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barron9/AudioManager.cs

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Created December 31, 2020 16:35
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  1. @sverrirs sverrirs created this gist Feb 1, 2016.
    620 changes: 620 additions & 0 deletions AudioManager.cs
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,620 @@
    using System;
    using System.Runtime.InteropServices;
    // ReSharper disable SuspiciousTypeConversion.Global
    // ReSharper disable InconsistentNaming

    namespace VideoPlayerController
    {
    /// <summary>
    /// Controls audio using the Windows CoreAudio API
    /// from: http://stackoverflow.com/questions/14306048/controling-volume-mixer
    /// and: http://netcoreaudio.codeplex.com/
    /// </summary>
    public static class AudioManager
    {
    #region Master Volume Manipulation

    /// <summary>
    /// Gets the current master volume in scalar values (percentage)
    /// </summary>
    /// <returns>-1 in case of an error, if successful the value will be between 0 and 100</returns>
    public static float GetMasterVolume()
    {
    IAudioEndpointVolume masterVol = null;
    try
    {
    masterVol = GetMasterVolumeObject();
    if (masterVol == null)
    return -1;

    float volumeLevel;
    masterVol.GetMasterVolumeLevelScalar(out volumeLevel);
    return volumeLevel*100;
    }
    finally
    {
    if (masterVol != null)
    Marshal.ReleaseComObject(masterVol);
    }
    }

    /// <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);
    }
    }

    /// <summary>
    /// Sets the master volume to a specific level
    /// </summary>
    /// <param name="newLevel">Value between 0 and 100 indicating the desired scalar value of the volume</param>
    public static void SetMasterVolume(float newLevel)
    {
    IAudioEndpointVolume masterVol = null;
    try
    {
    masterVol = GetMasterVolumeObject();
    if (masterVol == null)
    return;

    masterVol.SetMasterVolumeLevelScalar(newLevel/100, Guid.Empty);
    }
    finally
    {
    if (masterVol != null)
    Marshal.ReleaseComObject(masterVol);
    }
    }

    /// <summary>
    /// Increments or decrements the current volume level by the <see cref="stepAmount"/>.
    /// </summary>
    /// <param name="stepAmount">Value between -100 and 100 indicating the desired step amount. Use negative numbers to decrease
    /// the volume and positive numbers to increase it.</param>
    /// <returns>the new volume level assigned</returns>
    public static float StepMasterVolume(float stepAmount)
    {
    IAudioEndpointVolume masterVol = null;
    try
    {
    masterVol = GetMasterVolumeObject();
    if (masterVol == null)
    return -1;

    float stepAmountScaled = stepAmount/100;

    // Get the level
    float volumeLevel;
    masterVol.GetMasterVolumeLevelScalar(out volumeLevel);

    // Calculate the new level
    float newLevel = volumeLevel + stepAmountScaled;
    newLevel = Math.Min(1, newLevel);
    newLevel = Math.Max(0, newLevel);

    masterVol.SetMasterVolumeLevelScalar(newLevel, Guid.Empty);

    // Return the new volume level that was set
    return newLevel*100;
    }
    finally
    {
    if (masterVol != null)
    Marshal.ReleaseComObject(masterVol);
    }
    }

    /// <summary>
    /// Mute or unmute the master volume
    /// </summary>
    /// <param name="isMuted">true to mute the master volume, false to unmute</param>
    public static void SetMasterVolumeMute(bool isMuted)
    {
    IAudioEndpointVolume masterVol = null;
    try
    {
    masterVol = GetMasterVolumeObject();
    if (masterVol == null)
    return;

    masterVol.SetMute(isMuted, Guid.Empty);
    }
    finally
    {
    if (masterVol != null)
    Marshal.ReleaseComObject(masterVol);
    }
    }

    /// <summary>
    /// Switches between the master volume mute states depending on the current state
    /// </summary>
    /// <returns>the current mute state, true if the volume was muted, false if unmuted</returns>
    public static bool ToggleMasterVolumeMute()
    {
    IAudioEndpointVolume masterVol = null;
    try
    {
    masterVol = GetMasterVolumeObject();
    if (masterVol == null)
    return false;

    bool isMuted;
    masterVol.GetMute(out isMuted);
    masterVol.SetMute(!isMuted, Guid.Empty);

    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);
    }
    }

    #endregion

    #region Individual Application Volume Manipulation

    public static float? GetApplicationVolume(int pid)
    {
    ISimpleAudioVolume volume = GetVolumeObject(pid);
    if (volume == null)
    return null;

    float level;
    volume.GetMasterVolume(out level);
    Marshal.ReleaseComObject(volume);
    return level*100;
    }

    public static bool? GetApplicationMute(int pid)
    {
    ISimpleAudioVolume volume = GetVolumeObject(pid);
    if (volume == null)
    return null;

    bool mute;
    volume.GetMute(out mute);
    Marshal.ReleaseComObject(volume);
    return mute;
    }

    public static void SetApplicationVolume(int pid, float level)
    {
    ISimpleAudioVolume volume = GetVolumeObject(pid);
    if (volume == null)
    return;

    Guid guid = Guid.Empty;
    volume.SetMasterVolume(level/100, ref guid);
    Marshal.ReleaseComObject(volume);
    }

    public static void SetApplicationMute(int pid, bool mute)
    {
    ISimpleAudioVolume volume = GetVolumeObject(pid);
    if (volume == null)
    return;

    Guid guid = Guid.Empty;
    volume.SetMute(mute, ref guid);
    Marshal.ReleaseComObject(volume);
    }

    private static ISimpleAudioVolume GetVolumeObject(int pid)
    {
    IMMDeviceEnumerator deviceEnumerator = null;
    IAudioSessionEnumerator sessionEnumerator = null;
    IAudioSessionManager2 mgr = null;
    IMMDevice speakers = null;
    try
    {
    // get the speakers (1st render + multimedia) device
    deviceEnumerator = (IMMDeviceEnumerator) (new MMDeviceEnumerator());
    deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia, out speakers);

    // activate the session manager. we need the enumerator
    Guid IID_IAudioSessionManager2 = typeof (IAudioSessionManager2).GUID;
    object o;
    speakers.Activate(ref IID_IAudioSessionManager2, 0, IntPtr.Zero, out o);
    mgr = (IAudioSessionManager2) o;

    // enumerate sessions for on this device
    mgr.GetSessionEnumerator(out sessionEnumerator);
    int count;
    sessionEnumerator.GetCount(out count);

    // search for an audio session with the required process-id
    ISimpleAudioVolume volumeControl = null;
    for (int i = 0; i < count; ++i)
    {
    IAudioSessionControl2 ctl = null;
    try
    {
    sessionEnumerator.GetSession(i, out ctl);

    // NOTE: we could also use the app name from ctl.GetDisplayName()
    int cpid;
    ctl.GetProcessId(out cpid);

    if (cpid == pid)
    {
    volumeControl = ctl as ISimpleAudioVolume;
    break;
    }
    }
    finally
    {
    if (ctl != null) Marshal.ReleaseComObject(ctl);
    }
    }

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

    #endregion

    }

    #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);

    // the rest is not implemented
    }

    [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);

    // the rest is not implemented
    }

    [Guid("77AA99A0-1BD6-484F-8BC7-2C654C9A9B6F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IAudioSessionManager2
    {
    int NotImpl1();
    int NotImpl2();

    [PreserveSig]
    int GetSessionEnumerator(out IAudioSessionEnumerator SessionEnum);

    // the rest is not implemented
    }

    [Guid("E2F5BB11-0570-40CA-ACDD-3AA01277DEE8"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IAudioSessionEnumerator
    {
    [PreserveSig]
    int GetCount(out int SessionCount);

    [PreserveSig]
    int GetSession(int SessionCount, out IAudioSessionControl2 Session);
    }

    [Guid("87CE5498-68D6-44E5-9215-6DA47EF883D8"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface ISimpleAudioVolume
    {
    [PreserveSig]
    int SetMasterVolume(float fLevel, ref Guid EventContext);

    [PreserveSig]
    int GetMasterVolume(out float pfLevel);

    [PreserveSig]
    int SetMute(bool bMute, ref Guid EventContext);

    [PreserveSig]
    int GetMute(out bool pbMute);
    }

    [Guid("bfb7ff88-7239-4fc9-8fa2-07c950be9c6d"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    internal interface IAudioSessionControl2
    {
    // IAudioSessionControl
    [PreserveSig]
    int NotImpl0();

    [PreserveSig]
    int GetDisplayName([MarshalAs(UnmanagedType.LPWStr)] out string pRetVal);

    [PreserveSig]
    int SetDisplayName([MarshalAs(UnmanagedType.LPWStr)]string Value, [MarshalAs(UnmanagedType.LPStruct)] Guid EventContext);

    [PreserveSig]
    int GetIconPath([MarshalAs(UnmanagedType.LPWStr)] out string pRetVal);

    [PreserveSig]
    int SetIconPath([MarshalAs(UnmanagedType.LPWStr)] string Value, [MarshalAs(UnmanagedType.LPStruct)] Guid EventContext);

    [PreserveSig]
    int GetGroupingParam(out Guid pRetVal);

    [PreserveSig]
    int SetGroupingParam([MarshalAs(UnmanagedType.LPStruct)] Guid Override, [MarshalAs(UnmanagedType.LPStruct)] Guid EventContext);

    [PreserveSig]
    int NotImpl1();

    [PreserveSig]
    int NotImpl2();

    // IAudioSessionControl2
    [PreserveSig]
    int GetSessionIdentifier([MarshalAs(UnmanagedType.LPWStr)] out string pRetVal);

    [PreserveSig]
    int GetSessionInstanceIdentifier([MarshalAs(UnmanagedType.LPWStr)] out string pRetVal);

    [PreserveSig]
    int GetProcessId(out int pRetVal);

    [PreserveSig]
    int IsSystemSoundsSession();

    [PreserveSig]
    int SetDuckingPreference(bool optOut);
    }

    // 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);

    /// <summary>
    /// Increases the volume level by one step.
    /// </summary>
    /// <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 VolumeStepUp(
    [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

    /// <summary>
    /// Decreases the volume level by one step.
    /// </summary>
    /// <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 VolumeStepDown(
    [In] [MarshalAs(UnmanagedType.LPStruct)] Guid eventContext);

    /// <summary>
    /// Queries the audio endpoint device for its hardware-supported functions.
    /// </summary>
    /// <param name="hardwareSupportMask">A hardware support mask that indicates the capabilities of the endpoint.</param>
    /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
    [PreserveSig]
    int QueryHardwareSupport(
    [Out] [MarshalAs(UnmanagedType.U4)] out UInt32 hardwareSupportMask);

    /// <summary>
    /// Gets the volume range of the audio stream, in decibels.
    /// </summary>
    /// <param name="volumeMin">The minimum volume level in decibels.</param>
    /// <param name="volumeMax">The maximum volume level in decibels.</param>
    /// <param name="volumeStep">The volume increment level in decibels.</param>
    /// <returns>An HRESULT code indicating whether the operation passed of failed.</returns>
    [PreserveSig]
    int GetVolumeRange(
    [Out] [MarshalAs(UnmanagedType.R4)] out float volumeMin,
    [Out] [MarshalAs(UnmanagedType.R4)] out float volumeMax,
    [Out] [MarshalAs(UnmanagedType.R4)] out float volumeStep);
    }

    #endregion
    }