using System;

using System.Collections.Generic;

using System.Runtime.InteropServices;

using System.Collections;

using static FlowTimer.MMDeviceAPI;

namespace FlowTimer {

[StructLayout(LayoutKind.Sequential, Pack = 1)]

public struct WAVEFORMATEX {

public ushort wFormatTag;

public short nChannels;

public int nSamplesPerSec;

public int nAvgBytesPerSec;

public short nBlockAlign;

public short wBitsPerSample;

public short cbSize;

}

[StructLayout(LayoutKind.Explicit)]

public struct WAVEFORMATEXTENSIBLE {

[FieldOffset(0x00)] public WAVEFORMATEX Format;

[FieldOffset(0x12)] public short wValidBitsPerSample;

[FieldOffset(0x12)] public short wSamplesPerBlock;

[FieldOffset(0x12)] public short wValidBitsPewReservedrSample;

[FieldOffset(0x14)] public uint dwChannelMask;

[FieldOffset(0x18)] public Guid SubFormat;

}

[Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]

public interface IMMDevice {

int Activate(ref Guid iid, uint dwClsCtx, IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);

}

[Guid("0BD7A1BE-7A1A-44DB-8397-CC5392387B5E"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]

public interface IMMDeviceCollection {

int GetCount(out int pcDevices);

int Item(int nDevice, out IMMDevice ppDevice);

}

[Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]

public interface IMMDeviceEnumerator {

int EnumAudioEndpoints(DataFlow dataFlow, uint dwStateMask, out IMMDeviceCollection ppDevices);

int GetDefaultAudioEndpoint(DataFlow dataFlow, Role role, out IMMDevice ppEndPoint);

}

[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("7ED4EE07-8E67-4CD4-8C1A-2B7A5987AD42")]

public interface IAudioClient3 {

int Initialize(uint shareMode, uint streamFlags, long hnsBufferDuration, long hnsPeriodicity, WAVEFORMATEX pFormat, IntPtr audioSessionGuid);

int GetBufferSize(out uint bufferSize);

[return: MarshalAs(UnmanagedType.I8)] long GetStreamLatency();

int GetCurrentPadding(out int currentPadding);

int IsFormatSupported(uint shareMode, WAVEFORMATEX pFormat, out IntPtr closestMatchFormat);

int GetMixFormat(out IntPtr deviceFormatPointer);

int GetDevicePeriod(out long defaultDevicePeriod, out long minimumDevicePeriod);

int Start();

int Stop();

int Reset();

int SetEventHandle(IntPtr eventHandle);

int GetService([MarshalAs(UnmanagedType.LPStruct)] Guid interfaceId, [MarshalAs(UnmanagedType.IUnknown)] out object interfacePointer);

void IsOffloadCapable(int category, out bool pbOffloadCapable);

void SetClientProperties(IntPtr pProperties);

void GetBufferSizeLimits(IntPtr pFormat, bool bEventDriven, out long phnsMinBufferDuration, out long phnsMaxBufferDuration);

int GetSharedModeEnginePeriod(IntPtr pFormat, out int pDefaultPeriodInFrames, out int pFundementalPeriodInFrames, out int pMinPeriodInFrames, out int pMaxPeriodInFrames);

int GetCurrentSharedModeEnginePeriod(IntPtr ppFormat, out uint pCurrentPeriodInFrames);

}

public class MMDevice {

private IMMDevice Interface;

public MMDevice(IMMDevice interfaceIn) => Interface = interfaceIn;

public AudioClient CreateAudioCilent() {

Interface.Activate(ref IAudioClient3ID, CLSCTX_ALL, IntPtr.Zero, out object audioClientInterface);

return new AudioClient(audioClientInterface as IAudioClient3);

}

}

public class MMDeviceCollection : IEnumerable<MMDevice> {

private IMMDeviceCollection Interface;

public MMDeviceCollection(IMMDeviceCollection interfaceIn) => Interface = interfaceIn;

public int Count {

get {

Interface.GetCount(out int result);

return result;

}

}

public MMDevice this[int index] {

get {

Interface.Item(index, out IMMDevice result);

return new MMDevice(result);

}

}

public IEnumerator<MMDevice> GetEnumerator() {

for(int i = 0; i < Count; i++) {

yield return this[i];

}

}

IEnumerator IEnumerable.GetEnumerator() {

return GetEnumerator();

}

}

public class MMDeviceEnumerator {

private IMMDeviceEnumerator Interface;

public MMDeviceEnumerator(IMMDeviceEnumerator interfaceIn) => Interface = interfaceIn;

public MMDeviceCollection EnumerateAudioEndPoints(DataFlow dataFlow, uint dwStateMask) {

Interface.EnumAudioEndpoints(dataFlow, dwStateMask, out IMMDeviceCollection result);

return new MMDeviceCollection(result);

}

public MMDevice GetDefaultAudioEndpoint(DataFlow dataFlow, Role role) {

Interface.GetDefaultAudioEndpoint(dataFlow, role, out IMMDevice result);

return new MMDevice(result);

}

}

public class AudioClient {

private IAudioClient3 Interface;

public AudioClient(IAudioClient3 interfaceIn) => Interface = interfaceIn;

public IntPtr MixFormat {

get {

Interface.GetMixFormat(out IntPtr result);

return result;

}

}

public void GetSharedModeEnginePeriod(out int defaultPeriod, out int fundementalPeriod, out int minPeriod, out int maxPeriod) {

Interface.GetSharedModeEnginePeriod(MixFormat, out defaultPeriod, out fundementalPeriod, out minPeriod, out maxPeriod);

}

}

public enum DataFlow : uint {

Render,

Capture,

All,

}

public enum Role : uint {

Console,

Multimedia,

Communications,

}

public static class MMDeviceAPI {

public static Guid MMDeviceEnumeratorID = new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E");

public static Guid IAudioClient3ID = new Guid("7ED4EE07-8E67-4CD4-8C1A-2B7A5987AD42");

public const uint DEVICE_STATE_ACTIVATE = 0x1;

public const uint DEVICE_STATE_DISABLED = 0x2;

public const uint DEVICE_STATE_NOTPRESENT = 0x4;

public const uint DEVICE_STATE_UNPLUGGED = 0x8;

public const uint CLSCTX_INPROC_SERVER = 0x1;

public const uint CLSCTX_INPROC_HANDLER = 0x2;

public const uint CLSCTX_LOCAL_SERVER = 0x4;

public const uint CLSCTX_INPROC_SERVER16 = 0x8;

public const uint CLSCTX_REMOTE_SERVER = 0x10;

public const uint CLSCTX_INPROC_HANDLER16 = 0x20;

public const uint CLSCTX_RESERVED1 = 0x40;

public const uint CLSCTX_RESERVED2 = 0x80;

public const uint CLSCTX_RESERVED3 = 0x100;

public const uint CLSCTX_RESERVED4 = 0x200;

public const uint CLSCTX_NO_CODE_DOWNLOAD = 0x400;

public const uint CLSCTX_RESERVED5 = 0x800;

public const uint CLSCTX_NO_CUSTOM_MARSHAL = 0x1000;

public const uint CLSCTX_ENABLE_CODE_DOWNLOAD = 0x2000;

public const uint CLSCTX_NO_FAILURE_LOG = 0x4000;

public const uint CLSCTX_DISABLE_AAA = 0x8000;

public const uint CLSCTX_ENABLE_AAA = 0x10000;

public const uint CLSCTX_FROM_DEFAULT_CONTEXT = 0x20000;

public const uint CLSCTX_ACTIVATE_32_BIT_SERVER = 0x40000;

public const uint CLSCTX_ACTIVATE_64_BIT_SERVER = 0x80000;

public const uint CLSCTX_ENABLE_CLOAKING = 0x100000;

public const uint CLSCTX_PS_DLL = 0x80000000;

public const uint CLSCTX_INPROC = CLSCTX_INPROC_SERVER | CLSCTX_INPROC_HANDLER;

public const uint CLSCTX_SERVER = CLSCTX_INPROC_SERVER | CLSCTX_LOCAL_SERVER | CLSCTX_REMOTE_SERVER;

public const uint CLSCTX_ALL = CLSCTX_SERVER | CLSCTX_INPROC_HANDLER;

public static MMDeviceEnumerator CreateMMDeviceEnumerator() {

return new MMDeviceEnumerator(CreateInternal<IMMDeviceEnumerator>(MMDeviceEnumeratorID));

}

private static T CreateInternal<T>(Guid guid) {

Type type = Type.GetTypeFromCLSID(guid);

return (T) Activator.CreateInstance(type);

}

}

}