VNC-RFB-CLIENT

Pure node.js implementation of RFC 6143 (RFB Protocol / VNC) client with no external dependencies. Supports Raw, CopyRect, Hextile and ZRLE encodings.
Report Bug or Request Feature

User Contributions

ayunami2000

• qemu audio (PCM)
• qemu relative pointer
• documentation for these WIP

Getting Started

Requirements

Node.js >= 10

Installation

1. Install NPM packages

   npm install vnc-rfb-client

Usage

const VncClient = require('vnc-rfb-client');

const initOptions = {
    debug: false, // Set debug logging
    encodings: [ // Encodings sent to server, in order of preference
        VncClient.consts.encodings.copyRect,
        VncClient.consts.encodings.zrle,
        VncClient.consts.encodings.hextile,
        VncClient.consts.encodings.raw,
        VncClient.consts.encodings.pseudoDesktopSize,
    ]
};
const client = new VncClient(initOptions);

const connectionOptions = {
    host: '', // VNC Server
    password: '', // Password
    set8BitColor: false, // If set to true, client will request 8 bit color, only supported with Raw encoding
    port: 5900 // Remote server port
}
client.connect(connectionOptions);

// Client successfully connected
client.on('connected', () => {
    console.log('Client connected.');
});

// Connection timed out
client.on('connectTimeout', () => {
    console.log('Connection timeout.');
});

// Client successfully authenticated
client.on('authenticated', () => {
    console.log('Client authenticated.');
});

// Authentication error
client.on('authError', () => {
    console.log('Client authentication error.');
});

// Bell received from server
client.on('bell', () => {
    console.log('Bell received');
});

// Client disconnected
client.on('disconnect', () => {
    console.log('Client disconnected.');
    process.exit();
});

// Clipboard event on server
client.on('cutText', (text) => {
    console.log('clipboard text received: ' + text);
});

// Frame buffer updated
client.on('firstFrameUpdate', (fb) => {
   console.log('First Framebuffer update received.');
});

// Frame buffer updated
client.on('frameUpdated', (fb) => {
    console.log('Framebuffer updated.');
});

// Color map updated (8 bit color only)
client.on('colorMapUpdated', (colorMap) => {
    console.log('Color map updated. Colors: ' + colorMap.length);
});

// Rect processed
client.on('rectProcessed', (rect) => {
    console.log('rect processed');
});

Examples

Save frame to jpg

const VncClient = require('vnc-rfb-client');
const Jimp = require('jimp');

const client = new VncClient();

// Just 1 update per second
client.changeFps(1);
client.connect({host: '127.0.0.1', port: 5900, password: 'abc123'});

client.on('frameUpdated', (data) => {
   new Jimp({width: client.clientWidth, height: client.clientHeight, data}, (err, image) => {
      if (err) {
         console.log(err);
      }
      const fileName = `${Date.now()}.jpg`;
      console.log(`Saving frame to file. ${fileName}`);
      image.write(`${fileName}`);
   });
});

client.on('connectError', (err) => {
   console.log(err);
});

client.on('authError', () => {
   console.log('Authentication failed.');
});

Record session with FFMPEG

const VncClient = require('vnc-rfb-client');
const spawn = require('child_process').spawn;
const fps = 10;

let timerRef;
const client = new VncClient({fps});
let out;

client.connect({host: '127.0.0.1', port: 5900, password: 'abc123'});

client.on('firstFrameUpdate', () => {
   console.log('Start recording...');
   out = spawn('./ffmpeg.exe',
           `-loglevel error -hide_banner -y -f rawvideo -vcodec rawvideo -an -pix_fmt rgba -s ${client.clientWidth}x${client.clientHeight} -r ${fps} -i - -an -r ${fps} -vcodec libx264rgb session.h264`.split(' '));
   timer();
});

process.on('SIGINT', function () {
   console.log("Exiting.");
   close();
});

function timer() {
   timerRef = setTimeout(() => {
      timer();
      out?.stdin?.write(client.fb);
   }, 1000 / fps);
}

function close() {
   if (timerRef) {
      clearTimeout(timerRef);
   }
   if (out) {
      out.kill('SIGINT');
      out.on('exit', () => {
         process.exit(0);
      });
   }
}

client.on('disconnect', () => {
   console.log('Client disconnected.');
   close();
});

Methods

/**
 * Request a frame update to the server
 */
client.requestFrameUpdate(full, increment, x, y, width, height);

/**
 * Change the rate limit of frame buffer requests
 * If set to 0, a new update request will be sent as soon as the last update finish processing
 */
client.changeFps(10);

/**
 * Start the connection with the server
 */
const connectionOptions = {
    host: '', // VNC Server
    password: '', // Password
    set8BitColor: false, // If set to true, client will request 8 bit color, only supported with Raw encoding
    port: 5900 // Remote server port
}
client.connect(connectionOptions);

/**
 * Send a key board event
 * Check https://wiki.linuxquestions.org/wiki/List_of_keysyms for keycodes
 * down = true for keydown and down = false for keyup
 */
client.sendKeyEvent(keysym, down);

/**
 * Send pointer event (mouse or touch)
 * xPosition - X Position of the pointer
 * yPosition - Y Position of the pointer
 * button1 to button 8 - True for down, false for up
 */
client.sendPointerEvent(xPosition, yPosition, button1, button2, button3, button4, button5, button6, button7, button8);

/**
 * Send clipboard event to server
 * text - Text copied to clipboard
 */
client.clientCutText(text);

client.resetState(); // Reset the state of the client, clear the frame buffer and purge all data

Roadmap

Done

Encodings Supported

Raw
CopyRect
Hextile
ZRLE
PseudoDesktopSize
3.7 and 3.8 protocol implementations

TODO:

Tight Encoding
Pseudo Cursor Encoding
Save session data to file
Replay session from rect data saved to file

License

Distributed under the MIT License. See LICENSE for more information.

Contact

Filipe Calaça - [email protected]

Project Link: https://github.com/filipecbmoc/vnc-rfb-client