UseVideoDeviceAudio Property

Gets or sets the option to use the audio source in the current video device.

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public virtual bool UseVideoDeviceAudio {get; set;}

'Declaration
 
Public Overridable Property UseVideoDeviceAudio As Boolean

'Usage
 
Dim instance As CaptureCtrl
Dim value As Boolean
 
instance.UseVideoDeviceAudio = value
 
value = instance.UseVideoDeviceAudio

public virtual bool UseVideoDeviceAudio {get; set;}

 get_UseVideoDeviceAudio();
 set_UseVideoDeviceAudio(value);

public:
virtual property bool UseVideoDeviceAudio {
   bool get();
   void set (    bool value);
}

Property Value

true if the audio source in the video device is used; false, otherwise.

Remarks

The default value for this property is True. It specifies whether the CaptureCtrl object will use the audio from the video device, if no audio device has been explicitly selected. For instance, DV devices contain both audio and video. Normally, if you select a DV device with no audio device, the DV device's audio stream will be used. However, if you set this property to False, then no audio stream will be rendered. This helps build a slightly more efficient graph when processing video only from DV devices.

Example

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Public _result As Boolean = False
      Public _form As CaptureCtrlForm = New CaptureCtrlForm()
      Public Sub AnalogTVTunerExample()
         ' reference the forms capture control and tv tuner
         Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

         Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "TVTuner_AnalogTVTunerExample.avi")
         Dim testChan As Integer = 6
         Dim channel As Integer

         Try
            ' select the first device with analog in it's name
            ' Replace "Analog" with your video capture device name
            If capturectrl.VideoDevices("Analog") Is Nothing Then
               Throw New Exception("No Analog video devices available!")
            End If

            capturectrl.VideoDevices("Analog").Selected = True

            ' use the video capture device's audio
            capturectrl.UseVideoDeviceAudio = True

            ' 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.Cable)
               tvtuner.SetChannel(testChan, -1, -1)

               ' get the Video and Audio frequency
               Dim vidFreq As Integer = tvtuner.VideoFrequency
               Dim audFreq As Integer = tvtuner.AudioFrequency
            End If

            ' set the output file
            capturectrl.TargetFile = outFile

            ' set the video and audio compressors
            capturectrl.VideoCompressors.Mpeg2.Selected = True
            capturectrl.AudioCompressors.AC3.Selected = True

            ' check if we have can capture video
            If capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio) Then
               ' set the target format
               capturectrl.TargetFormat = TargetFormatType.AVI

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

               ' select the video subtype
               capturectrl.VideoCaptureSubTypes(Leadtools.Multimedia.Constants.MEDIASUBTYPE_YUY2).Selected = True

               ' start the capture
               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.
               Do While capturectrl.State = CaptureState.Running
                  Application.DoEvents()
               Loop

               ' if TV tuner is valid
               If Not tvtuner Is Nothing Then
                  ' check the channel
                  channel = tvtuner.Channel

                  ' and set the result to what we expect
                  _result = (channel = testChan)
               End If
            End If
         Catch e1 As Exception
            _result = False
         End Try
      End Sub

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

public bool _result = false;
      public CaptureCtrlForm _form = new CaptureCtrlForm();
      public void AnalogTVTunerExample()
      {
         // reference the forms capture control and tv tuner
         CaptureCtrl capturectrl = _form.CaptureCtrl;

         string outFile =Path.Combine(LEAD_VARS.MediaDir,"TVTuner_AnalogTVTunerExample.avi");
         int testChan = 6;
         int channel;

         try
         {
            // select the first device with analog in it's name
            // Replace "Analog" with your video capture device name
            if (capturectrl.VideoDevices["Analog"] == null)
               throw new Exception("No Analog video devices available!");

            capturectrl.VideoDevices["Analog"].Selected = true;

            // use the video capture device's audio
            capturectrl.UseVideoDeviceAudio = true;

            // get the TV Tuner device
            TVTuner tvtuner = capturectrl.TVTuner;

            // check whether the TV tuner is valid
            if (tvtuner != null)
            {
               // set the input type to cable and set the channel
               tvtuner.SetInputType(0, TunerInputType.Cable);
               tvtuner.SetChannel(testChan, -1, -1);

               // get the Video and Audio frequency
               int vidFreq = tvtuner.VideoFrequency;
               int audFreq = tvtuner.AudioFrequency;
            }

            // set the output file
            capturectrl.TargetFile = outFile;

            // set the video and audio compressors
            capturectrl.VideoCompressors.Mpeg2.Selected = true;
            capturectrl.AudioCompressors.AC3.Selected = true;

            // check whether we can capture video
            if (capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio))
            {
               // set the target format
               capturectrl.TargetFormat = TargetFormatType.AVI;

               capturectrl.TimeLimit = 10;     // just 10 seconds of capture time
               capturectrl.UseTimeLimit = true;

               // select the video subtype
               capturectrl.VideoCaptureSubTypes[Constants.MEDIASUBTYPE_YUY2].Selected = true;

               // start the capture
               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();

               // if TV tuner is valid
               if (tvtuner != null)
               {
                  // check the channel
                  channel = tvtuner.Channel;

                  // and set the result to what we expect
                  _result = (channel == testChan);
               }
            }
         }
         catch (Exception)
         {
            _result = false;
         }
      }

static class LEAD_VARS
{
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 175\Media";
}

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

CaptureCtrl Class
CaptureCtrl Members