PreviewTap Property

Gets or sets the tap location from which the preview output originates.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Overridable Property PreviewTap As CapturePreviewTap

'Usage
 
Dim instance As CaptureCtrl
Dim value As CapturePreviewTap
 
instance.PreviewTap = value
 
value = instance.PreviewTap

public virtual CapturePreviewTap PreviewTap {get; set;}

public:
virtual property CapturePreviewTap PreviewTap {
   CapturePreviewTap get();
   void set (    CapturePreviewTap value);
}

Property Value

A CapturePreviewTap value representing the preview tap location.

Remarks

The value is one of the CapturePreviewTap enumeration values. Assignment can raise an error exception.

For more information, refer to the Error Codes.

Example

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

Copy Code

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 18\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 18\Media";
}

Requirements

Target Platforms

Reference

CaptureCtrl Class
CaptureCtrl Members