GetSubObject Method (CaptureCtrl)

Gets the specified graph sub-object.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Overridable Function GetSubObject( _
   ByVal objType As CaptureObject _
) As Object

'Usage
 
Dim instance As CaptureCtrl
Dim objType As CaptureObject
Dim value As Object
 
value = instance.GetSubObject(objType)

public virtual object GetSubObject( 
   CaptureObject objType
)

public:
virtual Object^ GetSubObject( 
   CaptureObject objType
)

Parameters

objType: Value that specifies which graph sub-object to get. Must be one of the CaptureObject enumeration values.

Return Value

System.Object

Remarks

The specified graph sub-object includes a filter being cached from the capture graph.

If the method fails, an error is raised. For more information, refer to the Error Codes.

Note:This method should not be used to change properties when the TargetFilter object is a multiplexer or sink. Target filters are not added to the capture graph until the capture graph is built using ReadyCapture or StartCapture. At this point, the graph is in the running state. Some multiplexers or sinks may not be able to change some settings in running mode. By default, when you stop the capture, the multiplexer and sink are destroyed. As a result, the only way to change their settings in stopped mode is to create them before the capture starts. This is accomplished by first setting the TargetFormat.UseFilterCache property to true and then retrieving the objects using TargetFormat.GetCacheObject. For an example, refer to TargetFormat.UseFilterCache property or TargetFormat.UseFilterCache method.

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 GetSubObjectExample()
   ' reference the capture control
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

   ' input and output files
   Dim inFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_Source.avi")
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_GetSubObjectExample.avi")

   Try
      ' set the source video device
      If capturectrl.VideoDevices("USB") Is Nothing Then
         Throw New Exception("No USB video device available")
      End If

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

      ' set the source 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 the output files
      capturectrl.TargetFile = outFile

      ' set the audio and video compression
      capturectrl.VideoCompressors.Mpeg2.Selected = True
      capturectrl.AudioCompressors.AC3.Selected = True

      ' add the color adjustment processor
      capturectrl.SelectedVideoProcessors.Add(capturectrl.VideoProcessors.Color)

      ' access the Color filter directly via the GetSubObject method
      Dim lmvc As LMVColor = TryCast(capturectrl.GetSubObject(CaptureObject.SelVideoProcessor), LMVColor)

      If Not lmvc Is Nothing Then
         ' change some settings
         lmvc.Brightness = 85
         lmvc.Contrast = 85
         lmvc.Enabled = True
         lmvc.EffectAreaEnabled = False

         Marshal.ReleaseComObject(lmvc)
      End If

      ' 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

         ' 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

   ' 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 18\Media"
End Class

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

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

   // input and output files
   string inFile =Path.Combine(LEAD_VARS.MediaDir,"CaptureCtrl_Source.avi");
   string outFile = Path.Combine(LEAD_VARS.MediaDir,"CaptureCtrl_GetSubObjectExample.avi");

   try
   {
      // set the source video device
      if (capturectrl.VideoDevices["USB"] == null)
         throw new Exception("No USB video device available");

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

      // set the source audio device
      if (capturectrl.AudioDevices["USB"] == null)
         throw new Exception("No USB audio device available");

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

      // set the output files
      capturectrl.TargetFile = outFile;

      // set the audio and video compression
      capturectrl.VideoCompressors.Mpeg2.Selected = true;
      capturectrl.AudioCompressors.AC3.Selected = true;

      // add the color adjustment processor
      capturectrl.SelectedVideoProcessors.Add(capturectrl.VideoProcessors.Color);

      // access the Color filter directly via the GetSubObject method
      LMVColor lmvc = capturectrl.GetSubObject(CaptureObject.SelVideoProcessor) as LMVColor;

      if (lmvc != null)
      {
         // change some settings
         lmvc.Brightness = 85;
         lmvc.Contrast = 85;
         lmvc.Enabled = true;
         lmvc.EffectAreaEnabled = false;

         Marshal.ReleaseComObject(lmvc);
      }

      // 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;

         // 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;
   }

   // 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();
}

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