support for xscreensaver / display video in virtual root windows / include vroot.h

[florian.jostock@…]

Hello,

I need a possibility to play videos in a screensaver. So I found I could use
xscreensaver in combination with any video-player that can play videos in a root-
window.
But to work with xscreensaver, the videoplayer needs support for virtual root windows.
For this support, you only need to include a file "vroot.h" from the xscreensaver
distribution in mplayer.

So I copied the vroot.h from xscreensaver to the mplayer sources directory (into the
subdirectory libvo) and added the line
#include "vroot.h"
to the file libvo/x11_common.h
below the other includes, and recompiled mplayer.

With this patch, mplayer works together with xscreensvaer by adding the flowing
command in the .xscrensaver file to the "program:"-variable:
mplayer -rootwin -ao null -msglevel all=-1 -slave -fs -loop 0 /home/kiosk/foo.wmv
The -slave is important, without it xscreensaver crashes.

I think it would really be a good idea to include the vroot.h in the mplayer
distribution, so everybody can use it as a screensaver playing videos with
xscreensaver.

nice greets,

flo

here follows the vroot.h file:

---

/* -*- Mode: C; tab-width: 2 -*- */
/*/
/ Copyright 1991 by Andreas Stolcke /
/ Copyright 1990 by Solbourne Computer Inc. /
/ Longmont, Colorado /
/ /
/ All Rights Reserved /
/ /
/ Permission to use, copy, modify, and distribute this software and /
/ its documentation for any purpose and without fee is hereby /
/ granted, provided that the above copyright notice appear in all /
/ copies and that both that copyright notice and this permis- /
/ sion notice appear in supporting documentation, and that the /
/ name of Solbourne not be used in advertising /
/ in publicity pertaining to distribution of the software without /
/ specific, written prior permission. /
/ /
/ ANDREAS STOLCKE AND SOLBOURNE COMPUTER INC. DISCLAIMS ALL WARRANTIES /
/ WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF /
/ MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL ANDREAS STOLCKE /
/ OR SOLBOURNE BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL /
/ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA /
/ OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER /
/ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE /
/ OR PERFORMANCE OF THIS SOFTWARE. /
/*/
/*

• vroot.h -- Virtual Root Window handling header file *
• This header file redefines the X11 macros RootWindow and DefaultRootWindow,
• making them look for a virtual root window as provided by certain `virtual'
• window managers like swm and tvtwm. If none is found, the ordinary root
• window is returned, thus retaining backward compatibility with standard
• window managers.
• The function implementing the virtual root lookup remembers the result of
• its last invocation to avoid overhead in the case of repeated calls
• on the same display and screen arguments.
• The lookup code itself is taken from Tom LaStrange's ssetroot program. *
• Most simple root window changing X programs can be converted to using
• virtual roots by just including *
• #include <X11/vroot.h> *
• after all the X11 header files. It has been tested on such popular
• X clients as xphoon, xfroot, xloadimage, and xaqua.
• It also works with the core clients xprop, xwininfo, xwd, and editres
• (and is necessary to get those clients working under tvtwm).
• It does NOT work with xsetroot; get the xsetroot replacement included in
• the tvtwm distribution instead. *
• Andreas Stolcke <stolcke@…>, 9/7/90
• - replaced all NULL's with properly cast 0's, 5/6/91
• - free children list (suggested by Mark Martin <mmm@…>), 5/16/91
• - include X11/Xlib.h and support RootWindowOfScreen, too 9/17/91 *
• Jamie Zawinski <jwz@…>, 28-Apr-1997
• - use ANSI C *
• Jamie Zawinski <jwz@…>, 3-Sep-2003
• - if the environment variable "XSCREENSAVER_WINDOW" is set, use that
• as the root window instead of searching for SWM_VROOT. *
• Jamie Zawinski <jwz@…>, 14-Aug-2004
• - changes to get gcc to stop whining about "type punning". *
• Jamie Zawinski <jwz@…>, 16-Dec-2004
• - fixed that last fix. */

#ifndef _VROOT_H_
#define _VROOT_H_
#define _XSCREENSAVER_VROOT_H_

#if !defined(lint) && !defined(SABER)
static const char vroot_rcsid[] =

"#Id: vroot.h,v 1.8 2004/12/16 05:33:54 jwz Exp #" "\n"
"#Id: vroot.h,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke #";

#endif

#include <X11/X.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>

static Window
#ifdef STDC /* ANSIfication added by jwz, to avoid superfluous warnings. */
VirtualRootWindowOfScreen(Screen *screen)
#else /* __STDC */
VirtualRootWindowOfScreen(screen) Screen *screen;
#endif /* __STDC */
{

static Screen *save_screen = (Screen *)0;
static Window root = (Window)0;

if (screen != save_screen) {

Display *dpy = DisplayOfScreen(screen);
Atom SWM_VROOT = None;
int i;
Window rootReturn, parentReturn, *children;
unsigned int numChildren;

/* first check for a hex or decimal window ID in the environment */
const char *xss_id = getenv("XSCREENSAVER_WINDOW");
if (xss_id && *xss_id) {

unsigned long id = 0;
char c;

if (1 == sscanf (xss_id, " 0x%lx %c", &id, &c)

1 == sscanf (xss_id, " %lu %c", &id, &c)) {

root = (Window) id;
save_screen = screen;
return root;

}

}

root = RootWindowOfScreen(screen);

/* go look for a virtual root */
SWM_VROOT = XInternAtom(dpy, "SWM_VROOT", False);
if (XQueryTree(dpy, root, &rootReturn, &parentReturn,

&children, &numChildren)) {

for (i = 0; i < numChildren; i++) {

Atom actual_type;
int actual_format;
unsigned long nitems, bytesafter;
unsigned char *newRoot = 0;

if (XGetWindowProperty(dpy, children[i],

SWM_VROOT, 0, 1, False, XA_WINDOW,
&actual_type, &actual_format,
&nitems, &bytesafter,
&newRoot) == Success

&& newRoot) {
root = *((Window *) newRoot);
break;

}

}
if (children)

XFree((char *)children);

}

save_screen = screen;

}

return root;

}

#undef RootWindowOfScreen
#define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s)

#undef RootWindow
#define RootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen))

#undef DefaultRootWindow
#define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))

#endif /* _VROOT_H_ */