Preview Property (CaptureCtrl)

C#
Visual Basic
Objective-C
Java
C++

public virtual bool Preview {get; set;}

'Declaration

Public Overridable Property Preview As Boolean

'Usage

Dim instance As CaptureCtrl
Dim value As Boolean
 
instance.Preview = value
 
value = instance.Preview

public:
virtual property bool Preview {
   bool get();
   void set (    bool value);
}

Property Value

true if preview is enabled; false, otherwise.

Assignment can raise an error exception.

For more information, refer to the Error Codes.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

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Imports Leadtools
Imports Leadtools.Multimedia
Imports LeadtoolsMultimediaExamples.Fixtures

Public _result As Boolean = False
Public _form As CaptureCtrlForm = New CaptureCtrlForm()
Public Sub IsModeAvailableExample()
   ' reference the capture control
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

   ' output file for processor settings
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_IsModeAvailableExample.avi")

   Try
      ' try to find a USB camera
      If capturectrl.VideoDevices("USB") Is Nothing Then
         Throw New Exception("No USB video device available")
      End If

      capturectrl.VideoDevices("USB").Selected = True

      ' try to find a USB audio device
      If capturectrl.AudioDevices("USB") Is Nothing Then
         Throw New Exception("No USB audio device available")
      End If

      capturectrl.AudioDevices("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

      ' set the target output format
      capturectrl.TargetFormat = TargetFormatType.AVI

      ' check if we have can capture video
      If capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio) Then
         capturectrl.FrameRate = 5 ' 5 frames per second
         capturectrl.UseFrameRate = True
         capturectrl.TimeLimit = 10 ' just 10 seconds of capture time
         capturectrl.UseTimeLimit = True

         ' check to see if we can preview compressed output
         If capturectrl.IsPreviewTapSupported(CapturePreview.Video, CapturePreviewTap.Compressor) Then
            ' enable preview
            capturectrl.Preview = True

            ' enable preview video
            capturectrl.PreviewSource = CapturePreview.Video

            ' set the preview tap location
            capturectrl.PreviewTap = CapturePreviewTap.Compressor
         End If

         ' subscribe to the complete event
         AddHandler capturectrl.Complete, AddressOf CaptureCtrl_Complete

         ' start the capture process
         capturectrl.StartCapture(CaptureMode.VideoAndAudio)

         ' 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 If
   Catch e1 As Exception
      _result = False
   End Try
End Sub

Private Sub CaptureCtrl_Complete(ByVal sender As Object, ByVal e As EventArgs)
   _result = True
End Sub

Public NotInheritable Class LEAD_VARS
Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 19\Media"
End Class

using Leadtools;
using Leadtools.Multimedia;
using LeadtoolsMultimediaExamples.Fixtures;

public bool _result = false;
public CaptureCtrlForm _form = new CaptureCtrlForm();
public void IsModeAvailableExample()
{
   // reference the capture control
   CaptureCtrl capturectrl = _form.CaptureCtrl;

   // output file for processor settings
   string outFile = Path.Combine(LEAD_VARS.MediaDir,"CaptureCtrl_IsModeAvailableExample.avi");

   try
   {
      // try to find a USB camera
      if (capturectrl.VideoDevices["USB"] == null)
         throw new Exception("No USB video device available");

      capturectrl.VideoDevices["USB"].Selected = true;

      // try to find a USB audio device
      if (capturectrl.AudioDevices["USB"] == null)
         throw new Exception("No USB audio device available");

      capturectrl.AudioDevices["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;

      // set the target output format
      capturectrl.TargetFormat = TargetFormatType.AVI;

      // check whether we can capture video
      if (capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio))
      {
         capturectrl.FrameRate = 5;       // 5 frames per second 
         capturectrl.UseFrameRate = true;
         capturectrl.TimeLimit = 10;      // just 10 seconds of capture time
         capturectrl.UseTimeLimit = true;

         // check to see if we can preview compressed output
         if (capturectrl.IsPreviewTapSupported(CapturePreview.Video, CapturePreviewTap.Compressor))
         {
            // enable preview
            capturectrl.Preview = true;

            // enable preview video
            capturectrl.PreviewSource = CapturePreview.Video;

            // set the preview tap location
            capturectrl.PreviewTap = CapturePreviewTap.Compressor;
         }

         // subscribe to the complete event
         capturectrl.Complete += new EventHandler(CaptureCtrl_Complete);

         // start the capture process
         capturectrl.StartCapture(CaptureMode.VideoAndAudio);

         // 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();
      }
   }
   catch (Exception)
   {
      _result = false;
   }
}

void CaptureCtrl_Complete(object sender, EventArgs e)
{
   _result = true;
}

static class LEAD_VARS
{
public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 19\Media";
}

Target Platforms

Reference

CaptureCtrl Class
CaptureCtrl Members