2 * X11 video grab interface
4 * This file is part of Libav.
7 * Copyright (C) 2006 Clemens Fruhwirth <clemens@endorphin.org>
8 * Edouard Gomez <ed.gomez@free.fr>
10 * This file contains code from grab.c:
11 * Copyright (c) 2000-2001 Fabrice Bellard
13 * This file contains code from the xvidcap project:
14 * Copyright (C) 1997-1998 Rasca, Berlin
15 * 2003-2004 Karl H. Beckers, Frankfurt
17 * Libav 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.
22 * Libav 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.
27 * You should have received a copy of the GNU General Public License
28 * along with Libav; if not, write to the Free Software
29 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
34 * X11 frame device demuxer
35 * @author Clemens Fruhwirth <clemens@endorphin.org>
36 * @author Edouard Gomez <ed.gomez@free.fr>
46 #include <X11/Xlibint.h>
47 #include <X11/Xproto.h>
48 #include <X11/Xutil.h>
50 #include <X11/extensions/shape.h>
51 #include <X11/extensions/Xfixes.h>
52 #include <X11/extensions/XShm.h>
54 #include "libavutil/internal.h"
55 #include "libavutil/log.h"
56 #include "libavutil/opt.h"
57 #include "libavutil/parseutils.h"
58 #include "libavutil/time.h"
60 #include "libavformat/avformat.h"
61 #include "libavformat/internal.h"
63 /** X11 device demuxer context */
64 typedef struct X11GrabContext {
65 const AVClass *class; /**< Class for private options. */
66 int frame_size; /**< Size in bytes of a grabbed frame */
67 AVRational time_base; /**< Time base */
68 int64_t time_frame; /**< Current time */
70 char *video_size; /**< String describing video size, set by a private option. */
71 int height; /**< Height of the grab frame */
72 int width; /**< Width of the grab frame */
73 int x_off; /**< Horizontal top-left corner coordinate */
74 int y_off; /**< Vertical top-left corner coordinate */
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 char *framerate; /**< Set by a private option. */
85 Window region_win; /**< This is used by show_region option. */
88 #define REGION_WIN_BORDER 3
91 * Draw grabbing region window
93 * @param s x11grab context
95 static void x11grab_draw_region_win(X11GrabContext *s)
97 Display *dpy = s->dpy;
98 Window win = s->region_win;
99 int screen = DefaultScreen(dpy);
100 GC gc = XCreateGC(dpy, win, 0, 0);
102 XSetForeground(dpy, gc, WhitePixel(dpy, screen));
103 XSetBackground(dpy, gc, BlackPixel(dpy, screen));
104 XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0);
105 XDrawRectangle(dpy, win, gc, 1, 1,
106 (s->width + REGION_WIN_BORDER * 2) - 1 * 2 - 1,
107 (s->height + REGION_WIN_BORDER * 2) - 1 * 2 - 1);
112 * Initialize grabbing region window
114 * @param s x11grab context
116 static void x11grab_region_win_init(X11GrabContext *s)
118 Display *dpy = s->dpy;
120 XSetWindowAttributes attribs = { .override_redirect = True };
121 int screen = DefaultScreen(dpy);
123 s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
124 s->x_off - REGION_WIN_BORDER,
125 s->y_off - REGION_WIN_BORDER,
126 s->width + REGION_WIN_BORDER * 2,
127 s->height + REGION_WIN_BORDER * 2,
129 InputOutput, CopyFromParent,
130 CWOverrideRedirect, &attribs);
133 rect.width = s->width;
134 rect.height = s->height;
135 XShapeCombineRectangles(dpy, s->region_win,
136 ShapeBounding, REGION_WIN_BORDER, REGION_WIN_BORDER,
137 &rect, 1, ShapeSubtract, 0);
138 XMapWindow(dpy, s->region_win);
139 XSelectInput(dpy, s->region_win, ExposureMask | StructureNotifyMask);
140 x11grab_draw_region_win(s);
143 static int setup_shm(AVFormatContext *s, Display *dpy, XImage **image)
145 X11GrabContext *g = s->priv_data;
146 int scr = XDefaultScreen(dpy);
147 XImage *img = XShmCreateImage(dpy, DefaultVisual(dpy, scr),
148 DefaultDepth(dpy, scr), ZPixmap, NULL,
149 &g->shminfo, g->width, g->height);
151 g->shminfo.shmid = shmget(IPC_PRIVATE, img->bytes_per_line * img->height,
154 if (g->shminfo.shmid == -1) {
155 av_log(s, AV_LOG_ERROR, "Cannot get shared memory!\n");
156 return AVERROR(ENOMEM);
159 g->shminfo.shmaddr = img->data = shmat(g->shminfo.shmid, 0, 0);
160 g->shminfo.readOnly = False;
162 if (!XShmAttach(dpy, &g->shminfo)) {
163 av_log(s, AV_LOG_ERROR, "Failed to attach shared memory!\n");
164 /* needs some better error subroutine :) */
172 static int setup_mouse(Display *dpy, int screen)
176 if (XFixesQueryExtension(dpy, &ev_ret, &ev_err)) {
177 Window root = RootWindow(dpy, screen);
178 XFixesSelectCursorInput(dpy, root, XFixesDisplayCursorNotifyMask);
182 return AVERROR(ENOSYS);
185 static int pixfmt_from_image(AVFormatContext *s, XImage *image, int *pix_fmt)
187 av_log(s, AV_LOG_DEBUG,
188 "Image r 0x%.6lx g 0x%.6lx b 0x%.6lx and depth %i\n",
192 image->bits_per_pixel);
194 switch (image->bits_per_pixel) {
196 *pix_fmt = AV_PIX_FMT_PAL8;
199 if (image->red_mask == 0xf800 &&
200 image->green_mask == 0x07e0 &&
201 image->blue_mask == 0x001f) {
202 *pix_fmt = AV_PIX_FMT_RGB565;
203 } else if (image->red_mask == 0x7c00 &&
204 image->green_mask == 0x03e0 &&
205 image->blue_mask == 0x001f) {
206 *pix_fmt = AV_PIX_FMT_RGB555;
210 if (image->red_mask == 0xff0000 &&
211 image->green_mask == 0x00ff00 &&
212 image->blue_mask == 0x0000ff) {
213 *pix_fmt = AV_PIX_FMT_BGR24;
214 } else if (image->red_mask == 0x0000ff &&
215 image->green_mask == 0x00ff00 &&
216 image->blue_mask == 0xff0000) {
217 *pix_fmt = AV_PIX_FMT_RGB24;
221 *pix_fmt = AV_PIX_FMT_RGB32;
224 av_log(s, AV_LOG_ERROR,
225 "XImages with RGB mask 0x%.6lx 0x%.6lx 0x%.6lx and depth %i "
226 "are currently not supported.\n",
230 image->bits_per_pixel);
232 return AVERROR_PATCHWELCOME;
239 * Initialize the x11 grab device demuxer (public device demuxer API).
241 * @param s1 Context from avformat core
243 * <li>AVERROR(ENOMEM) no memory left</li>
244 * <li>AVERROR(EIO) other failure case</li>
248 static int x11grab_read_header(AVFormatContext *s1)
250 X11GrabContext *x11grab = s1->priv_data;
254 int x_off = 0, y_off = 0, ret = 0, screen, use_shm;
255 char *param, *offset;
256 AVRational framerate;
258 param = av_strdup(s1->filename);
262 offset = strchr(param, '+');
264 sscanf(offset, "%d,%d", &x_off, &y_off);
265 x11grab->draw_mouse = !strstr(offset, "nomouse");
269 ret = av_parse_video_size(&x11grab->width, &x11grab->height,
270 x11grab->video_size);
272 av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
276 ret = av_parse_video_rate(&framerate, x11grab->framerate);
278 av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n",
282 av_log(s1, AV_LOG_INFO,
283 "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
284 s1->filename, param, x_off, y_off, x11grab->width, x11grab->height);
286 dpy = XOpenDisplay(param);
288 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
293 st = avformat_new_stream(s1, NULL);
295 ret = AVERROR(ENOMEM);
298 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
300 screen = DefaultScreen(dpy);
302 if (x11grab->follow_mouse) {
303 int screen_w, screen_h;
306 screen_w = DisplayWidth(dpy, screen);
307 screen_h = DisplayHeight(dpy, screen);
308 XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off,
310 x_off -= x11grab->width / 2;
311 y_off -= x11grab->height / 2;
312 x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
313 y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
314 av_log(s1, AV_LOG_INFO,
315 "followmouse is enabled, resetting grabbing region to x: %d y: %d\n",
319 use_shm = XShmQueryExtension(dpy);
320 av_log(s1, AV_LOG_INFO,
321 "shared memory extension %sfound\n", use_shm ? "" : "not ");
323 if (use_shm && setup_shm(s1, dpy, &image) < 0) {
324 av_log(s1, AV_LOG_WARNING, "Falling back to XGetImage\n");
329 image = XGetImage(dpy, RootWindow(dpy, screen),
331 x11grab->width, x11grab->height,
335 if (x11grab->draw_mouse && setup_mouse(dpy, screen) < 0) {
336 av_log(s1, AV_LOG_WARNING,
337 "XFixes not available, cannot draw the mouse cursor\n");
338 x11grab->draw_mouse = 0;
341 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel / 8;
343 x11grab->time_base = (AVRational) { framerate.den, framerate.num };
344 x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
345 x11grab->x_off = x_off;
346 x11grab->y_off = y_off;
347 x11grab->image = image;
348 x11grab->use_shm = use_shm;
350 ret = pixfmt_from_image(s1, image, &st->codec->pix_fmt);
354 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
355 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
356 st->codec->width = x11grab->width;
357 st->codec->height = x11grab->height;
358 st->codec->time_base = x11grab->time_base;
359 st->codec->bit_rate = x11grab->frame_size * 1 / av_q2d(x11grab->time_base) * 8;
367 * Paint a mouse pointer in an X11 image.
369 * @param image image to paint the mouse pointer to
370 * @param s context used to retrieve original grabbing rectangle
373 static void paint_mouse_pointer(XImage *image, X11GrabContext *s)
375 int x_off = s->x_off;
376 int y_off = s->y_off;
377 int width = s->width;
378 int height = s->height;
379 Display *dpy = s->dpy;
380 XFixesCursorImage *xcim;
383 int to_line, to_column;
384 int pixstride = image->bits_per_pixel >> 3;
385 /* Warning: in its insanity, xlib provides unsigned image data through a
386 * char* pointer, so we have to make it uint8_t to make things not break.
387 * Anyone who performs further investigation of the xlib API likely risks
388 * permanent brain damage. */
389 uint8_t *pix = image->data;
391 /* Code doesn't currently support 16-bit or PAL8 */
392 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
395 xcim = XFixesGetCursorImage(dpy);
399 x = xcim->x - xcim->xhot;
400 y = xcim->y - xcim->yhot;
402 to_line = FFMIN((y + xcim->height), (height + y_off));
403 to_column = FFMIN((x + xcim->width), (width + x_off));
405 for (line = FFMAX(y, y_off); line < to_line; line++) {
406 for (column = FFMAX(x, x_off); column < to_column; column++) {
407 int xcim_addr = (line - y) * xcim->width + column - x;
408 int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
409 int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
410 int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
411 int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
412 int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
415 pix[image_addr + 0] = r;
416 pix[image_addr + 1] = g;
417 pix[image_addr + 2] = b;
419 /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
420 pix[image_addr + 0] = r + (pix[image_addr + 0] * (255 - a) + 255 / 2) / 255;
421 pix[image_addr + 1] = g + (pix[image_addr + 1] * (255 - a) + 255 / 2) / 255;
422 pix[image_addr + 2] = b + (pix[image_addr + 2] * (255 - a) + 255 / 2) / 255;
432 * Read new data in the image structure.
434 * @param dpy X11 display to grab from
436 * @param image Image where the grab will be put
437 * @param x Top-Left grabbing rectangle horizontal coordinate
438 * @param y Top-Left grabbing rectangle vertical coordinate
439 * @return 0 if error, !0 if successful
441 static int xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
451 GetReq(GetImage, req);
453 /* First set up the standard stuff in the request */
457 req->width = image->width;
458 req->height = image->height;
459 req->planeMask = (unsigned int)AllPlanes;
460 req->format = ZPixmap;
462 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
468 nbytes = (long)rep.length << 2;
469 _XReadPad(dpy, image->data, nbytes);
477 * Grab a frame from x11 (public device demuxer API).
479 * @param s1 Context from avformat core
480 * @param pkt Packet holding the brabbed frame
481 * @return frame size in bytes
483 static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
485 X11GrabContext *s = s1->priv_data;
486 Display *dpy = s->dpy;
487 XImage *image = s->image;
488 int x_off = s->x_off;
489 int y_off = s->y_off;
490 int follow_mouse = s->follow_mouse;
491 int screen, pointer_x, pointer_y, _, same_screen = 1;
493 int64_t curtime, delay;
496 /* Calculate the time of the next frame */
497 s->time_frame += INT64_C(1000000);
499 /* wait based on the frame rate */
501 curtime = av_gettime();
502 delay = s->time_frame * av_q2d(s->time_base) - curtime;
504 if (delay < INT64_C(-1000000) * av_q2d(s->time_base))
505 s->time_frame += INT64_C(1000000);
508 ts.tv_sec = delay / 1000000;
509 ts.tv_nsec = (delay % 1000000) * 1000;
510 nanosleep(&ts, NULL);
514 pkt->data = image->data;
515 pkt->size = s->frame_size;
518 screen = DefaultScreen(dpy);
519 root = RootWindow(dpy, screen);
521 if (follow_mouse || s->draw_mouse)
522 same_screen = XQueryPointer(dpy, root, &w, &w,
523 &pointer_x, &pointer_y, &_, &_, &_);
525 if (follow_mouse && same_screen) {
526 int screen_w, screen_h;
528 screen_w = DisplayWidth(dpy, screen);
529 screen_h = DisplayHeight(dpy, screen);
530 if (follow_mouse == -1) {
531 // follow the mouse, put it at center of grabbing region
532 x_off += pointer_x - s->width / 2 - x_off;
533 y_off += pointer_y - s->height / 2 - y_off;
535 // follow the mouse, but only move the grabbing region when mouse
536 // reaches within certain pixels to the edge.
537 if (pointer_x > x_off + s->width - follow_mouse)
538 x_off += pointer_x - (x_off + s->width - follow_mouse);
539 else if (pointer_x < x_off + follow_mouse)
540 x_off -= (x_off + follow_mouse) - pointer_x;
541 if (pointer_y > y_off + s->height - follow_mouse)
542 y_off += pointer_y - (y_off + s->height - follow_mouse);
543 else if (pointer_y < y_off + follow_mouse)
544 y_off -= (y_off + follow_mouse) - pointer_y;
546 // adjust grabbing region position if it goes out of screen.
547 s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
548 s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
550 if (s->show_region && s->region_win)
551 XMoveWindow(dpy, s->region_win,
552 s->x_off - REGION_WIN_BORDER,
553 s->y_off - REGION_WIN_BORDER);
556 if (s->show_region && same_screen) {
558 XEvent evt = { .type = NoEventMask };
559 // Clean up the events, and do the initial draw or redraw.
560 while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask,
564 x11grab_draw_region_win(s);
566 x11grab_region_win_init(s);
571 if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes))
572 av_log(s1, AV_LOG_INFO, "XShmGetImage() failed\n");
574 if (!xget_zpixmap(dpy, root, image, x_off, y_off))
575 av_log(s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
578 if (s->draw_mouse && same_screen)
579 paint_mouse_pointer(image, s);
581 return s->frame_size;
585 * Close x11 frame grabber (public device demuxer API).
587 * @param s1 Context from avformat core
588 * @return 0 success, !0 failure
590 static int x11grab_read_close(AVFormatContext *s1)
592 X11GrabContext *x11grab = s1->priv_data;
594 /* Detach cleanly from shared mem */
595 if (x11grab->use_shm) {
596 XShmDetach(x11grab->dpy, &x11grab->shminfo);
597 shmdt(x11grab->shminfo.shmaddr);
598 shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
601 /* Destroy X11 image */
602 if (x11grab->image) {
603 XDestroyImage(x11grab->image);
604 x11grab->image = NULL;
607 if (x11grab->region_win)
608 XDestroyWindow(x11grab->dpy, x11grab->region_win);
610 /* Free X11 display */
611 XCloseDisplay(x11grab->dpy);
615 #define OFFSET(x) offsetof(X11GrabContext, x)
616 #define DEC AV_OPT_FLAG_DECODING_PARAM
617 static const AVOption options[] = {
618 { "grab_x", "Initial x coordinate.", OFFSET(x_off), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, DEC },
619 { "grab_y", "Initial y coordinate.", OFFSET(y_off), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, DEC },
620 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC },
621 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
622 { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, DEC },
623 { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
624 OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 }, -1, INT_MAX, DEC, "follow_mouse" },
625 { "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, INT_MIN, INT_MAX, DEC, "follow_mouse" },
626 { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, DEC },
630 static const AVClass x11_class = {
631 .class_name = "X11grab indev",
632 .item_name = av_default_item_name,
634 .version = LIBAVUTIL_VERSION_INT,
637 /** x11 grabber device demuxer declaration */
638 AVInputFormat ff_x11grab_demuxer = {
640 .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
641 .priv_data_size = sizeof(X11GrabContext),
642 .read_header = x11grab_read_header,
643 .read_packet = x11grab_read_packet,
644 .read_close = x11grab_read_close,
645 .flags = AVFMT_NOFILE,
646 .priv_class = &x11_class,