Recompressing an AVI File Example for Visual Basic

The following code demonstrates recompressing an AVI file:

Private Sub cmdAbort_Click()
    ' if running then abort, else exit program
    If ltmmConvertCtrl1.State = ltmmConvert_State_Running Then
        ltmmConvertCtrl1.StopConvert
    Else
' enable the current state to be dumped
'        MsgBox "State = " & CStr(ltmmConvertCtrl1.State) & ", Error = " & CStr(ltmmConvertCtrl1.ConvertError) & ", Progress = " & CStr(ltmmConvertCtrl1.PercentComplete) & "%"
        Unload Me
    End If
End Sub

Private Sub convert_MediaEvent

(ByVal EventCode As Long, ByVal Param1 As Long, ByVal Param2 As Long)
  Select Case EventCode
      Case ltmmEC_DVD_DOMAIN_CHANGE
          txtStatus.Text = "The DVD domain is changed"
      Case ltmmEC_DVD_TITLE_CHANGE
          txtStatus.Text = "The DVD current title The name for a group of related video files (called "Chapters") on your DVD. For example, for a DVD called "My Summer Vacation," you might have the titles "Water Skiing," "New Friends," and "Hiking." For each of those titles, you might have one or more different video files. number is changed"
End Select

Private Sub convert_Complete ()
    ' indicate that the conversion is complete
    txtStatus = "Conversion completed."
    cmdAbort.Caption = "Exit"
End Sub

Private Sub convert_ErrorAbort (ByVal ErrorCode As Long)
    ' indicate that a conversion error has occurred

    txtStatus = "Error " & CStr(ErrorCode) & ". Conversion aborted."
    cmdAbort.Caption = "Exit"
End Sub

Private Sub convert_Progress (ByVal Percent As Long)

    ' update the percentage text
    txtProgress = CStr(Percent) & "%"
End Sub

Private Sub convert_Started ()
    ' indicate that the conversion has started
    Dim Source As String
    Dim Target As String

    If ltmmConvertCtrl1.SourceType = ltmmConvert_Source_File Then
        Source = ltmmConvertCtrl1.SourceFile
    ElseIf ltmmConvertCtrl1.SourceType = ltmmConvert_Source_Array Then
        Source = "[array]"
    ElseIf ltmmConvertCtrl1.SourceType = ltmmConvert_Source_HGlobal Then
        Source = "[hglobal]"
    End If

    If ltmmConvertCtrl1.TargetType = ltmmConvert_Target_File Then
        Target = ltmmConvertCtrl1.TargetFile
    ElseIf ltmmConvertCtrl1.TargetType = ltmmConvert_Target_Array Then
        Target = "[array]"
    End If

    If ((ltmmConvertCtrl1.RenderedStreams And ltmmConvert_Stream_Audio) <> 0 And (ltmmConvertCtrl1.RenderedStreams And ltmmConvert_Stream_Video) = 0) Then
        txtStatus = "Recompressing audio from " & Source & " to " & Target
    ElseIf ((ltmmConvertCtrl1.RenderedStreams And ltmmConvert_Stream_Audio) = 0 And (ltmmConvertCtrl1.RenderedStreams And ltmmConvert_Stream_Video) <> 0) Then
        txtStatus = "Recompressing video from " & Source & " to " & Target
    Else
        txtStatus = "Recompressing " & Source & " to " & Target
    End If
End Sub

Private Sub convert_UserAbort ()
    ' indicate that the user aborted
    txtStatus = "Conversion Aborted."
    cmdAbort.Caption = "Exit"
End Sub

Private Sub Form_Load()
    ' assign the input file
    ltmmConvertCtrl1.SourceFile = "c:\source.avi"
    ' assign the output file
    ltmmConvertCtrl1.TargetFile = "c:\target.avi"
    ' set the video compressor to the LEAD compressor
    ltmmConvertCtrl1.VideoCompressors.Selection = ltmmConvertCtrl1.VideoCompressors.Find ("@device:sw:{33D9A760-90C8-11D0-BD43-00A0C911CE86}\LEAD MCMP/MJPEG Codec A COmpressor Also known as an encoder, this is a module or algorithm to compress data. Playing that data back requires a decompressor, or decoder. combined with a DECompressor, or encoder Also known as compressor, this is a module or algorithm to compress data. Playing that data back requires a decompressor, or decoder. and a decoder Also known as a decompressor, this is a module or algorithm to decompress data., which allows you to both compress and decompress that same data. (2.0)")
    ' set the audio compressor to the MP3 compressor
    ltmmConvertCtrl1.AudioCompressors.Selection = ltmmConvertCtrl1.AudioCompressors.Find ("@device:cm:{33D9A761-90C8-11D0-BD43-00A0C911CE86}\85MPEG Layer-3")
    ' set the output format to AVI
    ltmmConvertCtrl1.TargetFormat = ltmmConvert_TargetFormat_Avi
    ' invoke the video compressor property dialog, if available
    If ltmmConvertCtrl1.HasDialog (ltmmConvert_Dlg_VideoCompressor) Then
        ltmmConvertCtrl1.ShowDialog ltmmConvert_Dlg_VideoCompressor, hWnd
    End If
    ' invoke the audio compressor property dialog, if available
    If ltmmConvertCtrl1.HasDialog(ltmmConvert_Dlg_AudioCompressor) Then
        ltmmConvertCtrl1.ShowDialog ltmmConvert_Dlg_AudioCompressor, hWnd
    End If
    cmdAbort.Caption = "Abort"
    On Error GoTo StartConvertError

    If ltmmConvertCtrl1.UnrenderedStreams <> 0 Then
        MsgBox "Not all of the available streams could be rendered"
    End If

    ' Assign the preview window handle to the Convert Ctrl property VideoWindowFrame
    ltmmConvertCtrl1.VideoWindowFrame = PreviewWnd.hWnd
    
    ' Set Preview Property to True
    ltmmConvertCtrl1.Preview = True
    
    ' now the convert object is ready to Preview the conversion process
    ' the user may be able to enable or disable preview during conversion
    ' this is done using ltmmConvertCtrl1.PreviewVisible  
    bPreviewVisible = ltmmConvert.PreviewVisible
    If bPreviewVisible = True Then
        chkPreview.Value = 1
    Else
        chkPreview.Value = 0
    End If

' uncomment the following line to view the graph with DirectShow GraphEdit
' ltmmConvertCtrl1.EditGraph

    ' start the conversion
    ltmmConvertCtrl1.StartConvert
    Exit Sub
StartConvertError:
    txtStatus = Err.Description & "... Error " & CStr(Err.Number)
    cmdAbort.Caption = "Exit"
End Sub

' Check box control to enable or disable the preview during conversion
Private Sub chkPreview_Click()
    If chkPreview.Value = 1 Then
        ltmmConvertCtrl1.PreviewVisible = True
    Else
        ltmmConvertCtrl1.PreviewVisible = False
        ' set the preview window back color to black if Preview is disabled.
        PreviewWnd.BackColor = 4 'black
    End If
End Sub

Private Sub btnPauseConvert_Click()
    ' Pause conversion
    ltmmConvertCtrl1.PauseConvert
End Sub

Private Sub btnRunConvert_Click()
    ' Run a Paused conversion
ltmmConvertCtrl1.RunConvert
End Sub