c-data-channels

c-data-channels

c-data-channels is a Pion WebRTC application that shows how you can send/recv DataChannel messages from a web browser that's mostly identical to the pure Go implementation, https://github.com/pion/webrtc/tree/master/examples/data-channels. The main difference is that the OnDataChannel is fully implemented in C.

Instructions

Clone c-data-channels

git clone https://github.com/pion/example-webrtc-applications.git

Go into the c-data-channels example directory

cd example-webrtc-applications/c-data-channels

Build it

make

Open data-channels example page

jsfiddle.net

Run data-channels, with your browsers SessionDescription as stdin

In the jsfiddle the top textarea is your browser's session description, copy that and:

Linux/macOS

Run echo $BROWSER_SDP | c-data-channels

Windows

1. Paste the SessionDescription into a file.
2. Run c-data-channels < my_file

Input data-channels's SessionDescription into your browser

Copy the text that c-data-channels just emitted and copy into second text area

Hit 'Start Session' in jsfiddle

Under Start Session you should see 'Checking' as it starts connecting. If everything worked you should see New DataChannel foo 1

Now you can put whatever you want in the Message textarea, and when you hit Send Message it should appear in your browser!

You can also type in your terminal, and when you hit enter it will appear in your web browser.

Congrats, you have used Pion WebRTC! Now start building something cool

Organization

bridge.go

This file contains all of the bridging between Go and C. This is the only file that contains cgo stuff.

webrtc.go

This file is pure Go. It is mostly identical to the original data-channel example.

Reference

• https://github.com/golang/go/issues/20639
• https://github.com/golang/go/issues/25832
• https://github.com/pion/webrtc/tree/master/examples/data-channels/jsfiddle - jsfiddle source codes