2 * X11 video grab interface
4 * This file is part of FFmpeg.
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 * 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.
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.
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
34 * X11 frame device demuxer
35 * @author Clemens Fruhwirth <clemens@endorphin.org>
36 * @author Edouard Gomez <ed.gomez@free.fr>
44 #include <X11/cursorfont.h>
47 #include <X11/Xlibint.h>
48 #include <X11/Xproto.h>
49 #include <X11/Xutil.h>
51 #include <X11/extensions/shape.h>
52 #include <X11/extensions/Xfixes.h>
53 #include <X11/extensions/XShm.h>
57 #include "libavutil/log.h"
58 #include "libavutil/opt.h"
59 #include "libavutil/parseutils.h"
60 #include "libavutil/time.h"
62 #include "libavformat/internal.h"
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 */
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 */
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];
88 Window region_win; /**< This is used by show_region option. */
91 #define REGION_WIN_BORDER 3
94 * Draw grabbing region window
96 * @param s x11grab context
98 static void x11grab_draw_region_win(X11GrabContext *s)
100 Display *dpy = s->dpy;
101 Window win = s->region_win;
102 int screen = DefaultScreen(dpy);
103 GC gc = XCreateGC(dpy, win, 0, 0);
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);
115 * Initialize grabbing region window
117 * @param s x11grab context
119 static void x11grab_region_win_init(X11GrabContext *s)
121 Display *dpy = s->dpy;
123 XSetWindowAttributes attribs = { .override_redirect = True };
124 int screen = DefaultScreen(dpy);
126 s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
127 s->x_off - REGION_WIN_BORDER,
128 s->y_off - REGION_WIN_BORDER,
129 s->width + REGION_WIN_BORDER * 2,
130 s->height + REGION_WIN_BORDER * 2,
132 InputOutput, CopyFromParent,
133 CWOverrideRedirect, &attribs);
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);
143 x11grab_draw_region_win(s);
146 static int setup_shm(AVFormatContext *s, Display *dpy, XImage **image)
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);
154 g->shminfo.shmid = shmget(IPC_PRIVATE, img->bytes_per_line * img->height,
157 if (g->shminfo.shmid == -1) {
158 av_log(s, AV_LOG_ERROR, "Cannot get shared memory!\n");
159 return AVERROR(ENOMEM);
162 g->shminfo.shmaddr = img->data = shmat(g->shminfo.shmid, 0, 0);
163 g->shminfo.readOnly = False;
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 :) */
175 static int setup_mouse(Display *dpy, int screen)
179 if (XFixesQueryExtension(dpy, &ev_ret, &ev_err)) {
180 Window root = RootWindow(dpy, screen);
181 XFixesSelectCursorInput(dpy, root, XFixesDisplayCursorNotifyMask);
185 return AVERROR(ENOSYS);
188 static int pixfmt_from_image(AVFormatContext *s, XImage *image, int *pix_fmt)
190 av_log(s, AV_LOG_DEBUG,
191 "Image r 0x%.6lx g 0x%.6lx b 0x%.6lx and depth %i\n",
195 image->bits_per_pixel);
197 *pix_fmt = AV_PIX_FMT_NONE;
199 switch (image->bits_per_pixel) {
201 *pix_fmt = AV_PIX_FMT_PAL8;
204 if (image->red_mask == 0xf800 &&
205 image->green_mask == 0x07e0 &&
206 image->blue_mask == 0x001f) {
207 *pix_fmt = AV_PIX_FMT_RGB565;
208 } else if (image->red_mask == 0x7c00 &&
209 image->green_mask == 0x03e0 &&
210 image->blue_mask == 0x001f) {
211 *pix_fmt = AV_PIX_FMT_RGB555;
215 if (image->red_mask == 0xff0000 &&
216 image->green_mask == 0x00ff00 &&
217 image->blue_mask == 0x0000ff) {
218 *pix_fmt = AV_PIX_FMT_BGR24;
219 } else if (image->red_mask == 0x0000ff &&
220 image->green_mask == 0x00ff00 &&
221 image->blue_mask == 0xff0000) {
222 *pix_fmt = AV_PIX_FMT_RGB24;
226 if (image->red_mask == 0xff0000 &&
227 image->green_mask == 0x00ff00 &&
228 image->blue_mask == 0x0000ff ) {
229 *pix_fmt = AV_PIX_FMT_0RGB32;
233 if (*pix_fmt == AV_PIX_FMT_NONE) {
234 av_log(s, AV_LOG_ERROR,
235 "XImages with RGB mask 0x%.6lx 0x%.6lx 0x%.6lx and depth %i "
236 "are currently not supported.\n",
240 image->bits_per_pixel);
242 return AVERROR_PATCHWELCOME;
249 * Initialize the x11 grab device demuxer (public device demuxer API).
251 * @param s1 Context from avformat core
253 * <li>AVERROR(ENOMEM) no memory left</li>
254 * <li>AVERROR(EIO) other failure case</li>
258 static int x11grab_read_header(AVFormatContext *s1)
260 X11GrabContext *x11grab = s1->priv_data;
264 int x_off = 0, y_off = 0, ret = 0, screen, use_shm = 0;
265 char *dpyname, *offset;
270 dpyname = av_strdup(s1->filename);
274 offset = strchr(dpyname, '+');
276 sscanf(offset, "%d,%d", &x_off, &y_off);
277 if (strstr(offset, "nomouse")) {
278 av_log(s1, AV_LOG_WARNING,
279 "'nomouse' specification in argument is deprecated: "
280 "use 'draw_mouse' option with value 0 instead\n");
281 x11grab->draw_mouse = 0;
286 av_log(s1, AV_LOG_INFO,
287 "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
288 s1->filename, dpyname, x_off, y_off, x11grab->width, x11grab->height);
290 dpy = XOpenDisplay(dpyname);
293 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
298 st = avformat_new_stream(s1, NULL);
300 ret = AVERROR(ENOMEM);
303 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
305 screen = DefaultScreen(dpy);
307 if (x11grab->follow_mouse) {
308 int screen_w, screen_h;
311 screen_w = DisplayWidth(dpy, screen);
312 screen_h = DisplayHeight(dpy, screen);
313 XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off,
315 x_off -= x11grab->width / 2;
316 y_off -= x11grab->height / 2;
317 x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
318 y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
319 av_log(s1, AV_LOG_INFO,
320 "followmouse is enabled, resetting grabbing region to x: %d y: %d\n",
324 if (x11grab->use_shm) {
325 use_shm = XShmQueryExtension(dpy);
326 av_log(s1, AV_LOG_INFO,
327 "shared memory extension %sfound\n", use_shm ? "" : "not ");
330 if (use_shm && setup_shm(s1, dpy, &image) < 0) {
331 av_log(s1, AV_LOG_WARNING, "Falling back to XGetImage\n");
336 image = XGetImage(dpy, RootWindow(dpy, screen),
338 x11grab->width, x11grab->height,
342 if (x11grab->draw_mouse && setup_mouse(dpy, screen) < 0) {
343 av_log(s1, AV_LOG_WARNING,
344 "XFixes not available, cannot draw the mouse cursor\n");
345 x11grab->draw_mouse = 0;
348 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel / 8;
350 x11grab->time_base = av_inv_q(x11grab->framerate);
351 x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
352 x11grab->x_off = x_off;
353 x11grab->y_off = y_off;
354 x11grab->image = image;
355 x11grab->use_shm = use_shm;
357 ret = pixfmt_from_image(s1, image, &st->codec->pix_fmt);
361 if (st->codec->pix_fmt == AV_PIX_FMT_PAL8) {
362 color_map = DefaultColormap(dpy, screen);
363 for (i = 0; i < 256; ++i)
365 XQueryColors(dpy, color_map, color, 256);
366 for (i = 0; i < 256; ++i)
367 x11grab->palette[i] = (color[i].red & 0xFF00) << 8 |
368 (color[i].green & 0xFF00) |
369 (color[i].blue & 0xFF00) >> 8;
370 x11grab->palette_changed = 1;
374 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
375 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
376 st->codec->width = x11grab->width;
377 st->codec->height = x11grab->height;
378 st->codec->time_base = x11grab->time_base;
379 st->codec->bit_rate = x11grab->frame_size * 1 / av_q2d(x11grab->time_base) * 8;
387 * Paint a mouse pointer in an X11 image.
389 * @param image image to paint the mouse pointer to
390 * @param s context used to retrieve original grabbing rectangle
393 static void paint_mouse_pointer(XImage *image, AVFormatContext *s1)
395 X11GrabContext *s = s1->priv_data;
396 int x_off = s->x_off;
397 int y_off = s->y_off;
398 int width = s->width;
399 int height = s->height;
400 Display *dpy = s->dpy;
401 XFixesCursorImage *xcim;
404 int to_line, to_column;
405 int pixstride = image->bits_per_pixel >> 3;
406 /* Warning: in its insanity, xlib provides unsigned image data through a
407 * char* pointer, so we have to make it uint8_t to make things not break.
408 * Anyone who performs further investigation of the xlib API likely risks
409 * permanent brain damage. */
410 uint8_t *pix = image->data;
412 XSetWindowAttributes attr;
414 /* Code doesn't currently support 16-bit or PAL8 */
415 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
419 s->c = XCreateFontCursor(dpy, XC_left_ptr);
420 root = DefaultRootWindow(dpy);
422 XChangeWindowAttributes(dpy, root, CWCursor, &attr);
424 xcim = XFixesGetCursorImage(dpy);
426 av_log(s1, AV_LOG_WARNING,
427 "XFixesGetCursorImage failed\n");
431 x = xcim->x - xcim->xhot;
432 y = xcim->y - xcim->yhot;
434 to_line = FFMIN((y + xcim->height), (height + y_off));
435 to_column = FFMIN((x + xcim->width), (width + x_off));
437 for (line = FFMAX(y, y_off); line < to_line; line++) {
438 for (column = FFMAX(x, x_off); column < to_column; column++) {
439 int xcim_addr = (line - y) * xcim->width + column - x;
440 int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
441 int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
442 int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
443 int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
444 int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
447 pix[image_addr + 0] = r;
448 pix[image_addr + 1] = g;
449 pix[image_addr + 2] = b;
451 /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
452 pix[image_addr + 0] = r + (pix[image_addr + 0] * (255 - a) + 255 / 2) / 255;
453 pix[image_addr + 1] = g + (pix[image_addr + 1] * (255 - a) + 255 / 2) / 255;
454 pix[image_addr + 2] = b + (pix[image_addr + 2] * (255 - a) + 255 / 2) / 255;
464 * Read new data in the image structure.
466 * @param dpy X11 display to grab from
468 * @param image Image where the grab will be put
469 * @param x Top-Left grabbing rectangle horizontal coordinate
470 * @param y Top-Left grabbing rectangle vertical coordinate
471 * @return 0 if error, !0 if successful
473 static int xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
483 GetReq(GetImage, req);
485 /* First set up the standard stuff in the request */
489 req->width = image->width;
490 req->height = image->height;
491 req->planeMask = (unsigned int)AllPlanes;
492 req->format = ZPixmap;
494 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
500 nbytes = (long)rep.length << 2;
501 _XReadPad(dpy, image->data, nbytes);
509 * Grab a frame from x11 (public device demuxer API).
511 * @param s1 Context from avformat core
512 * @param pkt Packet holding the brabbed frame
513 * @return frame size in bytes
515 static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
517 X11GrabContext *s = s1->priv_data;
518 Display *dpy = s->dpy;
519 XImage *image = s->image;
520 int x_off = s->x_off;
521 int y_off = s->y_off;
522 int follow_mouse = s->follow_mouse;
523 int screen, pointer_x, pointer_y, _, same_screen = 1;
525 int64_t curtime, delay;
528 /* Calculate the time of the next frame */
529 s->time_frame += INT64_C(1000000);
531 /* wait based on the frame rate */
533 curtime = av_gettime();
534 delay = s->time_frame * av_q2d(s->time_base) - curtime;
536 if (delay < INT64_C(-1000000) * av_q2d(s->time_base))
537 s->time_frame += INT64_C(1000000);
540 ts.tv_sec = delay / 1000000;
541 ts.tv_nsec = (delay % 1000000) * 1000;
542 nanosleep(&ts, NULL);
546 pkt->data = image->data;
547 pkt->size = s->frame_size;
549 if (s->palette_changed) {
550 uint8_t *pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
553 av_log(s, AV_LOG_ERROR, "Cannot append palette to packet\n");
555 memcpy(pal, s->palette, AVPALETTE_SIZE);
556 s->palette_changed = 0;
560 screen = DefaultScreen(dpy);
561 root = RootWindow(dpy, screen);
563 if (follow_mouse || s->draw_mouse)
564 same_screen = XQueryPointer(dpy, root, &w, &w,
565 &pointer_x, &pointer_y, &_, &_, &_);
567 if (follow_mouse && same_screen) {
568 int screen_w, screen_h;
570 screen_w = DisplayWidth(dpy, screen);
571 screen_h = DisplayHeight(dpy, screen);
572 if (follow_mouse == -1) {
573 // follow the mouse, put it at center of grabbing region
574 x_off += pointer_x - s->width / 2 - x_off;
575 y_off += pointer_y - s->height / 2 - y_off;
577 // follow the mouse, but only move the grabbing region when mouse
578 // reaches within certain pixels to the edge.
579 if (pointer_x > x_off + s->width - follow_mouse)
580 x_off += pointer_x - (x_off + s->width - follow_mouse);
581 else if (pointer_x < x_off + follow_mouse)
582 x_off -= (x_off + follow_mouse) - pointer_x;
583 if (pointer_y > y_off + s->height - follow_mouse)
584 y_off += pointer_y - (y_off + s->height - follow_mouse);
585 else if (pointer_y < y_off + follow_mouse)
586 y_off -= (y_off + follow_mouse) - pointer_y;
588 // adjust grabbing region position if it goes out of screen.
589 s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
590 s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
592 if (s->show_region && s->region_win)
593 XMoveWindow(dpy, s->region_win,
594 s->x_off - REGION_WIN_BORDER,
595 s->y_off - REGION_WIN_BORDER);
598 if (s->show_region && same_screen) {
600 XEvent evt = { .type = NoEventMask };
601 // Clean up the events, and do the initial draw or redraw.
602 while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask,
606 x11grab_draw_region_win(s);
608 x11grab_region_win_init(s);
613 if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes))
614 av_log(s1, AV_LOG_INFO, "XShmGetImage() failed\n");
616 if (!xget_zpixmap(dpy, root, image, x_off, y_off))
617 av_log(s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
620 if (s->draw_mouse && same_screen)
621 paint_mouse_pointer(image, s1);
623 return s->frame_size;
627 * Close x11 frame grabber (public device demuxer API).
629 * @param s1 Context from avformat core
630 * @return 0 success, !0 failure
632 static int x11grab_read_close(AVFormatContext *s1)
634 X11GrabContext *x11grab = s1->priv_data;
636 /* Detach cleanly from shared mem */
637 if (x11grab->use_shm) {
638 XShmDetach(x11grab->dpy, &x11grab->shminfo);
639 shmdt(x11grab->shminfo.shmaddr);
640 shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
643 /* Destroy X11 image */
644 if (x11grab->image) {
645 XDestroyImage(x11grab->image);
646 x11grab->image = NULL;
649 if (x11grab->region_win)
650 XDestroyWindow(x11grab->dpy, x11grab->region_win);
652 /* Free X11 display */
653 XCloseDisplay(x11grab->dpy);
657 #define OFFSET(x) offsetof(X11GrabContext, x)
658 #define DEC AV_OPT_FLAG_DECODING_PARAM
659 static const AVOption options[] = {
660 { "draw_mouse", "draw the mouse pointer", OFFSET(draw_mouse), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
662 { "follow_mouse", "move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region",
663 OFFSET(follow_mouse), AV_OPT_TYPE_INT, {.i64 = 0}, -1, INT_MAX, DEC, "follow_mouse" },
664 { "centered", "keep the mouse pointer at the center of grabbing region when following",
665 0, AV_OPT_TYPE_CONST, {.i64 = -1}, INT_MIN, INT_MAX, DEC, "follow_mouse" },
667 { "framerate", "set video frame rate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "ntsc"}, 0, 0, DEC },
668 { "show_region", "show the grabbing region", OFFSET(show_region), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
669 { "video_size", "set video frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = "vga"}, 0, 0, DEC },
670 { "use_shm", "use MIT-SHM extension", OFFSET(use_shm), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
674 static const AVClass x11_class = {
675 .class_name = "X11grab indev",
676 .item_name = av_default_item_name,
678 .version = LIBAVUTIL_VERSION_INT,
679 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
682 /** x11 grabber device demuxer declaration */
683 AVInputFormat ff_x11grab_demuxer = {
685 .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
686 .priv_data_size = sizeof(X11GrabContext),
687 .read_header = x11grab_read_header,
688 .read_packet = x11grab_read_packet,
689 .read_close = x11grab_read_close,
690 .flags = AVFMT_NOFILE,
691 .priv_class = &x11_class,