FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mss2.c
Go to the documentation of this file.
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 "mpeg_er.h"
30 #include "msmpeg4data.h"
31 #include "qpeldsp.h"
32 #include "vc1.h"
33 #include "mss12.h"
34 #include "mss2dsp.h"
35 
36 typedef struct MSS2Context {
44 } MSS2Context;
45 
47 {
48  while ((c->high >> 15) - (c->low >> 15) < 2) {
49  if ((c->low ^ c->high) & 0x10000) {
50  c->high ^= 0x8000;
51  c->value ^= 0x8000;
52  c->low ^= 0x8000;
53  }
54  c->high = c->high << 8 & 0xFFFFFF | 0xFF;
55  c->value = c->value << 8 & 0xFFFFFF | bytestream2_get_byte(c->gbc.gB);
56  c->low = c->low << 8 & 0xFFFFFF;
57  }
58 }
59 
60 ARITH_GET_BIT(arith2)
61 
62 /* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
63  * In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
64 
65 static int arith2_get_scaled_value(int value, int n, int range)
66 {
67  int split = (n << 1) - range;
68 
69  if (value > split)
70  return split + (value - split >> 1);
71  else
72  return value;
73 }
74 
75 static void arith2_rescale_interval(ArithCoder *c, int range,
76  int low, int high, int n)
77 {
78  int split = (n << 1) - range;
79 
80  if (high > split)
81  c->high = split + (high - split << 1);
82  else
83  c->high = high;
84 
85  c->high += c->low - 1;
86 
87  if (low > split)
88  c->low += split + (low - split << 1);
89  else
90  c->low += low;
91 }
92 
93 static int arith2_get_number(ArithCoder *c, int n)
94 {
95  int range = c->high - c->low + 1;
96  int scale = av_log2(range) - av_log2(n);
97  int val;
98 
99  if (n << scale > range)
100  scale--;
101 
102  n <<= scale;
103 
104  val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
105 
106  arith2_rescale_interval(c, range, val << scale, (val + 1) << scale, n);
107 
108  arith2_normalise(c);
109 
110  return val;
111 }
112 
113 static int arith2_get_prob(ArithCoder *c, int16_t *probs)
114 {
115  int range = c->high - c->low + 1, n = *probs;
116  int scale = av_log2(range) - av_log2(n);
117  int i = 0, val;
118 
119  if (n << scale > range)
120  scale--;
121 
122  n <<= scale;
123 
124  val = arith2_get_scaled_value(c->value - c->low, n, range) >> scale;
125  while (probs[++i] > val) ;
126 
127  arith2_rescale_interval(c, range,
128  probs[i] << scale, probs[i - 1] << scale, n);
129 
130  return i;
131 }
132 
133 ARITH_GET_MODEL_SYM(arith2)
134 
136 {
137  int diff = (c->high >> 16) - (c->low >> 16);
138  int bp = bytestream2_tell(c->gbc.gB) - 3 << 3;
139  int bits = 1;
140 
141  while (!(diff & 0x80)) {
142  bits++;
143  diff <<= 1;
144  }
145 
146  return (bits + bp + 7 >> 3) + ((c->low >> 16) + 1 == c->high >> 16);
147 }
148 
150 {
151  c->low = 0;
152  c->high = 0xFFFFFF;
153  c->value = bytestream2_get_be24(gB);
154  c->gbc.gB = gB;
155  c->get_model_sym = arith2_get_model_sym;
157 }
158 
159 static int decode_pal_v2(MSS12Context *ctx, const uint8_t *buf, int buf_size)
160 {
161  int i, ncol;
162  uint32_t *pal = ctx->pal + 256 - ctx->free_colours;
163 
164  if (!ctx->free_colours)
165  return 0;
166 
167  ncol = *buf++;
168  if (ncol > ctx->free_colours || buf_size < 2 + ncol * 3)
169  return AVERROR_INVALIDDATA;
170  for (i = 0; i < ncol; i++)
171  *pal++ = AV_RB24(buf + 3 * i);
172 
173  return 1 + ncol * 3;
174 }
175 
176 static int decode_555(GetByteContext *gB, uint16_t *dst, int stride,
177  int keyframe, int w, int h)
178 {
179  int last_symbol = 0, repeat = 0, prev_avail = 0;
180 
181  if (!keyframe) {
182  int x, y, endx, endy, t;
183 
184 #define READ_PAIR(a, b) \
185  a = bytestream2_get_byte(gB) << 4; \
186  t = bytestream2_get_byte(gB); \
187  a |= t >> 4; \
188  b = (t & 0xF) << 8; \
189  b |= bytestream2_get_byte(gB); \
190 
191  READ_PAIR(x, endx)
192  READ_PAIR(y, endy)
193 
194  if (endx >= w || endy >= h || x > endx || y > endy)
195  return AVERROR_INVALIDDATA;
196  dst += x + stride * y;
197  w = endx - x + 1;
198  h = endy - y + 1;
199  if (y)
200  prev_avail = 1;
201  }
202 
203  do {
204  uint16_t *p = dst;
205  do {
206  if (repeat-- < 1) {
207  int b = bytestream2_get_byte(gB);
208  if (b < 128)
209  last_symbol = b << 8 | bytestream2_get_byte(gB);
210  else if (b > 129) {
211  repeat = 0;
212  while (b-- > 130)
213  repeat = (repeat << 8) + bytestream2_get_byte(gB) + 1;
214  if (last_symbol == -2) {
215  int skip = FFMIN((unsigned)repeat, dst + w - p);
216  repeat -= skip;
217  p += skip;
218  }
219  } else
220  last_symbol = 127 - b;
221  }
222  if (last_symbol >= 0)
223  *p = last_symbol;
224  else if (last_symbol == -1 && prev_avail)
225  *p = *(p - stride);
226  } while (++p < dst + w);
227  dst += stride;
228  prev_avail = 1;
229  } while (--h);
230 
231  return 0;
232 }
233 
234 static int decode_rle(GetBitContext *gb, uint8_t *pal_dst, int pal_stride,
235  uint8_t *rgb_dst, int rgb_stride, uint32_t *pal,
236  int keyframe, int kf_slipt, int slice, int w, int h)
237 {
238  uint8_t bits[270] = { 0 };
239  uint32_t codes[270];
240  VLC vlc;
241 
242  int current_length = 0, read_codes = 0, next_code = 0, current_codes = 0;
243  int remaining_codes, surplus_codes, i;
244 
245  const int alphabet_size = 270 - keyframe;
246 
247  int last_symbol = 0, repeat = 0, prev_avail = 0;
248 
249  if (!keyframe) {
250  int x, y, clipw, cliph;
251 
252  x = get_bits(gb, 12);
253  y = get_bits(gb, 12);
254  clipw = get_bits(gb, 12) + 1;
255  cliph = get_bits(gb, 12) + 1;
256 
257  if (x + clipw > w || y + cliph > h)
258  return AVERROR_INVALIDDATA;
259  pal_dst += pal_stride * y + x;
260  rgb_dst += rgb_stride * y + x * 3;
261  w = clipw;
262  h = cliph;
263  if (y)
264  prev_avail = 1;
265  } else {
266  if (slice > 0) {
267  pal_dst += pal_stride * kf_slipt;
268  rgb_dst += rgb_stride * kf_slipt;
269  prev_avail = 1;
270  h -= kf_slipt;
271  } else
272  h = kf_slipt;
273  }
274 
275  /* read explicit codes */
276  do {
277  while (current_codes--) {
278  int symbol = get_bits(gb, 8);
279  if (symbol >= 204 - keyframe)
280  symbol += 14 - keyframe;
281  else if (symbol > 189)
282  symbol = get_bits1(gb) + (symbol << 1) - 190;
283  if (bits[symbol])
284  return AVERROR_INVALIDDATA;
285  bits[symbol] = current_length;
286  codes[symbol] = next_code++;
287  read_codes++;
288  }
289  current_length++;
290  next_code <<= 1;
291  remaining_codes = (1 << current_length) - next_code;
292  current_codes = get_bits(gb, av_ceil_log2(remaining_codes + 1));
293  if (current_length > 22 || current_codes > remaining_codes)
294  return AVERROR_INVALIDDATA;
295  } while (current_codes != remaining_codes);
296 
297  remaining_codes = alphabet_size - read_codes;
298 
299  /* determine the minimum length to fit the rest of the alphabet */
300  while ((surplus_codes = (2 << current_length) -
301  (next_code << 1) - remaining_codes) < 0) {
302  current_length++;
303  next_code <<= 1;
304  }
305 
306  /* add the rest of the symbols lexicographically */
307  for (i = 0; i < alphabet_size; i++)
308  if (!bits[i]) {
309  if (surplus_codes-- == 0) {
310  current_length++;
311  next_code <<= 1;
312  }
313  bits[i] = current_length;
314  codes[i] = next_code++;
315  }
316 
317  if (next_code != 1 << current_length)
318  return AVERROR_INVALIDDATA;
319 
320  if (i = init_vlc(&vlc, 9, alphabet_size, bits, 1, 1, codes, 4, 4, 0))
321  return i;
322 
323  /* frame decode */
324  do {
325  uint8_t *pp = pal_dst;
326  uint8_t *rp = rgb_dst;
327  do {
328  if (repeat-- < 1) {
329  int b = get_vlc2(gb, vlc.table, 9, 3);
330  if (b < 256)
331  last_symbol = b;
332  else if (b < 268) {
333  b -= 256;
334  if (b == 11)
335  b = get_bits(gb, 4) + 10;
336 
337  if (!b)
338  repeat = 0;
339  else
340  repeat = get_bits(gb, b);
341 
342  repeat += (1 << b) - 1;
343 
344  if (last_symbol == -2) {
345  int skip = FFMIN(repeat, pal_dst + w - pp);
346  repeat -= skip;
347  pp += skip;
348  rp += skip * 3;
349  }
350  } else
351  last_symbol = 267 - b;
352  }
353  if (last_symbol >= 0) {
354  *pp = last_symbol;
355  AV_WB24(rp, pal[last_symbol]);
356  } else if (last_symbol == -1 && prev_avail) {
357  *pp = *(pp - pal_stride);
358  memcpy(rp, rp - rgb_stride, 3);
359  }
360  rp += 3;
361  } while (++pp < pal_dst + w);
362  pal_dst += pal_stride;
363  rgb_dst += rgb_stride;
364  prev_avail = 1;
365  } while (--h);
366 
367  ff_free_vlc(&vlc);
368  return 0;
369 }
370 
371 static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
372  int x, int y, int w, int h, int wmv9_mask)
373 {
374  MSS2Context *ctx = avctx->priv_data;
375  MSS12Context *c = &ctx->c;
376  VC1Context *v = avctx->priv_data;
377  MpegEncContext *s = &v->s;
378  AVFrame *f;
379  int ret;
380 
381  ff_mpeg_flush(avctx);
382 
383  if ((ret = init_get_bits8(&s->gb, buf, buf_size)) < 0)
384  return ret;
385 
387 
388  if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
389  av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
390  return AVERROR_INVALIDDATA;
391  }
392 
393  if (s->pict_type != AV_PICTURE_TYPE_I) {
394  av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
395  return AVERROR_INVALIDDATA;
396  }
397 
398  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
399 
400  if ((ret = ff_mpv_frame_start(s, avctx)) < 0) {
401  av_log(v->s.avctx, AV_LOG_ERROR, "ff_mpv_frame_start error\n");
402  avctx->pix_fmt = AV_PIX_FMT_RGB24;
403  return ret;
404  }
405 
407 
408  v->bits = buf_size * 8;
409 
410  v->end_mb_x = (w + 15) >> 4;
411  s->end_mb_y = (h + 15) >> 4;
412  if (v->respic & 1)
413  v->end_mb_x = v->end_mb_x + 1 >> 1;
414  if (v->respic & 2)
415  s->end_mb_y = s->end_mb_y + 1 >> 1;
416 
418 
419  ff_er_frame_end(&s->er);
420 
421  ff_mpv_frame_end(s);
422 
423  f = s->current_picture.f;
424 
425  if (v->respic == 3) {
426  ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
427  ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w+1 >> 1, h+1 >> 1);
428  ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w+1 >> 1, h+1 >> 1);
429  } else if (v->respic)
431  "Asymmetric WMV9 rectangle subsampling");
432 
433  av_assert0(f->linesize[1] == f->linesize[2]);
434 
435  if (wmv9_mask != -1)
436  ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
437  c->rgb_stride, wmv9_mask,
438  c->pal_pic + y * c->pal_stride + x,
439  c->pal_stride,
440  f->data[0], f->linesize[0],
441  f->data[1], f->data[2], f->linesize[1],
442  w, h);
443  else
444  ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
445  c->rgb_stride,
446  f->data[0], f->linesize[0],
447  f->data[1], f->data[2], f->linesize[1],
448  w, h);
449 
450  avctx->pix_fmt = AV_PIX_FMT_RGB24;
451 
452  return 0;
453 }
454 
455 typedef struct Rectangle {
456  int coded, x, y, w, h;
457 } Rectangle;
458 
459 #define MAX_WMV9_RECTANGLES 20
460 #define ARITH2_PADDING 2
461 
462 static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
463  AVPacket *avpkt)
464 {
465  const uint8_t *buf = avpkt->data;
466  int buf_size = avpkt->size;
467  MSS2Context *ctx = avctx->priv_data;
468  MSS12Context *c = &ctx->c;
469  AVFrame *frame = data;
470  GetBitContext gb;
471  GetByteContext gB;
472  ArithCoder acoder;
473 
474  int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
475 
476  Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
477  int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
478 
480  ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
481 
482  if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
483  return ret;
484 
485  if (keyframe = get_bits1(&gb))
486  skip_bits(&gb, 7);
487  has_wmv9 = get_bits1(&gb);
488  has_mv = keyframe ? 0 : get_bits1(&gb);
489  is_rle = get_bits1(&gb);
490  is_555 = is_rle && get_bits1(&gb);
491  if (c->slice_split > 0)
492  ctx->split_position = c->slice_split;
493  else if (c->slice_split < 0) {
494  if (get_bits1(&gb)) {
495  if (get_bits1(&gb)) {
496  if (get_bits1(&gb))
497  ctx->split_position = get_bits(&gb, 16);
498  else
499  ctx->split_position = get_bits(&gb, 12);
500  } else
501  ctx->split_position = get_bits(&gb, 8) << 4;
502  } else {
503  if (keyframe)
504  ctx->split_position = avctx->height / 2;
505  }
506  } else
507  ctx->split_position = avctx->height;
508 
509  if (c->slice_split && (ctx->split_position < 1 - is_555 ||
510  ctx->split_position > avctx->height - 1))
511  return AVERROR_INVALIDDATA;
512 
513  align_get_bits(&gb);
514  buf += get_bits_count(&gb) >> 3;
515  buf_size -= get_bits_count(&gb) >> 3;
516 
517  if (buf_size < 1)
518  return AVERROR_INVALIDDATA;
519 
520  if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
521  return AVERROR_INVALIDDATA;
522 
523  avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
524  if (ctx->last_pic->format != avctx->pix_fmt)
525  av_frame_unref(ctx->last_pic);
526 
527  if (has_wmv9) {
528  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
529  arith2_init(&acoder, &gB);
530 
531  implicit_rect = !arith2_get_bit(&acoder);
532 
533  while (arith2_get_bit(&acoder)) {
534  if (used_rects == MAX_WMV9_RECTANGLES)
535  return AVERROR_INVALIDDATA;
536  r = &wmv9rects[used_rects];
537  if (!used_rects)
538  r->x = arith2_get_number(&acoder, avctx->width);
539  else
540  r->x = arith2_get_number(&acoder, avctx->width -
541  wmv9rects[used_rects - 1].x) +
542  wmv9rects[used_rects - 1].x;
543  r->y = arith2_get_number(&acoder, avctx->height);
544  r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
545  r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
546  used_rects++;
547  }
548 
549  if (implicit_rect && used_rects) {
550  av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
551  return AVERROR_INVALIDDATA;
552  }
553 
554  if (implicit_rect) {
555  wmv9rects[0].x = 0;
556  wmv9rects[0].y = 0;
557  wmv9rects[0].w = avctx->width;
558  wmv9rects[0].h = avctx->height;
559 
560  used_rects = 1;
561  }
562  for (i = 0; i < used_rects; i++) {
563  if (!implicit_rect && arith2_get_bit(&acoder)) {
564  av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
565  return AVERROR_INVALIDDATA;
566  }
567  if (!i) {
568  wmv9_mask = arith2_get_bit(&acoder) - 1;
569  if (!wmv9_mask)
570  wmv9_mask = arith2_get_number(&acoder, 256);
571  }
572  wmv9rects[i].coded = arith2_get_number(&acoder, 2);
573  }
574 
575  buf += arith2_get_consumed_bytes(&acoder);
576  buf_size -= arith2_get_consumed_bytes(&acoder);
577  if (buf_size < 1)
578  return AVERROR_INVALIDDATA;
579  }
580 
581  c->mvX = c->mvY = 0;
582  if (keyframe && !is_555) {
583  if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
584  return AVERROR_INVALIDDATA;
585  buf += i;
586  buf_size -= i;
587  } else if (has_mv) {
588  buf += 4;
589  buf_size -= 4;
590  if (buf_size < 1)
591  return AVERROR_INVALIDDATA;
592  c->mvX = AV_RB16(buf - 4) - avctx->width;
593  c->mvY = AV_RB16(buf - 2) - avctx->height;
594  }
595 
596  if (c->mvX < 0 || c->mvY < 0) {
597  FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
598 
599  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
600  return ret;
601 
602  if (ctx->last_pic->data[0]) {
603  av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
604  c->last_rgb_pic = ctx->last_pic->data[0] +
605  ctx->last_pic->linesize[0] * (avctx->height - 1);
606  } else {
607  av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
608  return AVERROR_INVALIDDATA;
609  }
610  } else {
611  if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0)
612  return ret;
613  if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
614  return ret;
615 
616  c->last_rgb_pic = NULL;
617  }
618  c->rgb_pic = frame->data[0] +
619  frame->linesize[0] * (avctx->height - 1);
620  c->rgb_stride = -frame->linesize[0];
621 
622  frame->key_frame = keyframe;
623  frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
624 
625  if (is_555) {
626  bytestream2_init(&gB, buf, buf_size);
627 
628  if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
629  keyframe, avctx->width, avctx->height))
630  return AVERROR_INVALIDDATA;
631 
632  buf_size -= bytestream2_tell(&gB);
633  } else {
634  if (keyframe) {
635  c->corrupted = 0;
637  if (c->slice_split)
639  }
640  if (is_rle) {
641  if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
642  return ret;
643  if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
644  c->rgb_pic, c->rgb_stride, c->pal, keyframe,
645  ctx->split_position, 0,
646  avctx->width, avctx->height))
647  return ret;
648  align_get_bits(&gb);
649 
650  if (c->slice_split)
651  if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
652  c->rgb_pic, c->rgb_stride, c->pal, keyframe,
653  ctx->split_position, 1,
654  avctx->width, avctx->height))
655  return ret;
656 
657  align_get_bits(&gb);
658  buf += get_bits_count(&gb) >> 3;
659  buf_size -= get_bits_count(&gb) >> 3;
660  } else if (!implicit_rect || wmv9_mask != -1) {
661  if (c->corrupted)
662  return AVERROR_INVALIDDATA;
663  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
664  arith2_init(&acoder, &gB);
665  c->keyframe = keyframe;
666  if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
667  avctx->width,
668  ctx->split_position))
669  return AVERROR_INVALIDDATA;
670 
671  buf += arith2_get_consumed_bytes(&acoder);
672  buf_size -= arith2_get_consumed_bytes(&acoder);
673  if (c->slice_split) {
674  if (buf_size < 1)
675  return AVERROR_INVALIDDATA;
676  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
677  arith2_init(&acoder, &gB);
678  if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
679  ctx->split_position,
680  avctx->width,
681  avctx->height - ctx->split_position))
682  return AVERROR_INVALIDDATA;
683 
684  buf += arith2_get_consumed_bytes(&acoder);
685  buf_size -= arith2_get_consumed_bytes(&acoder);
686  }
687  } else
688  memset(c->pal_pic, 0, c->pal_stride * avctx->height);
689  }
690 
691  if (has_wmv9) {
692  for (i = 0; i < used_rects; i++) {
693  int x = wmv9rects[i].x;
694  int y = wmv9rects[i].y;
695  int w = wmv9rects[i].w;
696  int h = wmv9rects[i].h;
697  if (wmv9rects[i].coded) {
698  int WMV9codedFrameSize;
699  if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
700  return AVERROR_INVALIDDATA;
701  if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
702  x, y, w, h, wmv9_mask))
703  return ret;
704  buf += WMV9codedFrameSize + 3;
705  buf_size -= WMV9codedFrameSize + 3;
706  } else {
707  uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
708  if (wmv9_mask != -1) {
709  ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
710  wmv9_mask,
711  c->pal_pic + y * c->pal_stride + x,
712  c->pal_stride,
713  w, h);
714  } else {
715  do {
716  memset(dst, 0x80, w * 3);
717  dst += c->rgb_stride;
718  } while (--h);
719  }
720  }
721  }
722  }
723 
724  if (buf_size)
725  av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
726 
727  if (c->mvX < 0 || c->mvY < 0) {
728  av_frame_unref(ctx->last_pic);
729  ret = av_frame_ref(ctx->last_pic, frame);
730  if (ret < 0)
731  return ret;
732  }
733 
734  *got_frame = 1;
735 
736  return avpkt->size;
737 }
738 
739 static av_cold int wmv9_init(AVCodecContext *avctx)
740 {
741  VC1Context *v = avctx->priv_data;
742  int ret;
743 
744  v->s.avctx = avctx;
745 
746  if ((ret = ff_vc1_init_common(v)) < 0)
747  return ret;
748  ff_vc1dsp_init(&v->vc1dsp);
749 
750  v->profile = PROFILE_MAIN;
751 
754  v->res_y411 = 0;
755  v->res_sprite = 0;
756 
757  v->frmrtq_postproc = 7;
758  v->bitrtq_postproc = 31;
759 
760  v->res_x8 = 0;
761  v->multires = 0;
762  v->res_fasttx = 1;
763 
764  v->fastuvmc = 0;
765 
766  v->extended_mv = 0;
767 
768  v->dquant = 1;
769  v->vstransform = 1;
770 
771  v->res_transtab = 0;
772 
773  v->overlap = 0;
774 
775  v->resync_marker = 0;
776  v->rangered = 0;
777 
778  v->s.max_b_frames = avctx->max_b_frames = 0;
779  v->quantizer_mode = 0;
780 
781  v->finterpflag = 0;
782 
783  v->res_rtm_flag = 1;
784 
786 
787  if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
788  (ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
789  return ret;
790 
791  /* error concealment */
794 
795  return 0;
796 }
797 
799 {
800  MSS2Context *const ctx = avctx->priv_data;
801 
802  av_frame_free(&ctx->last_pic);
803 
804  ff_mss12_decode_end(&ctx->c);
805  av_freep(&ctx->c.pal_pic);
806  av_freep(&ctx->c.last_pal_pic);
807  ff_vc1_decode_end(avctx);
808 
809  return 0;
810 }
811 
813 {
814  MSS2Context * const ctx = avctx->priv_data;
815  MSS12Context *c = &ctx->c;
816  int ret;
817  c->avctx = avctx;
818  if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
819  return ret;
820  ctx->last_pic = av_frame_alloc();
821  c->pal_stride = c->mask_stride;
822  c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
823  c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
824  if (!c->pal_pic || !c->last_pal_pic || !ctx->last_pic) {
825  mss2_decode_end(avctx);
826  return AVERROR(ENOMEM);
827  }
828  if (ret = wmv9_init(avctx)) {
829  mss2_decode_end(avctx);
830  return ret;
831  }
832  ff_mss2dsp_init(&ctx->dsp);
833  ff_qpeldsp_init(&ctx->qdsp);
834 
835  avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
837 
838 
839  return 0;
840 }
841 
843  .name = "mss2",
844  .long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
845  .type = AVMEDIA_TYPE_VIDEO,
846  .id = AV_CODEC_ID_MSS2,
847  .priv_data_size = sizeof(MSS2Context),
851  .capabilities = CODEC_CAP_DR1,
852 };