unity接入海康威视摄像头，获取人流量，unity需要添加的代码是哪些

接入海康威视摄像头需要使用海康威视提供的SDK，并且需要在Unity中编写C#脚本与SDK进行交互来实现摄像头视频流的获取和处理。以下是一个简单的示例代码，可以获取海康威视摄像头的视频流并进行人流量统计：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Runtime.InteropServices;

public class HikvisionCamera : MonoBehaviour 
{
    // SDK中提供的函数
    [DllImport("HCNetSDK")]
    private static extern bool NET_DVR_Init();
    [DllImport("HCNetSDK")]
    private static extern bool NET_DVR_Login_V30(string sDVRIP, int wDVRPort, string sUserName, string sPassword, ref NET_DVR_DEVICEINFO_V30 lpDeviceInfo);
    [DllImport("HCNetSDK")]
    private static extern bool NET_DVR_RealPlay_V40(int iUserID, ref NET_DVR_PREVIEWINFO lpPreviewInfo, RealDataCallBack_V30 fRealDataCallBack_V30, IntPtr pUser);
    [DllImport("HCNetSDK")]
    private static extern bool NET_DVR_Logout(int iUserID);
    [DllImport("HCNetSDK")]
    private static extern bool NET_DVR_Cleanup();

    // 回调函数
    public delegate void RealDataCallBack_V30(int lRealHandle, uint dwDataType, IntPtr pBuffer, uint dwBufSize, IntPtr pUser);

    // 设备信息结构体
    [StructLayout(LayoutKind.Sequential)]
    public struct NET_DVR_DEVICEINFO_V30
    {
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 48)]
        public string sSerialNumber;
        public byte byAlarmInPortNum;
        public byte byAlarmOutPortNum;
        public byte byDiskNum;
        public byte byDVRType;
        public byte byChanNum;
        public byte byStartChan;
        public byte byAudioChanNum;
        public byte byIPChanNum;
        public byte byZeroChanNum;
        public byte byMainProto;
        public byte bySubProto;
        public byte bySupport;
        public byte bySupport1;
        public byte bySupport2;
        public short wDevType;
        public byte bySupport3;
        public byte byMultiStreamProto;
        public byte byStartDChan;
        public byte byStartDTalkChan;
        public byte byHighDChanNum;
        public byte bySupport4;
        public byte byLanguageType;
        public byte byVoiceInChanNum;
        public byte byStartVoiceInChanNo;
        public byte bySupport5;
        public byte bySupport6;
        public byte byMirrorChanNum;
        public ushort wStartMirrorChanNo;
        public byte bySupport7;
        public byte byRes2;
    }

    // 预览参数结构体
    [StructLayout(LayoutKind.Sequential)]
    public struct NET_DVR_PREVIEWINFO
    {
        public int lChannel;
        public uint dwStreamType;
        public uint dwLinkMode;
        public IntPtr hPlayWnd;
        public uint bBlocked;
        public uint bPassbackRecord;
        public uint byPreviewMode;
        public uint byStreamID;
        public byte[] byReserve;
    }

    private int iUserID = -1; // 登录用户ID
    private int iRealHandle = -1; // 实时预览句柄

    void Start()
    {
        // 初始化SDK
        NET_DVR_Init();

        // 登录设备
        NET_DVR_DEVICEINFO_V30 devInfo = new NET_DVR_DEVICEINFO_V30();
        iUserID = NET_DVR_Login_V30("192.168.1.64", 8000, "admin", "password", ref devInfo);

        // 预览参数设置
        NET_DVR_PREVIEWINFO previewInfo = new NET_DVR_PREVIEWINFO();
        previewInfo.lChannel = 1;
        previewInfo.dwStreamType = 0;
        previewInfo.dwLinkMode = 0;
        previewInfo.hPlayWnd = IntPtr.Zero;
        previewInfo.bBlocked = 1;
        previewInfo.byPreviewMode = 0;

        // 开始实时预览
        RealDataCallBack_V30 callBack = new RealDataCallBack_V30(RealDataCallBack);
        iRealHandle = NET_DVR_RealPlay_V40(iUserID, ref previewInfo, callBack, IntPtr.Zero);
    }

    void OnDestroy()
    {
        // 释放资源
        NET_DVR_Logout(iUserID);
        NET_DVR_Cleanup();
    }

    // 实时数据回调函数
    void RealDataCallBack(int lRealHandle, uint dwDataType, IntPtr pBuffer, uint dwBufSize, IntPtr pUser)
    {
        // 处理视频流数据，进行人流量统计等操作
        // ...
    }
}

需要注意的是，此处只提供了获取视频流的代码示例，具体的人流量统计算法需要自行实现。