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 pixfmt_from_image(AVFormatContext *s, XImage *image, int *pix_fmt)
177 av_log(s, AV_LOG_DEBUG,
178 "Image r 0x%.6lx g 0x%.6lx b 0x%.6lx and depth %i\n",
182 image->bits_per_pixel);
184 *pix_fmt = AV_PIX_FMT_NONE;
186 switch (image->bits_per_pixel) {
188 *pix_fmt = AV_PIX_FMT_PAL8;
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;
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;
213 if (image->red_mask == 0xff0000 &&
214 image->green_mask == 0x00ff00 &&
215 image->blue_mask == 0x0000ff ) {
216 *pix_fmt = AV_PIX_FMT_0RGB32;
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",
227 image->bits_per_pixel);
229 return AVERROR_PATCHWELCOME;
236 * Initialize the x11 grab device demuxer (public device demuxer API).
238 * @param s1 Context from avformat core
240 * <li>AVERROR(ENOMEM) no memory left</li>
241 * <li>AVERROR(EIO) other failure case</li>
245 static int x11grab_read_header(AVFormatContext *s1)
247 X11GrabContext *x11grab = s1->priv_data;
251 int x_off = 0, y_off = 0, ret = 0, screen, use_shm = 0;
252 char *dpyname, *offset;
257 dpyname = av_strdup(s1->filename);
261 offset = strchr(dpyname, '+');
263 sscanf(offset, "%d,%d", &x_off, &y_off);
264 if (strstr(offset, "nomouse")) {
265 av_log(s1, AV_LOG_WARNING,
266 "'nomouse' specification in argument is deprecated: "
267 "use 'draw_mouse' option with value 0 instead\n");
268 x11grab->draw_mouse = 0;
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);
277 dpy = XOpenDisplay(dpyname);
280 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
285 st = avformat_new_stream(s1, NULL);
287 ret = AVERROR(ENOMEM);
290 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
292 screen = DefaultScreen(dpy);
294 if (x11grab->follow_mouse) {
295 int screen_w, screen_h;
298 screen_w = DisplayWidth(dpy, screen);
299 screen_h = DisplayHeight(dpy, screen);
300 XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off,
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",
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 ");
317 if (use_shm && setup_shm(s1, dpy, &image) < 0) {
318 av_log(s1, AV_LOG_WARNING, "Falling back to XGetImage\n");
323 image = XGetImage(dpy, RootWindow(dpy, screen),
325 x11grab->width, x11grab->height,
329 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel / 8;
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;
338 ret = pixfmt_from_image(s1, image, &st->codec->pix_fmt);
342 if (st->codec->pix_fmt == AV_PIX_FMT_PAL8) {
343 color_map = DefaultColormap(dpy, screen);
344 for (i = 0; i < 256; ++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;
355 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
356 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
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;
368 * Paint a mouse pointer in an X11 image.
370 * @param image image to paint the mouse pointer to
371 * @param s context used to retrieve original grabbing rectangle
374 static void paint_mouse_pointer(XImage *image, AVFormatContext *s1)
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;
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;
393 XSetWindowAttributes attr;
394 Bool pointer_on_screen;
398 root = DefaultRootWindow(dpy);
399 pointer_on_screen = XQueryPointer(dpy, root, &w, &w, &_, &_, &_, &_, &_);
400 if (!pointer_on_screen)
403 /* Code doesn't currently support 16-bit or PAL8 */
404 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
408 s->c = XCreateFontCursor(dpy, XC_left_ptr);
410 XChangeWindowAttributes(dpy, root, CWCursor, &attr);
412 xcim = XFixesGetCursorImage(dpy);
414 av_log(s1, AV_LOG_WARNING,
415 "XFixes extension not available, impossible to draw cursor\n");
420 x = xcim->x - xcim->xhot;
421 y = xcim->y - xcim->yhot;
423 to_line = FFMIN((y + xcim->height), (height + y_off));
424 to_column = FFMIN((x + xcim->width), (width + x_off));
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);
436 pix[image_addr + 0] = r;
437 pix[image_addr + 1] = g;
438 pix[image_addr + 2] = b;
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;
453 * Read new data in the image structure.
455 * @param dpy X11 display to grab from
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
462 static int xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
472 GetReq(GetImage, req);
474 /* First set up the standard stuff in the request */
478 req->width = image->width;
479 req->height = image->height;
480 req->planeMask = (unsigned int)AllPlanes;
481 req->format = ZPixmap;
483 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
489 nbytes = (long)rep.length << 2;
490 _XReadPad(dpy, image->data, nbytes);
498 * Grab a frame from x11 (public device demuxer API).
500 * @param s1 Context from avformat core
501 * @param pkt Packet holding the brabbed frame
502 * @return frame size in bytes
504 static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
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;
514 int64_t curtime, delay;
517 /* Calculate the time of the next frame */
518 s->time_frame += INT64_C(1000000);
520 /* wait based on the frame rate */
522 curtime = av_gettime();
523 delay = s->time_frame * av_q2d(s->time_base) - curtime;
525 if (delay < INT64_C(-1000000) * av_q2d(s->time_base))
526 s->time_frame += INT64_C(1000000);
529 ts.tv_sec = delay / 1000000;
530 ts.tv_nsec = (delay % 1000000) * 1000;
531 nanosleep(&ts, NULL);
535 pkt->data = image->data;
536 pkt->size = s->frame_size;
538 if (s->palette_changed) {
539 uint8_t *pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
542 av_log(s, AV_LOG_ERROR, "Cannot append palette to packet\n");
544 memcpy(pal, s->palette, AVPALETTE_SIZE);
545 s->palette_changed = 0;
549 screen = DefaultScreen(dpy);
550 root = RootWindow(dpy, screen);
552 int screen_w, screen_h;
553 int pointer_x, pointer_y, _;
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;
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;
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);
579 if (s->show_region && s->region_win)
580 XMoveWindow(dpy, s->region_win,
581 s->x_off - REGION_WIN_BORDER,
582 s->y_off - REGION_WIN_BORDER);
585 if (s->show_region) {
587 XEvent evt = { .type = NoEventMask };
588 // Clean up the events, and do the initial draw or redraw.
589 while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask,
593 x11grab_draw_region_win(s);
595 x11grab_region_win_init(s);
600 if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes))
601 av_log(s1, AV_LOG_INFO, "XShmGetImage() failed\n");
603 if (!xget_zpixmap(dpy, root, image, x_off, y_off))
604 av_log(s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
608 paint_mouse_pointer(image, s1);
610 return s->frame_size;
614 * Close x11 frame grabber (public device demuxer API).
616 * @param s1 Context from avformat core
617 * @return 0 success, !0 failure
619 static int x11grab_read_close(AVFormatContext *s1)
621 X11GrabContext *x11grab = s1->priv_data;
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);
630 /* Destroy X11 image */
631 if (x11grab->image) {
632 XDestroyImage(x11grab->image);
633 x11grab->image = NULL;
636 if (x11grab->region_win)
637 XDestroyWindow(x11grab->dpy, x11grab->region_win);
639 /* Free X11 display */
640 XCloseDisplay(x11grab->dpy);
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 },
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" },
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 },
661 static const AVClass x11_class = {
662 .class_name = "X11grab indev",
663 .item_name = av_default_item_name,
665 .version = LIBAVUTIL_VERSION_INT,
666 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
669 /** x11 grabber device demuxer declaration */
670 AVInputFormat ff_x11grab_demuxer = {
672 .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
673 .priv_data_size = sizeof(X11GrabContext),
674 .read_header = x11grab_read_header,
675 .read_packet = x11grab_read_packet,
676 .read_close = x11grab_read_close,
677 .flags = AVFMT_NOFILE,
678 .priv_class = &x11_class,