StreamMediator

Project description

Multiple "peer to peer" video-communication based on a modern browsers WebRTC-support. This web application contains a Java-backend and JavaScript-frontend. The server and additional STUN-servers are needed for the initial handshake between the peers of the video-streams only.

• video-/audio-chats
• video-boxes can be resized and dragged around.
• screen- or window-sharing
• language switching (german and english)
• simple text-chat-window
• auto-layout

Example

There is a server demonstrating the StreamMediator at www.ab32.de.

Motivation

I wanted an open-source video-communication solution. When I tried to download a well-known open-source implementation of a video-communication-system in march 2020 I was struck by a lot of different large components. For example jitsi and Nextcloud talk are full-fledged solutions containing a lot of nice features. I was struck by the complexity only.

So I started to write a multi-stream-WebRTC solution from scratch based on one single JavaScript-file on the client side. The initial requirements were:

• Simple WebRTC-session between two peers.
• Buttons for dragging and resizing video-boxes.
• Privacy: The participants of a session are not displayed. Hence you won't see a "room" when entering a session-id already used.
• WebRTC-sessions between multiple peers.

The current script is about 70 kb in size containing about 2150 lines of code (non-minified). The server side consists of about 1250 lines of code (Java).

The clients need to be able to communicate directly, there is no TURN-server, there are two STUN-servers only. Therefore proxies, some firewalls or routers of some providers can be a spoiler.

Building

You may use maven for building the project.

  mvn package

Installation

The StreamMediator expects a web application server containing jetty's websocket-support.

Usage

Assume there are three users A, B and C.

1. A connects to the server, gets the session a12b3c and connects to the server as user A.
2. A tells B and C about the session a12b3c via messenger or phone.
3. B connects to the server, overrides the given session with a12b3c and connects to the server as user B.
4. B calls user A, user A confirms and a video-communication between A and B will be established.
5. C connects to the server, overrides the given session with a12b3c and connects to the server as user C.
6. C calls user A, user A confirms and a video-communication between A and C will be established.
7. C calls user B, user B confirms and a video-communication between B and C will be established.