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mss2.c
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1 /*
2  * Microsoft Screen 2 (aka Windows Media Video V9 Screen) decoder
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  * Microsoft Screen 2 (aka Windows Media Video V9 Screen) decoder
24  */
25 
26 #include "libavutil/avassert.h"
27 #include "error_resilience.h"
28 #include "internal.h"
29 #include "msmpeg4data.h"
30 #include "vc1.h"
31 #include "mss12.h"
32 #include "mss2dsp.h"
33 
34 typedef struct MSS2Context {
41 } MSS2Context;
42 
44 {
45  while ((c->high >> 15) - (c->low >> 15) < 2) {
46  if ((c->low ^ c->high) & 0x10000) {
47  c->high ^= 0x8000;
48  c->value ^= 0x8000;
49  c->low ^= 0x8000;
50  }
51  c->high = c->high << 8 & 0xFFFFFF | 0xFF;
52  c->value = c->value << 8 & 0xFFFFFF | bytestream2_get_byte(c->gbc.gB);
53  c->low = c->low << 8 & 0xFFFFFF;
54  }
55 }
56 
58 
59 /* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
60  * In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
61 
62 static int arith2_get_scaled_value(int value, int n, int range)
63 {
64  int split = (n << 1) - range;
65 
66  if (value > split)
67  return split + (value - split >> 1);
68  else
69  return value;
70 }
71 
72 static void arith2_rescale_interval(ArithCoder *c, int range,
73  int low, int high, int n)
74 {
75  int split = (n << 1) - range;
76 
77  if (high > split)
78  c->high = split + (high - split << 1);
79  else
80  c->high = high;
81 
82  c->high += c->low - 1;
83 
84  if (low > split)
85  c->low += split + (low - split << 1);
86  else
87  c->low += low;
88 }
89 
90 static int arith2_get_number(ArithCoder *c, int n)
91 {
92  int range = c->high - c->low + 1;
93  int scale = av_log2(range) - av_log2(n);
94  int val;
95 
96  if (n << scale > range)
97  scale--;
98 
99  n <<= scale;
100 
101  val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
102 
103  arith2_rescale_interval(c, range, val << scale, (val + 1) << scale, n);
104 
105  arith2_normalise(c);
106 
107  return val;
108 }
109 
110 static int arith2_get_prob(ArithCoder *c, int16_t *probs)
111 {
112  int range = c->high - c->low + 1, n = *probs;
113  int scale = av_log2(range) - av_log2(n);
114  int i = 0, val;
115 
116  if (n << scale > range)
117  scale--;
118 
119  n <<= scale;
120 
121  val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
122  while (probs[++i] > val) ;
123 
124  arith2_rescale_interval(c, range,
125  probs[i] << scale, probs[i - 1] << scale, n);
126 
127  return i;
128 }
129 
131 
133 {
134  int diff = (c->high >> 16) - (c->low >> 16);
135  int bp = bytestream2_tell(c->gbc.gB) - 3 << 3;
136  int bits = 1;
137 
138  while (!(diff & 0x80)) {
139  bits++;
140  diff <<= 1;
141  }
142 
143  return (bits + bp + 7 >> 3) + ((c->low >> 16) + 1 == c->high >> 16);
144 }
145 
147 {
148  c->low = 0;
149  c->high = 0xFFFFFF;
150  c->value = bytestream2_get_be24(gB);
151  c->gbc.gB = gB;
152  c->get_model_sym = arith2_get_model_sym;
154 }
155 
156 static int decode_pal_v2(MSS12Context *ctx, const uint8_t *buf, int buf_size)
157 {
158  int i, ncol;
159  uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
160 
161  if (!ctx->free_colours)
162  return 0;
163 
164  ncol = *buf++;
165  if (ncol > ctx->free_colours || buf_size < 2 + ncol * 3)
166  return AVERROR_INVALIDDATA;
167  for (i = 0; i < ncol; i++)
168  *pal++ = AV_RB24(buf + 3 * i);
169 
170  return 1 + ncol * 3;
171 }
172 
173 static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
174  int keyframe, int w, int h)
175 {
176  int last_symbol = 0, repeat = 0, prev_avail = 0;
177 
178  if (!keyframe) {
179  int x, y, endx, endy, t;
180 
181 #define READ_PAIR(a, b) \
182  a = bytestream2_get_byte(gB) << 4; \
183  t = bytestream2_get_byte(gB); \
184  a |= t >> 4; \
185  b = (t & 0xF) << 8; \
186  b |= bytestream2_get_byte(gB); \
187 
188  READ_PAIR(x, endx)
189  READ_PAIR(y, endy)
190 
191  if (endx >= w || endy >= h || x > endx || y > endy)
192  return AVERROR_INVALIDDATA;
193  dst += x + stride * y;
194  w = endx - x + 1;
195  h = endy - y + 1;
196  if (y)
197  prev_avail = 1;
198  }
199 
200  do {
201  uint16_t *p = dst;
202  do {
203  if (repeat-- < 1) {
204  int b = bytestream2_get_byte(gB);
205  if (b < 128)
206  last_symbol = b << 8 | bytestream2_get_byte(gB);
207  else if (b > 129) {
208  repeat = 0;
209  while (b-- > 130)
210  repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
211  if (last_symbol == -2) {
212  int skip = FFMIN((unsigned)repeat, dst + w - p);
213  repeat -= skip;
214  p += skip;
215  }
216  } else
217  last_symbol = 127 - b;
218  }
219  if (last_symbol >= 0)
220  *p = last_symbol;
221  else if (last_symbol == -1 && prev_avail)
222  *p = *(p - stride);
223  } while (++p < dst + w);
224  dst += stride;
225  prev_avail = 1;
226  } while (--h);
227 
228  return 0;
229 }
230 
231 static int decode_rle(GetBitContext *gb, uint8_t *pal_dst, int pal_stride,
232  uint8_t *rgb_dst, int rgb_stride, uint32_t *pal,
233  int keyframe, int kf_slipt, int slice, int w, int h)
234 {
235  uint8_t bits[270] = { 0 };
236  uint32_t codes[270];
237  VLC vlc;
238 
239  int current_length = 0, read_codes = 0, next_code = 0, current_codes = 0;
240  int remaining_codes, surplus_codes, i;
241 
242  const int alphabet_size = 270 - keyframe;
243 
244  int last_symbol = 0, repeat = 0, prev_avail = 0;
245 
246  if (!keyframe) {
247  int x, y, clipw, cliph;
248 
249  x = get_bits(gb, 12);
250  y = get_bits(gb, 12);
251  clipw = get_bits(gb, 12) + 1;
252  cliph = get_bits(gb, 12) + 1;
253 
254  if (x + clipw > w || y + cliph > h)
255  return AVERROR_INVALIDDATA;
256  pal_dst += pal_stride * y + x;
257  rgb_dst += rgb_stride * y + x * 3;
258  w = clipw;
259  h = cliph;
260  if (y)
261  prev_avail = 1;
262  } else {
263  if (slice > 0) {
264  pal_dst += pal_stride * kf_slipt;
265  rgb_dst += rgb_stride * kf_slipt;
266  prev_avail = 1;
267  h -= kf_slipt;
268  } else
269  h = kf_slipt;
270  }
271 
272  /* read explicit codes */
273  do {
274  while (current_codes--) {
275  int symbol = get_bits(gb, 8);
276  if (symbol >= 204 - keyframe)
277  symbol += 14 - keyframe;
278  else if (symbol > 189)
279  symbol = get_bits1(gb) + (symbol << 1) - 190;
280  if (bits[symbol])
281  return AVERROR_INVALIDDATA;
282  bits[symbol] = current_length;
283  codes[symbol] = next_code++;
284  read_codes++;
285  }
286  current_length++;
287  next_code <<= 1;
288  remaining_codes = (1 << current_length) - next_code;
289  current_codes = get_bits(gb, av_ceil_log2(remaining_codes + 1));
290  if (current_length > 22 || current_codes > remaining_codes)
291  return AVERROR_INVALIDDATA;
292  } while (current_codes != remaining_codes);
293 
294  remaining_codes = alphabet_size - read_codes;
295 
296  /* determine the minimum length to fit the rest of the alphabet */
297  while ((surplus_codes = (2 << current_length) -
298  (next_code << 1) - remaining_codes) < 0) {
299  current_length++;
300  next_code <<= 1;
301  }
302 
303  /* add the rest of the symbols lexicographically */
304  for (i = 0; i < alphabet_size; i++)
305  if (!bits[i]) {
306  if (surplus_codes-- == 0) {
307  current_length++;
308  next_code <<= 1;
309  }
310  bits[i] = current_length;
311  codes[i] = next_code++;
312  }
313 
314  if (next_code != 1 << current_length)
315  return AVERROR_INVALIDDATA;
316 
317  if (i = init_vlc(&vlc, 9, alphabet_size, bits, 1, 1, codes, 4, 4, 0))
318  return i;
319 
320  /* frame decode */
321  do {
322  uint8_t *pp = pal_dst;
323  uint8_t *rp = rgb_dst;
324  do {
325  if (repeat-- < 1) {
326  int b = get_vlc2(gb, vlc.table, 9, 3);
327  if (b < 256)
328  last_symbol = b;
329  else if (b < 268) {
330  b -= 256;
331  if (b == 11)
332  b = get_bits(gb, 4) + 10;
333 
334  if (!b)
335  repeat = 0;
336  else
337  repeat = get_bits(gb, b);
338 
339  repeat += (1 << b) - 1;
340 
341  if (last_symbol == -2) {
342  int skip = FFMIN(repeat, pal_dst + w - pp);
343  repeat -= skip;
344  pp += skip;
345  rp += skip * 3;
346  }
347  } else
348  last_symbol = 267 - b;
349  }
350  if (last_symbol >= 0) {
351  *pp = last_symbol;
352  AV_WB24(rp, pal[last_symbol]);
353  } else if (last_symbol == -1 && prev_avail) {
354  *pp = *(pp - pal_stride);
355  memcpy(rp, rp - rgb_stride, 3);
356  }
357  rp += 3;
358  } while (++pp < pal_dst + w);
359  pal_dst += pal_stride;
360  rgb_dst += rgb_stride;
361  prev_avail = 1;
362  } while (--h);
363 
364  ff_free_vlc(&vlc);
365  return 0;
366 }
367 
368 static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
369  int x, int y, int w, int h, int wmv9_mask)
370 {
371  MSS2Context *ctx = avctx->priv_data;
372  MSS12Context *c = &ctx->c;
373  VC1Context *v = avctx->priv_data;
374  MpegEncContext *s = &v->s;
375  AVFrame *f;
376  int ret;
377 
378  ff_mpeg_flush(avctx);
379 
380  if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
381  int i = ff_find_unused_picture(s, 0);
382  if (i < 0)
383  return i;
384  s->current_picture_ptr = &s->picture[i];
385  }
386 
387  init_get_bits(&s->gb, buf, buf_size * 8);
388 
390 
391  if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
392  av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
393  return AVERROR_INVALIDDATA;
394  }
395 
396  if (s->pict_type != AV_PICTURE_TYPE_I) {
397  av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
398  return AVERROR_INVALIDDATA;
399  }
400 
401  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
402 
403  if ((ret = ff_MPV_frame_start(s, avctx)) < 0) {
404  av_log(v->s.avctx, AV_LOG_ERROR, "ff_MPV_frame_start error\n");
405  avctx->pix_fmt = AV_PIX_FMT_RGB24;
406  return ret;
407  }
408 
410 
411  v->bits = buf_size * 8;
412 
413  v->end_mb_x = (w + 15) >> 4;
414  s->end_mb_y = (h + 15) >> 4;
415  if (v->respic & 1)
416  v->end_mb_x = v->end_mb_x + 1 >> 1;
417  if (v->respic & 2)
418  s->end_mb_y = s->end_mb_y + 1 >> 1;
419 
421 
422  ff_er_frame_end(&s->er);
423 
424  ff_MPV_frame_end(s);
425 
426  f = &s->current_picture.f;
427 
428  if (v->respic == 3) {
429  ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
430  ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w >> 1, h >> 1);
431  ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w >> 1, h >> 1);
432  } else if (v->respic)
434  "Asymmetric WMV9 rectangle subsampling");
435 
436  av_assert0(f->linesize[1] == f->linesize[2]);
437 
438  if (wmv9_mask != -1)
439  ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
440  c->rgb_stride, wmv9_mask,
441  c->pal_pic + y * c->pal_stride + x,
442  c->pal_stride,
443  f->data[0], f->linesize[0],
444  f->data[1], f->data[2], f->linesize[1],
445  w, h);
446  else
447  ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
448  c->rgb_stride,
449  f->data[0], f->linesize[0],
450  f->data[1], f->data[2], f->linesize[1],
451  w, h);
452 
453  avctx->pix_fmt = AV_PIX_FMT_RGB24;
454 
455  return 0;
456 }
457 
458 typedef struct Rectangle {
459  int coded, x, y, w, h;
460 } Rectangle;
461 
462 #define MAX_WMV9_RECTANGLES 20
463 #define ARITH2_PADDING 2
464 
465 static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
466  AVPacket *avpkt)
467 {
468  const uint8_t *buf = avpkt->data;
469  int buf_size = avpkt->size;
470  MSS2Context *ctx = avctx->priv_data;
471  MSS12Context *c = &ctx->c;
472  AVFrame *frame = data;
473  GetBitContext gb;
474  GetByteContext gB;
475  ArithCoder acoder;
476 
477  int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
478 
479  Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
480  int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
481 
483  ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
484 
485  init_get_bits(&gb, buf, buf_size * 8);
486 
487  if (keyframe = get_bits1(&gb))
488  skip_bits(&gb, 7);
489  has_wmv9 = get_bits1(&gb);
490  has_mv = keyframe ? 0 : get_bits1(&gb);
491  is_rle = get_bits1(&gb);
492  is_555 = is_rle && get_bits1(&gb);
493  if (c->slice_split > 0)
494  ctx->split_position = c->slice_split;
495  else if (c->slice_split < 0) {
496  if (get_bits1(&gb)) {
497  if (get_bits1(&gb)) {
498  if (get_bits1(&gb))
499  ctx->split_position = get_bits(&gb, 16);
500  else
501  ctx->split_position = get_bits(&gb, 12);
502  } else
503  ctx->split_position = get_bits(&gb, 8) << 4;
504  } else {
505  if (keyframe)
506  ctx->split_position = avctx->height / 2;
507  }
508  } else
509  ctx->split_position = avctx->height;
510 
511  if (c->slice_split && (ctx->split_position < 1 - is_555 ||
512  ctx->split_position > avctx->height - 1))
513  return AVERROR_INVALIDDATA;
514 
515  align_get_bits(&gb);
516  buf += get_bits_count(&gb) >> 3;
517  buf_size -= get_bits_count(&gb) >> 3;
518 
519  if (buf_size < 1)
520  return AVERROR_INVALIDDATA;
521 
522  if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
523  return AVERROR_INVALIDDATA;
524 
525  avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
526  if (ctx->last_pic.format != avctx->pix_fmt)
527  av_frame_unref(&ctx->last_pic);
528 
529  if (has_wmv9) {
530  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
531  arith2_init(&acoder, &gB);
532 
533  implicit_rect = !arith2_get_bit(&acoder);
534 
535  while (arith2_get_bit(&acoder)) {
536  if (used_rects == MAX_WMV9_RECTANGLES)
537  return AVERROR_INVALIDDATA;
538  r = &wmv9rects[used_rects];
539  if (!used_rects)
540  r->x = arith2_get_number(&acoder, avctx->width);
541  else
542  r->x = arith2_get_number(&acoder, avctx->width -
543  wmv9rects[used_rects - 1].x) +
544  wmv9rects[used_rects - 1].x;
545  r->y = arith2_get_number(&acoder, avctx->height);
546  r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
547  r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
548  used_rects++;
549  }
550 
551  if (implicit_rect && used_rects) {
552  av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
553  return AVERROR_INVALIDDATA;
554  }
555 
556  if (implicit_rect) {
557  wmv9rects[0].x = 0;
558  wmv9rects[0].y = 0;
559  wmv9rects[0].w = avctx->width;
560  wmv9rects[0].h = avctx->height;
561 
562  used_rects = 1;
563  }
564  for (i = 0; i < used_rects; i++) {
565  if (!implicit_rect && arith2_get_bit(&acoder)) {
566  av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
567  return AVERROR_INVALIDDATA;
568  }
569  if (!i) {
570  wmv9_mask = arith2_get_bit(&acoder) - 1;
571  if (!wmv9_mask)
572  wmv9_mask = arith2_get_number(&acoder, 256);
573  }
574  wmv9rects[i].coded = arith2_get_number(&acoder, 2);
575  }
576 
577  buf += arith2_get_consumed_bytes(&acoder);
578  buf_size -= arith2_get_consumed_bytes(&acoder);
579  if (buf_size < 1)
580  return AVERROR_INVALIDDATA;
581  }
582 
583  c->mvX = c->mvY = 0;
584  if (keyframe && !is_555) {
585  if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
586  return AVERROR_INVALIDDATA;
587  buf += i;
588  buf_size -= i;
589  } else if (has_mv) {
590  buf += 4;
591  buf_size -= 4;
592  if (buf_size < 1)
593  return AVERROR_INVALIDDATA;
594  c->mvX = AV_RB16(buf - 4) - avctx->width;
595  c->mvY = AV_RB16(buf - 2) - avctx->height;
596  }
597 
598  if (c->mvX < 0 || c->mvY < 0) {
599  FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
600 
601  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
602  return ret;
603 
604  if (ctx->last_pic.data[0]) {
605  av_assert0(frame->linesize[0] == ctx->last_pic.linesize[0]);
606  c->last_rgb_pic = ctx->last_pic.data[0] +
607  ctx->last_pic.linesize[0] * (avctx->height - 1);
608  } else {
609  av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
610  return AVERROR_INVALIDDATA;
611  }
612  } else {
613  if ((ret = ff_reget_buffer(avctx, &ctx->last_pic)) < 0)
614  return ret;
615  if ((ret = av_frame_ref(frame, &ctx->last_pic)) < 0)
616  return ret;
617 
618  c->last_rgb_pic = NULL;
619  }
620  c->rgb_pic = frame->data[0] +
621  frame->linesize[0] * (avctx->height - 1);
622  c->rgb_stride = -frame->linesize[0];
623 
624  frame->key_frame = keyframe;
625  frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
626 
627  if (is_555) {
628  bytestream2_init(&gB, buf, buf_size);
629 
630  if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
631  keyframe, avctx->width, avctx->height))
632  return AVERROR_INVALIDDATA;
633 
634  buf_size -= bytestream2_tell(&gB);
635  } else {
636  if (keyframe) {
637  c->corrupted = 0;
639  if (c->slice_split)
641  }
642  if (is_rle) {
643  init_get_bits(&gb, buf, buf_size * 8);
644  if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
645  c->rgb_pic, c->rgb_stride, c->pal, keyframe,
646  ctx->split_position, 0,
647  avctx->width, avctx->height))
648  return ret;
649  align_get_bits(&gb);
650 
651  if (c->slice_split)
652  if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
653  c->rgb_pic, c->rgb_stride, c->pal, keyframe,
654  ctx->split_position, 1,
655  avctx->width, avctx->height))
656  return ret;
657 
658  align_get_bits(&gb);
659  buf += get_bits_count(&gb) >> 3;
660  buf_size -= get_bits_count(&gb) >> 3;
661  } else if (!implicit_rect || wmv9_mask != -1) {
662  if (c->corrupted)
663  return AVERROR_INVALIDDATA;
664  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
665  arith2_init(&acoder, &gB);
666  c->keyframe = keyframe;
667  if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
668  avctx->width,
669  ctx->split_position))
670  return AVERROR_INVALIDDATA;
671 
672  buf += arith2_get_consumed_bytes(&acoder);
673  buf_size -= arith2_get_consumed_bytes(&acoder);
674  if (c->slice_split) {
675  if (buf_size < 1)
676  return AVERROR_INVALIDDATA;
677  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
678  arith2_init(&acoder, &gB);
679  if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
680  ctx->split_position,
681  avctx->width,
682  avctx->height - ctx->split_position))
683  return AVERROR_INVALIDDATA;
684 
685  buf += arith2_get_consumed_bytes(&acoder);
686  buf_size -= arith2_get_consumed_bytes(&acoder);
687  }
688  } else
689  memset(c->pal_pic, 0, c->pal_stride * avctx->height);
690  }
691 
692  if (has_wmv9) {
693  for (i = 0; i < used_rects; i++) {
694  int x = wmv9rects[i].x;
695  int y = wmv9rects[i].y;
696  int w = wmv9rects[i].w;
697  int h = wmv9rects[i].h;
698  if (wmv9rects[i].coded) {
699  int WMV9codedFrameSize;
700  if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
701  return AVERROR_INVALIDDATA;
702  if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
703  x, y, w, h, wmv9_mask))
704  return ret;
705  buf += WMV9codedFrameSize + 3;
706  buf_size -= WMV9codedFrameSize + 3;
707  } else {
708  uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
709  if (wmv9_mask != -1) {
710  ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
711  wmv9_mask,
712  c->pal_pic + y * c->pal_stride + x,
713  c->pal_stride,
714  w, h);
715  } else {
716  do {
717  memset(dst, 0x80, w * 3);
718  dst += c->rgb_stride;
719  } while (--h);
720  }
721  }
722  }
723  }
724 
725  if (buf_size)
726  av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
727 
728  if (c->mvX < 0 || c->mvY < 0) {
729  av_frame_unref(&ctx->last_pic);
730  ret = av_frame_ref(&ctx->last_pic, frame);
731  if (ret < 0)
732  return ret;
733  }
734 
735  *got_frame = 1;
736 
737  return avpkt->size;
738 }
739 
740 static av_cold int wmv9_init(AVCodecContext *avctx)
741 {
742  VC1Context *v = avctx->priv_data;
743  int ret;
744 
745  v->s.avctx = avctx;
746  avctx->flags |= CODEC_FLAG_EMU_EDGE;
748 
749  if ((ret = ff_vc1_init_common(v)) < 0)
750  return ret;
751  ff_vc1dsp_init(&v->vc1dsp);
752 
753  v->profile = PROFILE_MAIN;
754 
757  v->res_y411 = 0;
758  v->res_sprite = 0;
759 
760  v->frmrtq_postproc = 7;
761  v->bitrtq_postproc = 31;
762 
763  v->res_x8 = 0;
764  v->multires = 0;
765  v->res_fasttx = 1;
766 
767  v->fastuvmc = 0;
768 
769  v->extended_mv = 0;
770 
771  v->dquant = 1;
772  v->vstransform = 1;
773 
774  v->res_transtab = 0;
775 
776  v->overlap = 0;
777 
778  v->s.resync_marker = 0;
779  v->rangered = 0;
780 
781  v->s.max_b_frames = avctx->max_b_frames = 0;
782  v->quantizer_mode = 0;
783 
784  v->finterpflag = 0;
785 
786  v->res_rtm_flag = 1;
787 
789 
790  if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
791  (ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
792  return ret;
793 
794  /* error concealment */
797 
798  return 0;
799 }
800 
802 {
803  MSS2Context *const ctx = avctx->priv_data;
804 
805  av_frame_unref(&ctx->last_pic);
806 
807  ff_mss12_decode_end(&ctx->c);
808  av_freep(&ctx->c.pal_pic);
809  av_freep(&ctx->c.last_pal_pic);
810  ff_vc1_decode_end(avctx);
811 
812  return 0;
813 }
814 
816 {
817  MSS2Context * const ctx = avctx->priv_data;
818  MSS12Context *c = &ctx->c;
819  int ret;
820  c->avctx = avctx;
821  if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
822  return ret;
823  c->pal_stride = c->mask_stride;
824  c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
825  c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
826  if (!c->pal_pic || !c->last_pal_pic) {
827  mss2_decode_end(avctx);
828  return AVERROR(ENOMEM);
829  }
830  if (ret = wmv9_init(avctx)) {
831  mss2_decode_end(avctx);
832  return ret;
833  }
834  ff_mss2dsp_init(&ctx->dsp);
835 
836  avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
838 
839  return 0;
840 }
841 
843  .name = "mss2",
844  .type = AVMEDIA_TYPE_VIDEO,
845  .id = AV_CODEC_ID_MSS2,
846  .priv_data_size = sizeof(MSS2Context),
850  .capabilities = CODEC_CAP_DR1,
851  .long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
852 };