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>
40 #include "libavformat/internal.h"
41 #include "libavutil/log.h"
42 #include "libavutil/opt.h"
43 #include "libavutil/parseutils.h"
44 #include "libavutil/time.h"
46 #include <X11/cursorfont.h>
49 #include <X11/Xlibint.h>
50 #include <X11/Xproto.h>
51 #include <X11/Xutil.h>
53 #include <X11/extensions/shape.h>
54 #include <X11/extensions/XShm.h>
55 #include <X11/extensions/Xfixes.h>
59 * X11 Device Demuxer context
62 const AVClass *class; /**< Class for private options. */
63 int frame_size; /**< Size in bytes of a grabbed frame */
64 AVRational time_base; /**< Time base */
65 int64_t time_frame; /**< Current time */
67 int width; /**< Width of the grab frame */
68 int height; /**< Height of the grab frame */
69 int x_off; /**< Horizontal top-left corner coordinate */
70 int y_off; /**< Vertical top-left corner coordinate */
72 Display *dpy; /**< X11 display from which x11grab grabs frames */
73 XImage *image; /**< X11 image holding the grab */
74 int use_shm; /**< !0 when using XShm extension */
75 XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
76 int draw_mouse; /**< Set by a private option. */
77 int follow_mouse; /**< Set by a private option. */
78 int show_region; /**< set by a private option. */
79 char *framerate; /**< Set by a private option. */
81 Window region_win; /**< This is used by show_region option. */
84 #define REGION_WIN_BORDER 3
86 * Draw grabbing region window
88 * @param s x11grab context
91 x11grab_draw_region_win(struct x11grab *s)
93 Display *dpy = s->dpy;
95 Window win = s->region_win;
98 screen = DefaultScreen(dpy);
99 gc = XCreateGC(dpy, win, 0, 0);
100 XSetForeground(dpy, gc, WhitePixel(dpy, screen));
101 XSetBackground(dpy, gc, BlackPixel(dpy, screen));
102 XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0);
103 XDrawRectangle(dpy, win, gc,
105 (s->width + REGION_WIN_BORDER * 2) - 1 * 2 - 1,
106 (s->height + REGION_WIN_BORDER * 2) - 1 * 2 - 1);
111 * Initialize grabbing region window
113 * @param s x11grab context
116 x11grab_region_win_init(struct x11grab *s)
118 Display *dpy = s->dpy;
120 XSetWindowAttributes attribs;
123 screen = DefaultScreen(dpy);
124 attribs.override_redirect = True;
125 s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
126 s->x_off - REGION_WIN_BORDER,
127 s->y_off - REGION_WIN_BORDER,
128 s->width + REGION_WIN_BORDER * 2,
129 s->height + REGION_WIN_BORDER * 2,
131 InputOutput, CopyFromParent,
132 CWOverrideRedirect, &attribs);
135 rect.width = s->width;
136 rect.height = s->height;
137 XShapeCombineRectangles(dpy, s->region_win,
138 ShapeBounding, REGION_WIN_BORDER, REGION_WIN_BORDER,
139 &rect, 1, ShapeSubtract, 0);
140 XMapWindow(dpy, s->region_win);
141 XSelectInput(dpy, s->region_win, ExposureMask | StructureNotifyMask);
142 x11grab_draw_region_win(s);
146 * Initialize the x11 grab device demuxer (public device demuxer API).
148 * @param s1 Context from avformat core
150 * <li>AVERROR(ENOMEM) no memory left</li>
151 * <li>AVERROR(EIO) other failure case</li>
156 x11grab_read_header(AVFormatContext *s1)
158 struct x11grab *x11grab = s1->priv_data;
161 enum AVPixelFormat input_pixfmt;
167 char *dpyname, *offset;
169 AVRational framerate;
171 dpyname = av_strdup(s1->filename);
175 offset = strchr(dpyname, '+');
177 sscanf(offset, "%d,%d", &x_off, &y_off);
178 if (strstr(offset, "nomouse")) {
179 av_log(s1, AV_LOG_WARNING,
180 "'nomouse' specification in argument is deprecated: "
181 "use 'draw_mouse' option with value 0 instead\n");
182 x11grab->draw_mouse = 0;
187 if ((ret = av_parse_video_rate(&framerate, x11grab->framerate)) < 0) {
188 av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n", x11grab->framerate);
191 av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
192 s1->filename, dpyname, x_off, y_off, x11grab->width, x11grab->height);
194 dpy = XOpenDisplay(dpyname);
197 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
202 st = avformat_new_stream(s1, NULL);
204 ret = AVERROR(ENOMEM);
207 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
209 screen = DefaultScreen(dpy);
211 if (x11grab->follow_mouse) {
212 int screen_w, screen_h;
215 screen_w = DisplayWidth(dpy, screen);
216 screen_h = DisplayHeight(dpy, screen);
217 XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off, &ret, &ret, &ret);
218 x_off -= x11grab->width / 2;
219 y_off -= x11grab->height / 2;
220 x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
221 y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
222 av_log(s1, AV_LOG_INFO, "followmouse is enabled, resetting grabbing region to x: %d y: %d\n", x_off, y_off);
225 use_shm = XShmQueryExtension(dpy);
226 av_log(s1, AV_LOG_INFO, "shared memory extension%s found\n", use_shm ? "" : " not");
229 int scr = XDefaultScreen(dpy);
230 image = XShmCreateImage(dpy,
231 DefaultVisual(dpy, scr),
232 DefaultDepth(dpy, scr),
236 x11grab->width, x11grab->height);
237 x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
238 image->bytes_per_line * image->height,
240 if (x11grab->shminfo.shmid == -1) {
241 av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
242 ret = AVERROR(ENOMEM);
245 x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
246 x11grab->shminfo.readOnly = False;
248 if (!XShmAttach(dpy, &x11grab->shminfo)) {
249 av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
250 /* needs some better error subroutine :) */
255 image = XGetImage(dpy, RootWindow(dpy, screen),
257 x11grab->width, x11grab->height,
261 switch (image->bits_per_pixel) {
263 av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
264 input_pixfmt = AV_PIX_FMT_PAL8;
267 if ( image->red_mask == 0xf800 &&
268 image->green_mask == 0x07e0 &&
269 image->blue_mask == 0x001f ) {
270 av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
271 input_pixfmt = AV_PIX_FMT_RGB565;
272 } else if (image->red_mask == 0x7c00 &&
273 image->green_mask == 0x03e0 &&
274 image->blue_mask == 0x001f ) {
275 av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
276 input_pixfmt = AV_PIX_FMT_RGB555;
278 av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
279 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);
285 if ( image->red_mask == 0xff0000 &&
286 image->green_mask == 0x00ff00 &&
287 image->blue_mask == 0x0000ff ) {
288 input_pixfmt = AV_PIX_FMT_BGR24;
289 } else if ( image->red_mask == 0x0000ff &&
290 image->green_mask == 0x00ff00 &&
291 image->blue_mask == 0xff0000 ) {
292 input_pixfmt = AV_PIX_FMT_RGB24;
294 av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
295 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);
301 input_pixfmt = AV_PIX_FMT_0RGB32;
304 av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
305 ret = AVERROR(EINVAL);
309 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel/8;
311 x11grab->time_base = av_inv_q(framerate);
312 x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
313 x11grab->x_off = x_off;
314 x11grab->y_off = y_off;
315 x11grab->image = image;
316 x11grab->use_shm = use_shm;
318 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
319 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
320 st->codec->width = x11grab->width;
321 st->codec->height = x11grab->height;
322 st->codec->pix_fmt = input_pixfmt;
323 st->codec->time_base = x11grab->time_base;
324 st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(x11grab->time_base) * 8;
332 * Paint a mouse pointer in an X11 image.
334 * @param image image to paint the mouse pointer to
335 * @param s context used to retrieve original grabbing rectangle
339 paint_mouse_pointer(XImage *image, struct x11grab *s)
341 int x_off = s->x_off;
342 int y_off = s->y_off;
343 int width = s->width;
344 int height = s->height;
345 Display *dpy = s->dpy;
346 XFixesCursorImage *xcim;
349 int to_line, to_column;
350 int pixstride = image->bits_per_pixel >> 3;
351 /* Warning: in its insanity, xlib provides unsigned image data through a
352 * char* pointer, so we have to make it uint8_t to make things not break.
353 * Anyone who performs further investigation of the xlib API likely risks
354 * permanent brain damage. */
355 uint8_t *pix = image->data;
358 XSetWindowAttributes attr;
360 /* Code doesn't currently support 16-bit or PAL8 */
361 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
364 c = XCreateFontCursor(dpy, XC_left_ptr);
365 w = DefaultRootWindow(dpy);
367 XChangeWindowAttributes(dpy, w, CWCursor, &attr);
369 xcim = XFixesGetCursorImage(dpy);
371 x = xcim->x - xcim->xhot;
372 y = xcim->y - xcim->yhot;
374 to_line = FFMIN((y + xcim->height), (height + y_off));
375 to_column = FFMIN((x + xcim->width), (width + x_off));
377 for (line = FFMAX(y, y_off); line < to_line; line++) {
378 for (column = FFMAX(x, x_off); column < to_column; column++) {
379 int xcim_addr = (line - y) * xcim->width + column - x;
380 int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
381 int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
382 int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
383 int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
384 int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
387 pix[image_addr+0] = r;
388 pix[image_addr+1] = g;
389 pix[image_addr+2] = b;
391 /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
392 pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;
393 pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;
394 pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;
405 * Read new data in the image structure.
407 * @param dpy X11 display to grab from
409 * @param image Image where the grab will be put
410 * @param x Top-Left grabbing rectangle horizontal coordinate
411 * @param y Top-Left grabbing rectangle vertical coordinate
412 * @return 0 if error, !0 if successful
415 xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
426 GetReq(GetImage, req);
428 /* First set up the standard stuff in the request */
432 req->width = image->width;
433 req->height = image->height;
434 req->planeMask = (unsigned int)AllPlanes;
435 req->format = ZPixmap;
437 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
443 nbytes = (long)rep.length << 2;
444 _XReadPad(dpy, image->data, nbytes);
452 * Grab a frame from x11 (public device demuxer API).
454 * @param s1 Context from avformat core
455 * @param pkt Packet holding the brabbed frame
456 * @return frame size in bytes
459 x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
461 struct x11grab *s = s1->priv_data;
462 Display *dpy = s->dpy;
463 XImage *image = s->image;
464 int x_off = s->x_off;
465 int y_off = s->y_off;
469 int follow_mouse = s->follow_mouse;
471 int64_t curtime, delay;
474 /* Calculate the time of the next frame */
475 s->time_frame += INT64_C(1000000);
477 /* wait based on the frame rate */
479 curtime = av_gettime();
480 delay = s->time_frame * av_q2d(s->time_base) - curtime;
482 if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
483 s->time_frame += INT64_C(1000000);
487 ts.tv_sec = delay / 1000000;
488 ts.tv_nsec = (delay % 1000000) * 1000;
489 nanosleep(&ts, NULL);
493 pkt->data = image->data;
494 pkt->size = s->frame_size;
497 screen = DefaultScreen(dpy);
498 root = RootWindow(dpy, screen);
500 int screen_w, screen_h;
501 int pointer_x, pointer_y, _;
504 screen_w = DisplayWidth(dpy, screen);
505 screen_h = DisplayHeight(dpy, screen);
506 XQueryPointer(dpy, root, &w, &w, &pointer_x, &pointer_y, &_, &_, &_);
507 if (follow_mouse == -1) {
508 // follow the mouse, put it at center of grabbing region
509 x_off += pointer_x - s->width / 2 - x_off;
510 y_off += pointer_y - s->height / 2 - y_off;
512 // follow the mouse, but only move the grabbing region when mouse
513 // reaches within certain pixels to the edge.
514 if (pointer_x > x_off + s->width - follow_mouse) {
515 x_off += pointer_x - (x_off + s->width - follow_mouse);
516 } else if (pointer_x < x_off + follow_mouse)
517 x_off -= (x_off + follow_mouse) - pointer_x;
518 if (pointer_y > y_off + s->height - follow_mouse) {
519 y_off += pointer_y - (y_off + s->height - follow_mouse);
520 } else if (pointer_y < y_off + follow_mouse)
521 y_off -= (y_off + follow_mouse) - pointer_y;
523 // adjust grabbing region position if it goes out of screen.
524 s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
525 s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
527 if (s->show_region && s->region_win)
528 XMoveWindow(dpy, s->region_win,
529 s->x_off - REGION_WIN_BORDER,
530 s->y_off - REGION_WIN_BORDER);
533 if (s->show_region) {
536 // clean up the events, and do the initinal draw or redraw.
537 for (evt.type = NoEventMask; XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask, &evt); );
539 x11grab_draw_region_win(s);
541 x11grab_region_win_init(s);
546 if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes)) {
547 av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
550 if (!xget_zpixmap(dpy, root, image, x_off, y_off)) {
551 av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
556 paint_mouse_pointer(image, s);
559 return s->frame_size;
563 * Close x11 frame grabber (public device demuxer API).
565 * @param s1 Context from avformat core
566 * @return 0 success, !0 failure
569 x11grab_read_close(AVFormatContext *s1)
571 struct x11grab *x11grab = s1->priv_data;
573 /* Detach cleanly from shared mem */
574 if (x11grab->use_shm) {
575 XShmDetach(x11grab->dpy, &x11grab->shminfo);
576 shmdt(x11grab->shminfo.shmaddr);
577 shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
580 /* Destroy X11 image */
581 if (x11grab->image) {
582 XDestroyImage(x11grab->image);
583 x11grab->image = NULL;
586 if (x11grab->region_win) {
587 XDestroyWindow(x11grab->dpy, x11grab->region_win);
590 /* Free X11 display */
591 XCloseDisplay(x11grab->dpy);
595 #define OFFSET(x) offsetof(struct x11grab, x)
596 #define DEC AV_OPT_FLAG_DECODING_PARAM
597 static const AVOption options[] = {
598 { "draw_mouse", "draw the mouse pointer", OFFSET(draw_mouse), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC },
600 { "follow_mouse", "move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region",
601 OFFSET(follow_mouse), AV_OPT_TYPE_INT, {.i64 = 0}, -1, INT_MAX, DEC, "follow_mouse" },
602 { "centered", "keep the mouse pointer at the center of grabbing region when following",
603 0, AV_OPT_TYPE_CONST, {.i64 = -1}, INT_MIN, INT_MAX, DEC, "follow_mouse" },
605 { "framerate", "set video frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
606 { "show_region", "show the grabbing region", OFFSET(show_region), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
607 { "video_size", "set video frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = "vga"}, 0, 0, DEC },
611 static const AVClass x11_class = {
612 .class_name = "X11grab indev",
613 .item_name = av_default_item_name,
615 .version = LIBAVUTIL_VERSION_INT,
618 /** x11 grabber device demuxer declaration */
619 AVInputFormat ff_x11grab_demuxer = {
621 .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
622 .priv_data_size = sizeof(struct x11grab),
623 .read_header = x11grab_read_header,
624 .read_packet = x11grab_read_packet,
625 .read_close = x11grab_read_close,
626 .flags = AVFMT_NOFILE,
627 .priv_class = &x11_class,