/* * X11 video grab interface * * This file is part of Libav. * * Libav integration: * Copyright (C) 2006 Clemens Fruhwirth * Edouard Gomez * * This file contains code from grab.c: * Copyright (c) 2000-2001 Fabrice Bellard * * This file contains code from the xvidcap project: * Copyright (C) 1997-1998 Rasca, Berlin * 2003-2004 Karl H. Beckers, Frankfurt * * Libav is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * X11 frame device demuxer * @author Clemens Fruhwirth * @author Edouard Gomez */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include "libavutil/internal.h" #include "libavutil/log.h" #include "libavutil/opt.h" #include "libavutil/parseutils.h" #include "libavutil/time.h" #include "libavformat/avformat.h" #include "libavformat/internal.h" /** X11 device demuxer context */ typedef struct X11GrabContext { const AVClass *class; /**< Class for private options. */ int frame_size; /**< Size in bytes of a grabbed frame */ AVRational time_base; /**< Time base */ int64_t time_frame; /**< Current time */ char *video_size; /**< String describing video size, set by a private option. */ int height; /**< Height of the grab frame */ int width; /**< Width of the grab frame */ int x_off; /**< Horizontal top-left corner coordinate */ int y_off; /**< Vertical top-left corner coordinate */ Display *dpy; /**< X11 display from which x11grab grabs frames */ XImage *image; /**< X11 image holding the grab */ int use_shm; /**< !0 when using XShm extension */ XShmSegmentInfo shminfo; /**< When using XShm, keeps track of XShm infos */ int draw_mouse; /**< Set by a private option. */ int follow_mouse; /**< Set by a private option. */ int show_region; /**< set by a private option. */ char *framerate; /**< Set by a private option. */ Window region_win; /**< This is used by show_region option. */ } X11GrabContext; #define REGION_WIN_BORDER 3 /** * Draw grabbing region window * * @param s x11grab context */ static void x11grab_draw_region_win(X11GrabContext *s) { Display *dpy = s->dpy; Window win = s->region_win; int screen = DefaultScreen(dpy); GC gc = XCreateGC(dpy, win, 0, 0); XSetForeground(dpy, gc, WhitePixel(dpy, screen)); XSetBackground(dpy, gc, BlackPixel(dpy, screen)); XSetLineAttributes(dpy, gc, REGION_WIN_BORDER, LineDoubleDash, 0, 0); XDrawRectangle(dpy, win, gc, 1, 1, (s->width + REGION_WIN_BORDER * 2) - 1 * 2 - 1, (s->height + REGION_WIN_BORDER * 2) - 1 * 2 - 1); XFreeGC(dpy, gc); } /** * Initialize grabbing region window * * @param s x11grab context */ static void x11grab_region_win_init(X11GrabContext *s) { Display *dpy = s->dpy; XRectangle rect; XSetWindowAttributes attribs = { .override_redirect = True }; int screen = DefaultScreen(dpy); s->region_win = XCreateWindow(dpy, RootWindow(dpy, screen), s->x_off - REGION_WIN_BORDER, s->y_off - REGION_WIN_BORDER, s->width + REGION_WIN_BORDER * 2, s->height + REGION_WIN_BORDER * 2, 0, CopyFromParent, InputOutput, CopyFromParent, CWOverrideRedirect, &attribs); rect.x = 0; rect.y = 0; rect.width = s->width; rect.height = s->height; XShapeCombineRectangles(dpy, s->region_win, ShapeBounding, REGION_WIN_BORDER, REGION_WIN_BORDER, &rect, 1, ShapeSubtract, 0); XMapWindow(dpy, s->region_win); XSelectInput(dpy, s->region_win, ExposureMask | StructureNotifyMask); x11grab_draw_region_win(s); } static int setup_shm(AVFormatContext *s, Display *dpy, XImage **image) { X11GrabContext *g = s->priv_data; int scr = XDefaultScreen(dpy); XImage *img = XShmCreateImage(dpy, DefaultVisual(dpy, scr), DefaultDepth(dpy, scr), ZPixmap, NULL, &g->shminfo, g->width, g->height); g->shminfo.shmid = shmget(IPC_PRIVATE, img->bytes_per_line * img->height, IPC_CREAT | 0777); if (g->shminfo.shmid == -1) { av_log(s, AV_LOG_ERROR, "Cannot get shared memory!\n"); return AVERROR(ENOMEM); } g->shminfo.shmaddr = img->data = shmat(g->shminfo.shmid, 0, 0); g->shminfo.readOnly = False; if (!XShmAttach(dpy, &g->shminfo)) { av_log(s, AV_LOG_ERROR, "Failed to attach shared memory!\n"); /* needs some better error subroutine :) */ return AVERROR(EIO); } *image = img; return 0; } static int setup_mouse(Display *dpy, int screen) { int ev_ret, ev_err; if (XFixesQueryExtension(dpy, &ev_ret, &ev_err)) { Window root = RootWindow(dpy, screen); XFixesSelectCursorInput(dpy, root, XFixesDisplayCursorNotifyMask); return 0; } return AVERROR(ENOSYS); } static int pixfmt_from_image(AVFormatContext *s, XImage *image, int *pix_fmt) { av_log(s, AV_LOG_DEBUG, "Image r 0x%.6lx g 0x%.6lx b 0x%.6lx and depth %i\n", image->red_mask, image->green_mask, image->blue_mask, image->bits_per_pixel); switch (image->bits_per_pixel) { case 8: *pix_fmt = AV_PIX_FMT_PAL8; break; case 16: if (image->red_mask == 0xf800 && image->green_mask == 0x07e0 && image->blue_mask == 0x001f) { *pix_fmt = AV_PIX_FMT_RGB565; } else if (image->red_mask == 0x7c00 && image->green_mask == 0x03e0 && image->blue_mask == 0x001f) { *pix_fmt = AV_PIX_FMT_RGB555; } break; case 24: if (image->red_mask == 0xff0000 && image->green_mask == 0x00ff00 && image->blue_mask == 0x0000ff) { *pix_fmt = AV_PIX_FMT_BGR24; } else if (image->red_mask == 0x0000ff && image->green_mask == 0x00ff00 && image->blue_mask == 0xff0000) { *pix_fmt = AV_PIX_FMT_RGB24; } break; case 32: *pix_fmt = AV_PIX_FMT_RGB32; break; default: av_log(s, AV_LOG_ERROR, "XImages with RGB mask 0x%.6lx 0x%.6lx 0x%.6lx and depth %i " "are currently not supported.\n", image->red_mask, image->green_mask, image->blue_mask, image->bits_per_pixel); return AVERROR_PATCHWELCOME; } return 0; } /** * Initialize the x11 grab device demuxer (public device demuxer API). * * @param s1 Context from avformat core * @return
    *
  • AVERROR(ENOMEM) no memory left
  • *
  • AVERROR(EIO) other failure case
  • *
  • 0 success
  • *
*/ static int x11grab_read_header(AVFormatContext *s1) { X11GrabContext *x11grab = s1->priv_data; Display *dpy; AVStream *st = NULL; XImage *image; int x_off = 0, y_off = 0, ret = 0, screen, use_shm; char *param, *offset; AVRational framerate; param = av_strdup(s1->filename); if (!param) goto out; offset = strchr(param, '+'); if (offset) { sscanf(offset, "%d,%d", &x_off, &y_off); x11grab->draw_mouse = !strstr(offset, "nomouse"); *offset = 0; } ret = av_parse_video_size(&x11grab->width, &x11grab->height, x11grab->video_size); if (ret < 0) { av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n"); goto out; } ret = av_parse_video_rate(&framerate, x11grab->framerate); if (ret < 0) { av_log(s1, AV_LOG_ERROR, "Could not parse framerate: %s.\n", x11grab->framerate); goto out; } av_log(s1, AV_LOG_INFO, "device: %s -> display: %s x: %d y: %d width: %d height: %d\n", s1->filename, param, x_off, y_off, x11grab->width, x11grab->height); dpy = XOpenDisplay(param); if (!dpy) { av_log(s1, AV_LOG_ERROR, "Could not open X display.\n"); ret = AVERROR(EIO); goto out; } st = avformat_new_stream(s1, NULL); if (!st) { ret = AVERROR(ENOMEM); goto out; } avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */ screen = DefaultScreen(dpy); if (x11grab->follow_mouse) { int screen_w, screen_h; Window w; screen_w = DisplayWidth(dpy, screen); screen_h = DisplayHeight(dpy, screen); XQueryPointer(dpy, RootWindow(dpy, screen), &w, &w, &x_off, &y_off, &ret, &ret, &ret); x_off -= x11grab->width / 2; y_off -= x11grab->height / 2; x_off = FFMIN(FFMAX(x_off, 0), screen_w - x11grab->width); y_off = FFMIN(FFMAX(y_off, 0), screen_h - x11grab->height); av_log(s1, AV_LOG_INFO, "followmouse is enabled, resetting grabbing region to x: %d y: %d\n", x_off, y_off); } use_shm = XShmQueryExtension(dpy); av_log(s1, AV_LOG_INFO, "shared memory extension %sfound\n", use_shm ? "" : "not "); if (use_shm && setup_shm(s1, dpy, &image) < 0) { av_log(s1, AV_LOG_WARNING, "Falling back to XGetImage\n"); use_shm = 0; } if (!use_shm) { image = XGetImage(dpy, RootWindow(dpy, screen), x_off, y_off, x11grab->width, x11grab->height, AllPlanes, ZPixmap); } if (x11grab->draw_mouse && setup_mouse(dpy, screen) < 0) { av_log(s1, AV_LOG_WARNING, "XFixes not available, cannot draw the mouse cursor\n"); x11grab->draw_mouse = 0; } x11grab->frame_size = x11grab->width * x11grab->height * image->bits_per_pixel / 8; x11grab->dpy = dpy; x11grab->time_base = (AVRational) { framerate.den, framerate.num }; x11grab->time_frame = av_gettime() / av_q2d(x11grab->time_base); x11grab->x_off = x_off; x11grab->y_off = y_off; x11grab->image = image; x11grab->use_shm = use_shm; ret = pixfmt_from_image(s1, image, &st->codecpar->format); if (ret < 0) goto out; st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO; st->codecpar->width = x11grab->width; st->codecpar->height = x11grab->height; st->codecpar->bit_rate = x11grab->frame_size * 1 / av_q2d(x11grab->time_base) * 8; st->avg_frame_rate = av_inv_q(x11grab->time_base); out: av_free(param); return ret; } /** * Paint a mouse pointer in an X11 image. * * @param image image to paint the mouse pointer to * @param s context used to retrieve original grabbing rectangle * coordinates */ static void paint_mouse_pointer(XImage *image, X11GrabContext *s) { int x_off = s->x_off; int y_off = s->y_off; int width = s->width; int height = s->height; Display *dpy = s->dpy; XFixesCursorImage *xcim; int x, y; int line, column; int to_line, to_column; int pixstride = image->bits_per_pixel >> 3; /* Warning: in its insanity, xlib provides unsigned image data through a * char* pointer, so we have to make it uint8_t to make things not break. * Anyone who performs further investigation of the xlib API likely risks * permanent brain damage. */ uint8_t *pix = image->data; /* Code doesn't currently support 16-bit or PAL8 */ if (image->bits_per_pixel != 24 && image->bits_per_pixel != 32) return; xcim = XFixesGetCursorImage(dpy); if (!xcim) return; x = xcim->x - xcim->xhot; y = xcim->y - xcim->yhot; to_line = FFMIN((y + xcim->height), (height + y_off)); to_column = FFMIN((x + xcim->width), (width + x_off)); for (line = FFMAX(y, y_off); line < to_line; line++) { for (column = FFMAX(x, x_off); column < to_column; column++) { int xcim_addr = (line - y) * xcim->width + column - x; int image_addr = ((line - y_off) * width + column - x_off) * pixstride; int r = (uint8_t)(xcim->pixels[xcim_addr] >> 0); int g = (uint8_t)(xcim->pixels[xcim_addr] >> 8); int b = (uint8_t)(xcim->pixels[xcim_addr] >> 16); int a = (uint8_t)(xcim->pixels[xcim_addr] >> 24); if (a == 255) { pix[image_addr + 0] = r; pix[image_addr + 1] = g; pix[image_addr + 2] = b; } else if (a) { /* pixel values from XFixesGetCursorImage come premultiplied by alpha */ pix[image_addr + 0] = r + (pix[image_addr + 0] * (255 - a) + 255 / 2) / 255; pix[image_addr + 1] = g + (pix[image_addr + 1] * (255 - a) + 255 / 2) / 255; pix[image_addr + 2] = b + (pix[image_addr + 2] * (255 - a) + 255 / 2) / 255; } } } XFree(xcim); xcim = NULL; } /** * Read new data in the image structure. * * @param dpy X11 display to grab from * @param d * @param image Image where the grab will be put * @param x Top-Left grabbing rectangle horizontal coordinate * @param y Top-Left grabbing rectangle vertical coordinate * @return 0 if error, !0 if successful */ static int xget_zpixmap(Display *dpy, Drawable d, XImage *image, int x, int y) { xGetImageReply rep; xGetImageReq *req; long nbytes; if (!image) return 0; LockDisplay(dpy); GetReq(GetImage, req); /* First set up the standard stuff in the request */ req->drawable = d; req->x = x; req->y = y; req->width = image->width; req->height = image->height; req->planeMask = (unsigned int)AllPlanes; req->format = ZPixmap; if (!_XReply(dpy, (xReply *)&rep, 0, xFalse) || !rep.length) { UnlockDisplay(dpy); SyncHandle(); return 0; } nbytes = (long)rep.length << 2; _XReadPad(dpy, image->data, nbytes); UnlockDisplay(dpy); SyncHandle(); return 1; } /** * Grab a frame from x11 (public device demuxer API). * * @param s1 Context from avformat core * @param pkt Packet holding the brabbed frame * @return frame size in bytes */ static int x11grab_read_packet(AVFormatContext *s1, AVPacket *pkt) { X11GrabContext *s = s1->priv_data; Display *dpy = s->dpy; XImage *image = s->image; int x_off = s->x_off; int y_off = s->y_off; int follow_mouse = s->follow_mouse; int screen, pointer_x, pointer_y, _, same_screen = 1; Window w, root; int64_t curtime, delay; struct timespec ts; /* Calculate the time of the next frame */ s->time_frame += INT64_C(1000000); /* wait based on the frame rate */ for (;;) { curtime = av_gettime(); delay = s->time_frame * av_q2d(s->time_base) - curtime; if (delay <= 0) { if (delay < INT64_C(-1000000) * av_q2d(s->time_base)) s->time_frame += INT64_C(1000000); break; } ts.tv_sec = delay / 1000000; ts.tv_nsec = (delay % 1000000) * 1000; nanosleep(&ts, NULL); } av_init_packet(pkt); pkt->data = image->data; pkt->size = s->frame_size; pkt->pts = curtime; screen = DefaultScreen(dpy); root = RootWindow(dpy, screen); if (follow_mouse || s->draw_mouse) same_screen = XQueryPointer(dpy, root, &w, &w, &pointer_x, &pointer_y, &_, &_, &_); if (follow_mouse && same_screen) { int screen_w, screen_h; screen_w = DisplayWidth(dpy, screen); screen_h = DisplayHeight(dpy, screen); if (follow_mouse == -1) { // follow the mouse, put it at center of grabbing region x_off += pointer_x - s->width / 2 - x_off; y_off += pointer_y - s->height / 2 - y_off; } else { // follow the mouse, but only move the grabbing region when mouse // reaches within certain pixels to the edge. if (pointer_x > x_off + s->width - follow_mouse) x_off += pointer_x - (x_off + s->width - follow_mouse); else if (pointer_x < x_off + follow_mouse) x_off -= (x_off + follow_mouse) - pointer_x; if (pointer_y > y_off + s->height - follow_mouse) y_off += pointer_y - (y_off + s->height - follow_mouse); else if (pointer_y < y_off + follow_mouse) y_off -= (y_off + follow_mouse) - pointer_y; } // adjust grabbing region position if it goes out of screen. s->x_off = x_off = FFMIN(FFMAX(x_off, 0), screen_w - s->width); s->y_off = y_off = FFMIN(FFMAX(y_off, 0), screen_h - s->height); if (s->show_region && s->region_win) XMoveWindow(dpy, s->region_win, s->x_off - REGION_WIN_BORDER, s->y_off - REGION_WIN_BORDER); } if (s->show_region && same_screen) { if (s->region_win) { XEvent evt = { .type = NoEventMask }; // Clean up the events, and do the initial draw or redraw. while (XCheckMaskEvent(dpy, ExposureMask | StructureNotifyMask, &evt)) ; if (evt.type) x11grab_draw_region_win(s); } else { x11grab_region_win_init(s); } } if (s->use_shm) { if (!XShmGetImage(dpy, root, image, x_off, y_off, AllPlanes)) av_log(s1, AV_LOG_INFO, "XShmGetImage() failed\n"); } else { if (!xget_zpixmap(dpy, root, image, x_off, y_off)) av_log(s1, AV_LOG_INFO, "XGetZPixmap() failed\n"); } if (s->draw_mouse && same_screen) paint_mouse_pointer(image, s); return s->frame_size; } /** * Close x11 frame grabber (public device demuxer API). * * @param s1 Context from avformat core * @return 0 success, !0 failure */ static int x11grab_read_close(AVFormatContext *s1) { X11GrabContext *x11grab = s1->priv_data; /* Detach cleanly from shared mem */ if (x11grab->use_shm) { XShmDetach(x11grab->dpy, &x11grab->shminfo); shmdt(x11grab->shminfo.shmaddr); shmctl(x11grab->shminfo.shmid, IPC_RMID, NULL); } /* Destroy X11 image */ if (x11grab->image) { XDestroyImage(x11grab->image); x11grab->image = NULL; } if (x11grab->region_win) XDestroyWindow(x11grab->dpy, x11grab->region_win); /* Free X11 display */ XCloseDisplay(x11grab->dpy); return 0; } #define OFFSET(x) offsetof(X11GrabContext, x) #define DEC AV_OPT_FLAG_DECODING_PARAM static const AVOption options[] = { { "grab_x", "Initial x coordinate.", OFFSET(x_off), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, DEC }, { "grab_y", "Initial y coordinate.", OFFSET(y_off), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, DEC }, { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = "vga"}, 0, 0, DEC }, { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "ntsc"}, 0, 0, DEC }, { "draw_mouse", "Draw the mouse pointer.", OFFSET(draw_mouse), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, DEC }, { "follow_mouse", "Move the grabbing region when the mouse pointer reaches within specified amount of pixels to the edge of region.", OFFSET(follow_mouse), AV_OPT_TYPE_INT, { .i64 = 0 }, -1, INT_MAX, DEC, "follow_mouse" }, { "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" }, { "show_region", "Show the grabbing region.", OFFSET(show_region), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, DEC }, { NULL }, }; static const AVClass x11_class = { .class_name = "X11grab indev", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; /** x11 grabber device demuxer declaration */ AVInputFormat ff_x11grab_demuxer = { .name = "x11grab", .long_name = NULL_IF_CONFIG_SMALL("X11grab"), .priv_data_size = sizeof(X11GrabContext), .read_header = x11grab_read_header, .read_packet = x11grab_read_packet, .read_close = x11grab_read_close, .flags = AVFMT_NOFILE, .priv_class = &x11_class, };