vfeedback(6)                  XScreenSaver manual                 vfeedback(6)

NAME
       vfeedback - Simulates video feedback.

SYNOPSIS
       vfeedback [--display host:display.screen] [--visual visual] [--window]
       [--root] [--window-id number] [--tv-color number] [--tv-tint number]
       [--noise number] [--tv-brightness number] [--tv-contrast number]
       [--fps]

DESCRIPTION
       Simulates video feedback: pointing a video camera at an NTSC
       television.

OPTIONS
       --visual visual
               Specify which visual to use.  Legal values are the name of a
               visual class, or the id number (decimal or hex) of a specific
               visual.

       --window
               Draw on a newly-created window.  This is the default.

       --root  Draw on the root window.

       --window-id number
               Draw on the specified window.

       --tv-color number
               Color Knob.  0 - 1000.   Default: 70.

       --tv-tint number
               Tint Knob.  0 - 100.  Default: 5.

       --noise number
               Analog noise.  0.0 - 0.2.  Default: 0.02.

       --darken number
               Darken the looped image. 0.0 - 1.0.  Default: 0.7.

       --tv-brightness number
               Brightness Knob.  0.0 - 100.0.     Default: 3.0.

       --tv-contrast number
               Contrast Knob. 0 - 1500.  Default: 1000.

       --fps | --no-fps
               Whether to show a frames-per-second display at the bottom of
               the screen.

ENVIRONMENT
       DISPLAY to get the default host and display number.

       XENVIRONMENT
               to get the name of a resource file that overrides the global
               resources stored in the RESOURCE_MANAGER property.

       XSCREENSAVER_WINDOW
               The window ID to use with --root.

SEE ALSO
       X(1), xscreensaver(1)

COPYRIGHT
       Copyright (C) 2018 by Jamie Zawinski.  Permission to use, copy, modify,
       distribute, and sell this software and its documentation for any
       purpose is hereby granted without fee, provided that the above
       copyright notice appear in all copies and that both that copyright
       notice and this permission notice appear in supporting documentation.
       No representations are made about the suitability of this software for
       any purpose.  It is provided "as is" without express or implied
       warranty.

AUTHOR
       Jamie Zawinski.

X Version 11                  6.08 (10-Oct-2023)                  vfeedback(6)