vncserv

Graphics and Screen4.0 (8.x)Screen Graphics Subsystem Developer's GuideAPIProgrammingUtilities

VNC server for QNX Screen

Syntax:

vncserv      [-auth]
             [-fps]
             [-license]
             [-password= password]
             [-name= host_name]
             [-verbose]
             [-display= display_id]
             [-format= format]

Runs on:

QNX OS

VNC options:

-auth
Uses encrypted passwords stored in /etc/passwd.vncserv for client authentication. Passwords can be generated using the password option.
-fps
Show the frame rate of the VNC server as a small number at the top-right corner of each frame transmitted to the VNC client.
-license
Display software license information then exit without starting the server.
-password= password
Generates encrypted passwords for authentication using the auth option. Passwords are stored in /etc/passwd.vncserv before exiting without starting the server.
-name= host_name
Specify the host name. To find the default server name, use the uname -m command.
-verbose
Do not daemonize the VNC server and make it verbose.

Screen options:

-display= display_id
Capture the display identified by display_id. You can specify display_id by its number.

Make sure you specify a valid display_id. If you don't have any display subsections configured, the virtual display has not been created, or Screen is not running, vncserv will continuously attempt to connect to the display using display_id. If you don't specify the display option, vncserv uses the default display.

-format= format
Set the pixel format for readback from a QNX Screen display. This option determines the number of bytes per pixel the framebuffer sends. It can affect the performance of the server, depending on what conversions are needed for framebuffer transmission. You can choose one of the following supported formats:
  • rgba8888 or rgbx8888
  • bgra8888 or bgrx8888
  • rgba5551 or rgbx5551
  • rgba4444 or rgbx4444
  • rgb565

Where "a" indicates alpha bits and "x" indicates that the alpha bits are ignored.

This format is internal and can be different from that of the display's. If you don't specify this option, vncserv uses rgb565, which is the best choice for the ratio of transmission/memory bandwidth to quality of video transmission. If you specify an unsupported format, vncserv will cycle through the formats to find a supported format.

Description:

The vncserv utility is a VNC server that allows VNC clients to remotely access the target's display through the Screen. It supports forwarding inputs from the client to Screen's input handling. Events from the keyboard and mouse are forwarded to Screen mimicking devices connected directly to the target.

You need to ensure that Screen is running on your system for vncserv to properly stream a display's content.

By default, vncserv runs as a daemon process. This means it runs in the background and is detached from the controlling terminal. When debugging, you can start vncserv in verbose mode using the -verbose option. This will not daemonize the process and will print debugging information to the console.

vncserv has the following features:
  • Robust network support. Including support for multiple clients streaming the same display.
  • Graceful handling of disconnecting and connecting to multiple clients.
  • Implicit internal selection of translation and encoding for transmission.
  • Support for encrypted passwords for authentication.
  • Support for connecting and disconnecting to Screen. vncserv will transmit stub frambuffers when Screen is not running.

Examples:

# vncserv

Start vncserv as a daemon process with no console output. The VNC server will use the system's default display.

# vncserv -verbose -display=2 -format=rgba8888

Run vncserv in verbose mode, which attaches vncserv to the controlling terminal and prints debugging information to the console. The VNC server streams to the display with ID=2 and has a readback format of rgba8888.

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