get the app output device

src/FocusVolumeControl/AudioHelpers/AudioHelper.cs

@@ -3,6 +3,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Runtime.InteropServices;
 
 namespace FocusVolumeControl.AudioHelpers;
 
@@ -38,6 +39,7 @@ public class AudioHelper
 
 	public IAudioSession FindSession(List<Process> processes)
 	{
+		//var blah = new AudioPolicyConfigFactoryImplFor21H2();
 		var results = new ActiveAudioSessionWrapper();
 		Process bestProcessMatch = null;
 
@@ -72,6 +74,16 @@ public class AudioHelper
 					continue;
 				}
 
+				/*
+				blah.GetPersistedDefaultAudioEndpoint(sessionProcessId, DataFlow.Render, Role.Multimedia, out var persistedDeviceId);
+				persistedDeviceId = UnpackDeviceId(persistedDeviceId);
+				if(!string.IsNullOrEmpty(persistedDeviceId) && persistedDeviceId != currentDeviceId)
+				{
+					continue;
+
+				}
+				*/
+
 				var index = processes.FindIndex(x => x.Id == sessionProcessId || x.ProcessName == audioProcess?.ProcessName);
 
 				if (index > -1)
@@ -287,4 +299,124 @@ public class AudioHelper
 		return new SystemVolumeAudioSession(endpointVolume);
 	}
 
+
+
+
+	class AudioPolicyConfigFactoryImplFor21H2
+	{
+		private readonly IAudioPolicyConfigFactoryVariantFor21H2 _factory;
+
+		internal AudioPolicyConfigFactoryImplFor21H2()
+		{
+			var iid = typeof(IAudioPolicyConfigFactoryVariantFor21H2).GUID;
+			Combase.RoGetActivationFactory("Windows.Media.Internal.AudioPolicyConfig", ref iid, out object factory);
+			_factory = (IAudioPolicyConfigFactoryVariantFor21H2)factory;
+		}
+
+		public uint ClearAllPersistedApplicationDefaultEndpoints()
+		{
+			return _factory.ClearAllPersistedApplicationDefaultEndpoints();
+		}
+
+		public uint GetPersistedDefaultAudioEndpoint(int processId, DataFlow flow, Role role, out string deviceId)
+		{
+			return _factory.GetPersistedDefaultAudioEndpoint(processId, flow, role, out deviceId);
+		}
+
+		public uint SetPersistedDefaultAudioEndpoint(int processId, DataFlow flow, Role role, IntPtr deviceId)
+		{
+			return _factory.SetPersistedDefaultAudioEndpoint(processId, flow, role, deviceId);
+		}
+	}
+
+
+	[Guid("ab3d4648-e242-459f-b02f-541c70306324")]
+	[InterfaceType(ComInterfaceType.InterfaceIsIInspectable)]
+	public interface IAudioPolicyConfigFactoryVariantFor21H2
+	{
+		int __incomplete__add_CtxVolumeChange();
+		int __incomplete__remove_CtxVolumeChanged();
+		int __incomplete__add_RingerVibrateStateChanged();
+		int __incomplete__remove_RingerVibrateStateChange();
+		int __incomplete__SetVolumeGroupGainForId();
+		int __incomplete__GetVolumeGroupGainForId();
+		int __incomplete__GetActiveVolumeGroupForEndpointId();
+		int __incomplete__GetVolumeGroupsForEndpoint();
+		int __incomplete__GetCurrentVolumeContext();
+		int __incomplete__SetVolumeGroupMuteForId();
+		int __incomplete__GetVolumeGroupMuteForId();
+		int __incomplete__SetRingerVibrateState();
+		int __incomplete__GetRingerVibrateState();
+		int __incomplete__SetPreferredChatApplication();
+		int __incomplete__ResetPreferredChatApplication();
+		int __incomplete__GetPreferredChatApplication();
+		int __incomplete__GetCurrentChatApplications();
+		int __incomplete__add_ChatContextChanged();
+		int __incomplete__remove_ChatContextChanged();
+		[PreserveSig]
+		uint SetPersistedDefaultAudioEndpoint(int processId, DataFlow flow, Role role, IntPtr deviceId);
+		[PreserveSig]
+		uint GetPersistedDefaultAudioEndpoint(int processId, DataFlow flow, Role role, [Out, MarshalAs(UnmanagedType.HString)] out string deviceId);
+		[PreserveSig]
+		uint ClearAllPersistedApplicationDefaultEndpoints();
+	}
+
+	[Guid("2a59116d-6c4f-45e0-a74f-707e3fef9258")]
+	[InterfaceType(ComInterfaceType.InterfaceIsIInspectable)]
+	public interface IAudioPolicyConfigFactoryVariantForDownlevel
+	{
+		int __incomplete__add_CtxVolumeChange();
+		int __incomplete__remove_CtxVolumeChanged();
+		int __incomplete__add_RingerVibrateStateChanged();
+		int __incomplete__remove_RingerVibrateStateChange();
+		int __incomplete__SetVolumeGroupGainForId();
+		int __incomplete__GetVolumeGroupGainForId();
+		int __incomplete__GetActiveVolumeGroupForEndpointId();
+		int __incomplete__GetVolumeGroupsForEndpoint();
+		int __incomplete__GetCurrentVolumeContext();
+		int __incomplete__SetVolumeGroupMuteForId();
+		int __incomplete__GetVolumeGroupMuteForId();
+		int __incomplete__SetRingerVibrateState();
+		int __incomplete__GetRingerVibrateState();
+		int __incomplete__SetPreferredChatApplication();
+		int __incomplete__ResetPreferredChatApplication();
+		int __incomplete__GetPreferredChatApplication();
+		int __incomplete__GetCurrentChatApplications();
+		int __incomplete__add_ChatContextChanged();
+		int __incomplete__remove_ChatContextChanged();
+		[PreserveSig]
+		uint SetPersistedDefaultAudioEndpoint(int processId, DataFlow flow, Role role, IntPtr deviceId);
+		[PreserveSig]
+		uint GetPersistedDefaultAudioEndpoint(int processId, DataFlow flow, Role role, [Out, MarshalAs(UnmanagedType.HString)] out string deviceId);
+		[PreserveSig]
+		uint ClearAllPersistedApplicationDefaultEndpoints();
+	}
+
+	static class Combase
+	{
+		[DllImport("combase.dll", PreserveSig = false)]
+		public static extern void RoGetActivationFactory(
+			[MarshalAs(UnmanagedType.HString)] string activatableClassId,
+			[In] ref Guid iid,
+			[Out, MarshalAs(UnmanagedType.IInspectable)] out Object factory);
+
+		[DllImport("combase.dll", PreserveSig = false)]
+		public static extern void WindowsCreateString(
+			[MarshalAs(UnmanagedType.LPWStr)] string src,
+			[In] uint length,
+			[Out] out IntPtr hstring);
+	}
+
+	private const string DEVINTERFACE_AUDIO_RENDER = "#{e6327cad-dcec-4949-ae8a-991e976a79d2}";
+	private const string DEVINTERFACE_AUDIO_CAPTURE = "#{2eef81be-33fa-4800-9670-1cd474972c3f}";
+	private const string MMDEVAPI_TOKEN = @"\\?\SWD#MMDEVAPI#";
+	private string UnpackDeviceId(string deviceId)
+	{
+		if (deviceId.StartsWith(MMDEVAPI_TOKEN)) deviceId = deviceId.Remove(0, MMDEVAPI_TOKEN.Length);
+		if (deviceId.EndsWith(DEVINTERFACE_AUDIO_RENDER)) deviceId = deviceId.Remove(deviceId.Length - DEVINTERFACE_AUDIO_RENDER.Length);
+		if (deviceId.EndsWith(DEVINTERFACE_AUDIO_CAPTURE)) deviceId = deviceId.Remove(deviceId.Length - DEVINTERFACE_AUDIO_CAPTURE.Length);
+		return deviceId;
+	}
+
+
 }