C# 如何在rtsp反向通道上发送音频数据?

C# 如何在rtsp反向通道上发送音频数据?,c#,audio,protocols,audio-streaming,rtsp,C#,Audio,Protocols,Audio Streaming,Rtsp,我正在使用支持音频输出(音频反向通道)的IP摄像头。我想做的是通过提供的RTSP URL实时传输我的PC麦克风音频数据,以便在PC麦克风上所说的话在摄像头扬声器端都能听到。我读过关于onvif流媒体规范的内容,该规范告诉我,一旦我获得了摄像头媒体的RTSP url,我就必须通过提供的RTSP url发送音频数据,以便在摄像头端进行音频输出。此外,我的相机还支持Onvif profile T 到目前为止,我所尝试的是- public static RtspClient rtspClient;

我正在使用支持音频输出(音频反向通道)的IP摄像头。我想做的是通过提供的RTSP URL实时传输我的PC麦克风音频数据,以便在PC麦克风上所说的话在摄像头扬声器端都能听到。我读过关于onvif流媒体规范的内容,该规范告诉我,一旦我获得了摄像头媒体的RTSP url,我就必须通过提供的RTSP url发送音频数据,以便在摄像头端进行音频输出。此外,我的相机还支持Onvif profile T

到目前为止,我所尝试的是-

  public static RtspClient rtspClient;
  public static IWaveIn sourceStream;

  private static void CallAudio()
    {
        string CameraIp = "192.168.1.69";
        string UserName = "admin";
        string Password = "admin123";
        var ClientMessageInspector = new ClientMessageInspector(UserName, Password);

        //Call Device Url and get Services.
        string DeviceServiceUrl = "http://" + CameraIp + "/onvif/device_service";
        var deviceClient = new DeviceClient("DeviceBinding", new EndpointAddress(DeviceServiceUrl));
        deviceClient.Endpoint.Behaviors.Add(ClientMessageInspector);
        var getServices = deviceClient.GetServices(false);                   
        
        //Call media2 getStreamingUri.
        string url = "http://" + CameraIp + "/onvif/media2_service";
        var Media2Client = new Media2Client("Media2Binding", new EndpointAddress(url));
        Media2Client.Endpoint.Behaviors.Add(ClientMessageInspector);
        var media2GetProfiles = Media2Client.GetProfiles(null, null);            
        var resp = Media2Client.GetAudioDecoderConfigurationOptions(null, null);
        var responseGetAudioStreamUri = Media2Client.GetStreamUri("tcp", profiles[0].token);  //This gets rtsp url of media from camera.

        rtspClient = new RtspClient(responseGetAudioStreamUri, UserName, Password);            
        sourceStream = new WaveInEvent();
        sourceStream.WaveFormat = new WaveFormat(64, 8, 1);   //8000 16
        sourceStream.DataAvailable += new EventHandler<WaveInEventArgs>(SourceStream_DataAvailable);
        sourceStream.StartRecording();

        Console.ReadKey();
    }

    //This method gets data from PC microphone and enocodes it into Mu-Law G711 and send to rtsp url.
    private static void SourceStream_DataAvailable(object sender, WaveInEventArgs e)
    {
        byte[] encoded = TwoWayAudio_Encode_MuLaw(e.Buffer, 0, e.BytesRecorded);
        rtspClient.SendData(encoded, encoded.Length, 3);
    }

    private static byte[] TwoWayAudio_Encode_MuLaw(byte[] data, int offset, int length)
    {
        byte[] encoded = new byte[length / 2];
        int outIndex = 0;
        for (int n = 0; n < length; n += 2)
        {
            encoded[outIndex++] = MuLawEncoder.LinearToMuLawSample(BitConverter.ToInt16(data, offset + n));
        }
        return encoded;
    }
从Play方法得到响应后,我开始使用Rtsp客户端中的send方法发送编码数据

但我认为在摄像机端听不到音频。我的问题很简单-

  • 是否可以通过RTSP URL发送音频数据
  • 我调用方法的方式有什么问题吗?这是错误的?请你指出
  • 是否有一个简单的方法(或示例/教程)来演示如何完成我的任务,请提供给
  • 请不要介意我是Rtsp的新手。提前谢谢。如果问题有任何问题,请告诉我,我将对其进行编辑以明确理解



    您可以共享您的相机规格的链接,以检查它是否支持双向媒体流。检查wireshark pcap以查看音频数据是否传输到相机。@mail2subhajit我使用的相机支持双向音频。作为RTSP一部分协商的SDP为“a=sendonly”音频和视频流只有一种方式。你能让它工作吗?
    using Rtsp;
    using Rtsp.Messages;
    using Rtsp.Sdp;
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.IO;
    using System.Security.Cryptography;
    using System.Text;
    using System.Text.RegularExpressions;
    
    namespace Rtsp
    {
       public class RtspClient
       {
        private RtspListener rtsp_client;
        private RtspTcpTransport tcp_socket;
        public string url;
        public bool canPlay = false;
        public string username;
        public string password;
        public ushort seqNo = 0;
        public event EventHandler<string> RtspError;
        public event EventHandler<byte[]> RtpDataReceived;
        public Stopwatch stopwatch { get; private set; }
    
        public RtspClient(string _url, string _username, string _password)
        {
            url = _url;
            username = _username;
            password = _password;
    
            var uri = new Uri(_url);
    
            tcp_socket = new RtspTcpTransport(uri.Host, 554); // 554);
    
            if (tcp_socket.Connected == false)
            {
                Console.WriteLine("Error - did not connect");
                return;
            }
    
            // Connect a RTSP Listener to the TCP Socket to send messages and listen for replies
            rtsp_client = new RtspListener(tcp_socket);
    
            rtsp_client.MessageReceived += Rtsp_client_MessageReceived;
            rtsp_client.DataReceived += DataReceived;
            rtsp_client.Start(); // start reading messages from the server
            rtsp_client.AutoReconnect = true;
            RtspRequest describe_message = new RtspRequestDescribe();
            describe_message.RtspUri = uri;            
            describe_message.AddHeader("Accept: application/sdp");
            describe_message.AddHeader("Require: www.onvif.org/ver20/backchannel");
            rtsp_client.SendMessage(describe_message);            
    
            stopwatch = new Stopwatch();
            stopwatch.Start();
        }
    
        private void DataReceived(object sender, RtspChunkEventArgs e)
        {
            int rtp_version = (e.Message.Data[0] >> 6);
            int rtp_padding = (e.Message.Data[0] >> 5) & 0x01;
            int rtp_extension = (e.Message.Data[0] >> 4) & 0x01;
            int rtp_csrc_count = (e.Message.Data[0] >> 0) & 0x0F;
            int rtp_marker = (e.Message.Data[1] >> 7) & 0x01;
            int rtp_payload_type = (e.Message.Data[1] >> 0) & 0x7F;
            uint rtp_sequence_number = ((uint)e.Message.Data[2] << 8) + (uint)(e.Message.Data[3]);
            uint rtp_timestamp = ((uint)e.Message.Data[4] << 24) + (uint)(e.Message.Data[5] << 16) + (uint)(e.Message.Data[6] << 8) + (uint)(e.Message.Data[7]);
            uint rtp_ssrc = ((uint)e.Message.Data[8] << 24) + (uint)(e.Message.Data[9] << 16) + (uint)(e.Message.Data[10] << 8) + (uint)(e.Message.Data[11]);
    
            int rtp_payload_start = 4 // V,P,M,SEQ
                                + 4 // time stamp
                                + 4 // ssrc
                                + (4 * rtp_csrc_count); // zero or more csrcs
    
            uint rtp_extension_id = 0;
            uint rtp_extension_size = 0;
            if (rtp_extension == 1)
            {
                rtp_extension_id = ((uint)e.Message.Data[rtp_payload_start + 0] << 8) + (uint)(e.Message.Data[rtp_payload_start + 1] << 0);
                rtp_extension_size = ((uint)e.Message.Data[rtp_payload_start + 2] << 8) + (uint)(e.Message.Data[rtp_payload_start + 3] << 0);
                rtp_payload_start += 4 + (int)rtp_extension_size;  // extension header and extension payload
            }
    
            Console.WriteLine("RTP Data"
                               + " V=" + rtp_version
                               + " P=" + rtp_padding
                               + " X=" + rtp_extension
                               + " CC=" + rtp_csrc_count
                               + " M=" + rtp_marker
                               + " PT=" + rtp_payload_type
                               + " Seq=" + rtp_sequence_number
                               + " Time=" + rtp_timestamp
                               + " SSRC=" + rtp_ssrc
                               + " Size=" + e.Message.Data.Length);
    
    
            // If rtp_marker is '1' then this is the final transmission for this packet.
            // If rtp_marker is '0' we need to accumulate data with the same timestamp
    
            // ToDo - Check Timestamp matches
    
            // Add to the tempoary_rtp List
            if (rtp_payload_type == 98 || rtp_payload_type == 0)
            {
                byte[] rtp_payload = new byte[e.Message.Data.Length - rtp_payload_start]; // payload with RTP header removed
                System.Array.Copy(e.Message.Data, rtp_payload_start, rtp_payload, 0, rtp_payload.Length); // copy payload
                RtpDataReceived?.Invoke(null, rtp_payload);
            }
        }
    
        public bool SendData(byte[] data, int count, int channel)
        {
            byte[] rtp_packet = new byte[12 + data.Length];
            int rtp_version = 2;
            int rtp_padding = 0;
            int rtp_extension = 0;
            int rtp_csrc_count = 0;
            int rtp_marker = 1; // set to 1 if the last NAL in the array
            //int rtp_payload_type = 98;
            int rtp_payload_type = 0;
    
            RTPPacketUtil.WriteHeader(rtp_packet, rtp_version, rtp_padding, rtp_extension, rtp_csrc_count, rtp_marker, rtp_payload_type);
    
            RTPPacketUtil.WriteSequenceNumber(rtp_packet, seqNo);
            seqNo++;
            RTPPacketUtil.WriteTS(rtp_packet, (uint)stopwatch.ElapsedMilliseconds);
    
            UInt32 empty_ssrc = 1293847657;
            RTPPacketUtil.WriteSSRC(rtp_packet, empty_ssrc);
    
            // Now append the raw NAL
            System.Array.Copy(data, 0, rtp_packet, 12, data.Length);
    
            if (canPlay)
            {
                rtsp_client.SendData(channel, rtp_packet);
                return true;
            }
            else return false;
        }
    
        private void Rtsp_client_MessageReceived(object sender, RtspChunkEventArgs e)
        {
            RtspResponse message = e.Message as RtspResponse;
            if (message.ReturnCode == 500)
            {
                RtspError?.Invoke(this, "Internal Server Error");
            }
            if (message.ReturnCode == 401)
            {
                Rtsp.Messages.RtspRequest msg = null;
                switch (message.OriginalRequest.Method)
                {
                    case "DESCRIBE":
                        msg = new RtspRequestDescribe();
                        break;
                    case "SETUP":
                        msg = new RtspRequestSetup();
                        break;
                    default:
                        break;
                }
                msg.RtspUri = new Uri(url);
                var header = message.Headers["WWW-Authenticate"];
                var _realm = GrabHeaderVar("realm", header);
                var _nonce = GrabHeaderVar("nonce", header);
                var ha1 = CalculateMd5Hash(string.Format("{0}:{1}:{2}", username, _realm, password));
                var ha2 = CalculateMd5Hash(string.Format("{0}:{1}", message.OriginalRequest.Method, url));
                var digestResponse = CalculateMd5Hash(string.Format("{0}:{1}:{2}", ha1, _nonce, ha2));
    
                var digest = string.Format("Digest username=\"{0}\", realm=\"{1}\", nonce=\"{2}\", uri=\"{3}\", response=\"{4}\" ",
                    username, _realm, _nonce, url, digestResponse);
                msg.AddHeader("Authorization: " + digest);
                msg.AddHeader("Accept: application/sdp");
                rtsp_client.SendMessage(msg);
                return;
            }
            Console.WriteLine("Received " + message.OriginalRequest.ToString());
    
            if (message.OriginalRequest != null && message.OriginalRequest is RtspRequestDescribe)
            {
                // Got a reply for DESCRIBE
                // Examine the SDP
                Console.Write(Encoding.UTF8.GetString(message.Data));
    
                SdpFile sdp_data;
                using (StreamReader sdp_stream = new StreamReader(new MemoryStream(message.Data)))
                {
                    sdp_data = SdpFile.Read(sdp_stream);
                }
    
                // Process each 'Media' Attribute in the SDP.
                // If the attribute is for Video, then send a SETUP
                for (int x = 0; x < sdp_data.Medias.Count; x++)
                {
                    if (sdp_data.Medias[x].MediaType == Rtsp.Sdp.Media.MediaTypes.audio || sdp_data.Medias[x].MediaType == Rtsp.Sdp.Media.MediaTypes.video)
                    {
                        // seach the atributes for control, fmtp and rtpmap
                        String control = "";  // the "track" or "stream id"
                        String fmtp = ""; // holds SPS and PPS
                        String rtpmap = ""; // holds the Payload format, 96 is often used with H264
                        foreach (Rtsp.Sdp.Attribut attrib in sdp_data.Medias[x].Attributs)
                        {
                            if (attrib.Key.Equals("control")) control = attrib.Value;
                            if (attrib.Key.Equals("fmtp")) fmtp = attrib.Value;
                            if (attrib.Key.Equals("rtpmap")) rtpmap = attrib.Value;
                        }
    
                        // Get the Payload format number for the Video Stream
                        String[] split_rtpmap = rtpmap.Split(' ');
                        var video_payload = 0;
                        bool result = Int32.TryParse(split_rtpmap[0], out video_payload);
                                          
                        // Send SETUP for the Video Stream
                        // using Interleaved mode (RTP frames over the RTSP socket)
                        Rtsp.Messages.RtspRequest setup_message = new Rtsp.Messages.RtspRequestSetup();
                        setup_message.RtspUri = new Uri(url + "/" + control);                        
                        //setup_message.AddHeader("Transport: RTP/AVP/TCP;interleaved=0");                       
                        setup_message.AddHeader("Require: www.onvif.org/ver20/backchannel");                                              
                        rtsp_client.SendMessage(setup_message);                                            
                    }
                }
            }
    
            if (message.OriginalRequest != null && message.OriginalRequest is RtspRequestSetup)
            {
                // Got Reply to SETUP
                Console.WriteLine("Got reply from Setup. Session is " + message.Session);
    
                String session = message.Session; // Session value used with Play, Pause, Teardown
    
                // Send PLAY
                RtspRequest play_message = new RtspRequestPlay();
                play_message.RtspUri = new Uri(url);               
                play_message.Session = session;
                play_message.AddHeader("Require: www.onvif.org/ver20/backchannel");
                rtsp_client.SendMessage(play_message);
            }
    
            if (message.OriginalRequest != null && message.OriginalRequest is RtspRequestPlay)
            {
                // Got Reply to PLAY
                Console.WriteLine("Got reply from Play  " + message.Command);
                canPlay = true;
    
            }
        }
    
        private static string GrabHeaderVar(string varName, string header)
        {
            var regHeader = new Regex(string.Format(@"{0}=""([^""]*)""", varName));
            var matchHeader = regHeader.Match(header);
            if (matchHeader.Success)
                return matchHeader.Groups[1].Value;
            throw new ApplicationException(string.Format("Header {0} not found", varName));
        }
    
        private static string CalculateMd5Hash(string input)
        {
            var inputBytes = Encoding.ASCII.GetBytes(input);
            var hash = MD5.Create().ComputeHash(inputBytes);
            var sb = new StringBuilder();
            foreach (var b in hash)
                sb.Append(b.ToString("x2"));
            return sb.ToString();
        }
    
        public void Dispose()
        {
            rtsp_client.Stop();
            rtsp_client.Dispose();
        }
    }
    
    Received Rtsp.Messages.RtspRequestDescribe
    v=0
    o=- 0 0 IN IP4 192.168.1.69
    s=LIVE VIEW
    c=IN IP4 0.0.0.0
    t=0 0
    a=control:rtsp://192.168.1.69/rtsp_tunnel?p=0&h26x=4&aon=1&aud=0
    m=video 0 RTP/AVP 35
    a=rtpmap:35 H264/90000
    a=control:rtsp://192.168.1.69/rtsp_tunnel?p=0&h26x=4&aon=1&aud=0&stream=video
    a=recvonly
    a=fmtp:35 packetization-mode=1;profile-level-id=4d0029;sprop-parameter- 
    sets=Z00AKZpkA8ARPy4C1BQEFAg=,aO48gA==
    m=audio 0 RTP/AVP 96
    a=rtpmap:96 mpeg4-generic/16000/1
    a=fmtp:96 streamtype=5; profile-level-id=5; mode=AAC-hbr; config=1408; SizeLength=13; IndexLength=3; 
    IndexDeltaLength=3
    a=control:rtsp://192.168.1.69/rtsp_tunnel?p=0&h26x=4&aon=1&aud=0&stream=audio
    a=recvonly
    m=audio 0 RTP/AVP 0
    a=rtpmap:0 PCMU/8000/1
    a=control:rtsp://192.168.1.69/rtsp_tunnel?p=0&h26x=4&aon=1&aud=0&stream=backchannel
    a=sendonly
    Received Rtsp.Messages.RtspRequestSetup
    Got reply from Setup. Session is 12346e9856840dc
    Received Rtsp.Messages.RtspRequestSetup
    Got reply from Setup. Session is 12346e9856840dc
    Received Rtsp.Messages.RtspRequestSetup
    Got reply from Setup. Session is 12346e9856840dc
    Received Rtsp.Messages.RtspRequestPlay
    Got reply from Play  RTSP/1.0 200 OK
    Received Rtsp.Messages.RtspRequestPlay
    Got reply from Play  RTSP/1.0 200 OK
    Received Rtsp.Messages.RtspRequestPlay
    Got reply from Play  RTSP/1.0 200 OK