MasterStream Property

Summary

Gets or sets the master stream that other streams must synchronize to after the file is written.

Syntax
C#
VB
C++
public virtual CaptureMasterStream MasterStream { get; set; } 
Public Overridable Property MasterStream As CaptureMasterStream 
public: 
virtual property CaptureMasterStream MasterStream { 
   CaptureMasterStream get(); 
   void set (    CaptureMasterStream ); 
} 

Property Value

An CaptureMasterStream representing the master stream selection.

Remarks

Gets or sets the master stream that other streams must synchronize to after the file is written. The value must be one of the CaptureMasterStream enumeration values. Different streams in the capture scenario can be captured at different rates if you are using separate audio and video capture cards. By specifying a master stream that all others must synchronize to, this method adjusts the frame rate or audio sampling rate to account for drifts in the rates. To eliminate capture drifts that can occur between audio sampling rates and video frame rates, it is best that you use combined audio/video cards for capture of large files. Assignment can raise an error exception. For more information, refer to the Error Codes.

Example
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
 
// capture control 
CaptureCtrl capturectrl; 
 
// output file 
string outFile = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_MasterStreamExample.avi"); 
 
public void MasterStreamExample() 
{ 
   // reference the capture control 
   capturectrl = _form.CaptureCtrl; 
 
   try 
   { 
      // set the source video device, select using your device name here 
      if (capturectrl.VideoDevices["USB"] == null) 
      { 
         throw new Exception("No USB video device available"); 
      } 
 
      capturectrl.VideoDevices["USB"].Selected = true; 
 
      // set the source audio device, select using your device name here 
      if (capturectrl.AudioDevices["USB"] == null) 
      { 
         throw new Exception("No USB audio device available"); 
      } 
 
      capturectrl.AudioDevices["USB"].Selected = true; 
 
      // select a video compressor 
      capturectrl.VideoCompressors.Mpeg4.Selected = true; 
 
      // select an audio compressor 
      capturectrl.AudioCompressors.AC3.Selected = true; 
 
      // set the target output file 
      capturectrl.TargetFile = outFile; 
 
      // subscribe to the started event 
      capturectrl.Started += CaptureCtrl_Started; 
 
      // set master stream to CaptureMasterStream.Video 
      capturectrl.MasterStream = CaptureMasterStream.Video; 
 
      // start capture 
      capturectrl.StartCapture(CaptureMode.VideoAndAudio); 
 
      // get master stream  
      CaptureMasterStream MasterStream = capturectrl.MasterStream; 
 
      // set the result to what we expect 
      _result = (MasterStream == CaptureMasterStream.Video); 
   } 
   catch (COMException) 
   { 
      _result = false; 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
} 
 
void CaptureCtrl_Started(object sender, EventArgs e) 
{ 
   // stop the capture (we do not need a complete capture for this example) 
   capturectrl.StopCapture(); 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media"; 
} 
Imports Leadtools 
Imports Leadtools.Multimedia 
Imports LeadtoolsMultimediaExamples.Fixtures 
 
Public _result As Boolean = False 
Public _form As CaptureCtrlForm = New CaptureCtrlForm() 
Public _capturectrl As CaptureCtrl 
 
Public Sub MasterStreamExample() 
   ' reference the capture control 
   _capturectrl = _form.CaptureCtrl 
 
   ' output file 
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_MasterStreamExample.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 the source audio device, select using your device name here 
      If _capturectrl.AudioDevices("USB") Is Nothing Then 
         Throw New Exception("No USB audio device available") 
      End If 
 
      _capturectrl.AudioDevices("USB").Selected = True 
 
      ' select a video compressor 
      _capturectrl.VideoCompressors.Mpeg4.Selected = True 
 
      ' select an audio compressor 
      _capturectrl.AudioCompressors.AC3.Selected = True 
 
      ' set the target output file 
      _capturectrl.TargetFile = outFile 
 
      ' subscribe to the started event 
      AddHandler _capturectrl.Started, AddressOf CaptureCtrl_Started 
 
      ' set master stream to CaptureMasterStream.Video 
      _capturectrl.MasterStream = CaptureMasterStream.Video 
 
      ' start capture 
      _capturectrl.StartCapture(CaptureMode.VideoAndAudio) 
 
      ' get master stream  
      Dim MasterStream As CaptureMasterStream = _capturectrl.MasterStream 
 
      ' set the result to what we expect 
      _result = (MasterStream = CaptureMasterStream.Video) 
 
   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 
 
Private Sub CaptureCtrl_Started(ByVal sender As Object, ByVal e As EventArgs) 
   ' stop the capture (we don't need a complete capture for this example) 
   _capturectrl.StopCapture() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media" 
End Class 
Requirements

Target Platforms

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Leadtools.Multimedia Assembly