How can I connect via peerjs without a browser? - javascript

My question is about whether I can connect to peerjs without a browser.
So if or how I can create a WebRtc video and data peer to peer connection between a device that send
and a device that can see the video through the browser.
So far I have a well working WebRtc connection from one browser to the other.
I have a website using NodeJS, a peerjs server as well as a stun and turn server running and I connect using the peerjs api
using the javascript code that is executed in the browser.
However, I would like to connect on one side without a browser, for example to make it more efficient on a Raspberry pi.
I found this example which provides a python port for peerjs, but it is very hard to understand and poorly documented.
https://github.com/ambianic/peerjs-python
I was able to connect to my peerjs server with this. Now I can't get any further.
I would appreciate any suggestions to solve this problem or any other ideas or examples to establish a connection using peerjs without a browser. Maybe with c++ or Nodejs.

You can use a native WebRTC library like libdatachannel. The examples show how to connect browsers to native clients, and you might adapt them to be compatible with the PeerJS signaling protocol. It features a C and C++ API but there is also a Node.js wrapper.

Related

How can I have a server stream a video with WebRTC?

My current use case is that I'm trying to mock a system that uses WebRTC for live video streaming (for a robot). This way, I don't have to be connected to the robot to develop the client.
My issue as of now is that I have no idea how to stream a video using WebRTC to connected peers. I've seen many examples of how to do this from client to client using a signaling server, but other than directly sending the video buffer using socket.io, I haven't seen an example of server -> client WebRTC streaming.
I'm planning to use Node.JS for mocking the video stream as I've been using it for the rest of the robot's systems.
It really isn't that different though client to client or server to client. You want to stream/broadcast a video to all the connected peers. Think of your server will be a client in the setup.
You can also use a WebRTC solution like Janus Repo it is a simple gateway and completely open source. Refer to - WebRTC & Dev API's for more info.
If you find latency issues after peers have increased in number you can check - Mesh, Routing, Multi peer architecture for some solutions for it.
Hope it helps.

WebRTC - help me understand a few concepts

I'm new to WebRTC, actually just heard about it a few days ago and I've read a lot about it. However, I still have a few questions.
What do I need to explore the usage of WebRTC? E.g.: do I need a server, any libraries etc.? I'm aware that new version of Chrome and Firefox support WebRTC, but besides these two browsers, is there anything else that is necessary?
What is the main purpose of WebRTC when addressing practical usage? To video chat? Audio chat? What about text-chatting?
Does WebRTC need a server for any kind of browser-to-browser interaction? I've seen some libraries, such as PeerJS that don't explicitly mention any kind of server... so is it possible to connect two clients directly? There's also a PeerServer, which supposedly helps broker connections between PeerJS clients. Can I use WebRTC without such a server?
What are the most commonly used libraries for WebRTC?
What's a good starting point for someone who's totally new in WebRTC? I'd like to setup a basic google-talk kind of service, to chat with one person.
Thank you so much guys.
You can find many docs here E.g. this one, this one and this one!
You can find a few libraries here.
A simple multi-user WebRTC app needs following things:
Signalling server to exchange sdp/ice/etc. ---- e.g. socket.io/websockets/xmpp/sip/XHR/etc.
ICE server i.e. STUN and/or TURN; to make sure Firewalls doesn't block UDP/TCP ports
JavaScript app to access/invoke RTCWeb JavaScript API i.e. RTCPeerConnection.
It just takes a few minutes to setup WebRTC peer-to-peer connection. You can setup peer-to-server connections as well where media-servers can be used to transcode/record/merge streams; or to relay to PSTN networks.
WebRTC DataChannels can be used for gaming, webpage synchronizing; fetching static contents, peer-to-peer or peer-to-server data transmission, etc.
What do I need to explore the usage of WebRTC? E.g.: do I need a
server, any libraries etc.? I'm aware that new version of Chrome and
Firefox support WebRTC, but besides these two browsers, is there
anything else that is necessary?
WebRTC it is JavaScript API for web developers which can be used for audio and video streaming.
But there are 2 notices:
You need a signaling path.
For example, if your first user is Alice using Firefox and second user is Bob using Chrome,
they should negotiate used codecs and streams.
WebRTC does not offer the signalling implementation. So you need to implement the signaling yourself. It is quite simple. You need to send SDP(stream config) to participant and receive an SDP answer. You can use plain HTTP via apahe server or use Websockets or any other transport to negotiate SDP.
So, it seems you need an intermediary signaling server workning with websockets or HTTP/HTTPS.
Once you negotiated the streams you are sending your audio or video stream, but the distanation user might have a simmetric NAT. It means that you stream will not be delivered to the target user. In such situation you need a TURN server to traverse the NAT.
Finally you will need 2 server-side logic items:
1) Signaling server
2) TURN or proxy server
To start, take a look Web Call Server.
The server implements HTML5 Websocket signaling and SRTP proxying as a TURN server.
You can also learn the webrtc application open source code.
First steps:
1. Download the signaling and streaming server.
2. Download and unzip web client.
3. Start the web client and debug javascript code to learn more how webrtc works.

WebRTC Data Channel server to clients UDP communication

Is it possible to use WebRTC Data Channels on Node.js in a way that mimics the functionality (and preferably API) of Socket.io (WebSockets) except using UDP?
In essence I want to have a server running Node.js with which browser clients can establish a full duplex bi directional UDP connection via JavaScript.
There is a WebRTC module for node.js: https://js-platform.github.io/node-webrtc/
The installation can be really cumbersome (to say the least) but if you succeed you'll be able to make your node.js server act as a WebRTC peer just as browsers do. This way you'd be able to open a Data Channel between a browser and your node.js server.
We have this in use in our research project to evaluate performance characteristics.
Yes, in theory you should be able to to do this. However, you'll need a node module that supports WebRTC data channels, so that you can connect to it like any other peer. Unfortunately, scanning through the current modules, I don't see one that implements the data channel.
The other thing to note is the WebRTC data channels can be configured for different reliability modes with the reliable mode being implemented with SCTP (Firefox and Chrome).
When testing the data channels I would recommend using Firefox since the WebRTC work was split such that Chrome initially focused on PeerConnection and Firefox on DataChannel (so Firefox is still ahead in their implementation of the DataChannel).

Socket reading and writing from a web browser app

There is a server I need to talk to that publishes a protocol over TCP/IP for querying data from a database and listening on a socket to receive notifications when data is updated. The sever guys provide a Java API which uses this TCP protocol. This means I could easily write a Swing App to talk to this server.
I would like a browser based solution. As the protocol is known to me, could I do this in JavaScript? My app will have to display the data in a table. I have heard of Web Sockets but I'm not sure if it will allow this two way communication. Is it feasible? Is there a better way that is cross platform and will work in most browsers? Should I be considering a Java Swing based solution that runs inside a browser?
EDIT: What about changing the code in my C++ server to add an additional interface that my Javascript code can communicate directly with it?
The WebSocket protocol differs from TCP/IP sockets. You will have to write something to link them together.
You can do this perfectly well in JavaScript: use Node.js. There's enough tutorials to be found on the subject. The best way to link it to your in-browser JS is through Socket.IO.
Create a Node.js server that connects to the api
Make the server talk to your web app
Use it :)
This will work cross-platform and cross-browser (Socket.IO can use/emulate websockets even on IE6(!!)). You'll have to run a server-app (the Node.js app) though.
My personal opinion is that if you want a web/browser based solution, you should use native technology, and not Java.
Hope this helps :)

Is there a Telnet library for JavaScript?

We have a network camera. It has an HTTP server to provides the current image. There is also a Telnet interface for controlling the camera (i.e. trigger, focus, etc.). I would like to add an HTML page to the camera that would provide a simple interface (we already have client software we write). I can "GET" the image and display that, but I would also like to have controls that use the Telnet interface to control the camera. So a button might have JavaScript code behind it that connects to the camera via Telnet (logs in) and issues the command to trigger the camera.
I know that JavaScript/browsers support connecting to the same host via XMLHttpRequest. In this case I would be looking to open a socket on port 23 and send text. I also know that I can do this through Flash, Java, or some other technology, but I would prefer to use JavaScript only. If that is possible.
Thomaschaaf is correct, while HTML5 introduces websockets you'll find they still require special server support as they post HTTP style information upon opening the socket:
JS/HTML5 WebSocket: Connect without HTTP call
The best way, currently, to have true sockets is to either
use a flash or Java component on the webpage that does the actual socket work.
use a proxy server with websockets that can handle the additional protocol overhead of websockets and connect to the real tcp/ip port with plain sockets.
The jsterm example Matt linked does the latter, and if your webcans are behind a firewall it will not work in your situation without also implementing another server.
There are libraries that implement the first method, two are linked here for convenience, many others can be found using a search engine:
http://stephengware.com/proj/javasocketbridge/ (Java)
http://matthaynes.net/blog/2008/07/17/socketbridge-flash-javascript-socket-bridge/ (Flash)
jsTerm is an HTML5 implementation of a Telnet client.
You'll need a browser that supports HTML5 WebSockets. WebSockets is the only method of doing non-HTTP requests with pure JavaScript.
Currently there is no way to do socket connections with JavaScript only.
But what you are searching for is a socket connection ;)
https://developer.mozilla.org/en/XML_Extras
If I interpret the question liberally as "is there a remote connectivity library for Javascript", then the answer is yes (quoting from https://xtermjs.org/):
A web based SSH2 client using xterm.js, socket.io, and ssh2: https://github.com/billchurch/WebSSH2
HTML5 Based SSHv2 Web Client with E2E encryption utilising xterm.js, SJCL & websockets: https://github.com/stuicey/SSHy
I've tried WebSSH2 with node.js briefly, it worked for me - I managed to connect to a Linux-based server with it.
(I know this probably doesn't help the OP but this is a 7-year old question anyway. Maybe it helps others who are needing an answer to a similar problem.)

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