UseVideoDeviceAudio Property

Summary

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

Syntax
C#
VB
C++
public virtual bool UseVideoDeviceAudio { get; set; } 
Public Overridable Property UseVideoDeviceAudio As Boolean 
public: 
virtual property bool UseVideoDeviceAudio { 
   bool get(); 
   void set (    bool ); 
} 

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
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
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 20\Media"; 
} 
Imports Leadtools 
Imports Leadtools.Multimedia 
Imports LeadtoolsMultimediaExamples.Fixtures 
 
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 20\Media" 
End Class 

Requirements

Target Platforms

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Leadtools.Multimedia Assembly