[C#, WebRTC] 비디오 채팅 애플리케이션을 구현하기 예제

C# WebRTC는 C# 언어로 작성된 WebRTC 라이브러리입니다. WebRTC는 웹 브라우저와 모바일 앱에서 실시간 오디오, 비디오 및 데이터를 전송하기 위한 오픈 소스 프로젝트입니다. WebRTC는 기본적으로 웹 브라우저에서 작동하도록 설계되었지만, C# WebRTC 라이브러리는 C# 언어를 사용하는 애플리케이션에서도 WebRTC를 사용할 수 있도록 지원합니다.

C# WebRTC를 사용하면 C# 개발자들은 WebRTC의 다양한 기능과 프로토콜을 사용하여 비디오 및 오디오 채팅, 스트리밍, 파일 전송 등의 다양한 실시간 통신 애플리케이션을 구축할 수 있습니다. 또한 C# WebRTC는 편리한 API 및 빌드 도구를 제공하여 개발자들이 쉽게 WebRTC 기반 애플리케이션을 개발하고 배포할 수 있도록 도와줍니다.

 

 

아래는 C# WebRTC를 사용하여 비디오 채팅 애플리케이션을 구현하는 예제입니다. 이 예제는 C#과 .NET Framework 4.5 이상을 사용하는 Windows 용으로 작성되었습니다.

using System;
using System.Threading.Tasks;
using System.Windows.Forms;
using Org.WebRtc;

namespace WebRtcSample
{
    public partial class MainForm : Form
    {
        private PeerConnectionFactory _factory;
        private MediaStream _localStream;
        private VideoTrack _localVideoTrack;
        private VideoTrack _remoteVideoTrack;
        private PeerConnection _peerConnection;
        private RTCConfiguration _config;

        public MainForm()
        {
            InitializeComponent();
            WebRtcLibraries.Init();
            _factory = new PeerConnectionFactory();
            _config = new RTCConfiguration
            {
                IceServers = new[] { new RTCIceServer { Urls = { "stun:stun.l.google.com:19302" } } }
            };
        }

        private async void MainForm_Load(object sender, EventArgs e)
        {
            try
            {
                // Request camera and microphone access
                _localStream = await GetUserMedia(new MediaStreamConstraints
                {
                    AudioEnabled = true,
                    VideoEnabled = true
                });

                // Display local video
                _localVideoTrack = (VideoTrack)_localStream.GetVideoTracks()[0];
                localVideoView.BeginInit();
                localVideoView.MediaStream = _localStream;
                localVideoView.Track = _localVideoTrack;
                localVideoView.EndInit();

                // Create PeerConnection
                _peerConnection = _factory.CreatePeerConnection(_config);
                _peerConnection.OnAddStream = OnAddStream;

                // Add local stream to PeerConnection
                _peerConnection.AddStream(_localStream);

                // Create offer and set as local description
                var offer = await _peerConnection.CreateOffer(null);
                await _peerConnection.SetLocalDescription(offer);

                // Send offer to remote peer (using signaling server)
                var offerJson = _peerConnection.LocalDescription.ToJson();
                SendOfferToRemotePeer(offerJson);
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error: {ex.Message}");
            }
        }

        private async Task<MediaStream> GetUserMedia(MediaStreamConstraints constraints)
        {
            var tcs = new TaskCompletionSource<MediaStream>();
            GetUserMedia(constraints, tcs.SetResult);
            return await tcs.Task;
        }

        private void GetUserMedia(MediaStreamConstraints constraints, Action<MediaStream> callback)
        {
            GetUserMedia(constraints, callback, () => { });
        }

        private void GetUserMedia(MediaStreamConstraints constraints, Action<MediaStream> callback, Action errorCallback)
        {
            GetUserMedia(constraints, stream =>
            {
                callback(stream);
                stream.Dispose();
            }, errorCallback);
        }

        private void GetUserMedia(MediaStreamConstraints constraints, Action<MediaStream> callback, Action<MediaStreamError> errorCallback)
        {
            var mediaConstraints = new MediaConstraints
            {
                AudioEnabled = constraints.AudioEnabled,
                VideoEnabled = constraints.VideoEnabled
            };
            Navigator.GetUserMedia(mediaConstraints, callback, errorCallback);
        }

        private void OnAddStream(MediaStream stream)
        {
            // Display remote video
            _remoteVideoTrack = (VideoTrack)stream.GetVideoTracks()[0];
            remoteVideoView.BeginInit();
            remoteVideoView.MediaStream = stream;
            remoteVideoView.Track = _remoteVideoTrack;
            remoteVideoView.EndInit();
        }

        private void SendOfferToRemotePeer(string offerJson)
        {
           
        // Code to send offer to remote peer using signaling server
        // ...
    }

    private async void ReceiveOfferFromRemotePeer(string offerJson)
    {
        try
        {
            // Parse offer from JSON
            var offer = new RTCSessionDescription(RTCSdpType.Offer, offerJson);

            // Create PeerConnection
            _peerConnection = _factory.CreatePeerConnection(_config);
            _peerConnection.OnAddStream = OnAddStream;

            // Set remote description
            await _peerConnection.SetRemoteDescription(offer);

            // Create answer and set as local description
            var answer = await _peerConnection.CreateAnswer(null);
            await _peerConnection.SetLocalDescription(answer);

            // Send answer to remote peer (using signaling server)
            var answerJson = _peerConnection.LocalDescription.ToJson();
            SendAnswerToRemotePeer(answerJson);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Error: {ex.Message}");
        }
    }

    private void SendAnswerToRemotePeer(string answerJson)
    {
        // Code to send answer to remote peer using signaling server
        // ...
    }

    private async void ReceiveAnswerFromRemotePeer(string answerJson)
    {
        try
        {
            // Parse answer from JSON
            var answer = new RTCSessionDescription(RTCSdpType.Answer, answerJson);

            // Set remote description
            await _peerConnection.SetRemoteDescription(answer);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Error: {ex.Message}");
        }
    }

    private async void MainForm_FormClosing(object sender, FormClosingEventArgs e)
    {
        try
        {
            // Close PeerConnection
            if (_peerConnection != null)
            {
                await _peerConnection.Close();
            }

            // Release resources
            if (_localStream != null)
            {
                _localStream.Dispose();
            }
            if (_localVideoTrack != null)
            {
                _localVideoTrack.Dispose();
            }
            if (_remoteVideoTrack != null)
            {
                _remoteVideoTrack.Dispose();
            }
            if (_factory != null)
            {
                _factory.Dispose();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Error: {ex.Message}");
        }
    }
}

 

이 예제는 WebRTC를 사용하여 비디오 채팅 애플리케이션을 구현하는 방법을 보여줍니다. 애플리케이션은 로컬 비디오 스트림을 표시하고, 로컬 PeerConnection을 만들고, 로컬 스트림을 PeerConnection에 추가하고, 로컬 PeerConnection에서 제공하는 Offer를 사용하여 원격 Peer에게 연결을 제안하고, 원격 Peer의 Answer를 수신하여 로컬 PeerConnection에 적용하는 방식으로 동작합니다. 원격 Peer와 연결하는 데 사용되는 시그널링 서버 코드는 이 예제에서 생략되었습니다.