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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 
57 ARITH_GET_BIT(arith2)
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 
130 ARITH_GET_MODEL_SYM(arith2)
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 ((ret = init_get_bits8(&s->gb, buf, buf_size)) < 0)
381  return ret;
382 
384 
385  if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
386  av_log(v->s.avctx, AV_LOG_ERROR, "header error\n");
387  return AVERROR_INVALIDDATA;
388  }
389 
390  if (s->pict_type != AV_PICTURE_TYPE_I) {
391  av_log(v->s.avctx, AV_LOG_ERROR, "expected I-frame\n");
392  return AVERROR_INVALIDDATA;
393  }
394 
395  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
396 
397  if ((ret = ff_MPV_frame_start(s, avctx)) < 0) {
398  av_log(v->s.avctx, AV_LOG_ERROR, "ff_MPV_frame_start error\n");
399  avctx->pix_fmt = AV_PIX_FMT_RGB24;
400  return ret;
401  }
402 
404 
405  v->bits = buf_size * 8;
406 
407  v->end_mb_x = (w + 15) >> 4;
408  s->end_mb_y = (h + 15) >> 4;
409  if (v->respic & 1)
410  v->end_mb_x = v->end_mb_x + 1 >> 1;
411  if (v->respic & 2)
412  s->end_mb_y = s->end_mb_y + 1 >> 1;
413 
415 
416  ff_er_frame_end(&s->er);
417 
418  ff_MPV_frame_end(s);
419 
420  f = &s->current_picture.f;
421 
422  if (v->respic == 3) {
423  ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w, h);
424  ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w+1 >> 1, h+1 >> 1);
425  ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w+1 >> 1, h+1 >> 1);
426  } else if (v->respic)
428  "Asymmetric WMV9 rectangle subsampling");
429 
430  av_assert0(f->linesize[1] == f->linesize[2]);
431 
432  if (wmv9_mask != -1)
433  ctx->dsp.mss2_blit_wmv9_masked(c->rgb_pic + y * c->rgb_stride + x * 3,
434  c->rgb_stride, wmv9_mask,
435  c->pal_pic + y * c->pal_stride + x,
436  c->pal_stride,
437  f->data[0], f->linesize[0],
438  f->data[1], f->data[2], f->linesize[1],
439  w, h);
440  else
441  ctx->dsp.mss2_blit_wmv9(c->rgb_pic + y * c->rgb_stride + x * 3,
442  c->rgb_stride,
443  f->data[0], f->linesize[0],
444  f->data[1], f->data[2], f->linesize[1],
445  w, h);
446 
447  avctx->pix_fmt = AV_PIX_FMT_RGB24;
448 
449  return 0;
450 }
451 
452 typedef struct Rectangle {
453  int coded, x, y, w, h;
454 } Rectangle;
455 
456 #define MAX_WMV9_RECTANGLES 20
457 #define ARITH2_PADDING 2
458 
459 static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
460  AVPacket *avpkt)
461 {
462  const uint8_t *buf = avpkt->data;
463  int buf_size = avpkt->size;
464  MSS2Context *ctx = avctx->priv_data;
465  MSS12Context *c = &ctx->c;
466  AVFrame *frame = data;
467  GetBitContext gb;
468  GetByteContext gB;
469  ArithCoder acoder;
470 
471  int keyframe, has_wmv9, has_mv, is_rle, is_555, ret;
472 
473  Rectangle wmv9rects[MAX_WMV9_RECTANGLES], *r;
474  int used_rects = 0, i, implicit_rect = 0, av_uninit(wmv9_mask);
475 
477  ARITH2_PADDING + (MIN_CACHE_BITS + 7) / 8);
478 
479  if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
480  return ret;
481 
482  if (keyframe = get_bits1(&gb))
483  skip_bits(&gb, 7);
484  has_wmv9 = get_bits1(&gb);
485  has_mv = keyframe ? 0 : get_bits1(&gb);
486  is_rle = get_bits1(&gb);
487  is_555 = is_rle && get_bits1(&gb);
488  if (c->slice_split > 0)
489  ctx->split_position = c->slice_split;
490  else if (c->slice_split < 0) {
491  if (get_bits1(&gb)) {
492  if (get_bits1(&gb)) {
493  if (get_bits1(&gb))
494  ctx->split_position = get_bits(&gb, 16);
495  else
496  ctx->split_position = get_bits(&gb, 12);
497  } else
498  ctx->split_position = get_bits(&gb, 8) << 4;
499  } else {
500  if (keyframe)
501  ctx->split_position = avctx->height / 2;
502  }
503  } else
504  ctx->split_position = avctx->height;
505 
506  if (c->slice_split && (ctx->split_position < 1 - is_555 ||
507  ctx->split_position > avctx->height - 1))
508  return AVERROR_INVALIDDATA;
509 
510  align_get_bits(&gb);
511  buf += get_bits_count(&gb) >> 3;
512  buf_size -= get_bits_count(&gb) >> 3;
513 
514  if (buf_size < 1)
515  return AVERROR_INVALIDDATA;
516 
517  if (is_555 && (has_wmv9 || has_mv || c->slice_split && ctx->split_position))
518  return AVERROR_INVALIDDATA;
519 
520  avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
521  if (ctx->last_pic->format != avctx->pix_fmt)
522  av_frame_unref(ctx->last_pic);
523 
524  if (has_wmv9) {
525  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
526  arith2_init(&acoder, &gB);
527 
528  implicit_rect = !arith2_get_bit(&acoder);
529 
530  while (arith2_get_bit(&acoder)) {
531  if (used_rects == MAX_WMV9_RECTANGLES)
532  return AVERROR_INVALIDDATA;
533  r = &wmv9rects[used_rects];
534  if (!used_rects)
535  r->x = arith2_get_number(&acoder, avctx->width);
536  else
537  r->x = arith2_get_number(&acoder, avctx->width -
538  wmv9rects[used_rects - 1].x) +
539  wmv9rects[used_rects - 1].x;
540  r->y = arith2_get_number(&acoder, avctx->height);
541  r->w = arith2_get_number(&acoder, avctx->width - r->x) + 1;
542  r->h = arith2_get_number(&acoder, avctx->height - r->y) + 1;
543  used_rects++;
544  }
545 
546  if (implicit_rect && used_rects) {
547  av_log(avctx, AV_LOG_ERROR, "implicit_rect && used_rects > 0\n");
548  return AVERROR_INVALIDDATA;
549  }
550 
551  if (implicit_rect) {
552  wmv9rects[0].x = 0;
553  wmv9rects[0].y = 0;
554  wmv9rects[0].w = avctx->width;
555  wmv9rects[0].h = avctx->height;
556 
557  used_rects = 1;
558  }
559  for (i = 0; i < used_rects; i++) {
560  if (!implicit_rect && arith2_get_bit(&acoder)) {
561  av_log(avctx, AV_LOG_ERROR, "Unexpected grandchildren\n");
562  return AVERROR_INVALIDDATA;
563  }
564  if (!i) {
565  wmv9_mask = arith2_get_bit(&acoder) - 1;
566  if (!wmv9_mask)
567  wmv9_mask = arith2_get_number(&acoder, 256);
568  }
569  wmv9rects[i].coded = arith2_get_number(&acoder, 2);
570  }
571 
572  buf += arith2_get_consumed_bytes(&acoder);
573  buf_size -= arith2_get_consumed_bytes(&acoder);
574  if (buf_size < 1)
575  return AVERROR_INVALIDDATA;
576  }
577 
578  c->mvX = c->mvY = 0;
579  if (keyframe && !is_555) {
580  if ((i = decode_pal_v2(c, buf, buf_size)) < 0)
581  return AVERROR_INVALIDDATA;
582  buf += i;
583  buf_size -= i;
584  } else if (has_mv) {
585  buf += 4;
586  buf_size -= 4;
587  if (buf_size < 1)
588  return AVERROR_INVALIDDATA;
589  c->mvX = AV_RB16(buf - 4) - avctx->width;
590  c->mvY = AV_RB16(buf - 2) - avctx->height;
591  }
592 
593  if (c->mvX < 0 || c->mvY < 0) {
594  FFSWAP(uint8_t *, c->pal_pic, c->last_pal_pic);
595 
596  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
597  return ret;
598 
599  if (ctx->last_pic->data[0]) {
600  av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
601  c->last_rgb_pic = ctx->last_pic->data[0] +
602  ctx->last_pic->linesize[0] * (avctx->height - 1);
603  } else {
604  av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
605  return AVERROR_INVALIDDATA;
606  }
607  } else {
608  if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0)
609  return ret;
610  if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
611  return ret;
612 
613  c->last_rgb_pic = NULL;
614  }
615  c->rgb_pic = frame->data[0] +
616  frame->linesize[0] * (avctx->height - 1);
617  c->rgb_stride = -frame->linesize[0];
618 
619  frame->key_frame = keyframe;
620  frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
621 
622  if (is_555) {
623  bytestream2_init(&gB, buf, buf_size);
624 
625  if (decode_555(&gB, (uint16_t *)c->rgb_pic, c->rgb_stride >> 1,
626  keyframe, avctx->width, avctx->height))
627  return AVERROR_INVALIDDATA;
628 
629  buf_size -= bytestream2_tell(&gB);
630  } else {
631  if (keyframe) {
632  c->corrupted = 0;
634  if (c->slice_split)
636  }
637  if (is_rle) {
638  if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
639  return ret;
640  if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
641  c->rgb_pic, c->rgb_stride, c->pal, keyframe,
642  ctx->split_position, 0,
643  avctx->width, avctx->height))
644  return ret;
645  align_get_bits(&gb);
646 
647  if (c->slice_split)
648  if (ret = decode_rle(&gb, c->pal_pic, c->pal_stride,
649  c->rgb_pic, c->rgb_stride, c->pal, keyframe,
650  ctx->split_position, 1,
651  avctx->width, avctx->height))
652  return ret;
653 
654  align_get_bits(&gb);
655  buf += get_bits_count(&gb) >> 3;
656  buf_size -= get_bits_count(&gb) >> 3;
657  } else if (!implicit_rect || wmv9_mask != -1) {
658  if (c->corrupted)
659  return AVERROR_INVALIDDATA;
660  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
661  arith2_init(&acoder, &gB);
662  c->keyframe = keyframe;
663  if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[0], &acoder, 0, 0,
664  avctx->width,
665  ctx->split_position))
666  return AVERROR_INVALIDDATA;
667 
668  buf += arith2_get_consumed_bytes(&acoder);
669  buf_size -= arith2_get_consumed_bytes(&acoder);
670  if (c->slice_split) {
671  if (buf_size < 1)
672  return AVERROR_INVALIDDATA;
673  bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
674  arith2_init(&acoder, &gB);
675  if (c->corrupted = ff_mss12_decode_rect(&ctx->sc[1], &acoder, 0,
676  ctx->split_position,
677  avctx->width,
678  avctx->height - ctx->split_position))
679  return AVERROR_INVALIDDATA;
680 
681  buf += arith2_get_consumed_bytes(&acoder);
682  buf_size -= arith2_get_consumed_bytes(&acoder);
683  }
684  } else
685  memset(c->pal_pic, 0, c->pal_stride * avctx->height);
686  }
687 
688  if (has_wmv9) {
689  for (i = 0; i < used_rects; i++) {
690  int x = wmv9rects[i].x;
691  int y = wmv9rects[i].y;
692  int w = wmv9rects[i].w;
693  int h = wmv9rects[i].h;
694  if (wmv9rects[i].coded) {
695  int WMV9codedFrameSize;
696  if (buf_size < 4 || !(WMV9codedFrameSize = AV_RL24(buf)))
697  return AVERROR_INVALIDDATA;
698  if (ret = decode_wmv9(avctx, buf + 3, buf_size - 3,
699  x, y, w, h, wmv9_mask))
700  return ret;
701  buf += WMV9codedFrameSize + 3;
702  buf_size -= WMV9codedFrameSize + 3;
703  } else {
704  uint8_t *dst = c->rgb_pic + y * c->rgb_stride + x * 3;
705  if (wmv9_mask != -1) {
706  ctx->dsp.mss2_gray_fill_masked(dst, c->rgb_stride,
707  wmv9_mask,
708  c->pal_pic + y * c->pal_stride + x,
709  c->pal_stride,
710  w, h);
711  } else {
712  do {
713  memset(dst, 0x80, w * 3);
714  dst += c->rgb_stride;
715  } while (--h);
716  }
717  }
718  }
719  }
720 
721  if (buf_size)
722  av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
723 
724  if (c->mvX < 0 || c->mvY < 0) {
725  av_frame_unref(ctx->last_pic);
726  ret = av_frame_ref(ctx->last_pic, frame);
727  if (ret < 0)
728  return ret;
729  }
730 
731  *got_frame = 1;
732 
733  return avpkt->size;
734 }
735 
736 static av_cold int wmv9_init(AVCodecContext *avctx)
737 {
738  VC1Context *v = avctx->priv_data;
739  int ret;
740 
741  v->s.avctx = avctx;
742 
743  if ((ret = ff_vc1_init_common(v)) < 0)
744  return ret;
745  ff_vc1dsp_init(&v->vc1dsp);
746 
747  v->profile = PROFILE_MAIN;
748 
751  v->res_y411 = 0;
752  v->res_sprite = 0;
753 
754  v->frmrtq_postproc = 7;
755  v->bitrtq_postproc = 31;
756 
757  v->res_x8 = 0;
758  v->multires = 0;
759  v->res_fasttx = 1;
760 
761  v->fastuvmc = 0;
762 
763  v->extended_mv = 0;
764 
765  v->dquant = 1;
766  v->vstransform = 1;
767 
768  v->res_transtab = 0;
769 
770  v->overlap = 0;
771 
772  v->resync_marker = 0;
773  v->rangered = 0;
774 
775  v->s.max_b_frames = avctx->max_b_frames = 0;
776  v->quantizer_mode = 0;
777 
778  v->finterpflag = 0;
779 
780  v->res_rtm_flag = 1;
781 
783 
784  if ((ret = ff_msmpeg4_decode_init(avctx)) < 0 ||
785  (ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
786  return ret;
787 
788  /* error concealment */
791 
792  return 0;
793 }
794 
796 {
797  MSS2Context *const ctx = avctx->priv_data;
798 
799  av_frame_free(&ctx->last_pic);
800 
801  ff_mss12_decode_end(&ctx->c);
802  av_freep(&ctx->c.pal_pic);
803  av_freep(&ctx->c.last_pal_pic);
804  ff_vc1_decode_end(avctx);
805 
806  return 0;
807 }
808 
810 {
811  MSS2Context * const ctx = avctx->priv_data;
812  MSS12Context *c = &ctx->c;
813  int ret;
814  c->avctx = avctx;
815  if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
816  return ret;
817  ctx->last_pic = av_frame_alloc();
818  c->pal_stride = c->mask_stride;
819  c->pal_pic = av_mallocz(c->pal_stride * avctx->height);
820  c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
821  if (!c->pal_pic || !c->last_pal_pic || !ctx->last_pic) {
822  mss2_decode_end(avctx);
823  return AVERROR(ENOMEM);
824  }
825  if (ret = wmv9_init(avctx)) {
826  mss2_decode_end(avctx);
827  return ret;
828  }
829  ff_mss2dsp_init(&ctx->dsp);
830 
831  avctx->pix_fmt = c->free_colours == 127 ? AV_PIX_FMT_RGB555
833 
834 
835  return 0;
836 }
837 
839  .name = "mss2",
840  .long_name = NULL_IF_CONFIG_SMALL("MS Windows Media Video V9 Screen"),
841  .type = AVMEDIA_TYPE_VIDEO,
842  .id = AV_CODEC_ID_MSS2,
843  .priv_data_size = sizeof(MSS2Context),
847  .capabilities = CODEC_CAP_DR1,
848 };