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 © 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.