 0x80)
510  return decode_region_intra(sc, acoder, x, y, width, height);
511  } else {
512  if (decode_region(acoder, c->mask, NULL,
513  x, y, width, height, c->mask_stride, 0,
514  &sc->inter_pix_ctx, &c->pal[0]) < 0)
515  return -1;
516  return decode_region_masked(c, acoder, c->pal_pic,
517  c->pal_stride, c->mask,
518  c->mask_stride,
519  x, y, width, height,
520  &sc->intra_pix_ctx);
521  }
522 
523  return 0;
524 }
525 
527  int x, int y, int width, int height)
528 {
529  int mode, pivot;
530 
531  mode = acoder->get_model_sym(acoder, &sc->split_mode);
532 
533  switch (mode) {
534  case SPLIT_VERT:
535  if ((pivot = decode_pivot(sc, acoder, height)) < 1)
536  return -1;
537  if (ff_mss12_decode_rect(sc, acoder, x, y, width, pivot))
538  return -1;
539  if (ff_mss12_decode_rect(sc, acoder, x, y + pivot, width, height - pivot))
540  return -1;
541  break;
542  case SPLIT_HOR:
543  if ((pivot = decode_pivot(sc, acoder, width)) < 1)
544  return -1;
545  if (ff_mss12_decode_rect(sc, acoder, x, y, pivot, height))
546  return -1;
547  if (ff_mss12_decode_rect(sc, acoder, x + pivot, y, width - pivot, height))
548  return -1;
549  break;
550  case SPLIT_NONE:
551  if (sc->c->keyframe)
552  return decode_region_intra(sc, acoder, x, y, width, height);
553  else
554  return decode_region_inter(sc, acoder, x, y, width, height);
555  default:
556  return -1;
557  }
558 
559  return 0;
560 }
561 
563  SliceContext* sc1, SliceContext *sc2)
564 {
565  AVCodecContext *avctx = c->avctx;
566  int i;
567 
568  if (avctx->extradata_size < 52 + 256 * 3) {
569  av_log(avctx, AV_LOG_ERROR, "Insufficient extradata size %d\n",
570  avctx->extradata_size);
571  return AVERROR_INVALIDDATA;
572  }
573 
574  if (AV_RB32(avctx->extradata) < avctx->extradata_size) {
575  av_log(avctx, AV_LOG_ERROR,
576  "Insufficient extradata size: expected %d got %d\n",
577  AV_RB32(avctx->extradata),
578  avctx->extradata_size);
579  return AVERROR_INVALIDDATA;
580  }
581 
582  avctx->coded_width = AV_RB32(avctx->extradata + 20);
583  avctx->coded_height = AV_RB32(avctx->extradata + 24);
584  if (avctx->coded_width > 4096 || avctx->coded_height > 4096) {
585  av_log(avctx, AV_LOG_ERROR, "Frame dimensions %dx%d too large",
586  avctx->coded_width, avctx->coded_height);
587  return AVERROR_INVALIDDATA;
588  }
589 
590  av_log(avctx, AV_LOG_DEBUG, "Encoder version %d.%d\n",
591  AV_RB32(avctx->extradata + 4), AV_RB32(avctx->extradata + 8));
592  if (version != AV_RB32(avctx->extradata + 4) > 1) {
593  av_log(avctx, AV_LOG_ERROR,
594  "Header version doesn't match codec tag\n");
595  return -1;
596  }
597 
598  c->free_colours = AV_RB32(avctx->extradata + 48);
599  if ((unsigned)c->free_colours > 256) {
600  av_log(avctx, AV_LOG_ERROR,
601  "Incorrect number of changeable palette entries: %d\n",
602  c->free_colours);
603  return AVERROR_INVALIDDATA;
604  }
605  av_log(avctx, AV_LOG_DEBUG, "%d free colour(s)\n", c->free_colours);
606 
607  av_log(avctx, AV_LOG_DEBUG, "Display dimensions %dx%d\n",
608  AV_RB32(avctx->extradata + 12), AV_RB32(avctx->extradata + 16));
609  av_log(avctx, AV_LOG_DEBUG, "Coded dimensions %dx%d\n",
610  avctx->coded_width, avctx->coded_height);
611  av_log(avctx, AV_LOG_DEBUG, "%g frames per second\n",
612  av_int2float(AV_RB32(avctx->extradata + 28)));
613  av_log(avctx, AV_LOG_DEBUG, "Bitrate %d bps\n",
614  AV_RB32(avctx->extradata + 32));
615  av_log(avctx, AV_LOG_DEBUG, "Max. lead time %g ms\n",
616  av_int2float(AV_RB32(avctx->extradata + 36)));
617  av_log(avctx, AV_LOG_DEBUG, "Max. lag time %g ms\n",
618  av_int2float(AV_RB32(avctx->extradata + 40)));
619  av_log(avctx, AV_LOG_DEBUG, "Max. seek time %g ms\n",
620  av_int2float(AV_RB32(avctx->extradata + 44)));
621 
622  if (version) {
623  if (avctx->extradata_size < 60 + 256 * 3) {
624  av_log(avctx, AV_LOG_ERROR,
625  "Insufficient extradata size %d for v2\n",
626  avctx->extradata_size);
627  return AVERROR_INVALIDDATA;
628  }
629 
630  c->slice_split = AV_RB32(avctx->extradata + 52);
631  av_log(avctx, AV_LOG_DEBUG, "Slice split %d\n", c->slice_split);
632 
633  c->full_model_syms = AV_RB32(avctx->extradata + 56);
634  if (c->full_model_syms < 2 || c->full_model_syms > 256) {
635  av_log(avctx, AV_LOG_ERROR,
636  "Incorrect number of used colours %d\n",
637  c->full_model_syms);
638  return AVERROR_INVALIDDATA;
639  }
640  av_log(avctx, AV_LOG_DEBUG, "Used colours %d\n",
641  c->full_model_syms);
642  } else {
643  c->slice_split = 0;
644  c->full_model_syms = 256;
645  }
646 
647  for (i = 0; i < 256; i++)
648  c->pal[i] = 0xFFU << 24 | AV_RB24(avctx->extradata + 52 +
649  (version ? 8 : 0) + i * 3);
650 
651  c->mask_stride = FFALIGN(avctx->width, 16);
652  c->mask = av_malloc(c->mask_stride * avctx->height);
653  if (!c->mask) {
654  av_log(avctx, AV_LOG_ERROR, "Cannot allocate mask plane\n");
655  return AVERROR(ENOMEM);
656  }
657 
658  sc1->c = c;
659  slicecontext_init(sc1, version, c->full_model_syms);
660  if (c->slice_split) {
661  sc2->c = c;
662  slicecontext_init(sc2, version, c->full_model_syms);
663  }
664  c->corrupted = 1;
665 
666  return 0;
667 }
668 
670 {
671  av_freep(&c->mask);
672 
673  return 0;
674 }