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TargetObject Property

Summary

Gets or sets the media target object.

Syntax

C++/CLI

public virtual object TargetObject { get; set; }

public: 
virtual property Object^ TargetObject { 
   Object^ get(); 
   void set (    Object^ ); 
}

Property Value

An object representing a COM target interface.

Remarks

This property allows the user to assign a COM object as the media target for the capturing process. The object may be the SampleTarget object or any other DirectShow renderer filter. The TargetType will be set to TargetObjectType.Object. Assignment can raise an error exception. For more information, refer to the Error Codes.

Example

using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
 
public void CaptureFrameExample() 
{ 
   // reference the capture control 
   CaptureCtrl capturectrl = _form.CaptureCtrl; 
 
   // output file 
   string outFile = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_CaptureFrameExample.bmp"); 
 
   try 
   { 
      // set the video capture device, use your capture device name here 
      if (capturectrl.VideoDevices["USB"] == null) 
         throw new Exception("No USB video device available"); 
 
      capturectrl.VideoDevices["USB"].Selected = true; 
 
      // create a new sample target 
      SampleTarget st = new SampleTarget(); 
 
      // set the target media type for the video stream 
      MediaType amt = new MediaType(); 
      amt.Type = Constants.MEDIATYPE_Video; 
      amt.SubType = Constants.MEDIASUBTYPE_RGB24; 
      st.SetAcceptedMediaType(amt); 
 
      // assign the sample target to the capture control 
      capturectrl.TargetObject = st; 
      capturectrl.TargetFormat = TargetFormatType.AVI; 
 
      // prepare the manual frames capture 
      capturectrl.ReadyCapture(CaptureMode.ManualFrames); 
 
      // do something before the capture starts 
      if (capturectrl.IsModeAvailable(CaptureMode.ManualFrames)) 
      { 
      } 
 
      // set the capture mode to manual frames 
      capturectrl.StartCapture(CaptureMode.ManualFrames); 
 
      // capture a frame 
      capturectrl.CaptureFrame(); 
 
      // create a media sample using the captured sample from above  
      MediaSample ms = st.GetSample(-1); 
 
      // get the sample target's connected media type 
      MediaType mt = st.GetConnectedMediaType(); 
 
      Bitmap bmp = WriteSampleBitmap(outFile, ms, mt); 
 
      // stop the capture 
      capturectrl.StopCapture(); 
 
      // check for the capture file and set the result 
      if (File.Exists(outFile)) 
      { 
         Image test = Bitmap.FromFile(outFile); 
         _result = (test.Width == bmp.Width && test.Height == bmp.Height && test.PixelFormat == bmp.PixelFormat); 
      } 
   } 
   catch (COMException) 
   { 
      _result = false; 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
 
   // we'll loop on the state and pump messages for this example. 
   // but you should not need to if running from a Windows Forms application. 
   while (capturectrl.State == CaptureState.Running) 
      Application.DoEvents(); 
} 
 
private Bitmap WriteSampleBitmap(string outFile, MediaSample ms, MediaType mt) 
{ 
   // get the video information  
   VideoInfoHeader vih = mt.GetVideoFormatData(); 
 
   // create a bitmap to hold the sample and copy it 
   Bitmap bmp = new Bitmap(vih.bmiHeader.biWidth, vih.bmiHeader.biHeight, FormatFromBitCount(vih.bmiHeader.biBitCount)); 
   BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadWrite, bmp.PixelFormat); 
   int bitmapSize = GetBitmapSize(bmp, vih.bmiHeader.biBitCount); 
   if(bitmapSize <= ms.BufferSize) 
      Marshal.Copy(ms.Buffer, 0, bmpData.Scan0, bitmapSize); 
   bmp.UnlockBits(bmpData); 
 
   // flip the upside down buffer 
   bmp.RotateFlip(RotateFlipType.Rotate180FlipX); 
 
   // save the image 
   bmp.Save(outFile, ImageFormat.Bmp); 
   return bmp; 
} 
 
private PixelFormat FormatFromBitCount(int bitCount) 
{ 
   switch (bitCount) 
   { 
      case 8: 
         return PixelFormat.Format8bppIndexed; 
      case 16: 
         return PixelFormat.Format16bppRgb555; 
      case 32: 
         return PixelFormat.Format32bppRgb; 
      case 48: 
         return PixelFormat.Format48bppRgb; 
      case 24: 
         return PixelFormat.Format24bppRgb; 
   } 
   throw new Exception("Unrecognized bit count"); 
} 
 
private int GetBitmapSize(Bitmap bmp, int bitCount) 
{ 
   int pixelSize = (int)Math.Log((double)bitCount); 
   return (bmp.Width * pixelSize + pixelSize & ~3) * bmp.Height; 
} 
 
private int GetBitmapScanRowSize(int bmpSize, int stride, int width) 
{ 
   return bmpSize / (stride / width); 
} 
 
public void CaptureFrame_Helper(object sender, EventArgs e) 
{ 
   // set result 
   _result = true; 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\LEADTOOLS23\Media"; 
}

Requirements

Target Platforms

Reference

ConvertCtrl Class

ConvertCtrl Members

ResetTarget Method

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Help Version 23.0.2024.2.29

Leadtools.Multimedia Assembly

Introduction

Getting Started

Namespaces

Leadtools.Multimedia Namespace

Leadtools.Multimedia.Common Namespace

Assemblies