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vmnc.c
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1 /*
2  * VMware Screen Codec (VMnc) decoder
3  * Copyright (c) 2006 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * VMware Screen Codec (VMnc) decoder
25  * As Alex Beregszaszi discovered, this is effectively RFB data dump
26  */
27 
28 #include <stdio.h>
29 #include <stdlib.h>
30 
31 #include "libavutil/common.h"
32 #include "libavutil/intreadwrite.h"
33 #include "avcodec.h"
34 #include "internal.h"
35 #include "bytestream.h"
36 
37 enum EncTypes {
38  MAGIC_WMVd = 0x574D5664,
45 };
46 
48  HT_RAW = 1, // tile is raw
49  HT_BKG = 2, // background color is present
50  HT_FG = 4, // foreground color is present
51  HT_SUB = 8, // subrects are present
52  HT_CLR = 16 // each subrect has own color
53 };
54 
55 /*
56  * Decoder context
57  */
58 typedef struct VmncContext {
61 
62  int bpp;
63  int bpp2;
64  int bigendian;
65  uint8_t pal[768];
66  int width, height;
68 
69  /* cursor data */
70  int cur_w, cur_h;
71  int cur_x, cur_y;
72  int cur_hx, cur_hy;
75 } VmncContext;
76 
77 /* read pixel value from stream */
78 static av_always_inline int vmnc_get_pixel(GetByteContext *gb, int bpp, int be)
79 {
80  switch (bpp * 2 + be) {
81  case 2:
82  case 3:
83  return bytestream2_get_byte(gb);
84  case 4:
85  return bytestream2_get_le16(gb);
86  case 5:
87  return bytestream2_get_be16(gb);
88  case 8:
89  return bytestream2_get_le32(gb);
90  case 9:
91  return bytestream2_get_be32(gb);
92  default: return 0;
93  }
94 }
95 
96 static void load_cursor(VmncContext *c)
97 {
98  int i, j, p;
99  const int bpp = c->bpp2;
100  uint8_t *dst8 = c->curbits;
101  uint16_t *dst16 = (uint16_t *)c->curbits;
102  uint32_t *dst32 = (uint32_t *)c->curbits;
103 
104  for (j = 0; j < c->cur_h; j++) {
105  for (i = 0; i < c->cur_w; i++) {
106  p = vmnc_get_pixel(&c->gb, bpp, c->bigendian);
107  if (bpp == 1)
108  *dst8++ = p;
109  if (bpp == 2)
110  *dst16++ = p;
111  if (bpp == 4)
112  *dst32++ = p;
113  }
114  }
115  dst8 = c->curmask;
116  dst16 = (uint16_t*)c->curmask;
117  dst32 = (uint32_t*)c->curmask;
118  for (j = 0; j < c->cur_h; j++) {
119  for (i = 0; i < c->cur_w; i++) {
120  p = vmnc_get_pixel(&c->gb, bpp, c->bigendian);
121  if (bpp == 1)
122  *dst8++ = p;
123  if (bpp == 2)
124  *dst16++ = p;
125  if (bpp == 4)
126  *dst32++ = p;
127  }
128  }
129 }
130 
131 static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)
132 {
133  int i, j;
134  int w, h, x, y;
135  w = c->cur_w;
136  if (c->width < c->cur_x + c->cur_w)
137  w = c->width - c->cur_x;
138  h = c->cur_h;
139  if (c->height < c->cur_y + c->cur_h)
140  h = c->height - c->cur_y;
141  x = c->cur_x;
142  y = c->cur_y;
143  if (x < 0) {
144  w += x;
145  x = 0;
146  }
147  if (y < 0) {
148  h += y;
149  y = 0;
150  }
151 
152  if ((w < 1) || (h < 1))
153  return;
154  dst += x * c->bpp2 + y * stride;
155 
156  if (c->bpp2 == 1) {
157  uint8_t *cd = c->curbits, *msk = c->curmask;
158  for (j = 0; j < h; j++) {
159  for (i = 0; i < w; i++)
160  dst[i] = (dst[i] & cd[i]) ^ msk[i];
161  msk += c->cur_w;
162  cd += c->cur_w;
163  dst += stride;
164  }
165  } else if (c->bpp2 == 2) {
166  uint16_t *cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;
167  uint16_t *dst2;
168  for (j = 0; j < h; j++) {
169  dst2 = (uint16_t*)dst;
170  for (i = 0; i < w; i++)
171  dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
172  msk += c->cur_w;
173  cd += c->cur_w;
174  dst += stride;
175  }
176  } else if (c->bpp2 == 4) {
177  uint32_t *cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;
178  uint32_t *dst2;
179  for (j = 0; j < h; j++) {
180  dst2 = (uint32_t*)dst;
181  for (i = 0; i < w; i++)
182  dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
183  msk += c->cur_w;
184  cd += c->cur_w;
185  dst += stride;
186  }
187  }
188 }
189 
190 /* fill rectangle with given color */
191 static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy,
192  int w, int h, int color,
193  int bpp, int stride)
194 {
195  int i, j;
196  dst += dx * bpp + dy * stride;
197  if (bpp == 1) {
198  for (j = 0; j < h; j++) {
199  memset(dst, color, w);
200  dst += stride;
201  }
202  } else if (bpp == 2) {
203  uint16_t *dst2;
204  for (j = 0; j < h; j++) {
205  dst2 = (uint16_t*)dst;
206  for (i = 0; i < w; i++)
207  *dst2++ = color;
208  dst += stride;
209  }
210  } else if (bpp == 4) {
211  uint32_t *dst2;
212  for (j = 0; j < h; j++) {
213  dst2 = (uint32_t*)dst;
214  for (i = 0; i < w; i++)
215  dst2[i] = color;
216  dst += stride;
217  }
218  }
219 }
220 
221 static av_always_inline void paint_raw(uint8_t *dst, int w, int h,
222  GetByteContext *gb, int bpp,
223  int be, int stride)
224 {
225  int i, j, p;
226  for (j = 0; j < h; j++) {
227  for (i = 0; i < w; i++) {
228  p = vmnc_get_pixel(gb, bpp, be);
229  switch (bpp) {
230  case 1:
231  dst[i] = p;
232  break;
233  case 2:
234  ((uint16_t*)dst)[i] = p;
235  break;
236  case 4:
237  ((uint32_t*)dst)[i] = p;
238  break;
239  }
240  }
241  dst += stride;
242  }
243 }
244 
246  int w, int h, int stride)
247 {
248  int i, j, k;
249  int bg = 0, fg = 0, rects, color, flags, xy, wh;
250  const int bpp = c->bpp2;
251  uint8_t *dst2;
252  int bw = 16, bh = 16;
253 
254  for (j = 0; j < h; j += 16) {
255  dst2 = dst;
256  bw = 16;
257  if (j + 16 > h)
258  bh = h - j;
259  for (i = 0; i < w; i += 16, dst2 += 16 * bpp) {
260  if (bytestream2_get_bytes_left(gb) <= 0) {
261  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
262  return AVERROR_INVALIDDATA;
263  }
264  if (i + 16 > w)
265  bw = w - i;
266  flags = bytestream2_get_byte(gb);
267  if (flags & HT_RAW) {
268  if (bytestream2_get_bytes_left(gb) < bw * bh * bpp) {
269  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
270  return AVERROR_INVALIDDATA;
271  }
272  paint_raw(dst2, bw, bh, gb, bpp, c->bigendian, stride);
273  } else {
274  if (flags & HT_BKG)
275  bg = vmnc_get_pixel(gb, bpp, c->bigendian);
276  if (flags & HT_FG)
277  fg = vmnc_get_pixel(gb, bpp, c->bigendian);
278  rects = 0;
279  if (flags & HT_SUB)
280  rects = bytestream2_get_byte(gb);
281  color = !!(flags & HT_CLR);
282 
283  paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);
284 
285  if (bytestream2_get_bytes_left(gb) < rects * (color * bpp + 2)) {
286  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
287  return AVERROR_INVALIDDATA;
288  }
289  for (k = 0; k < rects; k++) {
290  if (color)
291  fg = vmnc_get_pixel(gb, bpp, c->bigendian);
292  xy = bytestream2_get_byte(gb);
293  wh = bytestream2_get_byte(gb);
294  if ( (xy >> 4) + (wh >> 4) + 1 > w - i
295  || (xy & 0xF) + (wh & 0xF)+1 > h - j) {
296  av_log(c->avctx, AV_LOG_ERROR, "Rectangle outside picture\n");
297  return AVERROR_INVALIDDATA;
298  }
299  paint_rect(dst2, xy >> 4, xy & 0xF,
300  (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
301  }
302  }
303  }
304  dst += stride * 16;
305  }
306  return 0;
307 }
308 
310 {
311  av_freep(&c->curbits);
312  av_freep(&c->curmask);
313  av_freep(&c->screendta);
314  c->cur_w = c->cur_h = 0;
315  c->cur_hx = c->cur_hy = 0;
316 
317 }
318 
319 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
320  AVPacket *avpkt)
321 {
322  const uint8_t *buf = avpkt->data;
323  int buf_size = avpkt->size;
324  VmncContext * const c = avctx->priv_data;
325  GetByteContext *gb = &c->gb;
326  uint8_t *outptr;
327  int dx, dy, w, h, depth, enc, chunks, res, size_left, ret;
328 
329  if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
330  return ret;
331 
332  bytestream2_init(gb, buf, buf_size);
333 
334  c->pic->key_frame = 0;
336 
337  // restore screen after cursor
338  if (c->screendta) {
339  int i;
340  w = c->cur_w;
341  if (c->width < c->cur_x + w)
342  w = c->width - c->cur_x;
343  h = c->cur_h;
344  if (c->height < c->cur_y + h)
345  h = c->height - c->cur_y;
346  dx = c->cur_x;
347  if (dx < 0) {
348  w += dx;
349  dx = 0;
350  }
351  dy = c->cur_y;
352  if (dy < 0) {
353  h += dy;
354  dy = 0;
355  }
356  if ((w > 0) && (h > 0)) {
357  outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
358  for (i = 0; i < h; i++) {
359  memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2,
360  w * c->bpp2);
361  outptr += c->pic->linesize[0];
362  }
363  }
364  }
365  bytestream2_skip(gb, 2);
366  chunks = bytestream2_get_be16(gb);
367  while (chunks--) {
368  if (bytestream2_get_bytes_left(gb) < 12) {
369  av_log(avctx, AV_LOG_ERROR, "Premature end of data!\n");
370  return -1;
371  }
372  dx = bytestream2_get_be16(gb);
373  dy = bytestream2_get_be16(gb);
374  w = bytestream2_get_be16(gb);
375  h = bytestream2_get_be16(gb);
376  enc = bytestream2_get_be32(gb);
377  outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
378  size_left = bytestream2_get_bytes_left(gb);
379  switch (enc) {
380  case MAGIC_WMVd: // cursor
381  if (w*(int64_t)h*c->bpp2 > INT_MAX/2 - 2) {
382  av_log(avctx, AV_LOG_ERROR, "dimensions too large\n");
383  return AVERROR_INVALIDDATA;
384  }
385  if (size_left < 2 + w * h * c->bpp2 * 2) {
386  av_log(avctx, AV_LOG_ERROR,
387  "Premature end of data! (need %i got %i)\n",
388  2 + w * h * c->bpp2 * 2, size_left);
389  return AVERROR_INVALIDDATA;
390  }
391  bytestream2_skip(gb, 2);
392  c->cur_w = w;
393  c->cur_h = h;
394  c->cur_hx = dx;
395  c->cur_hy = dy;
396  if ((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
397  av_log(avctx, AV_LOG_ERROR,
398  "Cursor hot spot is not in image: "
399  "%ix%i of %ix%i cursor size\n",
400  c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
401  c->cur_hx = c->cur_hy = 0;
402  }
403  if (c->cur_w * c->cur_h >= INT_MAX / c->bpp2) {
404  reset_buffers(c);
405  return AVERROR(EINVAL);
406  } else {
407  int screen_size = c->cur_w * c->cur_h * c->bpp2;
408  if ((ret = av_reallocp(&c->curbits, screen_size)) < 0 ||
409  (ret = av_reallocp(&c->curmask, screen_size)) < 0 ||
410  (ret = av_reallocp(&c->screendta, screen_size)) < 0) {
411  reset_buffers(c);
412  return ret;
413  }
414  }
415  load_cursor(c);
416  break;
417  case MAGIC_WMVe: // unknown
418  bytestream2_skip(gb, 2);
419  break;
420  case MAGIC_WMVf: // update cursor position
421  c->cur_x = dx - c->cur_hx;
422  c->cur_y = dy - c->cur_hy;
423  break;
424  case MAGIC_WMVg: // unknown
425  bytestream2_skip(gb, 10);
426  break;
427  case MAGIC_WMVh: // unknown
428  bytestream2_skip(gb, 4);
429  break;
430  case MAGIC_WMVi: // ServerInitialization struct
431  c->pic->key_frame = 1;
433  depth = bytestream2_get_byte(gb);
434  if (depth != c->bpp) {
435  av_log(avctx, AV_LOG_INFO,
436  "Depth mismatch. Container %i bpp, "
437  "Frame data: %i bpp\n",
438  c->bpp, depth);
439  }
440  bytestream2_skip(gb, 1);
441  c->bigendian = bytestream2_get_byte(gb);
442  if (c->bigendian & (~1)) {
443  av_log(avctx, AV_LOG_INFO,
444  "Invalid header: bigendian flag = %i\n", c->bigendian);
445  return AVERROR_INVALIDDATA;
446  }
447  //skip the rest of pixel format data
448  bytestream2_skip(gb, 13);
449  break;
450  case MAGIC_WMVj: // unknown
451  bytestream2_skip(gb, 2);
452  break;
453  case 0x00000000: // raw rectangle data
454  if ((dx + w > c->width) || (dy + h > c->height)) {
455  av_log(avctx, AV_LOG_ERROR,
456  "Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
457  w, h, dx, dy, c->width, c->height);
458  return AVERROR_INVALIDDATA;
459  }
460  if (size_left < w * h * c->bpp2) {
461  av_log(avctx, AV_LOG_ERROR,
462  "Premature end of data! (need %i got %i)\n",
463  w * h * c->bpp2, size_left);
464  return AVERROR_INVALIDDATA;
465  }
466  paint_raw(outptr, w, h, gb, c->bpp2, c->bigendian,
467  c->pic->linesize[0]);
468  break;
469  case 0x00000005: // HexTile encoded rectangle
470  if ((dx + w > c->width) || (dy + h > c->height)) {
471  av_log(avctx, AV_LOG_ERROR,
472  "Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
473  w, h, dx, dy, c->width, c->height);
474  return AVERROR_INVALIDDATA;
475  }
476  res = decode_hextile(c, outptr, gb, w, h, c->pic->linesize[0]);
477  if (res < 0)
478  return res;
479  break;
480  default:
481  av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
482  chunks = 0; // leave chunks decoding loop
483  }
484  }
485  if (c->screendta) {
486  int i;
487  // save screen data before painting cursor
488  w = c->cur_w;
489  if (c->width < c->cur_x + w)
490  w = c->width - c->cur_x;
491  h = c->cur_h;
492  if (c->height < c->cur_y + h)
493  h = c->height - c->cur_y;
494  dx = c->cur_x;
495  if (dx < 0) {
496  w += dx;
497  dx = 0;
498  }
499  dy = c->cur_y;
500  if (dy < 0) {
501  h += dy;
502  dy = 0;
503  }
504  if ((w > 0) && (h > 0)) {
505  outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
506  for (i = 0; i < h; i++) {
507  memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr,
508  w * c->bpp2);
509  outptr += c->pic->linesize[0];
510  }
511  outptr = c->pic->data[0];
512  put_cursor(outptr, c->pic->linesize[0], c, c->cur_x, c->cur_y);
513  }
514  }
515  *got_frame = 1;
516  if ((ret = av_frame_ref(data, c->pic)) < 0)
517  return ret;
518 
519  /* always report that the buffer was completely consumed */
520  return buf_size;
521 }
522 
524 {
525  VmncContext * const c = avctx->priv_data;
526 
527  c->avctx = avctx;
528  c->width = avctx->width;
529  c->height = avctx->height;
530  c->bpp = avctx->bits_per_coded_sample;
531  c->bpp2 = c->bpp / 8;
532 
533  switch (c->bpp) {
534  case 8:
535  avctx->pix_fmt = AV_PIX_FMT_PAL8;
536  break;
537  case 16:
538  avctx->pix_fmt = AV_PIX_FMT_RGB555;
539  break;
540  case 32:
541  avctx->pix_fmt = AV_PIX_FMT_RGB32;
542  break;
543  default:
544  av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
545  return AVERROR_INVALIDDATA;
546  }
547 
548  c->pic = av_frame_alloc();
549  if (!c->pic)
550  return AVERROR(ENOMEM);
551 
552  return 0;
553 }
554 
556 {
557  VmncContext * const c = avctx->priv_data;
558 
559  av_frame_free(&c->pic);
560 
561  av_freep(&c->curbits);
562  av_freep(&c->curmask);
563  av_freep(&c->screendta);
564  return 0;
565 }
566 
568  .name = "vmnc",
569  .long_name = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),
570  .type = AVMEDIA_TYPE_VIDEO,
571  .id = AV_CODEC_ID_VMNC,
572  .priv_data_size = sizeof(VmncContext),
573  .init = decode_init,
574  .close = decode_end,
575  .decode = decode_frame,
576  .capabilities = CODEC_CAP_DR1,
577 };