开发环境：
操作系统：Win10 x64专业版2004
开发工具：VS2019 16.7.2
目标平台：x86
首先去下载IPC SDK（点击下载，需要华为授权账户。）
新建一个WPF的项目，Framework版本为4.7
把下载的sdk压缩包中的windows\output32目录中的HWPuSDK.dll和lib目录中的所有文件，都复制到项目的bin/debug目录中（和生成的exe同级），华为的这个SDK对64位支持不好，使用64位遇到不少问题，最终还是先采用32位的DLL。
项目中对图像的手动处理，经过对比，在Emgu CV和OpenCVSharp4中采用了OpenCVSharp4，个人感觉OpenCVSharp4使用起来更简洁方便。
项目中对视频流的回调手动处理展示，采用WriteableBitmap（参考吕毅大神的《WPF 高性能位图渲染 WriteableBitmap 及其高性能用法示例》），本来想采用D3D这种显卡加速的方法，无奈没有找到相关文章和资料，如果哪位大神有资料，还望告知一下。谢谢！
项目中引用了以下组件
在本次开发中，我们先实现自动预览摄像头视频和手动对摄像头视频流进行处理。
因为SDK自动播放需要传入一个控件的句柄，而WPF中窗体上所有控件的句柄都是窗体本身，所以我们还需要使用WindowsFromHost来使用Winform的一些控件来实现播放句柄的传入。
项目中引用WindowsFromsIntegeration
在项目的MainWindow.xaml中添加三个按钮、两个RadioButton、一个Winform的PictureBox和一个WPF的Image控件。大致布局如下：
详细的xaml代码：
<Window x:Class="HuaWeiCamera.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:wf="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms" mc:Ignorable="d" WindowStartupLocation="CenterScreen" Loaded="MainWindow_OnLoaded" Title="MainWindow" Height="800" Width="1200" Closed="MainWindow_OnClosed"> <Grid Margin="0,0,2,0"> <Grid.RowDefinitions> <RowDefinition Height="60"></RowDefinition> <RowDefinition Height="*"></RowDefinition> </Grid.RowDefinitions> <WrapPanel VerticalAlignment="Center"> <StackPanel Margin="30,5,0,0" VerticalAlignment="Center"> <Button Content="预览摄像头" HorizontalAlignment="Center" VerticalAlignment="Center" Width="75" Height="30" Click="ButtonView_OnClick" /> <WrapPanel Margin="0,5,0,0"> <RadioButton Content="自动处理" VerticalAlignment="Center" IsChecked="True" GroupName="PlayMode" x:Name="RadioButtonAuto" /> <RadioButton Content="手动处理" VerticalAlignment="Center" GroupName="PlayMode" x:Name="RadioButtonManual" Margin="10,0,0,0" /> </WrapPanel> </StackPanel> <Button x:Name="ButtonSaveOne" Content="抓拍一张" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="30,0,0,0" Width="75" Height="30" IsEnabled="False" Click="ButtonSave_OnClick" />
<Button Content="人脸抓拍" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="30,0,0,0" Width="75" Height="30" /> </WrapPanel> <WrapPanel Grid.Row="1"> <WindowsFormsHost HorizontalAlignment="Center" Width="1200" Height="700" VerticalAlignment="Center" x:Name="FormsHostVideo"> <wf:PictureBox x:Name="ImagePlay"></wf:PictureBox> </WindowsFormsHost> <Image VerticalAlignment="Center" HorizontalAlignment="Center" x:Name="CanvaVideo" Stretch="Fill" Source="{Binding Path=VideoWriteableBitmap}" /> </WrapPanel> </Grid> </Window>
在App.cs中定义下日志记录类
public partial class App : Application { public static NLog.Logger NewNLog; private void App_OnStartup(object sender, StartupEventArgs e) { DispatcherUnhandledException += App_DispatcherUnhandledException; NewNLog = NLog.LogManager.GetLogger("HuaWeiCameraLoger"); } }
根据华为的《SDC 8.0.1 SDK开发指南》，我们要实现摄像头预览，需要先定义以下几个struct和enum：
sturct：PU_REAL_PLAY_INFO_S（视频实时预览结构体）、PU_TIME_S（时间结构体）
enum：PU_PROTOCOL_TYPE（传输协议类型）、PU_STREAM_TYPE（码流类型）、PU_VIDEO_TYPE（数据流类型）、PU_MEDIA_CRYPTO_TYPE（加密类型）、PU_MEDIA_CALLBACK_TYPE（回调类型）
using System; using System.Runtime.InteropServices; using HuaWeiCamera.Enums; using HuaWeiCamera.Enums.Media; using HuaWeiCamera.Enums.Video; namespace HuaWeiCamera.Struct { /// <summary> /// 视频实时预览结构体,http://www.cnblogs.com/wdw984 /// </summary> [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)] public struct PU_REAL_PLAY_INFO_S { /// <summary> /// 设备通道号，一般为101。 /// </summary> public uint ulChannelId; /// <summary> /// 播放窗口句柄,为IntPtr.Zero表示用户自己处理视频数据流，不自动播放视频流 /// </summary> public IntPtr hPlayWnd; /// <summary> /// 码流类型,主码流、子码 /// </summary> public PU_STREAM_TYPE enStreamType; /// <summary> /// 流类型：视频流、音频流、复合流、录 像流、元数据 /// </summary> public PU_VIDEO_TYPE enVideoType; /// <summary> /// 传输协议类型，UDP,TCP /// </summary> public PU_PROTOCOL_TYPE enProtocolType; /// <summary> /// 回调类型：0:RTP解密1:RTP不解密 2:Frame 3:YUV /// </summary> public PU_MEDIA_CALLBACK_TYPE enMediaCallbackType; /// <summary> /// 请求端IP，第三方平台可以不填，SDK会 自动获取 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 16)] public string szLocalIp; /// <summary> /// 是否保活 /// </summary> public bool bKeepLive; /// <summary> /// 请求预录、录像开始时间（本地时 间）。 /// </summary> public PU_TIME_S stStartTime; /// <summary> /// 请求预录、录像结束时间（本地时 间）。 /// </summary> public PU_TIME_S stEndTime; /// <summary> /// 加密类型，只支持AES加密。 /// </summary> public PU_MEDIA_CRYPTO_TYPE enMediaCryptoType; /// <summary> /// 加密密钥 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 44)] public string szMediaCrypto; /// <summary> /// szReserved[0-15]表示组播IP地址 /// szReserved[16-19]表示组播端口 /// szReserved[22]表示智能分析数据打包 格式 0:XML,1:元数据 /// szReserved[23]表示元数据请求类型，取值参考枚举 PU_METADATA_REQUEST_TYPE_E定义 /// </summary> [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)] public byte[] szReserved; } }
namespace HuaWeiCamera.Enums { /// <summary> /// 视频流类型,http://www.cnblogs.com/wdw984 /// </summary> public enum PU_STREAM_TYPE { /// <summary> /// 视频主码流 /// </summary> PU_VIDEO_MAIN_STREAM=0, /// <summary> /// 视频子码流 /// </summary> PU_VIDEO_SUB_STREAM1, /// <summary> /// 视频子码流2（VWareC01 不支持） /// </summary> PU_VIDEO_SUB_STREAM2, /// <summary> /// 视频子码流3（VWareC01 不支持） /// </summary> PU_VIDEO_SUB_STREAM3, /// <summary> /// 视频子码流4 /// </summary> PU_VIDEO_SUB_STREAM4, /// <summary> /// 视频子码流5 /// </summary> PU_VIDEO_SUB_STREAM5, /// <summary> /// 预留值 /// </summary> PU_VIDEO_STREAM_MAX } }
namespace HuaWeiCamera.Enums.Video { /// <summary> /// 码流类型,http://www.cnblogs.com/wdw984 /// </summary> public enum PU_VIDEO_TYPE { /// <summary> /// 视频流 /// </summary> PU_VIDEO_TYPE_VIDEO = 0, /// <summary> /// 音频流 /// </summary> PU_VIDEO_TYPE_AUDIO, /// <summary> /// 复合流 /// </summary> PU_VIDEO_TYPE_MUX, /// <summary> /// 录像流 /// </summary> PU_VIDEO_TYPE_RECORD, /// <summary> /// 元数据流 /// </summary> PU_VIDEO_TYPE_META, /// <summary> /// 视频+元数据流 /// </summary> PU_VIDEO_TYPE_VIDEO_META, /// <summary> /// 预留值 /// </summary> PU_VIDEO_TYPE_MAX } }
namespace HuaWeiCamera.Enums { /// <summary> /// 数据传输类型,http://www.cnblogs.com/wdw984 /// </summary> public enum PU_PROTOCOL_TYPE { /// <summary> /// UDP /// </summary> PU_PROTOCOL_TYPE_UDP = 0, /// <summary> /// TCP /// </summary> PU_PROTOCOL_TYPE_TCP, /// <summary> /// 组播方式 /// </summary> PU_PROTOCOL_TYPE_MULTICAST, /// <summary> /// 预留值 /// </summary> PU_PROTOCOL_TYPE_MAX } }
namespace HuaWeiCamera.Enums.Media { /// <summary> /// 媒体回调类型,http://www.cnblogs.com/wdw984 /// </summary> public enum PU_MEDIA_CALLBACK_TYPE { /// <summary> /// RTP包方式 /// </summary> PU_MEDIA_CALLBACK_TYPE_RTP = 0, /// <summary> /// RTP包形式，不解密 /// </summary> PU_MEDIA_CALLBACK_TYPE_RTP_CRYPTO, /// <summary> /// 帧回调方式 /// </summary> PU_MEDIA_CALLBACK_TYPE_FRAME, /// <summary> /// YUV方式，Linux不支持 /// </summary> PU_MEDIA_CALLBACK_TYPE_YUV, /// <summary> /// 把RTP包回调给控件方处理方式，Linux不支持 /// </summary> PU_MEDIA_CALLBACK_TYPE_FOR_STORAGE, /// <summary> /// 智能元数据方式 /// </summary> PU_MEDIA_CALLBACK_TYPE_META_FRAME, /// <summary> /// 预留值 /// </summary> PU_MEDIA_CALLBACK_TYPE_MAX } }
using System.Runtime.InteropServices; namespace HuaWeiCamera.Struct { /// <summary> /// 时间结构体，http://www.cnblogs.com/wdw984 /// </summary> [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)] public struct PU_TIME_S { /// <summary> /// 年 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 5)] public string szYear; /// <summary> /// 月 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 3)] public string szMonth; /// <summary> /// 日 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 3)] public string szDay; /// <summary> /// 时 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 3)] public string szHour; /// <summary> /// 分 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 3)] public string szMinute; /// <summary> /// 秒 /// </summary> [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 3)] public string szSecond; } }
定义一个静态类，用来实现调用SDK和摄像头交互（HuaWeiSDKHelper）
using System; using System.Runtime.InteropServices; using HuaWeiCamera.Enums; using HuaWeiCamera.Enums.SnapShot; using HuaWeiCamera.Struct; namespace HuaWeiCamera.Class { /// <summary> /// 华为HoloSens SDC二次开发使用，http://www.cnblogs.com/wdw984 /// </summary> public static class HuaWeiSdkHelper { private const string SdkPath= "HWPuSDK.dll"; #region 初始化和登录 /// <summary> /// 初始化设备 /// </summary> /// <param name="ulLinkMode">0自动 1手动 3混合模式</param> /// <param name="szLocalIp">本地IP</param> /// <param name="ulLocalPort">本地端口</param> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_Init", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] public static extern bool IVS_Pu_Init(uint ulLinkMode, string szLocalIp, uint ulLocalPort); /// <summary> /// 远程登录设备 /// </summary> /// <param name="szLoginIp">设备IP</param> /// <param name="ulLoginPort">设备端口 6060</param> /// <param name="szUserName">登录名 ApiAdmin</param> /// <param name="szPasswd">登录密码 HuaWei123</param> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_Login", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] public static extern uint IVS_PU_Login(string szLoginIp, uint ulLoginPort, string szUserName, string szPasswd); /// <summary> /// 初始化和登录设备 /// </summary> /// <param name="sdcIp">SDC设备IP</param> /// <param name="sdcPort">SDC设备端口</param> /// <param name="sdcUser">SDC登录用户名</param> /// <param name="sdcPwd">SDC登录密码</param> /// <param name="errMsg">失败时的错误信息</param> /// <param name="ulIdentifyId">登录成功后返回登录句柄</param> public static void InitAndLogin(string sdcIp,uint sdcPort,string sdcUser,string sdcPwd,out uint ulIdentifyId,out string errMsg) { ulIdentifyId = 0; errMsg = ""; //要开启TLS的情况时：初始化调用IVS_PU_InitEx接口，登录调用IVS_PU_Login 接口时端口号设置为6061 if (!IVS_Pu_Init(1, "192.168.2.144", 6060)) { errMsg=($"设备初始化失败，{GetLastErrorInfo()}"); return; } ulIdentifyId = IVS_PU_Login(sdcIp, sdcPort, sdcUser, sdcPwd); if (ulIdentifyId == 0) { errMsg=$"设备登录失败，{GetLastErrorInfo()}"; } } #endregion #region 预览相关 /// <summary> /// 实时预览 /// </summary> /// <param name="ulIdentifyId">登录成功后返回的用户编号</param> /// <param name="pstRealPlayInfo">播放结构体</param> /// <param name="fRealDataCallBack">回调实现播放</param> /// <param name="pUsrData">传入码流数据 回调函数作为参数</param> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_RealPlay")] public static extern uint IVS_PU_RealPlay(uint ulIdentifyID, PU_REAL_PLAY_INFO_S[] pstRealPlayInfo, PfRealDataCallBack fRealDataCallBack, ref IntPtr pUsrData); public delegate void PfRealDataCallBack(IntPtr szBuffer, int lSize, IntPtr pUsrData); /// <summary> /// 停止实时预览 /// </summary> /// <param name="ulIdentifyId">登录成功后返回的用户编号</param> /// <param name="ulRealHandle">实时播放句柄</param> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_StopRealPlay", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] public static extern uint IVS_PU_StopRealPlay(uint ulIdentifyId, uint ulRealHandle); #endregion #region 错误信息相关 /// <summary> /// 获取最后一次错误代码 /// </summary> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_GetLastError", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] private static extern int IVS_PU_GetLastError(); /// <summary> /// 根据错误代码返回错误信息 /// </summary> /// <param name="ulErrorNo">错误编号</param> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_GetErrorMsg", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] private static extern IntPtr IVS_PU_GetErrorMsg(int ulErrorNo); /// <summary> /// 返回最后一次错误码和错误信息 /// </summary> /// <returns></returns> public static string GetLastErrorInfo() { var lastErrorCode = IVS_PU_GetLastError(); var lastErrorMsg = Marshal.PtrToStringAnsi(IVS_PU_GetErrorMsg(lastErrorCode)); return $"错误码：{IVS_PU_GetLastError()}，错误信息：{lastErrorMsg}"; } #endregion #region 退出登录 /// <summary> /// 退出登录 /// </summary> /// <param name="ulIdentifyId">登录成功后返回的句柄编号</param> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_Logout", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] public static extern bool IVS_PU_Logout(uint ulIdentifyId); /// <summary> /// 反注册设备，退出时进行设备释放 /// </summary> /// <returns></returns> [DllImport(SdkPath, EntryPoint = "IVS_PU_Cleanup", CharSet = CharSet.Ansi, SetLastError = true, PreserveSig = true, CallingConvention = CallingConvention.StdCall)] public static extern bool IVS_PU_Cleanup(); #endregion } }
在MainWindow.cs中我们需要定义一些变量：
private uint _ulIdentifyId;//登录摄像头后返回的编号 private uint _ulRealHandleId;//调用预览SDK返回的结果值 private static bool _isSave;//是否保存当前帧为图片 private static bool _isExit;//是否退出
private static HuaWeiSdkHelper.PfRealDataCallBack _fedRealPlayCallbackWithYUV;//手动处理摄像头回调时的委托事件
private const uint ByteLength = 1920 * 1080 * 4;//位图的大小 private static readonly VideoYuvModelView VideoYuvModelView = new VideoYuvModelView();//Image的数据源，用来手动处理视频时候展示图像 private IntPtr _videoPlayHandle = IntPtr.Zero;//自动预览时的控件句柄 [DllImport("kernel32.dll")] private static extern void CopyMemory(IntPtr destination, IntPtr source, uint length);//用来复制内存中的数据
在窗体初始化和加载事件中，我们来初始化一些数据的绑定
public MainWindow() { InitializeComponent(); VideoYuvModelView.VideoWriteableBitmap = new WriteableBitmap(1920, 1800, 96.0, 96.0, PixelFormats.Bgr32, null);//因为摄像头返回的图片大小时1920*1080，所以这里定义的大小要和返回的图片大小一致 } private void MainWindow_OnLoaded(object sender, RoutedEventArgs e) { CanvaVideo.DataContext = VideoYuvModelView;//手动处理时，Image控件数据源 _videoPlayHandle = ImagePlay.Handle;//自动处理时，使用Winform的控件句柄 }
预览摄像头按钮事件，中间根据选中的自动处理和手动处理来分别做出不同的相应
#region 视频预览（自动和手动处理视频流） private void ButtonView_OnClick(object sender, RoutedEventArgs e) { if (0 == _ulIdentifyId) {
//这里通过网络登录到摄像头，具体端口、用户名、密码请参考开发手册 HuaWeiSdkHelper.InitAndLogin("192.168.2.250", 6060, "ApiAdmin", "HuaWei123", out _ulIdentifyId, out string errMsg); if (0 == _ulIdentifyId) { MessageBox.Show(errMsg); return; } } var prpInfos = new PU_REAL_PLAY_INFO_S[1]; var clientInfo = new PU_REAL_PLAY_INFO_S { ulChannelId = 101, hPlayWnd = _videoPlayHandle, enProtocolType = PU_PROTOCOL_TYPE.PU_PROTOCOL_TYPE_TCP, enStreamType = PU_STREAM_TYPE.PU_VIDEO_MAIN_STREAM, enVideoType = PU_VIDEO_TYPE.PU_VIDEO_TYPE_VIDEO, enMediaCryptoType = PU_MEDIA_CRYPTO_TYPE.PU_MEDIA_CRYPTO_NONE, enMediaCallbackType = PU_MEDIA_CALLBACK_TYPE.PU_MEDIA_CALLBACK_TYPE_RTP, szReserved = new byte[32], bKeepLive = true }; IntPtr pUsrData = (IntPtr)_ulIdentifyId; if (RadioButtonManual.IsChecked == true) { //手动处理视频预览 FormsHostVideo.Visibility = Visibility.Collapsed; CanvaVideo.Visibility = Visibility.Visible; clientInfo.hPlayWnd = IntPtr.Zero; clientInfo.enMediaCallbackType = PU_MEDIA_CALLBACK_TYPE.PU_MEDIA_CALLBACK_TYPE_YUV; prpInfos[0] = clientInfo; _fedRealPlayCallbackWithYUV = FedRealPlayCallbackWithYUV; //手动处理回调 _ulRealHandleId = HuaWeiSdkHelper.IVS_PU_RealPlay(_ulIdentifyId, prpInfos, _fedRealPlayCallbackWithYUV, ref pUsrData); if (0 == _ulRealHandleId) { MessageBox.Show(HuaWeiSdkHelper.GetLastErrorInfo()); } ButtonSaveOne.IsEnabled = true;//点击 抓拍一张 按钮，会把_isSave变量设置为true，从而在回调事件中可以保存当前帧为图片 } else {
ButtonSaveOne.IsEnabled = false; CanvaVideo.Visibility = Visibility.Collapsed; FormsHostVideo.Visibility = Visibility.Visible; prpInfos[0] = clientInfo; //传入句柄，自动预览 _ulRealHandleId = HuaWeiSdkHelper.IVS_PU_RealPlay(_ulIdentifyId, prpInfos, null, ref pUsrData); if (0 == _ulRealHandleId) { MessageBox.Show(HuaWeiSdkHelper.GetLastErrorInfo()); } } } #region 手动解析YUV数据并展示在界面上 private static void FedRealPlayCallbackWithYUV(IntPtr szBuffer, int lSize, IntPtr pUsrData) { if (_isExit) return; try { Span<byte> nativeSpan; unsafe { nativeSpan = new Span<byte>(szBuffer.ToPointer(), lSize); } if (nativeSpan.Length > 0) { #region 处理视频流YUV图像 Mat yuvImg = new Mat(1080 * 3 / 2, 1920, MatType.CV_8UC1); Mat rgbImg = new Mat(1080, 1920, MatType.CV_8UC4); Marshal.Copy(nativeSpan.ToArray(), 0, yuvImg.Data, nativeSpan.Length); Cv2.CvtColor(yuvImg, rgbImg, ColorConversionCodes.YUV2RGBA_I420); Application.Current.Dispatcher?.InvokeAsync(() => { VideoYuvModelView.VideoWriteableBitmap.Lock(); unsafe { CopyMemory(VideoYuvModelView.VideoWriteableBitmap.BackBuffer, new IntPtr(rgbImg.DataPointer), ByteLength); } VideoYuvModelView.VideoWriteableBitmap.AddDirtyRect(new Int32Rect(0, 0, 1920, 1080)); VideoYuvModelView.VideoWriteableBitmap.Unlock(); }); if (_isSave) { Cv2.ImWrite(Path.Combine($"{AppDomain.CurrentDomain.BaseDirectory}", "jpg",$"{Guid.NewGuid()}.jpg"), rgbImg); _isSave = false; } #endregion } } catch (Exception e) { App.NewNLog.Error($"解析视频流出错：{e}"); } } #endregion #endregion
在程序关闭的时候进行资源释放。
private void MainWindow_OnClosed(object sender, EventArgs e) { _isExit = true;if (_ulRealHandleId > 0) { HuaWeiSdkHelper.IVS_PU_StopRealPlay(_ulIdentifyId, _ulRealHandleId);//停止预览 } if (_ulIdentifyId > 0) { HuaWeiSdkHelper.IVS_PU_Logout(_ulIdentifyId);//退出登录 } HuaWeiSdkHelper.IVS_PU_Cleanup();//SDK资源释放 }
具体效果如下：
1、自动预览
2、手动处理
但是这里的YUV回调填充到WriteableBitmap遇到个问题，就是无法填满WriteableBitmap（把WriteableBitmap中的数据保存下来也是和预览的效果一样，估计是填充的算法不对），只能填充一部分，这里涉及到本人的知识盲区，暂时没法解决掉。
3、一帧图像保存为本地图片
至此我们使用C#初步实现了华为IPC摄像头的预览和数据流处理（也可以把处理类型换成视频流，然后存本地视频文件，因为默认时h265编码格式，播放时使用PotPlayer播放器来播放），算是入门了。
下一章我们将实现调用SDK来实现人脸自动抓拍效果。