GetCacheObject Method

'Declaration
 
Public Function GetCacheObject( _
   ByVal ObjType As TargetFormatObject _
) As Object

Public _result As Boolean = False
         Public _form As CaptureCtrlForm = New CaptureCtrlForm()
         Public _pMpgMux As LMMpg2MxTLib.LMMpg2MxT
         ' This example will show you the correct way to set up a muxer's properties during capture
         ' Normally, the muxer is added only after the capture graph has been build with ReadyCapture or StartCapture
         ' But at this point, the graph is in running mode, so some muxer operations might fail
         ' If you need to make changes to the muxer in stopped state (like adding KLV data stream, for example),
         ' then you need to change the muxer before the graph is fully built. You can do so by instructing the toolkit
         ' to cache the target filters by setting the the TargetFormat.UseFilterCache property to true
         ' In this situation, the filters used to implement a certain target format are created and used whenever 
         ' you set that target format.

         ' This example will show you how to add KLV data to a MPEG-2 Transport Stream in a capture situation.

         Public Sub UseFilterCacheExample()
             ' reference the capture control
             Dim capturectrl As CaptureCtrl = _form.CaptureCtrl
             Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureKLV.mpg")

             Try
                 ' select the capture device
                 capturectrl.VideoDevices.Selection = 0 ' Use a different video device if you want 

                 ' capturectrl.Preview = true; -- enable this if you want 


                 ' set the video compressor (only if the capture device is not already capturing compressed video)

                 capturectrl.VideoCompressors.Mpeg2.Selected = True

                 ' set the target output file
                 capturectrl.TargetFile = outFile

                 ' subscribe to the compete event
                 AddHandler capturectrl.Started, AddressOf CaptureCtrl_Started

                 ' just 10 seconds of capture time
                 capturectrl.TimeLimit = 10
                 capturectrl.UseTimeLimit = True

                 ' subscribe to the compete event
                 AddHandler capturectrl.Complete, AddressOf CaptureCtrl_Complete

                 ' IN a capture situation 
                 'in order to get the mux in a capture situation, set the UseFilterCache property for the target format to TRUE
                 '      This tells the toolkit to create a Mux object and keep it around when building or rebuilding graphs
                 capturectrl.TargetFormats(Leadtools.Multimedia.TargetFormatType.MPEG2Transport).UseFilterCache = True
                 capturectrl.TargetFormat = Leadtools.Multimedia.TargetFormatType.MPEG2Transport

                 _pMpgMux = DirectCast(capturectrl.TargetFormats(Leadtools.Multimedia.TargetFormatType.MPEG2Transport).GetCacheObject(TargetFormatObject.Mux), LMMpg2MxTLib.LMMpg2MxT)
                 If _pMpgMux IsNot Nothing Then
                     _pMpgMux.PrivateDataPID = &H70
                     _pMpgMux.PrivateDataFormatID = &H41564C4B
                     _pMpgMux.EnablePrivateData = True
                 End If

                 ' start capture
                 capturectrl.StartCapture(Leadtools.Multimedia.CaptureMode.Video)
             Catch generatedExceptionName As Exception
                 _result = False
             End Try
         End Sub

         Private Sub WriteKLVData(ByVal pMpgMux As LMMpg2MxTLib.LMMpg2MxT)
             ' get the current time since Jan 1, 1970
             Dim basetime As TimeSpan = DateTime.UtcNow - New DateTime(1970, 1, 1, 0, 0, 0)
             ' get the number of microseconds since Jan 1, 1970
             Dim timestamp As Int64 = CLng(basetime.TotalSeconds) * 1000000
             ' don't really need to do this, since I am writing only one item
             pMpgMux.KlvBuilder.Clear()
             ' write the UDS timestamp (number of microseconds since Jan 1, 1970)
             pMpgMux.KlvBuilder.InsertUInt64(-1, "06 0E 2B 34 01 01 01 03 07 02 01 01 01 05 00 00", CULng(timestamp))
             ' write one KLV data at the beginning
             pMpgMux.WritePrivateData(CInt(LMMpg2MxTLib.Mpg2MxT_WriteFlags.Mpg2MxT_WriteFlag_PTSValid) _
                                      Or CInt(LMMpg2MxTLib.Mpg2MxT_WriteFlags.Mpg2MxT_WriteFlag_PTSInSeconds), _
                                      0.0, pMpgMux.KlvBuilder.GetData(), -1)
             ' close the stream
             pMpgMux.ClosePrivateData()
         End Sub

         Public Sub CaptureCtrl_Started(ByVal sender As Object, ByVal e As EventArgs)
             WriteKLVData(_pMpgMux)
         End Sub

         Public Sub CaptureCtrl_Complete(ByVal sender As Object, ByVal e As EventArgs)
             ' set result
             _result = True
         End Sub

Public NotInheritable Class LEAD_VARS
   Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 175\Media";
End Class