VideoSubChannel Property

Summary

Gets the current video sub-channel.

Syntax
C#
VB
C++
public int VideoSubChannel { get; } 
Public ReadOnly Property VideoSubChannel As Integer 
public: 
property int VideoSubChannel { 
   int get(); 
} 

Property Value

A TunerSubChannel enumeration value if default or not tuned; otherwise the current video sub-channel. For a list of frequencies for channels, refer to the Microsoft documentation on International Analog TV Tuning.

Remarks

Gets the current video sub-channel. This property is valid only for ATSC digital TV broadcasts.

Example
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
 
public void DigitalTVTunerExample() 
{ 
   // reference the forms capture control and tv tuner 
   CaptureCtrl capturectrl = _form.CaptureCtrl; 
 
   string outFile = Path.Combine(LEAD_VARS.MediaDir, "TVTuner_DigitalTVTunerExample.avi"); 
 
   int mainChannel = 27; 
   int subChannel = -1; 
   int newSubChannel = -1; 
   int[] subChannelList = null; 
 
   try 
   { 
      capturectrl.Preview = true; 
      // select the first digital tuner device with BDA in it's name  
      // Replace "BDA" with your video capture device name  
      if (capturectrl.VideoDevices["BDA"] != null) 
         capturectrl.VideoDevices["BDA"].Selected = true; 
 
      // set the video and audio compressors  
      capturectrl.VideoCompressors.Mpeg2.Selected = true; 
      capturectrl.AudioCompressors.AC3.Selected = true; 
 
      // get the TV Tuner device  
      TVTuner tvTuner = capturectrl.TVTuner; 
 
      // check whether the TV tuner is valid  
      if (tvTuner != null) 
      { 
         // set the input type to cable and set the channel  
         tvTuner.SetInputType(0, TunerInputType.Antenna); 
         tvTuner.SetChannel(mainChannel, -1, -1); 
 
         // get the current video sub channel 
         subChannel = tvTuner.VideoSubChannel; 
 
         // list the sub-channels for the main channle first 
         if (tvTuner.VideoSubChannelCount > 0) 
         { 
            System.Diagnostics.Debug.WriteLine(" Main Channel: " + mainChannel); 
            subChannelList = new int[tvTuner.VideoSubChannelCount]; 
            for (int i = 0; i < tvTuner.VideoSubChannelCount; i++) 
            { 
               subChannelList[i] = tvTuner.VideoSubChannelValue(i); 
               System.Diagnostics.Debug.WriteLine(" Sub Channel: " + subChannelList[i]); 
            } 
         } 
 
         // select the first sub-channel in the list 
         if (subChannelList != null && subChannelList.Length > 0) 
         { 
            tvTuner.SetChannel(mainChannel, subChannelList[0], -1); 
            mainChannel = tvTuner.Channel; 
            newSubChannel = tvTuner.VideoSubChannel; 
            System.Diagnostics.Debug.WriteLine("Selected Channel: " + mainChannel + "." + subChannel); 
         } 
 
         // if the Main and Sub channel value are postive,  
         // it means tv tuner is happay and dandy, let starts capture 
         if (mainChannel > 0 && subChannel > 0) 
         { 
            System.Diagnostics.Debug.WriteLine("Start Capturing"); 
            capturectrl.TimeLimit = 30;     // just 30 seconds of capture time  
            capturectrl.UseTimeLimit = true; 
 
            capturectrl.TargetFormat = TargetFormatType.AVI; 
            capturectrl.TargetFile = outFile; 
 
            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(); 
 
      System.Diagnostics.Debug.WriteLine("Finish Capturing"); 
 
      // if TV tuner is valid  
      if (tvTuner != null) 
      { 
         // and set the result to what we expect  
         _result = (subChannel != newSubChannel); 
      } 
   } 
   catch (Exception ex) 
   { 
      _result = false; 
      System.Diagnostics.Debug.WriteLine(ex); 
   } 
} 
 
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 Sub DigitalTVTunerExample() 
   ' reference the forms capture control and tv tuner 
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl 
 
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "TVTuner_DigitalTVTunerExample.avi") 
 
   Dim mainChannel As Integer = 27 
   Dim subChannel As Integer = -1 
   Dim newSubChannel As Integer = -1 
   Dim subChannelList As Integer() = Nothing 
 
   Try 
      capturectrl.Preview = True 
      ' select the first digital tuner device with BDA in it's name  
      ' Replace "BDA" with your video capture device name  
      If Not capturectrl.VideoDevices("BDA") Is Nothing Then 
         capturectrl.VideoDevices("BDA").Selected = True 
      End If 
 
      ' set the video and audio compressors  
      capturectrl.VideoCompressors.Mpeg2.Selected = True 
      capturectrl.AudioCompressors.AC3.Selected = True 
 
      ' get the TV Tuner device  
      Dim tvTuner As TVTuner = capturectrl.TVTuner 
 
      ' Check if TV tuner is valid  
      If Not tvTuner Is Nothing Then 
         ' set the input type to cable and set the channel  
         tvTuner.SetInputType(0, TunerInputType.Antenna) 
         tvTuner.SetChannel(mainChannel, -1, -1) 
 
         ' get the current video sub channel 
         subChannel = tvTuner.VideoSubChannel 
 
         ' list the sub-channels for the main channle first 
         If tvTuner.VideoSubChannelCount > 0 Then 
            System.Diagnostics.Debug.WriteLine(" Main Channel: " & mainChannel) 
            subChannelList = New Integer(tvTuner.VideoSubChannelCount - 1) {} 
            Dim i As Integer = 0 
            Do While i < tvTuner.VideoSubChannelCount 
               subChannelList(i) = tvTuner.VideoSubChannelValue(i) 
               System.Diagnostics.Debug.WriteLine(" Sub Channel: " & subChannelList(i)) 
               i += 1 
            Loop 
         End If 
 
         ' select the first sub-channel in the list 
         If Not subChannelList Is Nothing AndAlso subChannelList.Length > 0 Then 
            tvTuner.SetChannel(mainChannel, subChannelList(0), -1) 
            mainChannel = tvTuner.Channel 
            newSubChannel = tvTuner.VideoSubChannel 
            System.Diagnostics.Debug.WriteLine("Selected Channel: " & mainChannel & "." & subChannel) 
         End If 
 
         ' if the Main and Sub channel value are postive, it means tv tuner is happay and dandy, let starts capture 
         If mainChannel > 0 AndAlso subChannel > 0 Then 
            System.Diagnostics.Debug.WriteLine("Start Capturing") 
            capturectrl.TimeLimit = 30 ' just 30 seconds of capture time 
            capturectrl.UseTimeLimit = True 
 
            capturectrl.TargetFormat = TargetFormatType.AVI 
            capturectrl.TargetFile = outFile 
 
            capturectrl.StartCapture(CaptureMode.VideoAndAudio) 
         End If 
      End If 
 
      ' 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 
 
      System.Diagnostics.Debug.WriteLine("Finish Capturing") 
 
      ' if TV tuner is valid  
      If Not tvTuner Is Nothing Then 
         ' and set the result to what we expect  
         _result = (subChannel <> newSubChannel) 
      End If 
   Catch ex As Exception 
      _result = False 
      System.Diagnostics.Debug.WriteLine(ex) 
   End Try 
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

See Also

Reference

TVTuner Class

TVTuner Members

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