Windows 10 Get System Audio Mute Status in C#

Question

I have attempted to use winmm.dll to no avail, I have used several other projects Ive found like this well laid out tutorial but I haven't been able to get anything except for -1 returned for the getVolume method and nonsense values for other methods.

Is there a library I can use for this? Are there any more modern examples (this is from pre-2010)? I have looked into IAudioEndpointVolume interface, but it is not available through .NET and I'm not a c++ guy.

Any help much appreciated.

Answer 1

IAudioEndpointVolume is avalable in Windows Core Audio APIs .Net wrapper.

You can get whether master volume is muted or not by calling int GetMute([Out] [MarshalAs(UnmanagedType.Bool)] out Boolean isMuted) method:

// http://netcoreaudio.codeplex.com/SourceControl/latest#trunk/Code/CoreAudio/Interfaces/IAudioEndpointVolume.cs
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IAudioEndpointVolume
{
    /// <summary>
    /// Gets the muting state of the audio stream.
    /// </summary>
    /// <param name="isMuted">The muting state. True if the stream is muted, false otherwise.</param>
    /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
    [PreserveSig]
    int GetMute([Out] [MarshalAs(UnmanagedType.Bool)] out Boolean isMuted);
}

I have created simple realization of GetMute function (and all necessary interfaces abstractions from Windows CoreAudio API).

AudioManager class code:

public static class AudioManager
{
    /// <summary>
    /// Gets the mute state of the master volume. 
    /// While the volume can be muted the <see cref="GetMasterVolume"/> will still return the pre-muted volume value.
    /// </summary>
    /// <returns>false if not muted, true if volume is muted</returns>
    public static bool GetMasterVolumeMute()
    {
        IAudioEndpointVolume masterVol = null;
        try
        {
            masterVol = GetMasterVolumeObject();
            if (masterVol == null)
                return false;

            bool isMuted;
            masterVol.GetMute(out isMuted);
            return isMuted;
        }
        finally
        {
            if (masterVol != null)
                Marshal.ReleaseComObject(masterVol);
        }
    }

    private static IAudioEndpointVolume GetMasterVolumeObject()
    {
        IMMDeviceEnumerator deviceEnumerator = null;
        IMMDevice speakers = null;
        try
        {
            deviceEnumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
            deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia, out speakers);

            Guid IID_IAudioEndpointVolume = typeof(IAudioEndpointVolume).GUID;
            object o;
            speakers.Activate(ref IID_IAudioEndpointVolume, 0, IntPtr.Zero, out o);
            IAudioEndpointVolume masterVol = (IAudioEndpointVolume)o;

            return masterVol;
        }
        finally
        {
            if (speakers != null) Marshal.ReleaseComObject(speakers);
            if (deviceEnumerator != null) Marshal.ReleaseComObject(deviceEnumerator);
        }
    }

    #region Abstracted COM interfaces from Windows CoreAudio API

    [ComImport]
    [Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
    internal class MMDeviceEnumerator
    {
    }

    internal enum EDataFlow
    {
        eRender,
        eCapture,
        eAll,
        EDataFlow_enum_count
    }

    internal enum ERole
    {
        eConsole,
        eMultimedia,
        eCommunications,
        ERole_enum_count
    }

    [Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IMMDeviceEnumerator
    {
        int NotImpl1();

        [PreserveSig]
        int GetDefaultAudioEndpoint(EDataFlow dataFlow, ERole role, out IMMDevice ppDevice);
    }

    [Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IMMDevice
    {
        [PreserveSig]
        int Activate(ref Guid iid, int dwClsCtx, IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);
    }


    // http://netcoreaudio.codeplex.com/SourceControl/latest#trunk/Code/CoreAudio/Interfaces/IAudioEndpointVolume.cs
    [Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface IAudioEndpointVolume
    {
        [PreserveSig]
        int NotImpl1();

        [PreserveSig]
        int NotImpl2();

        /// <summary>
        /// Gets a count of the channels in the audio stream.
        /// </summary>
        /// <param name="channelCount">The number of channels.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetChannelCount(
            [Out] [MarshalAs(UnmanagedType.U4)] out UInt32 channelCount);

        /// <summary>
        /// Sets the master volume level of the audio stream, in decibels.
        /// </summary>
        /// <param name="level">The new master volume level in decibels.</param>
        /// <param name="eventContext">A user context value that is passed to the notification callback.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int SetMasterVolumeLevel(
            [In] [MarshalAs(UnmanagedType.R4)] float level,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Sets the master volume level, expressed as a normalized, audio-tapered value.
        /// </summary>
        /// <param name="level">The new master volume level expressed as a normalized value between 0.0 and 1.0.</param>
        /// <param name="eventContext">A user context value that is passed to the notification callback.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int SetMasterVolumeLevelScalar(
            [In] [MarshalAs(UnmanagedType.R4)] float level,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Gets the master volume level of the audio stream, in decibels.
        /// </summary>
        /// <param name="level">The volume level in decibels.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetMasterVolumeLevel(
            [Out] [MarshalAs(UnmanagedType.R4)] out float level);

        /// <summary>
        /// Gets the master volume level, expressed as a normalized, audio-tapered value.
        /// </summary>
        /// <param name="level">The volume level expressed as a normalized value between 0.0 and 1.0.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetMasterVolumeLevelScalar(
            [Out] [MarshalAs(UnmanagedType.R4)] out float level);

        /// <summary>
        /// Sets the volume level, in decibels, of the specified channel of the audio stream.
        /// </summary>
        /// <param name="channelNumber">The channel number.</param>
        /// <param name="level">The new volume level in decibels.</param>
        /// <param name="eventContext">A user context value that is passed to the notification callback.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int SetChannelVolumeLevel(
            [In] [MarshalAs(UnmanagedType.U4)] UInt32 channelNumber,
            [In] [MarshalAs(UnmanagedType.R4)] float level,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Sets the normalized, audio-tapered volume level of the specified channel in the audio stream.
        /// </summary>
        /// <param name="channelNumber">The channel number.</param>
        /// <param name="level">The new master volume level expressed as a normalized value between 0.0 and 1.0.</param>
        /// <param name="eventContext">A user context value that is passed to the notification callback.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int SetChannelVolumeLevelScalar(
            [In] [MarshalAs(UnmanagedType.U4)] UInt32 channelNumber,
            [In] [MarshalAs(UnmanagedType.R4)] float level,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Gets the volume level, in decibels, of the specified channel in the audio stream.
        /// </summary>
        /// <param name="channelNumber">The zero-based channel number.</param>
        /// <param name="level">The volume level in decibels.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetChannelVolumeLevel(
            [In] [MarshalAs(UnmanagedType.U4)] UInt32 channelNumber,
            [Out] [MarshalAs(UnmanagedType.R4)] out float level);

        /// <summary>
        /// Gets the normalized, audio-tapered volume level of the specified channel of the audio stream.
        /// </summary>
        /// <param name="channelNumber">The zero-based channel number.</param>
        /// <param name="level">The volume level expressed as a normalized value between 0.0 and 1.0.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetChannelVolumeLevelScalar(
            [In] [MarshalAs(UnmanagedType.U4)] UInt32 channelNumber,
            [Out] [MarshalAs(UnmanagedType.R4)] out float level);

        /// <summary>
        /// Sets the muting state of the audio stream.
        /// </summary>
        /// <param name="isMuted">True to mute the stream, or false to unmute the stream.</param>
        /// <param name="eventContext">A user context value that is passed to the notification callback.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int SetMute(
            [In] [MarshalAs(UnmanagedType.Bool)] Boolean isMuted,
            [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

        /// <summary>
        /// Gets the muting state of the audio stream.
        /// </summary>
        /// <param name="isMuted">The muting state. True if the stream is muted, false otherwise.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetMute(
            [Out] [MarshalAs(UnmanagedType.Bool)] out Boolean isMuted);

        /// <summary>
        /// Gets information about the current step in the volume range.
        /// </summary>
        /// <param name="step">The current zero-based step index.</param>
        /// <param name="stepCount">The total number of steps in the volume range.</param>
        /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
        [PreserveSig]
        int GetVolumeStepInfo(
            [Out] [MarshalAs(UnmanagedType.U4)] out UInt32 step,
            [Out] [MarshalAs(UnmanagedType.U4)] out UInt32 stepCount);

    }

    #endregion
}

Usage:

Call GetMasterVolumeMute() method:

bool isMuted = AudioManager.GetMasterVolumeMute();

Answer 2

What kind of project are you creating? One idea is to create a media player (in the background) and test for the media playback volume.

_mediaPlayer = new MediaPlayer();
_systemMediaTransportControls = _mediaPlayer.SystemMediaTransportControls;
double volume = _systemMediaTransportControls.Volume;