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/intreadwrite.h"
32 #include "avcodec.h"
33 
34 enum EncTypes {
35  MAGIC_WMVd = 0x574D5664,
42 };
43 
45  HT_RAW = 1, // tile is raw
46  HT_BKG = 2, // background color is present
47  HT_FG = 4, // foreground color is present
48  HT_SUB = 8, // subrects are present
49  HT_CLR = 16 // each subrect has own color
50 };
51 
52 /*
53  * Decoder context
54  */
55 typedef struct VmncContext {
58 
59  int bpp;
60  int bpp2;
61  int bigendian;
62  uint8_t pal[768];
63  int width, height;
64 
65  /* cursor data */
66  int cur_w, cur_h;
67  int cur_x, cur_y;
68  int cur_hx, cur_hy;
69  uint8_t* curbits, *curmask;
70  uint8_t* screendta;
71 } VmncContext;
72 
73 /* read pixel value from stream */
74 static av_always_inline int vmnc_get_pixel(const uint8_t* buf, int bpp, int be) {
75  switch(bpp * 2 + be) {
76  case 2:
77  case 3: return *buf;
78  case 4: return AV_RL16(buf);
79  case 5: return AV_RB16(buf);
80  case 8: return AV_RL32(buf);
81  case 9: return AV_RB32(buf);
82  default: return 0;
83  }
84 }
85 
86 static void load_cursor(VmncContext *c, const uint8_t *src)
87 {
88  int i, j, p;
89  const int bpp = c->bpp2;
90  uint8_t *dst8 = c->curbits;
91  uint16_t *dst16 = (uint16_t*)c->curbits;
92  uint32_t *dst32 = (uint32_t*)c->curbits;
93 
94  for(j = 0; j < c->cur_h; j++) {
95  for(i = 0; i < c->cur_w; i++) {
96  p = vmnc_get_pixel(src, bpp, c->bigendian);
97  src += bpp;
98  if(bpp == 1) *dst8++ = p;
99  if(bpp == 2) *dst16++ = p;
100  if(bpp == 4) *dst32++ = p;
101  }
102  }
103  dst8 = c->curmask;
104  dst16 = (uint16_t*)c->curmask;
105  dst32 = (uint32_t*)c->curmask;
106  for(j = 0; j < c->cur_h; j++) {
107  for(i = 0; i < c->cur_w; i++) {
108  p = vmnc_get_pixel(src, bpp, c->bigendian);
109  src += bpp;
110  if(bpp == 1) *dst8++ = p;
111  if(bpp == 2) *dst16++ = p;
112  if(bpp == 4) *dst32++ = p;
113  }
114  }
115 }
116 
117 static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)
118 {
119  int i, j;
120  int w, h, x, y;
121  w = c->cur_w;
122  if(c->width < c->cur_x + c->cur_w) w = c->width - c->cur_x;
123  h = c->cur_h;
124  if(c->height < c->cur_y + c->cur_h) h = c->height - c->cur_y;
125  x = c->cur_x;
126  y = c->cur_y;
127  if(x < 0) {
128  w += x;
129  x = 0;
130  }
131  if(y < 0) {
132  h += y;
133  y = 0;
134  }
135 
136  if((w < 1) || (h < 1)) return;
137  dst += x * c->bpp2 + y * stride;
138 
139  if(c->bpp2 == 1) {
140  uint8_t* cd = c->curbits, *msk = c->curmask;
141  for(j = 0; j < h; j++) {
142  for(i = 0; i < w; i++)
143  dst[i] = (dst[i] & cd[i]) ^ msk[i];
144  msk += c->cur_w;
145  cd += c->cur_w;
146  dst += stride;
147  }
148  } else if(c->bpp2 == 2) {
149  uint16_t* cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;
150  uint16_t* dst2;
151  for(j = 0; j < h; j++) {
152  dst2 = (uint16_t*)dst;
153  for(i = 0; i < w; i++)
154  dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
155  msk += c->cur_w;
156  cd += c->cur_w;
157  dst += stride;
158  }
159  } else if(c->bpp2 == 4) {
160  uint32_t* cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;
161  uint32_t* dst2;
162  for(j = 0; j < h; j++) {
163  dst2 = (uint32_t*)dst;
164  for(i = 0; i < w; i++)
165  dst2[i] = (dst2[i] & cd[i]) ^ msk[i];
166  msk += c->cur_w;
167  cd += c->cur_w;
168  dst += stride;
169  }
170  }
171 }
172 
173 /* fill rectangle with given color */
174 static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy, int w, int h, int color, int bpp, int stride)
175 {
176  int i, j;
177  dst += dx * bpp + dy * stride;
178  if(bpp == 1){
179  for(j = 0; j < h; j++) {
180  memset(dst, color, w);
181  dst += stride;
182  }
183  }else if(bpp == 2){
184  uint16_t* dst2;
185  for(j = 0; j < h; j++) {
186  dst2 = (uint16_t*)dst;
187  for(i = 0; i < w; i++) {
188  *dst2++ = color;
189  }
190  dst += stride;
191  }
192  }else if(bpp == 4){
193  uint32_t* dst2;
194  for(j = 0; j < h; j++) {
195  dst2 = (uint32_t*)dst;
196  for(i = 0; i < w; i++) {
197  dst2[i] = color;
198  }
199  dst += stride;
200  }
201  }
202 }
203 
204 static av_always_inline void paint_raw(uint8_t *dst, int w, int h, const uint8_t* src, int bpp, int be, int stride)
205 {
206  int i, j, p;
207  for(j = 0; j < h; j++) {
208  for(i = 0; i < w; i++) {
209  p = vmnc_get_pixel(src, bpp, be);
210  src += bpp;
211  switch(bpp){
212  case 1:
213  dst[i] = p;
214  break;
215  case 2:
216  ((uint16_t*)dst)[i] = p;
217  break;
218  case 4:
219  ((uint32_t*)dst)[i] = p;
220  break;
221  }
222  }
223  dst += stride;
224  }
225 }
226 
227 static int decode_hextile(VmncContext *c, uint8_t* dst, const uint8_t* src, int ssize, int w, int h, int stride)
228 {
229  int i, j, k;
230  int bg = 0, fg = 0, rects, color, flags, xy, wh;
231  const int bpp = c->bpp2;
232  uint8_t *dst2;
233  int bw = 16, bh = 16;
234  const uint8_t *ssrc=src;
235 
236  for(j = 0; j < h; j += 16) {
237  dst2 = dst;
238  bw = 16;
239  if(j + 16 > h) bh = h - j;
240  for(i = 0; i < w; i += 16, dst2 += 16 * bpp) {
241  if(src - ssrc >= ssize) {
242  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
243  return -1;
244  }
245  if(i + 16 > w) bw = w - i;
246  flags = *src++;
247  if(flags & HT_RAW) {
248  if(src - ssrc > ssize - bw * bh * bpp) {
249  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
250  return -1;
251  }
252  paint_raw(dst2, bw, bh, src, bpp, c->bigendian, stride);
253  src += bw * bh * bpp;
254  } else {
255  if(flags & HT_BKG) {
256  bg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
257  }
258  if(flags & HT_FG) {
259  fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
260  }
261  rects = 0;
262  if(flags & HT_SUB)
263  rects = *src++;
264  color = !!(flags & HT_CLR);
265 
266  paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);
267 
268  if(src - ssrc > ssize - rects * (color * bpp + 2)) {
269  av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
270  return -1;
271  }
272  for(k = 0; k < rects; k++) {
273  if(color) {
274  fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
275  }
276  xy = *src++;
277  wh = *src++;
278  paint_rect(dst2, xy >> 4, xy & 0xF, (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
279  }
280  }
281  }
282  dst += stride * 16;
283  }
284  return src - ssrc;
285 }
286 
287 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
288 {
289  const uint8_t *buf = avpkt->data;
290  int buf_size = avpkt->size;
291  VmncContext * const c = avctx->priv_data;
292  uint8_t *outptr;
293  const uint8_t *src = buf;
294  int dx, dy, w, h, depth, enc, chunks, res, size_left;
295 
296  c->pic.reference = 1;
298  if(avctx->reget_buffer(avctx, &c->pic) < 0){
299  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
300  return -1;
301  }
302 
303  c->pic.key_frame = 0;
305 
306  //restore screen after cursor
307  if(c->screendta) {
308  int i;
309  w = c->cur_w;
310  if(c->width < c->cur_x + w) w = c->width - c->cur_x;
311  h = c->cur_h;
312  if(c->height < c->cur_y + h) h = c->height - c->cur_y;
313  dx = c->cur_x;
314  if(dx < 0) {
315  w += dx;
316  dx = 0;
317  }
318  dy = c->cur_y;
319  if(dy < 0) {
320  h += dy;
321  dy = 0;
322  }
323  if((w > 0) && (h > 0)) {
324  outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
325  for(i = 0; i < h; i++) {
326  memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2, w * c->bpp2);
327  outptr += c->pic.linesize[0];
328  }
329  }
330  }
331  src += 2;
332  chunks = AV_RB16(src); src += 2;
333  while(chunks--) {
334  dx = AV_RB16(src); src += 2;
335  dy = AV_RB16(src); src += 2;
336  w = AV_RB16(src); src += 2;
337  h = AV_RB16(src); src += 2;
338  enc = AV_RB32(src); src += 4;
339  outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
340  size_left = buf_size - (src - buf);
341  switch(enc) {
342  case MAGIC_WMVd: // cursor
343  if(size_left < 2 + w * h * c->bpp2 * 2) {
344  av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", 2 + w * h * c->bpp2 * 2, size_left);
345  return -1;
346  }
347  src += 2;
348  c->cur_w = w;
349  c->cur_h = h;
350  c->cur_hx = dx;
351  c->cur_hy = dy;
352  if((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
353  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);
354  c->cur_hx = c->cur_hy = 0;
355  }
356  c->curbits = av_realloc(c->curbits, c->cur_w * c->cur_h * c->bpp2);
357  c->curmask = av_realloc(c->curmask, c->cur_w * c->cur_h * c->bpp2);
358  c->screendta = av_realloc(c->screendta, c->cur_w * c->cur_h * c->bpp2);
359  load_cursor(c, src);
360  src += w * h * c->bpp2 * 2;
361  break;
362  case MAGIC_WMVe: // unknown
363  src += 2;
364  break;
365  case MAGIC_WMVf: // update cursor position
366  c->cur_x = dx - c->cur_hx;
367  c->cur_y = dy - c->cur_hy;
368  break;
369  case MAGIC_WMVg: // unknown
370  src += 10;
371  break;
372  case MAGIC_WMVh: // unknown
373  src += 4;
374  break;
375  case MAGIC_WMVi: // ServerInitialization struct
376  c->pic.key_frame = 1;
378  depth = *src++;
379  if(depth != c->bpp) {
380  av_log(avctx, AV_LOG_INFO, "Depth mismatch. Container %i bpp, Frame data: %i bpp\n", c->bpp, depth);
381  }
382  src++;
383  c->bigendian = *src++;
384  if(c->bigendian & (~1)) {
385  av_log(avctx, AV_LOG_INFO, "Invalid header: bigendian flag = %i\n", c->bigendian);
386  return -1;
387  }
388  //skip the rest of pixel format data
389  src += 13;
390  break;
391  case MAGIC_WMVj: // unknown
392  src += 2;
393  break;
394  case 0x00000000: // raw rectangle data
395  if((dx + w > c->width) || (dy + h > c->height)) {
396  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);
397  return -1;
398  }
399  if(size_left < w * h * c->bpp2) {
400  av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", w * h * c->bpp2, size_left);
401  return -1;
402  }
403  paint_raw(outptr, w, h, src, c->bpp2, c->bigendian, c->pic.linesize[0]);
404  src += w * h * c->bpp2;
405  break;
406  case 0x00000005: // HexTile encoded rectangle
407  if((dx + w > c->width) || (dy + h > c->height)) {
408  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);
409  return -1;
410  }
411  res = decode_hextile(c, outptr, src, size_left, w, h, c->pic.linesize[0]);
412  if(res < 0)
413  return -1;
414  src += res;
415  break;
416  default:
417  av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
418  chunks = 0; // leave chunks decoding loop
419  }
420  }
421  if(c->screendta){
422  int i;
423  //save screen data before painting cursor
424  w = c->cur_w;
425  if(c->width < c->cur_x + w) w = c->width - c->cur_x;
426  h = c->cur_h;
427  if(c->height < c->cur_y + h) h = c->height - c->cur_y;
428  dx = c->cur_x;
429  if(dx < 0) {
430  w += dx;
431  dx = 0;
432  }
433  dy = c->cur_y;
434  if(dy < 0) {
435  h += dy;
436  dy = 0;
437  }
438  if((w > 0) && (h > 0)) {
439  outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
440  for(i = 0; i < h; i++) {
441  memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr, w * c->bpp2);
442  outptr += c->pic.linesize[0];
443  }
444  outptr = c->pic.data[0];
445  put_cursor(outptr, c->pic.linesize[0], c, c->cur_x, c->cur_y);
446  }
447  }
448  *data_size = sizeof(AVFrame);
449  *(AVFrame*)data = c->pic;
450 
451  /* always report that the buffer was completely consumed */
452  return buf_size;
453 }
454 
455 
456 
457 /*
458  *
459  * Init VMnc decoder
460  *
461  */
463 {
464  VmncContext * const c = avctx->priv_data;
465 
466  c->avctx = avctx;
467 
468  c->width = avctx->width;
469  c->height = avctx->height;
470 
471  c->bpp = avctx->bits_per_coded_sample;
472  c->bpp2 = c->bpp/8;
473 
474  switch(c->bpp){
475  case 8:
476  avctx->pix_fmt = PIX_FMT_PAL8;
477  break;
478  case 16:
479  avctx->pix_fmt = PIX_FMT_RGB555;
480  break;
481  case 32:
482  avctx->pix_fmt = PIX_FMT_RGB32;
483  break;
484  default:
485  av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
486  return AVERROR_INVALIDDATA;
487  }
488 
489  return 0;
490 }
491 
492 
493 
494 /*
495  *
496  * Uninit VMnc decoder
497  *
498  */
500 {
501  VmncContext * const c = avctx->priv_data;
502 
503  if (c->pic.data[0])
504  avctx->release_buffer(avctx, &c->pic);
505 
506  av_free(c->curbits);
507  av_free(c->curmask);
508  av_free(c->screendta);
509  return 0;
510 }
511 
513  .name = "vmnc",
514  .type = AVMEDIA_TYPE_VIDEO,
515  .id = CODEC_ID_VMNC,
516  .priv_data_size = sizeof(VmncContext),
517  .init = decode_init,
518  .close = decode_end,
519  .decode = decode_frame,
520  .capabilities = CODEC_CAP_DR1,
521  .long_name = NULL_IF_CONFIG_SMALL("VMware Screen Codec / VMware Video"),
522 };
523