SampleFrequency Property

Visual Basic
C#
C++/CLI

'Declaration
 
Public ReadOnly Property SampleFrequency As Integer

'Usage
 
Dim instance As AudioFormat
Dim value As Integer
 
value = instance.SampleFrequency

public int SampleFrequency {get;}

public:
property int SampleFrequency {
   int get();
}

Property Value

The sample frequency, in hertz.

This is the number of audio samples received in one second.

The AudioFormats object contains all the audio formats available for the current capture device. The AudioFormats object contains an AudioFormat object for each of the supported audio formats. The properties of each AudioFormat object, obtained using the [] indexer, contain information for the specific audio format. This information includes the BitsPerSample property, Channels property, and the SampleFrequency property.

The AudioFormat.Channels property is the number of channels for the audio format. The AudioFormat.BitsPerSample property is the number of bits per sample for the audio format

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

Copy Code

Imports Leadtools
Imports Leadtools.Multimedia
Imports LeadtoolsMultimediaExamples.Fixtures

Public _form As CaptureCtrlForm = New CaptureCtrlForm()
Public _result As Boolean = False
Public Sub AudioFormatExample()
  Try
     Dim count As Integer, freq As Integer = 0, bits As Integer = 0, channels As Integer = 0
     Dim found As Integer, selected As Integer = -1

     ' reference the capture control
     Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

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

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

     ' get count of available audio formats
     count = capturectrl.AudioCaptureFormats.Count

     ' reset the current selection to -1
     capturectrl.AudioCaptureFormats.Reset()

     ' reference the audioformats property
     Dim audioformats As AudioFormats = capturectrl.AudioCaptureFormats

     ' enumerate formats and select one
     For Each af As AudioFormat In audioformats
       freq = af.SampleFrequency
       bits = af.BitsPerSample
       channels = af.Channels

       ' select the format if it matches some criteria
       If freq = 8000 AndAlso bits = 16 AndAlso channels = 2 Then
         af.Selected = True
         Exit For
       End If
     Next af

     ' get the currently selected format
     selected = audioformats.Selection

     ' find a format based on frequency, bits/channel and number of channels
     found = audioformats.IndexOf(8000, 8, 2)

     ' our found format is not selected, so select it
     If found <> selected Then
       audioformats.Selection = found
     End If

     ' get the new selected format
     selected = audioformats.Selection

     ' set our result based on what we expect
     _result = (count > 0 AndAlso selected = found)
  Catch e1 As Exception
     _result = False
  End Try
End Sub

using Leadtools;
using Leadtools.Multimedia;
using LeadtoolsMultimediaExamples.Fixtures;

public CaptureCtrlForm _form = new CaptureCtrlForm();
public bool _result = false;
public void AudioFormatExample()
{
   try
   {
      int count, freq = 0, bits = 0, channels = 0;
      int found, selected = -1;

      // reference the capture control
      CaptureCtrl capturectrl = _form.CaptureCtrl;

      // set an audio device, use the name of your device here
      if (capturectrl.AudioDevices["USB"] == null)
         throw new Exception("No USB audio device available");

      capturectrl.AudioDevices["USB"].Selected = true;

      // get a count of the available audio formats
      count = capturectrl.AudioCaptureFormats.Count;

      // reset the current selection to -1
      capturectrl.AudioCaptureFormats.Reset();

      // reference the audioformats property
      AudioFormats audioformats = capturectrl.AudioCaptureFormats;

      // enumerate formats and select one
      foreach (AudioFormat af in audioformats)
      {
         freq = af.SampleFrequency;
         bits = af.BitsPerSample;
         channels = af.Channels;

         // select the format if it matches some criteria
         if (freq == 8000 && bits == 16 && channels == 2)
         {
            af.Selected = true;
            break;
         }
      }

      // get the currently selected format
      selected = audioformats.Selection;

      // find a format based on frequency, bits/channel and number of channels
      found = audioformats.IndexOf(8000, 8, 2);

      // the format found format is not selected, so select it
      if (found != selected)
         audioformats.Selection = found;

      // get the new selected format
      selected = audioformats.Selection;

      // set our result based on what we expect
      _result = (count > 0 && selected == found);
   }
   catch (Exception)
   {
      _result = false;
   }
}

Target Platforms

Reference

AudioFormat Class
AudioFormat Members
AudioCaptureFormats Property