Set sample rate in windows 7

Question

I'm currently struggling to find a solution to programmatically set the sample rate and bit rate of a USB sound card. I'm working on switching over our test program from Windows XP to Windows 7, and we have a product that acts like a USB soundcard. Some of our tests are sending out 48k signals though the soundcard, and the measuring the signal after routing it though a DAC. I think the measurement hardwares firmware/software isn't putting its signal generator in exclusive mode, and Windows is getting confused and putting the device in shared mode, which defaults the sample rate to 44.1k/16bit, I would like to change this value when we start the unit up to 48k/24bit.

I'm hoping someone could push me in the right direction, because everything I'm seeing is telling me that this isn't possible... (also, I'd prefer .NET solutions, or anything I can call/execute from .NET would be fine).

Here is one thing I tried, but this ended up only setting up a object to use to play back audio, it doesn't set the sample/bit depth for good.

Imports NAudio.Wave

Module ConfigureDevice

    Private Const SAMPLE_RATE As Integer = 48000
    Private Const CHANNELS As Integer = 2

    Sub Main(ByVal args() As String)

        ConfigureDirectSound(args(0))

    End Sub


    Private Sub ConfigureDirectSound(ByVal name As String)

        Dim out As New DirectSoundOut(GetWaveOutDeviceNumber(name))
        Dim waveFormat = New WaveFormat(SAMPLE_RATE, CHANNELS)
        Dim waveProvider = New BufferedWaveProvider(waveFormat)

        out.Init(waveProvider)

    End Sub

    Private Function GetWaveOutDeviceNumber(ByVal name As String) As System.Guid

        Dim devices = DirectSoundOut.Devices

        For Each d In devices
            If d.Description = name Then
                Return d.Guid
            End If
        Next

        Return Nothing

    End Function

End Module

Answer 1

It looks like you'll need to explore the WASAPI. From what I'm reading, that's the only way to programmatically force the output sample rate, besides changing the audio file itself.

http://msdn.microsoft.com/en-us/library/windows/desktop/dd371455(v=vs.85).aspx

You may have to search around for a C++/CLI wrapper for it (or write it yourself) to get any use out of it in .NET.