SetAudioType Method

Imports Leadtools
Imports Leadtools.MediaFoundation
Imports LeadtoolsMediaFoundationExamples.Fixtures

Public _result As Boolean = False
Public _form As New CaptureCtrlForm()
Public Sub AudioTypesExample()
   ' reference the capture control
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

   Try
      ' set an audio device first, you should use your audio device name here
      If capturectrl.AudioDevices("USB") Is Nothing Then
         Throw New Exception("No USB audio device available")
      End If

      capturectrl.AudioDevices("USB").Selected = True

      ' reference the target formats collection
      Dim formats As TargetFormats = capturectrl.TargetFormats

      ' reference the target format object
      Dim tf As TargetFormat = formats(TargetFormatType.WMV)

      ' reference the target audio formats object
      Dim taformats As TargetAudioFormats = tf.AudioFormats

      ' check the index using a name string
      Dim i As Integer = taformats.IndexOf("{00000161-0000-0010-8000-00AA00389B71}") ' Windows Media Audio (WMA)

      ' get target audio format object
      Dim taf As TargetAudioFormat = taformats(i)

      ' make sure the target audio format object's name equals {00000161-0000-0010-8000-00AA00389B71}
      If taf.Name = "{00000161-0000-0010-8000-00AA00389B71}" Then
         ' get target audio format friendly name, use it for view propose.
         Dim friendlyname As String = taf.FriendlyName
      Else
         Throw New Exception()
      End If

      ' select it
      taf.Selected = True

      ' get target audio types collection
      Dim targetaudiotypes As TargetAudioTypes = taf.AudioTypes

      ' if target audio types larger than 0, loop through all of them
      If targetaudiotypes.Count > 0 Then
         ' enumerate through the list of audio types
         ' demonstrating the target audio types properties
         For Each targetaudiotype As TargetAudioType In targetaudiotypes
            ' get name of the target type.
            Dim name As String = targetaudiotype.Name

            ' get friendly name of the target type.
            Dim friendlyname As String = targetaudiotype.FriendlyName

            ' set the audio type into the target format if:
            ' AudioAvgBytesPerSecond == 24000 (192 kbps)
            ' AudioBitsPerSample == 16
            ' AudioNumChannels == 2 (stereo)
            ' AudioSamplesPerSecond == 44100 Hz
            If targetaudiotype.AudioAvgBytesPerSecond = 24000 AndAlso targetaudiotype.AudioBitsPerSample = 16 AndAlso targetaudiotype.AudioNumChannels = 2 AndAlso targetaudiotype.AudioSamplesPerSecond = 44100 Then
               tf.SetAudioType(targetaudiotype)
               Exit For
            End If
         Next
      End If

      ' check if we have can capture video and audio
      If capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio) Then
         ' start the capture process
         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()
         End While
      End If

      _result = True
   Catch generatedExceptionName As Exception
      _result = False
   End Try
End Sub