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GetSubObject Method (CaptureCtrl)

Summary

Gets the specified graph sub-object.

Syntax

C++

public virtual object GetSubObject(  
   Leadtools.Multimedia.CaptureObject objType 
)

Public Overridable Function GetSubObject( _ 
   ByVal objType As Leadtools.Multimedia.CaptureObject _ 
) As Object

public: 
virtual Object^ GetSubObject(  
   Leadtools.Multimedia.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

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 19\Media"; 
}

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 19\Media" 
End Class