Sending custom messages via DataChannel. Help me please.

Unity Engine
,
1

Hello everyone ,
I am connecting with Unity render streaming. I am creating a channel for sending data. The channel status appears as open and inputReceiver.Channel.Send(bytes); I send the message data with the command or I think it is sent. From the other side dataChannel.OnMessage += OnMessage; I am waiting for the message content to arrive with the connected event, but no message is received. I need help creating a channel and sending messages, please help me.

using UnityEngine;
using Unity.WebRTC;
using TMPro;
using Unity.RenderStreaming;
using System.Collections;

public class DataChannelTest : MonoBehaviour
{
    #region Veriables
    [SerializeField] private TextMeshProUGUI receivedMessage;
    [SerializeField] private SignalingManager renderStreaming;
    [SerializeField] private InputSender inputSender;
    [SerializeField] private InputReceiver inputReceiver;

    private RTCDataChannel dataChannel;
    #endregion
    public void OnStart()
    {
        dataChannel = renderStreaming.CreateDataChannel();
        SetupDataChannelEvents();
    }
    private void SetupDataChannelEvents()
    {
        if (dataChannel != null)
            dataChannel.OnMessage += OnMessage;

        inputSender.SetChannel(renderStreaming.connectionId, dataChannel);
        inputReceiver.SetChannel(renderStreaming.connectionId, dataChannel);
    }
    public void SendData()
    {
        if (dataChannel != null && dataChannel.ReadyState == RTCDataChannelState.Open)
        {
            string message = "Hello world.";
            byte[] bytes = System.Text.Encoding.UTF8.GetBytes(message);
            inputReceiver.Channel.Send(bytes);
        }
        else
            Debug.Log("Data channel is not open.");

    }
    private void OnMessage(byte[] bytes)
    {
        string message = System.Text.Encoding.UTF8.GetString(bytes);
        receivedMessage.text = message;
        Debug.Log("Received message: " + message);
    }

    void OnDestroy()
    {
        if (dataChannel != null)
            dataChannel.Close();

    }
}
2

This code looks strange.
One channel is referenced by the sender and the receiver. You should set two channels to the sender and the receiver separately.
In Addition, you don’t need to use the InputSender and InputReceiver to send custom messages. You can use RTCDataChannel class directly.
https://docs.unity3d.com/Packages/com.unity.webrtc@3.0/manual/datachannel.html

3

I tried it with RTCDataChannel but my datachannel.isOpen never receives a callback ? Any idea why this might be happening?

4

I think the reason is that the negotiation process between peers is not completed.

5

I am getting the stream as usual on the web so i guess the negotiation process is completed, can you tell me how do i get access to RTCPeerConnection obect to setup a custom data channel ? I am currently using multiplay sample of render streaming ?

6

Unity Render Streaming doesn’t support creating Custom Data Channel, therefore you need to make the component using WebRTC package by yourself.