directvnc - a vnc client for the linux framebuffer device
directvnc server:display [options]
DirectVNC is a client implementing the remote framebuffer protocol
(rfb) which is used by VNC servers. If a VNC server is running on a
machine you can connect to it using this client and have the contents
of its display shown on your screen. Keyboard and mouse events are sent
to the server, so you can basically control a VNC server remotely.
There are servers (and other clients) freely available for all
operating systems. To find out more about VNC check out its home on the
web at AT&T labs.
What makes DirectVNC different from other unix vnc clients is that it
uses the linux framebuffer device through the DirectFB library which
enables it to run on anything that has a framebuffer without the need
for a running X server. This includes embedded devices. DirectFB even
uses acceleration features of certain graphics cards. Thus a lot of
configuration can be done by creating the library specific
configuration file /etc/directfbrc or the program-specific
configuration file /etc/directfbrc.directvnc. See directfbrc(5) or find
out all about DirectFB here:
DirectVNC basically provides a very thin VNC client for unix
Hitting <ctrl-q> exits the viewer.
display help output and exit
output version information and exit
password string to be passed to the server for authentication. Use
this with care!
the bits per pixel to be used by the client. Currently only 16 bpp
DirectVNC supports several different compression methods to encode
screen updates; this option specifies a set of them to use in
order of preference. Encodings are specified separated with
spaces, and must thus be enclosed in quotes if more than one is
specified. Available encodings, in default order for a remote
connection, are "copyrect tight hextile zlib corre rre raw". For a
local connection (to the same machine), the default order to try
is "raw copyrect tight hextile zlib corre rre". Raw encoding is
always assumed as a last option if no other encoding can be used
for some reason.
time in ms to wait between polls for screen updates when no events
are to be processed. This reduces cpu and network load. Default is
-s, --shared (default)
Don’t disconnect already connected clients.
Disconnect already connected clients.
Disable local cursor tracking By default, and if the server is
capable of the SoftCursor encoding, mouse movements do not
generate framebuffer updates and the cursor state is kept locally.
This removes mouse pointer lag and lets the connection appear
-c --compresslevel level
Use specified compression level (0..9) for "tight" and "zlib"
encodings (only usable with servers capable of those encodings).
Level 1 uses minimum of CPU time and achieves weak compression
ratios, while level 9 offers best compression but is slow in terms
of CPU time consumption on the server side. Use high levels with
very slow network connections, and low levels when working over
high-speed LANs. It’s not recommended to use compression level 0,
reasonable choices start from the level 1.
-q --quality level
Use the specified image quality level (0..9) for "tight" encoding
(only usable with servers capable of those encodings). Specifying
this option allows "tight" encoder to use lossy JPEG compression.
Quality level 0 denotes bad image quality but very impressive
compression ratios, while level 9 offers very good image quality
at lower compression ratios. Note that "tight" encoder uses JPEG
to encode only those screen areas that look suitable for lossy
compression, so quality level 0 does not always mean unacceptable
Currently only 16 bpp color depth is supported.
Copyright Till Adam 2001
Aug 26, 2001 directvnc(1)