Libav
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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
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  paint_rect(dst2, xy >> 4, xy & 0xF,
295  (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
296  }
297  }
298  }
299  dst += stride * 16;
300  }
301  return 0;
302 }
303 
304 static void reset_buffers(VmncContext *c)
305 {
306  av_freep(&c->curbits);
307  av_freep(&c->curmask);
308  av_freep(&c->screendta);
309  c->cur_w = c->cur_h = 0;
310 }
311 
312 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
313  AVPacket *avpkt)
314 {
315  const uint8_t *buf = avpkt->data;
316  int buf_size = avpkt->size;
317  VmncContext * const c = avctx->priv_data;
318  GetByteContext *gb = &c->gb;
319  uint8_t *outptr;
320  int dx, dy, w, h, depth, enc, chunks, res, size_left, ret;
321 
322  if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) {
323  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
324  return ret;
325  }
326 
327  bytestream2_init(gb, buf, buf_size);
328 
329  c->pic->key_frame = 0;
331 
332  // restore screen after cursor
333  if (c->screendta) {
334  int i;
335  w = c->cur_w;
336  if (c->width < c->cur_x + w)
337  w = c->width - c->cur_x;
338  h = c->cur_h;
339  if (c->height < c->cur_y + h)
340  h = c->height - c->cur_y;
341  dx = c->cur_x;
342  if (dx < 0) {
343  w += dx;
344  dx = 0;
345  }
346  dy = c->cur_y;
347  if (dy < 0) {
348  h += dy;
349  dy = 0;
350  }
351  if ((w > 0) && (h > 0)) {
352  outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
353  for (i = 0; i < h; i++) {
354  memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2,
355  w * c->bpp2);
356  outptr += c->pic->linesize[0];
357  }
358  }
359  }
360  bytestream2_skip(gb, 2);
361  chunks = bytestream2_get_be16(gb);
362  while (chunks--) {
363  dx = bytestream2_get_be16(gb);
364  dy = bytestream2_get_be16(gb);
365  w = bytestream2_get_be16(gb);
366  h = bytestream2_get_be16(gb);
367  enc = bytestream2_get_be32(gb);
368  outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
369  size_left = bytestream2_get_bytes_left(gb);
370  switch (enc) {
371  case MAGIC_WMVd: // cursor
372  if (size_left < 2 + w * h * c->bpp2 * 2) {
373  av_log(avctx, AV_LOG_ERROR,
374  "Premature end of data! (need %i got %i)\n",
375  2 + w * h * c->bpp2 * 2, size_left);
376  return AVERROR_INVALIDDATA;
377  }
378  bytestream2_skip(gb, 2);
379  c->cur_w = w;
380  c->cur_h = h;
381  c->cur_hx = dx;
382  c->cur_hy = dy;
383  if ((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
384  av_log(avctx, AV_LOG_ERROR,
385  "Cursor hot spot is not in image: "
386  "%ix%i of %ix%i cursor size\n",
387  c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
388  c->cur_hx = c->cur_hy = 0;
389  }
390  if (c->cur_w * c->cur_h >= INT_MAX / c->bpp2) {
391  reset_buffers(c);
392  return AVERROR(EINVAL);
393  } else {
394  int screen_size = c->cur_w * c->cur_h * c->bpp2;
395  if ((ret = av_reallocp(&c->curbits, screen_size)) < 0 ||
396  (ret = av_reallocp(&c->curmask, screen_size)) < 0 ||
397  (ret = av_reallocp(&c->screendta, screen_size)) < 0) {
398  reset_buffers(c);
399  return ret;
400  }
401  }
402  load_cursor(c);
403  break;
404  case MAGIC_WMVe: // unknown
405  bytestream2_skip(gb, 2);
406  break;
407  case MAGIC_WMVf: // update cursor position
408  c->cur_x = dx - c->cur_hx;
409  c->cur_y = dy - c->cur_hy;
410  break;
411  case MAGIC_WMVg: // unknown
412  bytestream2_skip(gb, 10);
413  break;
414  case MAGIC_WMVh: // unknown
415  bytestream2_skip(gb, 4);
416  break;
417  case MAGIC_WMVi: // ServerInitialization struct
418  c->pic->key_frame = 1;
420  depth = bytestream2_get_byte(gb);
421  if (depth != c->bpp) {
422  av_log(avctx, AV_LOG_INFO,
423  "Depth mismatch. Container %i bpp, "
424  "Frame data: %i bpp\n",
425  c->bpp, depth);
426  }
427  bytestream2_skip(gb, 1);
428  c->bigendian = bytestream2_get_byte(gb);
429  if (c->bigendian & (~1)) {
430  av_log(avctx, AV_LOG_INFO,
431  "Invalid header: bigendian flag = %i\n", c->bigendian);
432  return AVERROR_INVALIDDATA;
433  }
434  //skip the rest of pixel format data
435  bytestream2_skip(gb, 13);
436  break;
437  case MAGIC_WMVj: // unknown
438  bytestream2_skip(gb, 2);
439  break;
440  case 0x00000000: // raw rectangle data
441  if ((dx + w > c->width) || (dy + h > c->height)) {
442  av_log(avctx, AV_LOG_ERROR,
443  "Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
444  w, h, dx, dy, c->width, c->height);
445  return AVERROR_INVALIDDATA;
446  }
447  if (size_left < w * h * c->bpp2) {
448  av_log(avctx, AV_LOG_ERROR,
449  "Premature end of data! (need %i got %i)\n",
450  w * h * c->bpp2, size_left);
451  return AVERROR_INVALIDDATA;
452  }
453  paint_raw(outptr, w, h, gb, c->bpp2, c->bigendian,
454  c->pic->linesize[0]);
455  break;
456  case 0x00000005: // HexTile encoded rectangle
457  if ((dx + w > c->width) || (dy + h > c->height)) {
458  av_log(avctx, AV_LOG_ERROR,
459  "Incorrect frame size: %ix%i+%ix%i of %ix%i\n",
460  w, h, dx, dy, c->width, c->height);
461  return AVERROR_INVALIDDATA;
462  }
463  res = decode_hextile(c, outptr, gb, w, h, c->pic->linesize[0]);
464  if (res < 0)
465  return res;
466  break;
467  default:
468  av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
469  chunks = 0; // leave chunks decoding loop
470  }
471  }
472  if (c->screendta) {
473  int i;
474  // save screen data before painting cursor
475  w = c->cur_w;
476  if (c->width < c->cur_x + w)
477  w = c->width - c->cur_x;
478  h = c->cur_h;
479  if (c->height < c->cur_y + h)
480  h = c->height - c->cur_y;
481  dx = c->cur_x;
482  if (dx < 0) {
483  w += dx;
484  dx = 0;
485  }
486  dy = c->cur_y;
487  if (dy < 0) {
488  h += dy;
489  dy = 0;
490  }
491  if ((w > 0) && (h > 0)) {
492  outptr = c->pic->data[0] + dx * c->bpp2 + dy * c->pic->linesize[0];
493  for (i = 0; i < h; i++) {
494  memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr,
495  w * c->bpp2);
496  outptr += c->pic->linesize[0];
497  }
498  outptr = c->pic->data[0];
499  put_cursor(outptr, c->pic->linesize[0], c, c->cur_x, c->cur_y);
500  }
501  }
502  *got_frame = 1;
503  if ((ret = av_frame_ref(data, c->pic)) < 0)
504  return ret;
505 
506  /* always report that the buffer was completely consumed */
507  return buf_size;
508 }
509 
511 {
512  VmncContext * const c = avctx->priv_data;
513 
514  c->avctx = avctx;
515  c->width = avctx->width;
516  c->height = avctx->height;
517  c->bpp = avctx->bits_per_coded_sample;
518  c->bpp2 = c->bpp / 8;
519 
520  switch (c->bpp) {
521  case 8:
522  avctx->pix_fmt = AV_PIX_FMT_PAL8;
523  break;
524  case 16:
525  avctx->pix_fmt = AV_PIX_FMT_RGB555;
526  break;
527  case 32:
528  avctx->pix_fmt = AV_PIX_FMT_RGB32;
529  break;
530  default:
531  av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
532  return AVERROR_INVALIDDATA;
533  }
534 
535  c->pic = av_frame_alloc();
536  if (!c->pic)
537  return AVERROR(ENOMEM);
538 
539  return 0;
540 }
541 
543 {
544  VmncContext * const c = avctx->priv_data;
545 
546  av_frame_free(&c->pic);
547 
548  av_free(c->curbits);
549  av_free(c->curmask);
550  av_free(c->screendta);
551  return 0;
552 }
553 
555  .name = "vmnc",
556  .long_name = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),
557  .type = AVMEDIA_TYPE_VIDEO,
558  .id = AV_CODEC_ID_VMNC,
559  .priv_data_size = sizeof(VmncContext),
560  .init = decode_init,
561  .close = decode_end,
562  .decode = decode_frame,
563  .capabilities = CODEC_CAP_DR1,
564 };