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Format Property

Summary

Gets the direct reference to the format buffer.

Syntax

C++/CLI

public object Format { get; }

public: 
property Object^ Format { 
   Object^ get(); 
}

Property Value

An object representing the format buffer.

Remarks

This property allows direct access to the format buffer for in-process servers. However, if the interface is marshaled across process boundaries, then the client will only be accessing a copy of the data. In such a case, the client should call SetFormatData to alter the contents of the format buffer. The array cannot be resized. To resize the format buffer, set the FormatSize property and then access the MediaType.Format property again.

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["Logitech"] == null) 
         throw new Exception("No Logitech video device available"); 
 
      capturectrl.VideoDevices["Logitech"].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); 
   Marshal.Copy(ms.Buffer, 0, bmpData.Scan0, GetBitmapSize(bmp, vih.bmiHeader.biBitCount)); 
   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:\LEADTOOLS22\Media"; 
}

Requirements

Target Platforms

Reference

MediaType Class

MediaType Members

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Help Version 22.0.2022.12.7

Leadtools.Multimedia Assembly

Introduction

Getting Started

Namespaces

Leadtools.Multimedia Namespace

Leadtools.Multimedia.Common Namespace

Assemblies