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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 static int setup_shm(AVFormatContext *s, Display *dpy, XImage **image)
147 {
148  X11GrabContext *g = s->priv_data;
149  int scr = XDefaultScreen(dpy);
150  XImage *img = XShmCreateImage(dpy, DefaultVisual(dpy, scr),
151  DefaultDepth(dpy, scr), ZPixmap, NULL,
152  &g->shminfo, g->width, g->height);
153 
154  g->shminfo.shmid = shmget(IPC_PRIVATE, img->bytes_per_line * img->height,
155  IPC_CREAT | 0777);
156 
157  if (g->shminfo.shmid == -1) {
158  av_log(s, AV_LOG_ERROR, "Cannot get shared memory!\n");
159  return AVERROR(ENOMEM);
160  }
161 
162  g->shminfo.shmaddr = img->data = shmat(g->shminfo.shmid, 0, 0);
163  g->shminfo.readOnly = False;
164 
165  if (!XShmAttach(dpy, &g->shminfo)) {
166  av_log(s, AV_LOG_ERROR, "Failed to attach shared memory!\n");
167  /* needs some better error subroutine :) */
168  return AVERROR(EIO);
169  }
170 
171  *image = img;
172  return 0;
173 }
174 
175 static int pixfmt_from_image(AVFormatContext *s, XImage *image, int *pix_fmt)
176 {
177  av_log(s, AV_LOG_DEBUG,
178  "Image r 0x%.6lx g 0x%.6lx b 0x%.6lx and depth %i\n",
179  image->red_mask,
180  image->green_mask,
181  image->blue_mask,
182  image->bits_per_pixel);
183 
184  *pix_fmt = AV_PIX_FMT_NONE;
185 
186  switch (image->bits_per_pixel) {
187  case 8:
188  *pix_fmt = AV_PIX_FMT_PAL8;
189  break;
190  case 16:
191  if (image->red_mask == 0xf800 &&
192  image->green_mask == 0x07e0 &&
193  image->blue_mask == 0x001f) {
194  *pix_fmt = AV_PIX_FMT_RGB565;
195  } else if (image->red_mask == 0x7c00 &&
196  image->green_mask == 0x03e0 &&
197  image->blue_mask == 0x001f) {
198  *pix_fmt = AV_PIX_FMT_RGB555;
199  }
200  break;
201  case 24:
202  if (image->red_mask == 0xff0000 &&
203  image->green_mask == 0x00ff00 &&
204  image->blue_mask == 0x0000ff) {
205  *pix_fmt = AV_PIX_FMT_BGR24;
206  } else if (image->red_mask == 0x0000ff &&
207  image->green_mask == 0x00ff00 &&
208  image->blue_mask == 0xff0000) {
209  *pix_fmt = AV_PIX_FMT_RGB24;
210  }
211  break;
212  case 32:
213  if (image->red_mask == 0xff0000 &&
214  image->green_mask == 0x00ff00 &&
215  image->blue_mask == 0x0000ff ) {
216  *pix_fmt = AV_PIX_FMT_0RGB32;
217  }
218  break;
219  }
220  if (*pix_fmt == AV_PIX_FMT_NONE) {
221  av_log(s, AV_LOG_ERROR,
222  "XImages with RGB mask 0x%.6lx 0x%.6lx 0x%.6lx and depth %i "
223  "are currently not supported.\n",
224  image->red_mask,
225  image->green_mask,
226  image->blue_mask,
227  image->bits_per_pixel);
228 
229  return AVERROR_PATCHWELCOME;
230  }
231 
232  return 0;
233 }
234 
235 /**
236  * Initialize the x11 grab device demuxer (public device demuxer API).
237  *
238  * @param s1 Context from avformat core
239  * @return <ul>
240  * <li>AVERROR(ENOMEM) no memory left</li>
241  * <li>AVERROR(EIO) other failure case</li>
242  * <li>0 success</li>
243  * </ul>
244  */
246 {
247  X11GrabContext *x11grab = s1->priv_data;
248  Display *dpy;
249  AVStream *st = NULL;
250  XImage *image;
251  int x_off = 0, y_off = 0, ret = 0, screen, use_shm = 0;
252  char *dpyname, *offset;
253  Colormap color_map;
254  XColor color[256];
255  int i;
256 
257  dpyname = av_strdup(s1->filename);
258  if (!dpyname)
259  goto out;
260 
261  offset = strchr(dpyname, '+');
262  if (offset) {
263  sscanf(offset, "%d,%d", &x_off, &y_off);
264  if (strstr(offset, "nomouse")) {
266  "'nomouse' specification in argument is deprecated: "
267  "use 'draw_mouse' option with value 0 instead\n");
268  x11grab->draw_mouse = 0;
269  }
270  *offset = 0;
271  }
272 
273  av_log(s1, AV_LOG_INFO,
274  "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
275  s1->filename, dpyname, x_off, y_off, x11grab->width, x11grab->height);
276 
277  dpy = XOpenDisplay(dpyname);
278  av_freep(&dpyname);
279  if (!dpy) {
280  av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
281  ret = AVERROR(EIO);
282  goto out;
283  }
284 
285  st = avformat_new_stream(s1, NULL);
286  if (!st) {
287  ret = AVERROR(ENOMEM);
288  goto out;
289  }
290  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
291 
292  screen = DefaultScreen(dpy);
293 
294  if (x11grab->follow_mouse) {
295  int screen_w, screen_h;
296  Window w;
297 
298  screen_w = DisplayWidth(dpy, screen);
299  screen_h = DisplayHeight(dpy, screen);
300  XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off,
301  &ret, &ret, &ret);
302  x_off -= x11grab->width / 2;
303  y_off -= x11grab->height / 2;
304  x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
305  y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
306  av_log(s1, AV_LOG_INFO,
307  "followmouse is enabled, resetting grabbing region to x: %d y: %d\n",
308  x_off, y_off);
309  }
310 
311  if (x11grab->use_shm) {
312  use_shm = XShmQueryExtension(dpy);
313  av_log(s1, AV_LOG_INFO,
314  "shared memory extension %sfound\n", use_shm ? "" : "not ");
315  }
316 
317  if (use_shm && setup_shm(s1, dpy, &image) < 0) {
318  av_log(s1, AV_LOG_WARNING, "Falling back to XGetImage\n");
319  use_shm = 0;
320  }
321 
322  if (!use_shm) {
323  image = XGetImage(dpy, RootWindow(dpy, screen),
324  x_off, y_off,
325  x11grab->width, x11grab->height,
326  AllPlanes, ZPixmap);
327  }
328 
329  x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel / 8;
330  x11grab->dpy = dpy;
331  x11grab->time_base = av_inv_q(x11grab->framerate);
332  x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
333  x11grab->x_off = x_off;
334  x11grab->y_off = y_off;
335  x11grab->image = image;
336  x11grab->use_shm = use_shm;
337 
338  ret = pixfmt_from_image(s1, image, &st->codec->pix_fmt);
339  if (ret < 0)
340  goto out;
341 
342  if (st->codec->pix_fmt == AV_PIX_FMT_PAL8) {
343  color_map = DefaultColormap(dpy, screen);
344  for (i = 0; i < 256; ++i)
345  color[i].pixel = i;
346  XQueryColors(dpy, color_map, color, 256);
347  for (i = 0; i < 256; ++i)
348  x11grab->palette[i] = (color[i].red & 0xFF00) << 8 |
349  (color[i].green & 0xFF00) |
350  (color[i].blue & 0xFF00) >> 8;
351  x11grab->palette_changed = 1;
352  }
353 
354 
357  st->codec->width = x11grab->width;
358  st->codec->height = x11grab->height;
359  st->codec->time_base = x11grab->time_base;
360  st->codec->bit_rate = x11grab->frame_size * 1 / av_q2d(x11grab->time_base) * 8;
361 
362 out:
363  av_free(dpyname);
364  return ret;
365 }
366 
367 /**
368  * Paint a mouse pointer in an X11 image.
369  *
370  * @param image image to paint the mouse pointer to
371  * @param s context used to retrieve original grabbing rectangle
372  * coordinates
373  */
374 static void paint_mouse_pointer(XImage *image, AVFormatContext *s1)
375 {
376  X11GrabContext *s = s1->priv_data;
377  int x_off = s->x_off;
378  int y_off = s->y_off;
379  int width = s->width;
380  int height = s->height;
381  Display *dpy = s->dpy;
382  XFixesCursorImage *xcim;
383  int x, y;
384  int line, column;
385  int to_line, to_column;
386  int pixstride = image->bits_per_pixel >> 3;
387  /* Warning: in its insanity, xlib provides unsigned image data through a
388  * char* pointer, so we have to make it uint8_t to make things not break.
389  * Anyone who performs further investigation of the xlib API likely risks
390  * permanent brain damage. */
391  uint8_t *pix = image->data;
392  Window root;
393  XSetWindowAttributes attr;
394  Bool pointer_on_screen;
395  Window w;
396  int _;
397 
398  root = DefaultRootWindow(dpy);
399  pointer_on_screen = XQueryPointer(dpy, root, &w, &w, &_, &_, &_, &_, &_);
400  if (!pointer_on_screen)
401  return;
402 
403  /* Code doesn't currently support 16-bit or PAL8 */
404  if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
405  return;
406 
407  if (!s->c)
408  s->c = XCreateFontCursor(dpy, XC_left_ptr);
409  attr.cursor = s->c;
410  XChangeWindowAttributes(dpy, root, CWCursor, &attr);
411 
412  xcim = XFixesGetCursorImage(dpy);
413  if (!xcim) {
415  "XFixes extension not available, impossible to draw cursor\n");
416  s->draw_mouse = 0;
417  return;
418  }
419 
420  x = xcim->x - xcim->xhot;
421  y = xcim->y - xcim->yhot;
422 
423  to_line = FFMIN((y + xcim->height), (height + y_off));
424  to_column = FFMIN((x + xcim->width), (width + x_off));
425 
426  for (line = FFMAX(y, y_off); line < to_line; line++) {
427  for (column = FFMAX(x, x_off); column < to_column; column++) {
428  int xcim_addr = (line - y) * xcim->width + column - x;
429  int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
430  int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
431  int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
432  int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
433  int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
434 
435  if (a == 255) {
436  pix[image_addr + 0] = r;
437  pix[image_addr + 1] = g;
438  pix[image_addr + 2] = b;
439  } else if (a) {
440  /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
441  pix[image_addr + 0] = r + (pix[image_addr + 0] * (255 - a) + 255 / 2) / 255;
442  pix[image_addr + 1] = g + (pix[image_addr + 1] * (255 - a) + 255 / 2) / 255;
443  pix[image_addr + 2] = b + (pix[image_addr + 2] * (255 - a) + 255 / 2) / 255;
444  }
445  }
446  }
447 
448  XFree(xcim);
449  xcim = NULL;
450 }
451 
452 /**
453  * Read new data in the image structure.
454  *
455  * @param dpy X11 display to grab from
456  * @param d
457  * @param image Image where the grab will be put
458  * @param x Top-Left grabbing rectangle horizontal coordinate
459  * @param y Top-Left grabbing rectangle vertical coordinate
460  * @return 0 if error, !0 if successful
461  */
462 static int xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
463 {
464  xGetImageReply rep;
465  xGetImageReq *req;
466  long nbytes;
467 
468  if (!image)
469  return 0;
470 
471  LockDisplay(dpy);
472  GetReq(GetImage, req);
473 
474  /* First set up the standard stuff in the request */
475  req->drawable = d;
476  req->x = x;
477  req->y = y;
478  req->width = image->width;
479  req->height = image->height;
480  req->planeMask = (unsigned int)AllPlanes;
481  req->format = ZPixmap;
482 
483  if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
484  UnlockDisplay(dpy);
485  SyncHandle();
486  return 0;
487  }
488 
489  nbytes = (long)rep.length << 2;
490  _XReadPad(dpy, image->data, nbytes);
491 
492  UnlockDisplay(dpy);
493  SyncHandle();
494  return 1;
495 }
496 
497 /**
498  * Grab a frame from x11 (public device demuxer API).
499  *
500  * @param s1 Context from avformat core
501  * @param pkt Packet holding the brabbed frame
502  * @return frame size in bytes
503  */
505 {
506  X11GrabContext *s = s1->priv_data;
507  Display *dpy = s->dpy;
508  XImage *image = s->image;
509  int x_off = s->x_off;
510  int y_off = s->y_off;
511  int follow_mouse = s->follow_mouse;
512  int screen;
513  Window root;
514  int64_t curtime, delay;
515  struct timespec ts;
516 
517  /* Calculate the time of the next frame */
518  s->time_frame += INT64_C(1000000);
519 
520  /* wait based on the frame rate */
521  for (;;) {
522  curtime = av_gettime();
523  delay = s->time_frame * av_q2d(s->time_base) - curtime;
524  if (delay <= 0) {
525  if (delay < INT64_C(-1000000) * av_q2d(s->time_base))
526  s->time_frame += INT64_C(1000000);
527  break;
528  }
529  ts.tv_sec = delay / 1000000;
530  ts.tv_nsec = (delay % 1000000) * 1000;
531  nanosleep(&ts, NULL);
532  }
533 
534  av_init_packet(pkt);
535  pkt->data = image->data;
536  pkt->size = s->frame_size;
537  pkt->pts = curtime;
538  if (s->palette_changed) {
541  if (!pal) {
542  av_log(s, AV_LOG_ERROR, "Cannot append palette to packet\n");
543  } else {
544  memcpy(pal, s->palette, AVPALETTE_SIZE);
545  s->palette_changed = 0;
546  }
547  }
548 
549  screen = DefaultScreen(dpy);
550  root = RootWindow(dpy, screen);
551  if (follow_mouse) {
552  int screen_w, screen_h;
553  int pointer_x, pointer_y, _;
554  Window w;
555 
556  screen_w = DisplayWidth(dpy, screen);
557  screen_h = DisplayHeight(dpy, screen);
558  XQueryPointer(dpy, root, &w, &w, &pointer_x, &pointer_y, &_, &_, &_);
559  if (follow_mouse == -1) {
560  // follow the mouse, put it at center of grabbing region
561  x_off += pointer_x - s->width / 2 - x_off;
562  y_off += pointer_y - s->height / 2 - y_off;
563  } else {
564  // follow the mouse, but only move the grabbing region when mouse
565  // reaches within certain pixels to the edge.
566  if (pointer_x > x_off + s->width - follow_mouse)
567  x_off += pointer_x - (x_off + s->width - follow_mouse);
568  else if (pointer_x < x_off + follow_mouse)
569  x_off -= (x_off + follow_mouse) - pointer_x;
570  if (pointer_y > y_off + s->height - follow_mouse)
571  y_off += pointer_y - (y_off + s->height - follow_mouse);
572  else if (pointer_y < y_off + follow_mouse)
573  y_off -= (y_off + follow_mouse) - pointer_y;
574  }
575  // adjust grabbing region position if it goes out of screen.
576  s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
577  s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
578 
579  if (s->show_region && s->region_win)
580  XMoveWindow(dpy, s->region_win,
582  s->y_off - REGION_WIN_BORDER);
583  }
584 
585  if (s->show_region) {
586  if (s->region_win) {
587  XEvent evt = { .type = NoEventMask };
588  // Clean up the events, and do the initial draw or redraw.
589  while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask,
590  &evt))
591  ;
592  if (evt.type)
594  } else {
596  }
597  }
598 
599  if (s->use_shm) {
600  if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes))
601  av_log(s1, AV_LOG_INFO, "XShmGetImage() failed\n");
602  } else {
603  if (!xget_zpixmap(dpy, root, image, x_off, y_off))
604  av_log(s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
605  }
606 
607  if (s->draw_mouse)
608  paint_mouse_pointer(image, s1);
609 
610  return s->frame_size;
611 }
612 
613 /**
614  * Close x11 frame grabber (public device demuxer API).
615  *
616  * @param s1 Context from avformat core
617  * @return 0 success, !0 failure
618  */
620 {
621  X11GrabContext *x11grab = s1->priv_data;
622 
623  /* Detach cleanly from shared mem */
624  if (x11grab->use_shm) {
625  XShmDetach(x11grab->dpy, &x11grab->shminfo);
626  shmdt(x11grab->shminfo.shmaddr);
627  shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
628  }
629 
630  /* Destroy X11 image */
631  if (x11grab->image) {
632  XDestroyImage(x11grab->image);
633  x11grab->image = NULL;
634  }
635 
636  if (x11grab->region_win)
637  XDestroyWindow(x11grab->dpy, x11grab->region_win);
638 
639  /* Free X11 display */
640  XCloseDisplay(x11grab->dpy);
641  return 0;
642 }
643 
644 #define OFFSET(x) offsetof(X11GrabContext, x)
645 #define DEC AV_OPT_FLAG_DECODING_PARAM
646 static const AVOption options[] = {
647  { "draw_mouse", "draw the mouse pointer", OFFSET(draw_mouse), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
648 
649  { "follow_mouse", "move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region",
650  OFFSET(follow_mouse), AV_OPT_TYPE_INT, {.i64 = 0}, -1, INT_MAX, DEC, "follow_mouse" },
651  { "centered", "keep the mouse pointer at the center of grabbing region when following",
652  0, AV_OPT_TYPE_CONST, {.i64 = -1}, INT_MIN, INT_MAX, DEC, "follow_mouse" },
653 
654  { "framerate", "set video frame rate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "ntsc"}, 0, 0, DEC },
655  { "show_region", "show the grabbing region", OFFSET(show_region), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
656  { "video_size", "set video frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = "vga"}, 0, 0, DEC },
657  { "use_shm", "use MIT-SHM extension", OFFSET(use_shm), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
658  { NULL },
659 };
660 
661 static const AVClass x11_class = {
662  .class_name = "X11grab indev",
663  .item_name = av_default_item_name,
664  .option = options,
665  .version = LIBAVUTIL_VERSION_INT,
667 };
668 
669 /** x11 grabber device demuxer declaration */
671  .name = "x11grab",
672  .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
673  .priv_data_size = sizeof(X11GrabContext),
677  .flags = AVFMT_NOFILE,
678  .priv_class = &x11_class,
679 };