AllocTarget Method

Summary

Pre-allocates the capture target to the specified size.

Syntax
C#
VB
C++
public virtual void AllocTarget( 
   int size 
) 
Public Overridable Sub AllocTarget( _ 
   ByVal size As Integer _ 
)  
public: 
virtual void AllocTarget(  
   int size 
)  

Parameters

size
Value containing the size of the target to be allocated, in megabytes.

Remarks

Pre-allocates the capture target to the specified size. This method is typically used when the target is defined as a file. For best capture results, always capture to a defragmented, pre-allocated capture file that is larger than the size of the capture data. If the method fails, an error is raised. For more information, refer to the Error Codes.

Example
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
string outFile = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_AllocTargetExample.avi"); 
 
public void AllocTargetExample() 
{ 
   // reference the capture control 
   CaptureCtrl capturectrl = _form.CaptureCtrl; 
 
   try 
   { 
      // set the target output file 
      capturectrl.TargetFile = outFile; 
 
      // allocate a file 
      capturectrl.AllocTarget(1000); 
 
      _result = File.Exists(outFile); 
   } 
   catch (COMException) 
   { 
      _result = false; 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media"; 
} 
Imports Leadtools 
Imports Leadtools.Multimedia 
Imports LeadtoolsMultimediaExamples.Fixtures 
 
Public _result As Boolean = False 
Public _form As CaptureCtrlForm = New CaptureCtrlForm() 
 
Public Sub AllocTargetExample() 
   ' reference the capture control 
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl 
 
   ' output file names 
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_AllocTargetExample.avi") 
 
   Try 
      ' set the source video device, select using your device name here 
      If capturectrl.VideoDevices("USB") Is Nothing Then 
         Throw New Exception("No USB video device available") 
      End If 
 
      capturectrl.VideoDevices("USB").Selected = True 
 
      ' set MPEG2 as the video compressor 
      capturectrl.VideoCompressors.Mpeg2.Selected = True 
 
      ' set AC3 as the audio compressor 
      capturectrl.AudioCompressors.AC3.Selected = True 
 
      ' set the target output file 
      capturectrl.TargetFile = outFile 
 
      ' preallocate file to 10 MB 
      capturectrl.AllocTarget(10) 
 
      ' set the result 
      _result = File.Exists(outFile) 
 
   Catch e1 As Exception 
      _result = False 
   End Try 
 
   ' 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. 
   Do While capturectrl.State = CaptureState.Running 
      Application.DoEvents() 
   Loop 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media" 
End Class 

Requirements

Target Platforms

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Leadtools.Multimedia Assembly