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x11grab.c
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1 /*
2  * X11 video grab interface
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg integration:
7  * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
8  * Edouard Gomez <ed.gomez@free.fr>
9  *
10  * This file contains code from grab.c:
11  * Copyright (c) 2000-2001 Fabrice Bellard
12  *
13  * This file contains code from the xvidcap project:
14  * Copyright (C) 1997-1998 Rasca, Berlin
15  * 2003-2004 Karl H. Beckers, Frankfurt
16  *
17  * FFmpeg is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License as published by
19  * the Free Software Foundation; either version 2 of the License, or
20  * (at your option) any later version.
21  *
22  * FFmpeg is distributed in the hope that it will be useful,
23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25  * GNU General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with FFmpeg; if not, write to the Free Software
29  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30  */
31 
32 /**
33  * @file
34  * X11 frame device demuxer
35  * @author Clemens Fruhwirth <clemens@endorphin.org>
36  * @author Edouard Gomez <ed.gomez@free.fr>
37  */
38 
39 #include "config.h"
40 
41 #include <time.h>
42 #include <sys/shm.h>
43 
44 #include <X11/cursorfont.h>
45 #include <X11/X.h>
46 #include <X11/Xlib.h>
47 #include <X11/Xlibint.h>
48 #include <X11/Xproto.h>
49 #include <X11/Xutil.h>
50 
51 #include <X11/extensions/shape.h>
52 #include <X11/extensions/Xfixes.h>
53 #include <X11/extensions/XShm.h>
54 
55 #include "avdevice.h"
56 
57 #include "libavutil/log.h"
58 #include "libavutil/opt.h"
59 #include "libavutil/parseutils.h"
60 #include "libavutil/time.h"
61 
62 #include "libavformat/internal.h"
63 
64 /** X11 device demuxer context */
65 typedef struct X11GrabContext {
66  const AVClass *class; /**< Class for private options. */
67  int frame_size; /**< Size in bytes of a grabbed frame */
68  AVRational time_base; /**< Time base */
69  int64_t time_frame; /**< Current time */
70 
71  int width; /**< Width of the grab frame */
72  int height; /**< Height of the grab frame */
73  int x_off; /**< Horizontal top-left corner coordinate */
74  int y_off; /**< Vertical top-left corner coordinate */
75 
76  Display *dpy; /**< X11 display from which x11grab grabs frames */
77  XImage *image; /**< X11 image holding the grab */
78  int use_shm; /**< !0 when using XShm extension */
79  XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
80  int draw_mouse; /**< Set by a private option. */
81  int follow_mouse; /**< Set by a private option. */
82  int show_region; /**< set by a private option. */
83  AVRational framerate; /**< Set by a private option. */
85  uint32_t palette[256];
86 
87  Cursor c;
88  Window region_win; /**< This is used by show_region option. */
90 
91 #define REGION_WIN_BORDER 3
92 
93 /**
94  * Draw grabbing region window
95  *
96  * @param s x11grab context
97  */
99 {
100  Display *dpy = s->dpy;
101  Window win = s->region_win;
102  int screen = DefaultScreen(dpy);
103  GC gc = XCreateGC(dpy, win, 0, 0);
104 
105  XSetForeground(dpy, gc, WhitePixel(dpy, screen));
106  XSetBackground(dpy, gc, BlackPixel(dpy, screen));
107  XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0);
108  XDrawRectangle(dpy, win, gc, 1, 1,
109  (s->width + REGION_WIN_BORDER * 2) - 1 * 2 - 1,
110  (s->height + REGION_WIN_BORDER * 2) - 1 * 2 - 1);
111  XFreeGC(dpy, gc);
112 }
113 
114 /**
115  * Initialize grabbing region window
116  *
117  * @param s x11grab context
118  */
120 {
121  Display *dpy = s->dpy;
122  XRectangle rect;
123  XSetWindowAttributes attribs = { .override_redirect = True };
124  int screen = DefaultScreen(dpy);
125 
126  s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
129  s->width + REGION_WIN_BORDER * 2,
130  s->height + REGION_WIN_BORDER * 2,
131  0, CopyFromParent,
132  InputOutput, CopyFromParent,
133  CWOverrideRedirect, &attribs);
134  rect.x = 0;
135  rect.y = 0;
136  rect.width = s->width;
137  rect.height = s->height;
138  XShapeCombineRectangles(dpy, s->region_win,
139  ShapeBounding, REGION_WIN_BORDER, REGION_WIN_BORDER,
140  &rect, 1, ShapeSubtract, 0);
141  XMapWindow(dpy, s->region_win);
142  XSelectInput(dpy, s->region_win, ExposureMask | StructureNotifyMask);
144 }
145 
146 /**
147  * Initialize the x11 grab device demuxer (public device demuxer API).
148  *
149  * @param s1 Context from avformat core
150  * @return <ul>
151  * <li>AVERROR(ENOMEM) no memory left</li>
152  * <li>AVERROR(EIO) other failure case</li>
153  * <li>0 success</li>
154  * </ul>
155  */
157 {
158  X11GrabContext *x11grab = s1->priv_data;
159  Display *dpy;
160  AVStream *st = NULL;
161  enum AVPixelFormat input_pixfmt;
162  XImage *image;
163  int x_off = 0, y_off = 0, ret = 0, screen, use_shm = 0;
164  char *dpyname, *offset;
165  Colormap color_map;
166  XColor color[256];
167  int i;
168 
169  dpyname = av_strdup(s1->filename);
170  if (!dpyname)
171  goto out;
172 
173  offset = strchr(dpyname, '+');
174  if (offset) {
175  sscanf(offset, "%d,%d", &x_off, &y_off);
176  if (strstr(offset, "nomouse")) {
178  "'nomouse' specification in argument is deprecated: "
179  "use 'draw_mouse' option with value 0 instead\n");
180  x11grab->draw_mouse = 0;
181  }
182  *offset = 0;
183  }
184 
185  av_log(s1, AV_LOG_INFO,
186  "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
187  s1->filename, dpyname, x_off, y_off, x11grab->width, x11grab->height);
188 
189  dpy = XOpenDisplay(dpyname);
190  av_freep(&dpyname);
191  if (!dpy) {
192  av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
193  ret = AVERROR(EIO);
194  goto out;
195  }
196 
197  st = avformat_new_stream(s1, NULL);
198  if (!st) {
199  ret = AVERROR(ENOMEM);
200  goto out;
201  }
202  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
203 
204  screen = DefaultScreen(dpy);
205 
206  if (x11grab->follow_mouse) {
207  int screen_w, screen_h;
208  Window w;
209 
210  screen_w = DisplayWidth(dpy, screen);
211  screen_h = DisplayHeight(dpy, screen);
212  XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off,
213  &ret, &ret, &ret);
214  x_off -= x11grab->width / 2;
215  y_off -= x11grab->height / 2;
216  x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
217  y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
218  av_log(s1, AV_LOG_INFO,
219  "followmouse is enabled, resetting grabbing region to x: %d y: %d\n",
220  x_off, y_off);
221  }
222 
223  if (x11grab->use_shm) {
224  use_shm = XShmQueryExtension(dpy);
225  av_log(s1, AV_LOG_INFO,
226  "shared memory extension %sfound\n", use_shm ? "" : "not ");
227  }
228 
229  if (use_shm) {
230  int scr = XDefaultScreen(dpy);
231  image = XShmCreateImage(dpy,
232  DefaultVisual(dpy, scr),
233  DefaultDepth(dpy, scr),
234  ZPixmap,
235  NULL,
236  &x11grab->shminfo,
237  x11grab->width, x11grab->height);
238  x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
239  image->bytes_per_line * image->height,
240  IPC_CREAT | 0777);
241  if (x11grab->shminfo.shmid == -1) {
242  av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
243  ret = AVERROR(ENOMEM);
244  goto out;
245  }
246  x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
247  x11grab->shminfo.readOnly = False;
248 
249  if (!XShmAttach(dpy, &x11grab->shminfo)) {
250  av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
251  /* needs some better error subroutine :) */
252  ret = AVERROR(EIO);
253  goto out;
254  }
255  } else {
256  image = XGetImage(dpy, RootWindow(dpy, screen),
257  x_off, y_off,
258  x11grab->width, x11grab->height,
259  AllPlanes, ZPixmap);
260  }
261 
262  switch (image->bits_per_pixel) {
263  case 8:
264  av_log(s1, AV_LOG_DEBUG, "8 bit palette\n");
265  input_pixfmt = AV_PIX_FMT_PAL8;
266  color_map = DefaultColormap(dpy, screen);
267  for (i = 0; i < 256; ++i)
268  color[i].pixel = i;
269  XQueryColors(dpy, color_map, color, 256);
270  for (i = 0; i < 256; ++i)
271  x11grab->palette[i] = (color[i].red & 0xFF00) << 8 |
272  (color[i].green & 0xFF00) |
273  (color[i].blue & 0xFF00) >> 8;
274  x11grab->palette_changed = 1;
275  break;
276  case 16:
277  if (image->red_mask == 0xf800 &&
278  image->green_mask == 0x07e0 &&
279  image->blue_mask == 0x001f) {
280  av_log(s1, AV_LOG_DEBUG, "16 bit RGB565\n");
281  input_pixfmt = AV_PIX_FMT_RGB565;
282  } else if (image->red_mask == 0x7c00 &&
283  image->green_mask == 0x03e0 &&
284  image->blue_mask == 0x001f) {
285  av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
286  input_pixfmt = AV_PIX_FMT_RGB555;
287  } else {
288  av_log(s1, AV_LOG_ERROR,
289  "RGB ordering at image depth %i not supported ... aborting\n",
290  image->bits_per_pixel);
291  av_log(s1, AV_LOG_ERROR,
292  "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n",
293  image->red_mask, image->green_mask, image->blue_mask);
295  goto out;
296  }
297  break;
298  case 24:
299  if (image->red_mask == 0xff0000 &&
300  image->green_mask == 0x00ff00 &&
301  image->blue_mask == 0x0000ff) {
302  input_pixfmt = AV_PIX_FMT_BGR24;
303  } else if (image->red_mask == 0x0000ff &&
304  image->green_mask == 0x00ff00 &&
305  image->blue_mask == 0xff0000) {
306  input_pixfmt = AV_PIX_FMT_RGB24;
307  } else {
308  av_log(s1, AV_LOG_ERROR,
309  "rgb ordering at image depth %i not supported ... aborting\n",
310  image->bits_per_pixel);
311  av_log(s1, AV_LOG_ERROR,
312  "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n",
313  image->red_mask, image->green_mask, image->blue_mask);
315  goto out;
316  }
317  break;
318  case 32:
319  if ( image->red_mask == 0xff0000 &&
320  image->green_mask == 0x00ff00 &&
321  image->blue_mask == 0x0000ff ) {
322  input_pixfmt = AV_PIX_FMT_0RGB32;
323  } else {
324  av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
325  av_log(s1, AV_LOG_ERROR, "color masks: r 0x%.6lx g 0x%.6lx b 0x%.6lx\n", image->red_mask, image->green_mask, image->blue_mask);
327  goto out;
328  }
329  break;
330  default:
331  av_log(s1, AV_LOG_ERROR,
332  "image depth %i not supported ... aborting\n",
333  image->bits_per_pixel);
335  goto out;
336  }
337 
338  x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel / 8;
339  x11grab->dpy = dpy;
340  x11grab->time_base = av_inv_q(x11grab->framerate);
341  x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
342  x11grab->x_off = x_off;
343  x11grab->y_off = y_off;
344  x11grab->image = image;
345  x11grab->use_shm = use_shm;
346 
349  st->codec->width = x11grab->width;
350  st->codec->height = x11grab->height;
351  st->codec->pix_fmt = input_pixfmt;
352  st->codec->time_base = x11grab->time_base;
353  st->codec->bit_rate = x11grab->frame_size * 1 / av_q2d(x11grab->time_base) * 8;
354 
355 out:
356  av_free(dpyname);
357  return ret;
358 }
359 
360 /**
361  * Paint a mouse pointer in an X11 image.
362  *
363  * @param image image to paint the mouse pointer to
364  * @param s context used to retrieve original grabbing rectangle
365  * coordinates
366  */
367 static void paint_mouse_pointer(XImage *image, AVFormatContext *s1)
368 {
369  X11GrabContext *s = s1->priv_data;
370  int x_off = s->x_off;
371  int y_off = s->y_off;
372  int width = s->width;
373  int height = s->height;
374  Display *dpy = s->dpy;
375  XFixesCursorImage *xcim;
376  int x, y;
377  int line, column;
378  int to_line, to_column;
379  int pixstride = image->bits_per_pixel >> 3;
380  /* Warning: in its insanity, xlib provides unsigned image data through a
381  * char* pointer, so we have to make it uint8_t to make things not break.
382  * Anyone who performs further investigation of the xlib API likely risks
383  * permanent brain damage. */
384  uint8_t *pix = image->data;
385  Window w;
386  XSetWindowAttributes attr;
387 
388  /* Code doesn't currently support 16-bit or PAL8 */
389  if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
390  return;
391 
392  if (!s->c)
393  s->c = XCreateFontCursor(dpy, XC_left_ptr);
394  w = DefaultRootWindow(dpy);
395  attr.cursor = s->c;
396  XChangeWindowAttributes(dpy, w, CWCursor, &attr);
397 
398  xcim = XFixesGetCursorImage(dpy);
399  if (!xcim) {
401  "XFixes extension not available, impossible to draw cursor\n");
402  s->draw_mouse = 0;
403  return;
404  }
405 
406  x = xcim->x - xcim->xhot;
407  y = xcim->y - xcim->yhot;
408 
409  to_line = FFMIN((y + xcim->height), (height + y_off));
410  to_column = FFMIN((x + xcim->width), (width + x_off));
411 
412  for (line = FFMAX(y, y_off); line < to_line; line++) {
413  for (column = FFMAX(x, x_off); column < to_column; column++) {
414  int xcim_addr = (line - y) * xcim->width + column - x;
415  int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
416  int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
417  int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
418  int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
419  int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
420 
421  if (a == 255) {
422  pix[image_addr + 0] = r;
423  pix[image_addr + 1] = g;
424  pix[image_addr + 2] = b;
425  } else if (a) {
426  /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
427  pix[image_addr + 0] = r + (pix[image_addr + 0] * (255 - a) + 255 / 2) / 255;
428  pix[image_addr + 1] = g + (pix[image_addr + 1] * (255 - a) + 255 / 2) / 255;
429  pix[image_addr + 2] = b + (pix[image_addr + 2] * (255 - a) + 255 / 2) / 255;
430  }
431  }
432  }
433 
434  XFree(xcim);
435  xcim = NULL;
436 }
437 
438 /**
439  * Read new data in the image structure.
440  *
441  * @param dpy X11 display to grab from
442  * @param d
443  * @param image Image where the grab will be put
444  * @param x Top-Left grabbing rectangle horizontal coordinate
445  * @param y Top-Left grabbing rectangle vertical coordinate
446  * @return 0 if error, !0 if successful
447  */
448 static int xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
449 {
450  xGetImageReply rep;
451  xGetImageReq *req;
452  long nbytes;
453 
454  if (!image)
455  return 0;
456 
457  LockDisplay(dpy);
458  GetReq(GetImage, req);
459 
460  /* First set up the standard stuff in the request */
461  req->drawable = d;
462  req->x = x;
463  req->y = y;
464  req->width = image->width;
465  req->height = image->height;
466  req->planeMask = (unsigned int)AllPlanes;
467  req->format = ZPixmap;
468 
469  if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
470  UnlockDisplay(dpy);
471  SyncHandle();
472  return 0;
473  }
474 
475  nbytes = (long)rep.length << 2;
476  _XReadPad(dpy, image->data, nbytes);
477 
478  UnlockDisplay(dpy);
479  SyncHandle();
480  return 1;
481 }
482 
483 /**
484  * Grab a frame from x11 (public device demuxer API).
485  *
486  * @param s1 Context from avformat core
487  * @param pkt Packet holding the brabbed frame
488  * @return frame size in bytes
489  */
491 {
492  X11GrabContext *s = s1->priv_data;
493  Display *dpy = s->dpy;
494  XImage *image = s->image;
495  int x_off = s->x_off;
496  int y_off = s->y_off;
497  int follow_mouse = s->follow_mouse;
498  int screen;
499  Window root;
500  int64_t curtime, delay;
501  struct timespec ts;
502 
503  /* Calculate the time of the next frame */
504  s->time_frame += INT64_C(1000000);
505 
506  /* wait based on the frame rate */
507  for (;;) {
508  curtime = av_gettime();
509  delay = s->time_frame * av_q2d(s->time_base) - curtime;
510  if (delay <= 0) {
511  if (delay < INT64_C(-1000000) * av_q2d(s->time_base))
512  s->time_frame += INT64_C(1000000);
513  break;
514  }
515  ts.tv_sec = delay / 1000000;
516  ts.tv_nsec = (delay % 1000000) * 1000;
517  nanosleep(&ts, NULL);
518  }
519 
520  av_init_packet(pkt);
521  pkt->data = image->data;
522  pkt->size = s->frame_size;
523  pkt->pts = curtime;
524  if (s->palette_changed) {
527  if (!pal) {
528  av_log(s, AV_LOG_ERROR, "Cannot append palette to packet\n");
529  } else {
530  memcpy(pal, s->palette, AVPALETTE_SIZE);
531  s->palette_changed = 0;
532  }
533  }
534 
535  screen = DefaultScreen(dpy);
536  root = RootWindow(dpy, screen);
537  if (follow_mouse) {
538  int screen_w, screen_h;
539  int pointer_x, pointer_y, _;
540  Window w;
541 
542  screen_w = DisplayWidth(dpy, screen);
543  screen_h = DisplayHeight(dpy, screen);
544  XQueryPointer(dpy, root, &w, &w, &pointer_x, &pointer_y, &_, &_, &_);
545  if (follow_mouse == -1) {
546  // follow the mouse, put it at center of grabbing region
547  x_off += pointer_x - s->width / 2 - x_off;
548  y_off += pointer_y - s->height / 2 - y_off;
549  } else {
550  // follow the mouse, but only move the grabbing region when mouse
551  // reaches within certain pixels to the edge.
552  if (pointer_x > x_off + s->width - follow_mouse)
553  x_off += pointer_x - (x_off + s->width - follow_mouse);
554  else if (pointer_x < x_off + follow_mouse)
555  x_off -= (x_off + follow_mouse) - pointer_x;
556  if (pointer_y > y_off + s->height - follow_mouse)
557  y_off += pointer_y - (y_off + s->height - follow_mouse);
558  else if (pointer_y < y_off + follow_mouse)
559  y_off -= (y_off + follow_mouse) - pointer_y;
560  }
561  // adjust grabbing region position if it goes out of screen.
562  s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
563  s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
564 
565  if (s->show_region && s->region_win)
566  XMoveWindow(dpy, s->region_win,
568  s->y_off - REGION_WIN_BORDER);
569  }
570 
571  if (s->show_region) {
572  if (s->region_win) {
573  XEvent evt = { .type = NoEventMask };
574  // Clean up the events, and do the initial draw or redraw.
575  while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask,
576  &evt))
577  ;
578  if (evt.type)
580  } else {
582  }
583  }
584 
585  if (s->use_shm) {
586  if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes))
587  av_log(s1, AV_LOG_INFO, "XShmGetImage() failed\n");
588  } else {
589  if (!xget_zpixmap(dpy, root, image, x_off, y_off))
590  av_log(s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
591  }
592 
593  if (s->draw_mouse)
594  paint_mouse_pointer(image, s1);
595 
596  return s->frame_size;
597 }
598 
599 /**
600  * Close x11 frame grabber (public device demuxer API).
601  *
602  * @param s1 Context from avformat core
603  * @return 0 success, !0 failure
604  */
606 {
607  X11GrabContext *x11grab = s1->priv_data;
608 
609  /* Detach cleanly from shared mem */
610  if (x11grab->use_shm) {
611  XShmDetach(x11grab->dpy, &x11grab->shminfo);
612  shmdt(x11grab->shminfo.shmaddr);
613  shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
614  }
615 
616  /* Destroy X11 image */
617  if (x11grab->image) {
618  XDestroyImage(x11grab->image);
619  x11grab->image = NULL;
620  }
621 
622  if (x11grab->region_win)
623  XDestroyWindow(x11grab->dpy, x11grab->region_win);
624 
625  /* Free X11 display */
626  XCloseDisplay(x11grab->dpy);
627  return 0;
628 }
629 
630 #define OFFSET(x) offsetof(X11GrabContext, x)
631 #define DEC AV_OPT_FLAG_DECODING_PARAM
632 static const AVOption options[] = {
633  { "draw_mouse", "draw the mouse pointer", OFFSET(draw_mouse), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
634 
635  { "follow_mouse", "move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region",
636  OFFSET(follow_mouse), AV_OPT_TYPE_INT, {.i64 = 0}, -1, INT_MAX, DEC, "follow_mouse" },
637  { "centered", "keep the mouse pointer at the center of grabbing region when following",
638  0, AV_OPT_TYPE_CONST, {.i64 = -1}, INT_MIN, INT_MAX, DEC, "follow_mouse" },
639 
640  { "framerate", "set video frame rate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "ntsc"}, 0, 0, DEC },
641  { "show_region", "show the grabbing region", OFFSET(show_region), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
642  { "video_size", "set video frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = "vga"}, 0, 0, DEC },
643  { "use_shm", "use MIT-SHM extension", OFFSET(use_shm), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
644  { NULL },
645 };
646 
647 static const AVClass x11_class = {
648  .class_name = "X11grab indev",
649  .item_name = av_default_item_name,
650  .option = options,
651  .version = LIBAVUTIL_VERSION_INT,
653 };
654 
655 /** x11 grabber device demuxer declaration */
657  .name = "x11grab",
658  .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
659  .priv_data_size = sizeof(X11GrabContext),
663  .flags = AVFMT_NOFILE,
664  .priv_class = &x11_class,
665 };