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AllocTarget Method

Summary

Pre-allocates the capture target to the specified size.

Syntax

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

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:\LEADTOOLS21\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:\LEADTOOLS21\Media" 
End Class

Requirements

Target Platforms

Reference

CaptureCtrl Class

CaptureCtrl Members

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Help Version 21.0.2021.7.2

Leadtools.Multimedia Assembly

Introduction

Getting Started

Namespaces

Leadtools.Multimedia Namespace

Leadtools.Multimedia.Common Namespace

Assemblies