SeekTimecode Method

Imports Leadtools
Imports Leadtools.Multimedia
Imports LeadtoolsMultimediaExamples.Fixtures

Public _result As Boolean = False
Public _form As ConvertCtrlForm = New ConvertCtrlForm()
Public _convertctrl As ConvertCtrl
Public _testing As Boolean
Public _startTimeCode As Integer
Public _stopTimeCode As Integer
Public Sub ReadTimecodeExample()
  ' reference the convert control
  _convertctrl = _form.ConvertCtrl

  ' input file
            Dim inFile As String = Path.Combine(LEAD_VARS.MediaDir, "ConvertCtrl_Source.avi")

  Try
     ' check to see if we have the desired target device
     If _convertctrl.TargetDevices("Microsoft DV Camera and VCR") Is Nothing Then
       Throw New Exception("No Microsoft DV Camera target devices available!")
     End If

     ' set the video capture device, use your capture device name here
     _convertctrl.SourceFile = inFile

     ' select video and audio compressors to none
     _convertctrl.VideoCompressors.Uncompressed.Selected = True
     _convertctrl.AudioCompressors.Uncompressed.Selected = True

     ' select the target format
     _convertctrl.TargetFormats(TargetFormatType.DVSD).Selected = True

     ' select only Audio for this example
     _convertctrl.AllowedStreams = StreamFormatType.AudioVideo

     ' set a target device
     _convertctrl.TargetDevices("Microsoft DV Camera and VCR").Selected = True

     ' check the target device VCRControl 
             If _convertctrl.TargetVCRControl Is Nothing OrElse (_convertctrl.TargetVCRControl.DeviceType = VCRControlDeviceType.NotPresent _
                                                                 OrElse _convertctrl.TargetVCRControl.DeviceType = VCRControlDeviceType.Unknown) Then
                 Throw New Exception("MS DV Camera's Target VCR control is not present!")
             End If

     ' subscribe to convert control events for VCR control input
     AddHandler _convertctrl.Started, AddressOf ConvertCtrl_Started
     AddHandler _convertctrl.Complete, AddressOf ConvertCtrl_Complete
     AddHandler _convertctrl.Progress, AddressOf ConvertCtrl_Progress
     AddHandler _convertctrl.KeyPress, AddressOf ConvertCtrl_KeyPress

        ' start the conversion
     _convertctrl.StartConvert()
  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 _convertctrl.State = ConvertState.Running
     Application.DoEvents()
  Loop

  ' switch to playback and test
  _testing = True

  ' again, we'll loop and pump messages for this example for 
  ' playback testing, (setting _testing == true will exit)
  Do While _testing
     Application.DoEvents()
  Loop
End Sub

Private Sub ConvertCtrl_Started(ByVal sender As Object, ByVal e As EventArgs)
  ' start recording
  If _convertctrl.TargetVCRControl.Mode <> VCRControlMode.Record Then
     ' pause the graph to prevent frame loss
     _convertctrl.PauseConvert()
     ' start the record on the VCR control
     _convertctrl.TargetVCRControl.Record()
     ' resume graph now
     _convertctrl.RunConvert()
  End If

  ' get our VCR start timecode
  _startTimeCode = _convertctrl.TargetVCRControl.ReadTimecode()
End Sub

Private Sub ConvertCtrl_Complete(ByVal sender As Object, ByVal e As EventArgs)
  ' stop recording
  If _convertctrl.TargetVCRControl.Mode <> VCRControlMode.Stop Then
     _convertctrl.TargetVCRControl.Stop()
  End If

  ' get our VCR start timecode
  _stopTimeCode = _convertctrl.TargetVCRControl.ReadTimecode()

  ' set the result to what we expect
  _result = (_stopTimeCode > _startTimeCode)
End Sub

Private Sub ConvertCtrl_KeyPress(ByVal sender As Object, ByVal e As Leadtools.Multimedia.KeyPressEventArgs)
  ' if ok to perform playback functions 
  If _testing AndAlso Not _convertctrl.TargetVCRControl Is Nothing Then
     ' reference the target VCR control
     Dim vcr As VCRControl = _convertctrl.TargetVCRControl
        Select Case e.keyAscii
           Case CShort("*")
              ' seek to the beginning of the capture 
              If vcr.Mode <> VCRControlMode.Stop Then
                 vcr.Stop()
              End If
              vcr.SeekTimecode(_startTimeCode)
           Case CShort("~")
              ' seek to the end of the capture
              If vcr.Mode <> VCRControlMode.Stop Then
                 vcr.Stop()
              End If
              vcr.SeekTimecode(_stopTimeCode)
           Case CShort("p")
              ' start playback
              If vcr.Mode <> VCRControlMode.Play Then
                 vcr.Play()
              End If
           Case CShort("s")
              ' skip ahead 1000 units from the current timecode 
              vcr.Pause()
              Dim tc As Integer = vcr.ReadTimecode()
              vcr.SeekTimecode(tc + 1000)
              vcr.Play()
           Case CShort("+")
              ' step forward one frame
              If vcr.Mode <> VCRControlMode.Pause Then
                 vcr.Pause()
              End If
              vcr.StepForward()
           Case CShort("-")
              ' step backward one frame
              If vcr.Mode <> VCRControlMode.Pause Then
                 vcr.Pause()
              End If
              vcr.StepBackward()
           Case CShort("f")
              ' slowest forward
              vcr.SlowestForward()
           Case CShort("r")
              ' slowest reverse
              vcr.SlowestReverse()
           Case CShort(">")
              ' fastest forward
              vcr.FastestForward()
           Case CShort("<")
              ' fastest reverse
              vcr.FastestReverse()
           Case CShort("x")
              ' stop playback and exit
              If vcr.Mode <> VCRControlMode.Stop Then
                 vcr.Stop()
              End If
              _testing = False
        End Select
  End If
End Sub

Private Sub ConvertCtrl_Progress(ByVal sender As Object, ByVal e As ProgressEventArgs)
  If Not _convertctrl.TargetVCRControl Is Nothing Then
     ' reference the VCR control
     Dim vcr As VCRControl = _convertctrl.TargetVCRControl

     ' get the current time code
     Dim timeCode As Integer = vcr.ReadTimecode()
  End If
End Sub

Public NotInheritable Class LEAD_VARS
Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 18\Media"
End Class