No keyboard or mouse events are sent from the viewer to theserver. The server screen can only be viewed, but notcontrolled.
The viewer window is automatically scaled to fit the size ofyour local screen.
Use DSM Plugin
Choose a DSM (Data Stream Modification) Plugin and configureit.
To use an encryption plugin, for instance, check this option andselect the plugin in the combo box. The plugin file must be inthe same directory than the vncviewer.exe program. And of course,the same plugin must
be used by the UltraVNC server you connectto.
Specify the repeater address here.
Save connection settings as default
If checked, the current settings are saved as default optionsin a configuration file. So next time you run the viewer, youdon’t have to reselect all your favorite settings.
Further viewer configuration can be done when pressing the Options button.
Format and Encoding
See Encodings section below.
Note: Grey colors only works with 32 bits color screenresolution. 16/24 bits color resolutions just don’t work withgrey colors.
 number of time the reconnect is attempted
0 (default), never reconnect
9 (maximum) 9 time trying reconnect.
gui reconnectnumber only for now.
This is the number of times a reconnect is made before the viewer close the connection.
The server supplies information in whatever format is desiredby the client, in order to make the client as easy as possible toimplement. If the client represents itself as able to usemultiple formats, the server will choose one.
Pixel format refers to the representation of anindividual pixel. The most common formats are 24 and 16 bit”true-color” values, and 8-bit “color map” representations, wherean arbitrary map converts the color number to RGB values.
Encoding refers to how a rectangle of pixels are sent(all pixel information in VNC is sent as rectangles). Allrectangles come with a header giving the location and size of therectangle and an encoding type used by the data which follows.These types are listed below.
The raw encoding simply sends width*height pixel values. Allclients are required to support this encoding type. Raw is alsothe fastest when the server and viewer are on the same machine,as the connection speed is essentially infinite and raw encodingminimizes processing time.
The Copy Rectangle encoding is efficient when something isbeing moved; the only data sent is the location of a rectanglefrom which data should be copied to the current location.Copyrect could also be used to efficiently transmit a repeatedpattern.
The Rise-and-Run-length-Encoding is basically a 2D version ofrun-length encoding (RLE). In this encoding, a sequence ofidentical pixels are compressed to a single value and repeatcount. In VNC, this is implemented with a background color, andthen specifications of an arbitrary number of sub rectangles andcolor for each. This is an efficient encoding for large blocks ofconstant color.
This is a minor variation on RRE, using a maximum of 255x255pixel rectangles. This allows for single-byte values to be used,reducing packet size. This is in general more efficient, becausethe savings from sending 1-byte values generally outweighs thelosses from the (relatively rare) cases where very large regionsare painted the same color.
Here, rectangles are split up in to 16×16 tiles, which aresent in a predetermined order. The data within the tiles is senteither raw or as a variant on RRE. Hextile encoding is usuallythe best choice for using in high-speed network environments(e.g. Ethernet local-area networks).
Zlib is a very simple encoding that uses zlib library tocompress raw pixel data. This encoding achieves good compression,but consumes a lot of CPU time. Support for this encoding isprovided for compatibility with VNC servers that might notunderstand Tight encoding which is more efficient than Zlib innearly all real-life situations.
Like Zlib encoding, Tight encoding uses zlib library tocompress the pixel data, but it pre-processes data to maximizecompression ratios, and to minimize CPU usage on compression.Also, JPEG compression may be used to encode color-rich screenareas (see the description of -quality and -nojpeg optionsabove). Tight encoding is usually the best choice forlow-bandwidth network environments (e.g. slow modemconnections).
Experimental, Ultra encoding provides real time performanceover a LAN by utilizing LZO compression. LZO is a datacompression scheme which is suitable for data de-/compression inreal-time. This means it favors speed over compressionratio.
UltraVNC Viewer Commandline Parameters