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 by Clemens Fruhwirth <clemens@endorphin.org>
35 * and Edouard Gomez <ed.gomez@free.fr>.
39 #include "libavformat/internal.h"
40 #include "libavutil/log.h"
41 #include "libavutil/opt.h"
42 #include "libavutil/parseutils.h"
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/XShm.h>
52 #include <X11/extensions/Xfixes.h>
56 * X11 Device Demuxer context
60 const AVClass *class; /**< Class for private options. */
61 int frame_size; /**< Size in bytes of a grabbed frame */
62 AVRational time_base; /**< Time base */
63 int64_t time_frame; /**< Current time */
65 char *video_size; /**< String describing video size, set by a private option. */
66 int height; /**< Height of the grab frame */
67 int width; /**< Width of the grab frame */
68 int x_off; /**< Horizontal top-left corner coordinate */
69 int y_off; /**< Vertical top-left corner coordinate */
71 Display *dpy; /**< X11 display from which x11grab grabs frames */
72 XImage *image; /**< X11 image holding the grab */
73 int use_shm; /**< !0 when using XShm extension */
74 XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */
75 int draw_mouse; /**< Set by a private option. */
76 int follow_mouse; /**< Set by a private option. */
77 int show_region; /**< set by a private option. */
78 char *framerate; /**< Set by a private option. */
80 Window region_win; /**< This is used by show_region option. */
83 #define REGION_WIN_BORDER 3
85 * Draw grabbing region window
87 * @param s x11_grab context
90 x11grab_draw_region_win(struct x11_grab *s)
92 Display *dpy = s->dpy;
94 Window win = s->region_win;
97 screen = DefaultScreen(dpy);
98 gc = XCreateGC(dpy, win, 0, 0);
99 XSetForeground(dpy, gc, WhitePixel(dpy, screen));
100 XSetBackground(dpy, gc, BlackPixel(dpy, screen));
101 XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0);
102 XDrawRectangle(dpy, win, gc,
104 (s->width + REGION_WIN_BORDER * 2) - 1 * 2 - 1,
105 (s->height + REGION_WIN_BORDER * 2) - 1 * 2 - 1);
110 * Initialize grabbing region window
112 * @param s x11_grab context
115 x11grab_region_win_init(struct x11_grab *s)
117 Display *dpy = s->dpy;
119 XSetWindowAttributes attribs;
122 screen = DefaultScreen(dpy);
123 attribs.override_redirect = True;
124 s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen),
125 s->x_off - REGION_WIN_BORDER,
126 s->y_off - REGION_WIN_BORDER,
127 s->width + REGION_WIN_BORDER * 2,
128 s->height + REGION_WIN_BORDER * 2,
130 InputOutput, CopyFromParent,
131 CWOverrideRedirect, &attribs);
134 rect.width = s->width;
135 rect.height = s->height;
136 XShapeCombineRectangles(dpy, s->region_win,
137 ShapeBounding, REGION_WIN_BORDER, REGION_WIN_BORDER,
138 &rect, 1, ShapeSubtract, 0);
139 XMapWindow(dpy, s->region_win);
140 XSelectInput(dpy, s->region_win, ExposureMask | StructureNotifyMask);
141 x11grab_draw_region_win(s);
145 * Initialize the x11 grab device demuxer (public device demuxer API).
147 * @param s1 Context from avformat core
148 * @param ap Parameters 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, AVFormatParameters *ap)
158 struct x11_grab *x11grab = s1->priv_data;
161 enum PixelFormat input_pixfmt;
167 char *dpyname, *offset;
169 AVRational framerate;
171 dpyname = av_strdup(s1->filename);
172 offset = strchr(dpyname, '+');
174 sscanf(offset, "%d,%d", &x_off, &y_off);
175 x11grab->draw_mouse = !strstr(offset, "nomouse");
179 if ((ret = av_parse_video_size(&x11grab->width, &x11grab->height, x11grab->video_size)) < 0) {
180 av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
183 if ((ret = av_parse_video_rate(&framerate, x11grab->framerate)) < 0) {
184 av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n", x11grab->framerate);
187 av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n",
188 s1->filename, dpyname, x_off, y_off, x11grab->width, x11grab->height);
190 dpy = XOpenDisplay(dpyname);
193 av_log(s1, AV_LOG_ERROR, "Could not open X display.\n");
198 st = avformat_new_stream(s1, NULL);
200 ret = AVERROR(ENOMEM);
203 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
205 screen = DefaultScreen(dpy);
207 if (x11grab->follow_mouse) {
208 int screen_w, screen_h;
211 screen_w = DisplayWidth(dpy, screen);
212 screen_h = DisplayHeight(dpy, screen);
213 XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off, &ret, &ret, &ret);
214 x_off -= x11grab->width / 2;
215 y_off -= x11grab->height / 2;
216 x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width);
217 y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height);
218 av_log(s1, AV_LOG_INFO, "followmouse is enabled, resetting grabbing region to x: %d y: %d\n", x_off, y_off);
221 use_shm = XShmQueryExtension(dpy);
222 av_log(s1, AV_LOG_INFO, "shared memory extension%s found\n", use_shm ? "" : " not");
225 int scr = XDefaultScreen(dpy);
226 image = XShmCreateImage(dpy,
227 DefaultVisual(dpy, scr),
228 DefaultDepth(dpy, scr),
232 x11grab->width, x11grab->height);
233 x11grab->shminfo.shmid = shmget(IPC_PRIVATE,
234 image->bytes_per_line * image->height,
236 if (x11grab->shminfo.shmid == -1) {
237 av_log(s1, AV_LOG_ERROR, "Fatal: Can't get shared memory!\n");
238 ret = AVERROR(ENOMEM);
241 x11grab->shminfo.shmaddr = image->data = shmat(x11grab->shminfo.shmid, 0, 0);
242 x11grab->shminfo.readOnly = False;
244 if (!XShmAttach(dpy, &x11grab->shminfo)) {
245 av_log(s1, AV_LOG_ERROR, "Fatal: Failed to attach shared memory!\n");
246 /* needs some better error subroutine :) */
251 image = XGetImage(dpy, RootWindow(dpy, screen),
253 x11grab->width, x11grab->height,
257 switch (image->bits_per_pixel) {
259 av_log (s1, AV_LOG_DEBUG, "8 bit palette\n");
260 input_pixfmt = PIX_FMT_PAL8;
263 if ( image->red_mask == 0xf800 &&
264 image->green_mask == 0x07e0 &&
265 image->blue_mask == 0x001f ) {
266 av_log (s1, AV_LOG_DEBUG, "16 bit RGB565\n");
267 input_pixfmt = PIX_FMT_RGB565;
268 } else if (image->red_mask == 0x7c00 &&
269 image->green_mask == 0x03e0 &&
270 image->blue_mask == 0x001f ) {
271 av_log(s1, AV_LOG_DEBUG, "16 bit RGB555\n");
272 input_pixfmt = PIX_FMT_RGB555;
274 av_log(s1, AV_LOG_ERROR, "RGB ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
275 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);
281 if ( image->red_mask == 0xff0000 &&
282 image->green_mask == 0x00ff00 &&
283 image->blue_mask == 0x0000ff ) {
284 input_pixfmt = PIX_FMT_BGR24;
285 } else if ( image->red_mask == 0x0000ff &&
286 image->green_mask == 0x00ff00 &&
287 image->blue_mask == 0xff0000 ) {
288 input_pixfmt = PIX_FMT_RGB24;
290 av_log(s1, AV_LOG_ERROR,"rgb ordering at image depth %i not supported ... aborting\n", image->bits_per_pixel);
291 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);
297 input_pixfmt = PIX_FMT_RGB32;
300 av_log(s1, AV_LOG_ERROR, "image depth %i not supported ... aborting\n", image->bits_per_pixel);
301 ret = AVERROR(EINVAL);
305 x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel/8;
307 x11grab->time_base = (AVRational){framerate.den, framerate.num};
308 x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base);
309 x11grab->x_off = x_off;
310 x11grab->y_off = y_off;
311 x11grab->image = image;
312 x11grab->use_shm = use_shm;
314 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
315 st->codec->codec_id = CODEC_ID_RAWVIDEO;
316 st->codec->width = x11grab->width;
317 st->codec->height = x11grab->height;
318 st->codec->pix_fmt = input_pixfmt;
319 st->codec->time_base = x11grab->time_base;
320 st->codec->bit_rate = x11grab->frame_size * 1/av_q2d(x11grab->time_base) * 8;
327 * Paint a mouse pointer in an X11 image.
329 * @param image image to paint the mouse pointer to
330 * @param s context used to retrieve original grabbing rectangle
334 paint_mouse_pointer(XImage *image, struct x11_grab *s)
336 int x_off = s->x_off;
337 int y_off = s->y_off;
338 int width = s->width;
339 int height = s->height;
340 Display *dpy = s->dpy;
341 XFixesCursorImage *xcim;
344 int to_line, to_column;
345 int pixstride = image->bits_per_pixel >> 3;
346 /* Warning: in its insanity, xlib provides unsigned image data through a
347 * char* pointer, so we have to make it uint8_t to make things not break.
348 * Anyone who performs further investigation of the xlib API likely risks
349 * permanent brain damage. */
350 uint8_t *pix = image->data;
352 /* Code doesn't currently support 16-bit or PAL8 */
353 if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32)
356 xcim = XFixesGetCursorImage(dpy);
358 x = xcim->x - xcim->xhot;
359 y = xcim->y - xcim->yhot;
361 to_line = FFMIN((y + xcim->height), (height + y_off));
362 to_column = FFMIN((x + xcim->width), (width + x_off));
364 for (line = FFMAX(y, y_off); line < to_line; line++) {
365 for (column = FFMAX(x, x_off); column < to_column; column++) {
366 int xcim_addr = (line - y) * xcim->width + column - x;
367 int image_addr = ((line - y_off) * width + column - x_off) * pixstride;
368 int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0);
369 int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8);
370 int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16);
371 int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24);
374 pix[image_addr+0] = r;
375 pix[image_addr+1] = g;
376 pix[image_addr+2] = b;
378 /* pixel values from XFixesGetCursorImage come premultiplied by alpha */
379 pix[image_addr+0] = r + (pix[image_addr+0]*(255-a) + 255/2) / 255;
380 pix[image_addr+1] = g + (pix[image_addr+1]*(255-a) + 255/2) / 255;
381 pix[image_addr+2] = b + (pix[image_addr+2]*(255-a) + 255/2) / 255;
392 * Read new data in the image structure.
394 * @param dpy X11 display to grab from
396 * @param image Image where the grab will be put
397 * @param x Top-Left grabbing rectangle horizontal coordinate
398 * @param y Top-Left grabbing rectangle vertical coordinate
399 * @return 0 if error, !0 if successful
402 xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y)
413 GetReq(GetImage, req);
415 /* First set up the standard stuff in the request */
419 req->width = image->width;
420 req->height = image->height;
421 req->planeMask = (unsigned int)AllPlanes;
422 req->format = ZPixmap;
424 if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) {
430 nbytes = (long)rep.length << 2;
431 _XReadPad(dpy, image->data, nbytes);
439 * Grab a frame from x11 (public device demuxer API).
441 * @param s1 Context from avformat core
442 * @param pkt Packet holding the brabbed frame
443 * @return frame size in bytes
446 x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
448 struct x11_grab *s = s1->priv_data;
449 Display *dpy = s->dpy;
450 XImage *image = s->image;
451 int x_off = s->x_off;
452 int y_off = s->y_off;
456 int follow_mouse = s->follow_mouse;
458 int64_t curtime, delay;
461 /* Calculate the time of the next frame */
462 s->time_frame += INT64_C(1000000);
464 /* wait based on the frame rate */
466 curtime = av_gettime();
467 delay = s->time_frame * av_q2d(s->time_base) - curtime;
469 if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) {
470 s->time_frame += INT64_C(1000000);
474 ts.tv_sec = delay / 1000000;
475 ts.tv_nsec = (delay % 1000000) * 1000;
476 nanosleep(&ts, NULL);
480 pkt->data = image->data;
481 pkt->size = s->frame_size;
484 screen = DefaultScreen(dpy);
485 root = RootWindow(dpy, screen);
487 int screen_w, screen_h;
488 int pointer_x, pointer_y, _;
491 screen_w = DisplayWidth(dpy, screen);
492 screen_h = DisplayHeight(dpy, screen);
493 XQueryPointer(dpy, root, &w, &w, &pointer_x, &pointer_y, &_, &_, &_);
494 if (follow_mouse == -1) {
495 // follow the mouse, put it at center of grabbing region
496 x_off += pointer_x - s->width / 2 - x_off;
497 y_off += pointer_y - s->height / 2 - y_off;
499 // follow the mouse, but only move the grabbing region when mouse
500 // reaches within certain pixels to the edge.
501 if (pointer_x > x_off + s->width - follow_mouse) {
502 x_off += pointer_x - (x_off + s->width - follow_mouse);
503 } else if (pointer_x < x_off + follow_mouse)
504 x_off -= (x_off + follow_mouse) - pointer_x;
505 if (pointer_y > y_off + s->height - follow_mouse) {
506 y_off += pointer_y - (y_off + s->height - follow_mouse);
507 } else if (pointer_y < y_off + follow_mouse)
508 y_off -= (y_off + follow_mouse) - pointer_y;
510 // adjust grabbing region position if it goes out of screen.
511 s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width);
512 s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height);
514 if (s->show_region && s->region_win)
515 XMoveWindow(dpy, s->region_win,
516 s->x_off - REGION_WIN_BORDER,
517 s->y_off - REGION_WIN_BORDER);
520 if (s->show_region) {
523 // clean up the events, and do the initinal draw or redraw.
524 for (evt.type = NoEventMask; XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask, &evt); );
526 x11grab_draw_region_win(s);
528 x11grab_region_win_init(s);
533 if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes)) {
534 av_log (s1, AV_LOG_INFO, "XShmGetImage() failed\n");
537 if (!xget_zpixmap(dpy, root, image, x_off, y_off)) {
538 av_log (s1, AV_LOG_INFO, "XGetZPixmap() failed\n");
541 if (image->bits_per_pixel == 32)
542 XAddPixel(image, 0xFF000000);
545 paint_mouse_pointer(image, s);
548 return s->frame_size;
552 * Close x11 frame grabber (public device demuxer API).
554 * @param s1 Context from avformat core
555 * @return 0 success, !0 failure
558 x11grab_read_close(AVFormatContext *s1)
560 struct x11_grab *x11grab = s1->priv_data;
562 /* Detach cleanly from shared mem */
563 if (x11grab->use_shm) {
564 XShmDetach(x11grab->dpy, &x11grab->shminfo);
565 shmdt(x11grab->shminfo.shmaddr);
566 shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL);
569 /* Destroy X11 image */
570 if (x11grab->image) {
571 XDestroyImage(x11grab->image);
572 x11grab->image = NULL;
575 if (x11grab->region_win) {
576 XDestroyWindow(x11grab->dpy, x11grab->region_win);
579 /* Free X11 display */
580 XCloseDisplay(x11grab->dpy);
584 #define OFFSET(x) offsetof(struct x11_grab, x)
585 #define DEC AV_OPT_FLAG_DECODING_PARAM
586 static const AVOption options[] = {
587 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC },
588 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC },
589 { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { 1 }, 0, 1, DEC },
590 { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.",
591 OFFSET(follow_mouse), AV_OPT_TYPE_INT, { 0 }, -1, INT_MAX, DEC, "follow_mouse" },
592 { "centered", "Keep the mouse pointer at the center of grabbing region when following.", 0, AV_OPT_TYPE_CONST, { -1 }, INT_MIN, INT_MAX, DEC, "follow_mouse" },
593 { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { 0 }, 0, 1, DEC },
597 static const AVClass x11_class = {
598 .class_name = "X11grab indev",
599 .item_name = av_default_item_name,
601 .version = LIBAVUTIL_VERSION_INT,
604 /** x11 grabber device demuxer declaration */
605 AVInputFormat ff_x11_grab_device_demuxer = {
607 .long_name = NULL_IF_CONFIG_SMALL("X11grab"),
608 .priv_data_size = sizeof(struct x11_grab),
609 .read_header = x11grab_read_header,
610 .read_packet = x11grab_read_packet,
611 .read_close = x11grab_read_close,
612 .flags = AVFMT_NOFILE,
613 .priv_class = &x11_class,