简述
使用海康摄像头采集图像时，需要在图像上添加图标、文字等额外数据。可选择使用海康SDK绘图回调函数叠加字符、图像等（请参考上一篇文章）；也可使用海康SDK的解码回调函数，对视频流数据进行解码后处理。该方法流程为：调用视频预览函数NET_DVR_RealPlay_V40()时将第三个参数设置为实时数据回调函数RealDataCallBack()的函数指针，然后在RealDataCallBack()回调函数中注册视频流数据解码函数DecCallbackFUN()，最后在DecCallbackFUN()函数中对数据解析解码、叠加字符等处理。
本文只调用解码回调函数将YV12格式视频流数据转换为RGB32格式数据，然后将RGB32格式数据转换为Image，并使用PictrueBox显示该Image数据，暂不做叠加字符、图像等处理。
代码
1、摄像头操作代码
struct CameraInfo
{
public string strIP;
public short nPort;
public string strUserName;
public string strPassword;
}
class IDeviceCamera
{
public Image m_img = null;
public virtual bool InitCamera( CameraInfo stInfo )
{
return true;
}
}
class DeviceCamera : IDeviceCamera
{
private CameraInfo m_stCameraInfo;
private bool m_bInitSDK = false;
private Int32 m_lUserID = -1;
private Int32 m_lRealHandle = -1;
private Int32 m_lPort = -1;
CHCNetSDK.REALDATACALLBACK RealData = null; //必须得定义为成员变量
public override bool InitCamera( CameraInfo stInfo )
{
m_stCameraInfo = stInfo;
m_bInitSDK = CHCNetSDK.NET_DVR_Init();
if ( !m_bInitSDK )
{
uint nError = CHCNetSDK.NET_DVR_GetLastError();
}
CHCNetSDK.NET_DVR_SetConnectTime( 5000, 1 );
CHCNetSDK.NET_DVR_SetReconnect( 10000, 1 );
if ( m_bInitSDK == false )
{
MessageBox.Show( "NET_DVR_Init error!" );
return false;
}
else
{
//保存SDK日志 To save the SDK log
CHCNetSDK.NET_DVR_SetLogToFile( 3, "C:\\SdkLog\\", true );
}
string DVRIPAddress = stInfo.strIP; //设备IP地址或者域名 Device IP
Int16 DVRPortNumber = stInfo.nPort; //设备服务端口号 Device Port
string DVRUserName = stInfo.strUserName;//设备登录用户名 User name to login
string DVRPassword = stInfo.strPassword;//设备登录密码 Password to login
CHCNetSDK.NET_DVR_DEVICEINFO_V30 DeviceInfo = new CHCNetSDK.NET_DVR_DEVICEINFO_V30();
m_lUserID = CHCNetSDK.NET_DVR_Login_V30( DVRIPAddress, DVRPortNumber, DVRUserName, DVRPassword, ref DeviceInfo );
if ( m_lUserID < 0 )
{
MessageBox.Show( "登录失败！" );
CHCNetSDK.NET_DVR_Cleanup();
return false;
}
//
CHCNetSDK.NET_DVR_PREVIEWINFO lpPreviewInfo = new CHCNetSDK.NET_DVR_PREVIEWINFO();
lpPreviewInfo.hPlayWnd = (IntPtr)null;
lpPreviewInfo.lChannel = 1;
lpPreviewInfo.dwStreamType = 0; //码流类型：0-主码流，1-子码流，2-码流3，3-码流4，以此类推
lpPreviewInfo.dwLinkMode = 0; //连接方式：0- TCP方式，1- UDP方式，2- 多播方式，3- RTP方式，4-RTP/RTSP，5-RSTP/HTTP
lpPreviewInfo.bBlocked = true; //0- 非阻塞取流，1- 阻塞取流
lpPreviewInfo.dwDisplayBufNum = 15; //播放库播放缓冲区最大缓冲帧数
//使用回调函数取摄像头数据
RealData = new CHCNetSDK.REALDATACALLBACK( RealDataCallBack );//预览实时流回调函数
IntPtr pUser = new IntPtr();//用户数据
m_lRealHandle = CHCNetSDK.NET_DVR_RealPlay_V40( m_lUserID, ref lpPreviewInfo, RealData, pUser );
CHCNetSDK.NET_DVR_RigisterDrawFun( m_lRealHandle, new CHCNetSDK.DRAWFUN( cbDrawFun ), 0 );//回调函数：绘制图标
return true;
}
private uint nLastErr = 0;
private static PlayCtrl.DECCBFUN m_fDisplayFun = null;
private IntPtr m_ptrRealHandle;
public void RealDataCallBack( Int32 lRealHandle, UInt32 dwDataType, IntPtr pBuffer, UInt32 dwBufSize, IntPtr pUser )
{
//下面数据处理建议使用委托的方式
switch ( dwDataType )
{
case CHCNetSDK.NET_DVR_SYSHEAD: // sys head
if ( dwBufSize > 0 )
{
if ( m_lPort >= 0 )
return; //同一路码流不需要多次调用开流接口
//获取播放句柄 Get the port to play
if ( !PlayCtrl.PlayM4_GetPort( ref m_lPort ) )
{
nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
break;
}
//设置流播放模式 Set the stream mode: real-time stream mode
if ( !PlayCtrl.PlayM4_SetStreamOpenMode( m_lPort, PlayCtrl.STREAME_REALTIME ) )
{
nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
//str = "Set STREAME_REALTIME mode failed, error code= " + nLastErr;
//this.BeginInvoke( AlarmInfo, str );
}
//打开码流，送入头数据 Open stream
if ( !PlayCtrl.PlayM4_OpenStream( m_lPort, pBuffer, dwBufSize, 2 * 1024 * 1024 ) )
{
nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
//str = "PlayM4_OpenStream failed, error code= " + nLastErr;
//this.BeginInvoke( AlarmInfo, str );
break;
}
//设置显示缓冲区个数 Set the display buffer number
if ( !PlayCtrl.PlayM4_SetDisplayBuf( m_lPort, 15 ) )
{
nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
//str = "PlayM4_SetDisplayBuf failed, error code= " + nLastErr;
//this.BeginInvoke( AlarmInfo, str );
}
//设置显示模式 Set the display mode
//if ( !PlayCtrl.PlayM4_SetOverlayMode( m_lPort, 0, 0) ) //play off screen
//{
// nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
// //str = "PlayM4_SetOverlayMode failed, error code= " + nLastErr;
// //this.BeginInvoke( AlarmInfo, str );
//}
//设置解码回调函数，获取解码后音视频原始数据 Set callback function of decoded data
m_fDisplayFun = new PlayCtrl.DECCBFUN( DecCallbackFUN );
if ( !PlayCtrl.PlayM4_SetDecCallBackEx( m_lPort, m_fDisplayFun, IntPtr.Zero, 0 ) )
{
//this.BeginInvoke( AlarmInfo, "PlayM4_SetDisplayCallBack fail" );
}
//开始解码 Start to play
if ( !PlayCtrl.PlayM4_Play( m_lPort, m_ptrRealHandle ) )
{
nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
//str = "PlayM4_Play failed, error code= " + nLastErr;
//this.BeginInvoke( AlarmInfo, str );
break;
}
}
break;
case CHCNetSDK.NET_DVR_STREAMDATA: // video stream data
default: //the other data
if ( dwBufSize > 0 && m_lPort != -1 )
{
for ( int i = 0; i < 999; i++ )
{
//送入码流数据进行解码 Input the stream data to decode
if ( !PlayCtrl.PlayM4_InputData( m_lPort, pBuffer, dwBufSize ) )
{
nLastErr = PlayCtrl.PlayM4_GetLastError( m_lPort );
//str = "PlayM4_InputData failed, error code= " + nLastErr;
Thread.Sleep( 2 );
}
else
break;
}
}
break;
}
}
//解码回调函数
private void DecCallbackFUN( int nPort, IntPtr pBuf, int nSize, ref PlayCtrl.FRAME_INFO pFrameInfo, int nReserved1, int nReserved2 )
{
if ( pFrameInfo.nType == 3 ) //#define T_YV12 3
{
byte[] byteBuffYV12 = new byte[ nSize ];
Marshal.Copy( pBuf, byteBuffYV12, 0, nSize );
long lRGBSize = (long)pFrameInfo.nWidth * pFrameInfo.nHeight * 4;
byte[] bufferRGB32 = new byte[ lRGBSize ];
CommonFun.YV12_to_RGB32( byteBuffYV12, bufferRGB32, pFrameInfo.nWidth, pFrameInfo.nHeight );
byteBuffYV12 = null;
Bitmap bmpFromGRB32 = CommonFun.RGB32_to_Image( bufferRGB32, pFrameInfo.nWidth, pFrameInfo.nHeight );
bufferRGB32 = null;
if ( null == bmpFromGRB32 )
return;
m_img = bmpFromGRB32;
}
}
}注：得到的m_img用于PictureBox进行显示。
2、YV12转换为RGB32、RGB32转换为Image代码
class CommonFun
{
public static bool YV12_to_RGB32( byte[] buffYV12, byte[] bufferRGB32, int nWidth, int nHeight )
{
if( buffYV12.Length < 0 || bufferRGB32.Length < 0 )
return false;
long nYLen = (long)nWidth * nHeight;
int nHfWidth = ( nWidth >> 1 );
if ( nYLen < 1 || nHfWidth < 1 )
return false;
byte[] byteYData = buffYV12.Skip( 0 ).Take( nWidth*nHeight ).ToArray();
byte[] byteUData = buffYV12.Skip( nWidth*nHeight ).Take( (nHeight/2)*(nWidth/2) ).ToArray();
byte[] byteVData = buffYV12.Skip( nWidth*nHeight + (nHeight/2)*(nWidth/2) ).Take( (nHeight/2)*(nWidth/2) ).ToArray();
if ( byteYData.Length < 0 || byteVData.Length < 0 || byteUData.Length < 0 )
return false;
int[] nRgb = new int[4];
for( int nRow = 0; nRow < nHeight; nRow++ )
{
for( int nCol = 0; nCol < nWidth; nCol++ )
{
int Y = byteYData[nRow*nWidth + nCol];
int U = byteUData[(nRow / 2)*(nWidth / 2) + (nCol / 2)];
int V = byteVData[(nRow / 2)*(nWidth / 2) + (nCol / 2)];
int R = Y + (U - 128) + (((U - 128) * 103) >> 8);
int G = Y - (((V - 128) * 88) >> 8) - (((U - 128) * 183) >> 8);
int B = Y + (V - 128) + (((V - 128) * 198) >> 8);
// r分量值
R = R<0 ? 0 : R;
nRgb[2] = R > 255 ? 255 : R;
// g分量值
G = G<0 ? 0 : G;
nRgb[1] = G > 255 ? 255 : G;
// b分量值
B = B<0 ? 0 : B;
nRgb[0] = B > 255 ? 255 : B;
//A分量值
nRgb[ 3 ] = 255;
//Out RGB Buffer
bufferRGB32[4 * (nRow*nWidth + nCol) + 0] = (byte)nRgb[0];
bufferRGB32[4 * (nRow*nWidth + nCol) + 1] = (byte)nRgb[1];
bufferRGB32[4 * (nRow*nWidth + nCol) + 2] = (byte)nRgb[2];
bufferRGB32[4 * (nRow*nWidth + nCol) + 3] = (byte)nRgb[3];
}
}
return true;
}
public static Bitmap RGB32_to_Image( byte[] byteBuff, int nWidth, int nHeight )
{
if ( byteBuff.Length <= 0 || byteBuff.Length < nWidth*nHeight )
return null;
Bitmap bmp = new Bitmap( nWidth, nHeight, PixelFormat.Format32bppArgb );
//锁定内存数据
BitmapData bmpData = bmp.LockBits( new Rectangle( 0, 0, nWidth, nHeight ), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb );
//输入颜色数据
System.Runtime.InteropServices.Marshal.Copy( byteBuff, 0, bmpData.Scan0, byteBuff.Length );
//解锁
bmp.UnlockBits( bmpData );
return bmp;
}
}效果
