dispmanx_vnc

VNC Server for Raspberry PI using dispmanx

Build with "make"

Building requires that the following is installed: libvncserver-dev, libconfig++-dev and g++ 4.7 or newer.

Features

• Practically no CPU usage when a VNC client is not connected. No need to stop when not in use.
• Runs well as a service
• Stable even when changing resolution
• Password support
• Configurable port number
• Configurable target frame rate, with automatic frame rate reduction down to 2/second when no updates are detected.
• Adaptable algorithm for the best performance both for update intensive applications like video and animations, and low CPU usage for updates to smaller regions of the screen
• Supports efficient downscaling to a quarter of the resoltion on the server side. Saves CPU, bandwidth and is practical for remote control of e.g. Kodi in high resolution from a computer with lower resolution

On raspbian wheezy, prepare using the following steps

sudo apt-get install g++-4.8 libvncserver-dev libconfig++-dev

Followed by

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.6 
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 40 --slave /usr/bin/g++ g++ /usr/bin/g++-4.8 

And finally select the version you want to use with the following command

sudo update-alternatives --config gcc

...or simply build with

make CXX=g++-4.8

On raspbian jessie, prepare using the following

sudo apt-get install g++ libvncserver-dev libconfig++-dev

On OSMC, prepare using the following

sudo apt-get install build-essential rbp-userland-dev-osmc libvncserver-dev libconfig++-dev

If the keyboard or mouse does not work

Make sure the appropriate driver is loaded by issuing

sudo modprobe evdev

Make this load automatically at boot by adding the following on a separate row in /etc/modules

evdev

After build

Run the program by issuing

sudo ./dispmanx_vncserver

Parameters Usage: ./dispmanx_vncserver [OPTION]...

-a, --absolute               absolute mouse movements
-c, --config-file=FILE       use the specified configuration file
-d, --downscale              downscales the screen to a quarter in vnc
-f, --fullscreen             always runs fullscreen mode
-l, --localhost              only listens to local ports
-m, --multi-threaded         runs vnc in a separate thread
-p, --port=PORT              makes vnc available on the speficied port
-P, --password=PASSWORD      protects the session with PASSWORD
-r, --relative               relative mouse movements
-s, --screen=SCREEN          opens the specified screen number
-t, --frame-rate=RATE        sets the target frame rate, default is 15
-u, --unsafe                 disables more robust handling of resolution
                             change at a small performance gain
-v, --vnc-params             parameters to send to libvncserver
    --help                   displays this help and exit

Config file

The program supports reading all the settings from a configuration file. See the attached .conf.sample-file. The default name of the config file is the same as of the binary with the extension ".conf". The program will first look in the same folder as the binary is placed, if not found there it will try /etc/. The configuration file name and location may be specified with the --config-file command line parameter. Any command line arguments will override those of the config file.

Screen resolution / Headless operation

By default, when HDMI not connected, the composite port is active with a resolution of 720x480. Edit the /boot/config.txt file to change resolution.

sudo nano /boot/config.txt

Add or replace the following settings to enable 1080p 50Hz suitable for a TV set

# This enables HDMI resolutions when HDMI is not connected
hdmi_force_hotplug=1

# Group
# 1=CEA, used for connecting to consumer TV sets
# 2=DMT, used for connecting to a computer monitor
hdmi_group=1

# CEA Modes
#  4 =  720p     60Hz
# 19 =  720p     50Hz
# 16 = 1080p     60Hz
# 31 = 1080p     50Hz
# DMT Modes
# 39 = 1360x768    60Hz
# 82 = 1920x1080   60Hz
hdmi_mode=31

The modes specified here are just a few useful examples, please refer to the documentation of config.txt at raspberrypi.org for further information https://www.raspberrypi.org/documentation/configuration/config-txt.md

If you occasionally connect to a monitor with HDMI, it is an advantage to specify hdmi_group and hdmi_mode that matches the monitor.

A reboot is required after changing this file for the changes to take effect.

Other

Relative mode makes hello_triangle2 to work. And also mouse moving in minecraft is better. Still the mouse is tricky.