c# – 使用新的Unity 5.1传输层API流式传输WebCamTexture

2023年2月22日 260次阅读

正如问题所述,我一直在尝试将WebCamTexture从带有网络摄像头的客户端流式传输到服务器.双方(客户端和服务器)都在Unity中.之后,客户端将部署到
Android,服务器将成为桌面应用程序.

目前我正在使用以下方法获取纹理的像素：

tex.GetPixels32();

并使用自定义序列化程序对它们进行序列化(以优化其大小).我目前有一个未压缩的字节数组,每帧大约3,5MB,可以发送.我知道它很大,但我希望在开始之前将其传输到压缩部分和实时部分.

该过程的最后一部分应该是使用新的Unity NetworkTransport静态类发送它.自从我上次使用套接字以来已经很长时间了,我真的很烂.目前我无法让它工作.

这是我的服务器端代码(为清晰起见省略了序列化代码)：

void Start()
{
    webcamTexture = new WebCamTexture();
    Background.texture = webcamTexture;
    Background.material.mainTexture = webcamTexture;
    webcamTexture.Play();

    if (!_isStarted)
    {
        _isStarted = true;

        NetworkTransport.Init();
        m_Config = new ConnectionConfig();
        m_CommunicationChannel  = m_Config.AddChannel(QosType.ReliableFragmented);
        HostTopology topology = new HostTopology(m_Config, 12);
        m_GenericHostId = NetworkTransport.AddHost(topology, 0);
        byte error;
        m_ConnectionId = NetworkTransport.Connect(m_GenericHostId, ip, port, 0, out error);
    }
}

void Update()
{
    if (!_isStarted)
        return;

    NetworkEventType recData = NetworkTransport.Receive(out recHostId, out connectionId, out channelId, recBuffer, bufferSize, out dataSize, out error);

    switch (recData)
    {
        case NetworkEventType.Nothing:         //1
            break;
        case NetworkEventType.ConnectEvent:    //2
            Debug.Log("Received connection confirmation");
            _readyToSend = true;
            break;
        case NetworkEventType.DataEvent:       //3

            break;
        case NetworkEventType.DisconnectEvent: //4
            //one of the established connection has been disconnected
            Debug.Log(String.Format("Disconnect from host {0} connection {1}", recHostId, connectionId));

            break;
    }

    if (_readyToSend)
    {
        _readyToSend = false; // To send just the first frame

        byte[] colourArray = SerializeObject(MakeSerializable(GetRenderTexturePixels(webcamTexture))); // Serialize the webcam texture

        // Sending total size
        byte[] sizeToSend = BitConverter.GetBytes(colourArray.Length);
        NetworkTransport.Send(m_GenericHostId, m_ConnectionId, m_CommunicationChannel, sizeToSend, sizeToSend.Length, out error);

        byte[] bytes = new byte[bufferLenght];
        int remainingBytes = colourArray.Length;
        int index = 0;
        int i = 1;

        while (remainingBytes >= bufferLenght)
        {
            System.Buffer.BlockCopy(colourArray, index, bytes, 0, bufferLenght);
            NetworkTransport.Send(m_GenericHostId, m_ConnectionId, m_CommunicationChannel, bytes, bytes.Length, out error);
            remainingBytes -= bufferLenght;
            Debug.Log(i++ + "Remaining bytes: " + remainingBytes + " - Error: "+error);
            index += bufferLenght;
        }

        if (remainingBytes > 0) // Send the last fragment below bufferLenght bytes
        {
            System.Buffer.BlockCopy(colourArray, index, bytes, 0, remainingBytes);
            NetworkTransport.Send(m_GenericHostId, m_ConnectionId, m_CommunicationChannel, bytes, remainingBytes, out error);
            Debug.Log("Error: "+error);
        }
    }
}

这是客户方：

void Start()
{
    if (!_isStarted)
    {
        _isStarted = true;

        NetworkTransport.Init();

        m_Config = new ConnectionConfig();

        m_CommunicationChannel  = m_Config.AddChannel(QosType.ReliableFragmented);

        HostTopology topology = new HostTopology(m_Config, 12);

        m_GenericHostId = NetworkTransport.AddHost(topology, port, null);
    }
}

void Update()
{
    if (!_isStarted)
        return;

    int recHostId; 
    int connectionId; 
    int channelId; 
    byte[] recBuffer = new byte[bufferLenght]; 
    int bufferSize = bufferLenght;
    int dataSize;
    byte error;

    NetworkEventType recData = NetworkTransport.Receive(out recHostId, out connectionId, out channelId, recBuffer, bufferSize, out dataSize, out error);

    switch (recData)
    {
        case NetworkEventType.Nothing:         //1
            break;

        case NetworkEventType.ConnectEvent:    //2

                //somebody else connect to me
            Log.text += string.Format("Connect from host {0} connection {1}\n", recHostId, connectionId);
            break;

        case NetworkEventType.DataEvent:       //3

            if (!sizeReceived)
            {
                sizeReceived = true;

                if (dataSize == 2)
                {
                    bytesToReceive = BitConverter.ToInt16(recBuffer, 0);
                }
                else if (dataSize == 4)
                {
                    bytesToReceive = BitConverter.ToInt32(recBuffer, 0);
                }

                Debug.Log("We will receive: "+bytesToReceive);
            }
            else
            {
                Log.text = string.Format("Received event host {0} connection {1} channel {2} message length {3}\n", recHostId, connectionId, channelId, dataSize);

                Log.text += "Received " + bufferSize + " bytes\n";
                bytesToReceive -= bufferSize;
                Log.text += "Remaining " + bytesToReceive + " bytes\n";
            }
            break;

        case NetworkEventType.DisconnectEvent: //4

            break;

    }
}

我知道它会阻止Update函数直到发送,但现在对我来说并不重要,因为我只是试图让一个帧被传输以了解这个新系统如何工作,并从那里开始.目前我在第一个包发送后收到此错误,缓冲区为32768字节：

no free events for long message
UnityEngine.Networking.NetworkTransport:Send(Int32, Int32, Int32, Byte[], Int32, Byte&)
CameraStreamer:Update() (at Assets/Scripts/Client/CameraStreamer.cs:112)

我还尝试使用1024缓冲区,显示消息只需要更长时间(超过100个成功发送包后).

根据this thread,它与发送的消息太快并填满队列有关,但所提出的解决方案都不适用于我.
我很感激任何帮助或方向,因为Unity文档真的很差.

最佳答案 即使使用Unity 5.2补丁,这个特定的测试代码/示例仍然会出现问题.

在Unity 5.3.4f1中运行代码,我能够看到错误4(NetworkError.NoResource)在大约200个数据包之后发生并且之后不久就停止发送.我认为原因是因为它是阻塞发送,因此消息队列永远不会正常刷新.

我重写了代码,以便在延迟2秒后从纹理中抓取网络摄像头图像(因为网络摄像头需要时间进行初始化,否则您会发送空白图像).

然后通过网络摄像头图像发送,每次执行Update的单个数据包现在看起来很好.可能是因为Update有时间运行并且没有被阻止.因此,发送数据包并退出Update函数,将索引和其他变量移出Update.

希望这有助于其他任何人看着这个,花了3天时间才弄明白.

编辑：对于测试,一个更简单的方法是移出阻塞发送(同时位)并将其添加到协同例程中.似乎也是这样工作的.

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