SetChannel Method

Imports Leadtools 
Imports Leadtools.MediaFoundation 
Imports LeadtoolsMediaFoundationExamples.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.wmv") 
 
   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 
 
      ' 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.WMV 
            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