Need help with Janus and Datachannels with a raspi

General
1

Hi all!
I’ve recently configured a Janus Gateway server and successfully connected a raspi to the video room using UV4l.

What I’m trying to do:
I’m trying to implement datachannels so I can send information to the raspi by connecting to Janus with another computer via browser.

What is configured:
The raspi has a python script that should detect messages sent via /tmp/uv4l.socket
I’m able to see the script work when it connects to the Janus Gateway room but I can’t receive any further data.

Using examples from the room plugin I created a function to try and send data via datachannels directly in the video room

function sendData() {
let data = “test”;

let message = {
textroom: “message”,
transaction: Janus.randomString(12),
room: myroom,
ptype: “publisher”,
text: data,
ack: true,
};
console.log(“Sent”);

sfutest.data({
text: JSON.stringify(message),
error: function(reason) { bootbox.alert(reason); },
success: function() { $(‘#datasend’).val(‘’); }
});
}

The problem:
Listening to /tmp/uv4l.socket in the raspi doesn’t return any data (aside from the first connection to Janus) regardless of what videoroom/textroom I connect and use the senddata function using another computer.
The raspi can only be connected with a publisher option as when I try to connect with publisher and subscriber I get an invalid ptype error in UV4L.

Any help appreciated:
I’m not sure if it’s the function that is wrong, or it’s because I need the raspi to connect in both publisher and subscriber mode, so any insights or help will be appreciated.

Thanks in advance!

2

Uv4l is not our project, you may want to contact their support for help on that.

4

But Janus Gateway is and I’m not sure if it’s part of the problem.
Regarding Janus:

  • Do you need to be connected as a publisher AND subscriber to be able to receive data via datachannels?
  • Does the senddata function seem correct? I’m using sfutest.data as it’s declared in the videoconference plugin attachment.
5

In the VideoRoom, datachannels are monodirectional: publisher can only send data, subscribers can only receive data. TextRoom datachannels are bidirectional, so use those if you can’t open more than one.

6

Thanks for the clarification, I really appreciate it!

Do you have any suggestions of other software aside uv4l that could be used to connect to Janus from a raspberry pi to send video and receive data on datachannels?