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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 
35 enum EncTypes {
36  MAGIC_WMVd = 0x574D5664,
43 };
44 
46  HT_RAW = 1, // tile is raw
47  HT_BKG = 2, // background color is present
48  HT_FG = 4, // foreground color is present
49  HT_SUB = 8, // subrects are present
50  HT_CLR = 16 // each subrect has own color
51 };
52 
53 /*
54  * Decoder context
55  */
56 typedef struct VmncContext {
59 
60  int bpp;
61  int bpp2;
62  int bigendian;
63  uint8_t pal[768];
64  int width, height;
65 
66  /* cursor data */
67  int cur_w, cur_h;
68  int cur_x, cur_y;
69  int cur_hx, cur_hy;
72 } VmncContext;
73 
74 /* read pixel value from stream */
75 static av_always_inline int vmnc_get_pixel(const uint8_t* buf, int bpp, int be) {
76  switch(bpp * 2 + be) {
77  case 2:
78  case 3: return *buf;
79  case 4: return AV_RL16(buf);
80  case 5: return AV_RB16(buf);
81  case 8: return AV_RL32(buf);
82  case 9: return AV_RB32(buf);
83  default: return 0;
84  }
85 }
86 
87 static void load_cursor(VmncContext *c, const uint8_t *src)
88 {
89  int i, j, p;
90  const int bpp = c->bpp2;
91  uint8_t *dst8 = c->curbits;
92  uint16_t *dst16 = (uint16_t*)c->curbits;
93  uint32_t *dst32 = (uint32_t*)c->curbits;
94 
95  for(j = 0; j < c->cur_h; j++) {
96  for(i = 0; i < c->cur_w; i++) {
97  p = vmnc_get_pixel(src, bpp, c->bigendian);
98  src += bpp;
99  if(bpp == 1) *dst8++ = p;
100  if(bpp == 2) *dst16++ = p;
101  if(bpp == 4) *dst32++ = p;
102  }
103  }
104  dst8 = c->curmask;
105  dst16 = (uint16_t*)c->curmask;
106  dst32 = (uint32_t*)c->curmask;
107  for(j = 0; j < c->cur_h; j++) {
108  for(i = 0; i < c->cur_w; i++) {
109  p = vmnc_get_pixel(src, bpp, c->bigendian);
110  src += bpp;
111  if(bpp == 1) *dst8++ = p;
112  if(bpp == 2) *dst16++ = p;
113  if(bpp == 4) *dst32++ = p;
114  }
115  }
116 }
117 
118 static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)
119 {
120  int i, j;
121  int w, h, x, y;
122  w = c->cur_w;
123  if(c->width < c->cur_x + c->cur_w) w = c->width - c->cur_x;
124  h = c->cur_h;
125  if(c->height < c->cur_y + c->cur_h) h = c->height - c->cur_y;
126  x = c->cur_x;
127  y = c->cur_y;
128  if(x < 0) {
129  w += x;
130  x = 0;
131  }
132  if(y < 0) {
133  h += y;
134  y = 0;
135  }
136 
137  if((w < 1) || (h < 1)) return;
138  dst += x * c->bpp2 + y * stride;
139 
140  if(c->bpp2 == 1) {
141  uint8_t* cd = c->curbits, *msk = c->curmask;
142  for(j = 0; j < h; j++) {
143  for(i = 0; i < w; i++)
144  dst[i] = (dst[i] & cd[i]) ^ msk[i];
145  msk += c->cur_w;
146  cd += c->cur_w;
147  dst += stride;
148  }
149  } else if(c->bpp2 == 2) {
150  uint16_t* cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;
151  uint16_t* dst2;
152  for(j = 0; j < h; j++) {
153  dst2 = (uint16_t*)dst;
154  for(i = 0; i < w; i++)
155  dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
156  msk += c->cur_w;
157  cd += c->cur_w;
158  dst += stride;
159  }
160  } else if(c->bpp2 == 4) {
161  uint32_t* cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;
162  uint32_t* dst2;
163  for(j = 0; j < h; j++) {
164  dst2 = (uint32_t*)dst;
165  for(i = 0; i < w; i++)
166  dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
167  msk += c->cur_w;
168  cd += c->cur_w;
169  dst += stride;
170  }
171  }
172 }
173 
174 /* fill rectangle with given color */
175 static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy, int w, int h, int color, int bpp, int stride)
176 {
177  int i, j;
178  dst += dx * bpp + dy * stride;
179  if(bpp == 1){
180  for(j = 0; j < h; j++) {
181  memset(dst, color, w);
182  dst += stride;
183  }
184  }else if(bpp == 2){
185  uint16_t* dst2;
186  for(j = 0; j < h; j++) {
187  dst2 = (uint16_t*)dst;
188  for(i = 0; i < w; i++) {
189  *dst2++ = color;
190  }
191  dst += stride;
192  }
193  }else if(bpp == 4){
194  uint32_t* dst2;
195  for(j = 0; j < h; j++) {
196  dst2 = (uint32_t*)dst;
197  for(i = 0; i < w; i++) {
198  dst2[i] = color;
199  }
200  dst += stride;
201  }
202  }
203 }
204 
205 static av_always_inline void paint_raw(uint8_t *dst, int w, int h, const uint8_t* src, int bpp, int be, int stride)
206 {
207  int i, j, p;
208  for(j = 0; j < h; j++) {
209  for(i = 0; i < w; i++) {
210  p = vmnc_get_pixel(src, bpp, be);
211  src += bpp;
212  switch(bpp){
213  case 1:
214  dst[i] = p;
215  break;
216  case 2:
217  ((uint16_t*)dst)[i] = p;
218  break;
219  case 4:
220  ((uint32_t*)dst)[i] = p;
221  break;
222  }
223  }
224  dst += stride;
225  }
226 }
227 
228 static int decode_hextile(VmncContext *c, uint8_t* dst, const uint8_t* src, int ssize, int w, int h, int stride)
229 {
230  int i, j, k;
231  int bg = 0, fg = 0, rects, color, flags, xy, wh;
232  const int bpp = c->bpp2;
233  uint8_t *dst2;
234  int bw = 16, bh = 16;
235  const uint8_t *ssrc=src;
236 
237  for(j = 0; j < h; j += 16) {
238  dst2 = dst;
239  bw = 16;
240  if(j + 16 > h) bh = h - j;
241  for(i = 0; i < w; i += 16, dst2 += 16 * bpp) {
242  if(src - ssrc >= ssize) {
243  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
244  return -1;
245  }
246  if(i + 16 > w) bw = w - i;
247  flags = *src++;
248  if(flags & HT_RAW) {
249  if(src - ssrc > ssize - bw * bh * bpp) {
250  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
251  return -1;
252  }
253  paint_raw(dst2, bw, bh, src, bpp, c->bigendian, stride);
254  src += bw * bh * bpp;
255  } else {
256  if(flags & HT_BKG) {
257  bg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
258  }
259  if(flags & HT_FG) {
260  fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
261  }
262  rects = 0;
263  if(flags & HT_SUB)
264  rects = *src++;
265  color = !!(flags & HT_CLR);
266 
267  paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);
268 
269  if(src - ssrc > ssize - rects * (color * bpp + 2)) {
270  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
271  return -1;
272  }
273  for(k = 0; k < rects; k++) {
274  if(color) {
275  fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
276  }
277  xy = *src++;
278  wh = *src++;
279  paint_rect(dst2, xy >> 4, xy & 0xF, (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
280  }
281  }
282  }
283  dst += stride * 16;
284  }
285  return src - ssrc;
286 }
287 
288 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
289  AVPacket *avpkt)
290 {
291  const uint8_t *buf = avpkt->data;
292  int buf_size = avpkt->size;
293  VmncContext * const c = avctx->priv_data;
294  uint8_t *outptr;
295  const uint8_t *src = buf;
296  int dx, dy, w, h, depth, enc, chunks, res, size_left;
297 
298  c->pic.reference = 3;
300  if(avctx->reget_buffer(avctx, &c->pic) < 0){
301  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
302  return -1;
303  }
304 
305  c->pic.key_frame = 0;
307 
308  //restore screen after cursor
309  if(c->screendta) {
310  int i;
311  w = c->cur_w;
312  if(c->width < c->cur_x + w) w = c->width - c->cur_x;
313  h = c->cur_h;
314  if(c->height < c->cur_y + h) h = c->height - c->cur_y;
315  dx = c->cur_x;
316  if(dx < 0) {
317  w += dx;
318  dx = 0;
319  }
320  dy = c->cur_y;
321  if(dy < 0) {
322  h += dy;
323  dy = 0;
324  }
325  if((w > 0) && (h > 0)) {
326  outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
327  for(i = 0; i < h; i++) {
328  memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2, w * c->bpp2);
329  outptr += c->pic.linesize[0];
330  }
331  }
332  }
333  src += 2;
334  chunks = AV_RB16(src); src += 2;
335  while(chunks--) {
336  if(buf_size - (src - buf) < 12) {
337  av_log(avctx, AV_LOG_ERROR, "Premature end of data!\n");
338  return -1;
339  }
340  dx = AV_RB16(src); src += 2;
341  dy = AV_RB16(src); src += 2;
342  w = AV_RB16(src); src += 2;
343  h = AV_RB16(src); src += 2;
344  enc = AV_RB32(src); src += 4;
345  outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
346  size_left = buf_size - (src - buf);
347  switch(enc) {
348  case MAGIC_WMVd: // cursor
349  if (w*(int64_t)h*c->bpp2 > INT_MAX/2 - 2) {
350  av_log(avctx, AV_LOG_ERROR, "dimensions too large\n");
351  return AVERROR_INVALIDDATA;
352  }
353  if(size_left < 2 + w * h * c->bpp2 * 2) {
354  av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", 2 + w * h * c->bpp2 * 2, size_left);
355  return -1;
356  }
357  src += 2;
358  c->cur_w = w;
359  c->cur_h = h;
360  c->cur_hx = dx;
361  c->cur_hy = dy;
362  if((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
363  av_log(avctx, AV_LOG_ERROR, "Cursor hot spot is not in image: %ix%i of %ix%i cursor size\n", c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
364  c->cur_hx = c->cur_hy = 0;
365  }
366  c->curbits = av_realloc(c->curbits, c->cur_w * c->cur_h * c->bpp2);
367  c->curmask = av_realloc(c->curmask, c->cur_w * c->cur_h * c->bpp2);
368  c->screendta = av_realloc(c->screendta, c->cur_w * c->cur_h * c->bpp2);
369  load_cursor(c, src);
370  src += w * h * c->bpp2 * 2;
371  break;
372  case MAGIC_WMVe: // unknown
373  src += 2;
374  break;
375  case MAGIC_WMVf: // update cursor position
376  c->cur_x = dx - c->cur_hx;
377  c->cur_y = dy - c->cur_hy;
378  break;
379  case MAGIC_WMVg: // unknown
380  src += 10;
381  break;
382  case MAGIC_WMVh: // unknown
383  src += 4;
384  break;
385  case MAGIC_WMVi: // ServerInitialization struct
386  c->pic.key_frame = 1;
388  depth = *src++;
389  if(depth != c->bpp) {
390  av_log(avctx, AV_LOG_INFO, "Depth mismatch. Container %i bpp, Frame data: %i bpp\n", c->bpp, depth);
391  }
392  src++;
393  c->bigendian = *src++;
394  if(c->bigendian & (~1)) {
395  av_log(avctx, AV_LOG_INFO, "Invalid header: bigendian flag = %i\n", c->bigendian);
396  return -1;
397  }
398  //skip the rest of pixel format data
399  src += 13;
400  break;
401  case MAGIC_WMVj: // unknown
402  src += 2;
403  break;
404  case 0x00000000: // raw rectangle data
405  if((dx + w > c->width) || (dy + h > c->height)) {
406  av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
407  return -1;
408  }
409  if(size_left < w * h * c->bpp2) {
410  av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", w * h * c->bpp2, size_left);
411  return -1;
412  }
413  paint_raw(outptr, w, h, src, c->bpp2, c->bigendian, c->pic.linesize[0]);
414  src += w * h * c->bpp2;
415  break;
416  case 0x00000005: // HexTile encoded rectangle
417  if((dx + w > c->width) || (dy + h > c->height)) {
418  av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
419  return -1;
420  }
421  res = decode_hextile(c, outptr, src, size_left, w, h, c->pic.linesize[0]);
422  if(res < 0)
423  return -1;
424  src += res;
425  break;
426  default:
427  av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
428  chunks = 0; // leave chunks decoding loop
429  }
430  }
431  if(c->screendta){
432  int i;
433  //save screen data before painting cursor
434  w = c->cur_w;
435  if(c->width < c->cur_x + w) w = c->width - c->cur_x;
436  h = c->cur_h;
437  if(c->height < c->cur_y + h) h = c->height - c->cur_y;
438  dx = c->cur_x;
439  if(dx < 0) {
440  w += dx;
441  dx = 0;
442  }
443  dy = c->cur_y;
444  if(dy < 0) {
445  h += dy;
446  dy = 0;
447  }
448  if((w > 0) && (h > 0)) {
449  outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
450  for(i = 0; i < h; i++) {
451  memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr, w * c->bpp2);
452  outptr += c->pic.linesize[0];
453  }
454  outptr = c->pic.data[0];
455  put_cursor(outptr, c->pic.linesize[0], c, c->cur_x, c->cur_y);
456  }
457  }
458  *got_frame = 1;
459  *(AVFrame*)data = c->pic;
460 
461  /* always report that the buffer was completely consumed */
462  return buf_size;
463 }
464 
465 
466 
467 /*
468  *
469  * Init VMnc decoder
470  *
471  */
473 {
474  VmncContext * const c = avctx->priv_data;
475 
476  c->avctx = avctx;
477 
478  c->width = avctx->width;
479  c->height = avctx->height;
480 
481  c->bpp = avctx->bits_per_coded_sample;
482  c->bpp2 = c->bpp/8;
484 
485  switch(c->bpp){
486  case 8:
487  avctx->pix_fmt = AV_PIX_FMT_PAL8;
488  break;
489  case 16:
490  avctx->pix_fmt = AV_PIX_FMT_RGB555;
491  break;
492  case 32:
493  avctx->pix_fmt = AV_PIX_FMT_RGB32;
494  break;
495  default:
496  av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
497  return AVERROR_INVALIDDATA;
498  }
499 
500  return 0;
501 }
502 
503 
504 
505 /*
506  *
507  * Uninit VMnc decoder
508  *
509  */
511 {
512  VmncContext * const c = avctx->priv_data;
513 
514  if (c->pic.data[0])
515  avctx->release_buffer(avctx, &c->pic);
516 
517  av_free(c->curbits);
518  av_free(c->curmask);
519  av_free(c->screendta);
520  return 0;
521 }
522 
524  .name = "vmnc",
525  .type = AVMEDIA_TYPE_VIDEO,
526  .id = AV_CODEC_ID_VMNC,
527  .priv_data_size = sizeof(VmncContext),
528  .init = decode_init,
529  .close = decode_end,
530  .decode = decode_frame,
531  .capabilities = CODEC_CAP_DR1,
532  .long_name = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),
533 };