From 543a7ed991b005c2261e9b6e59ee825e42e86413 Mon Sep 17 00:00:00 2001
From: David Reid <mackron@gmail.com>
Date: Fri, 9 Sep 2022 10:07:09 +1000
Subject: [PATCH] WASAPI: Use the correct virtual device for process-specific
 loopback.

Public issue https://github.com/mackron/miniaudio/issues/484
---
 miniaudio.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/miniaudio.h b/miniaudio.h
index 3546101e..c0aec9c4 100644
--- a/miniaudio.h
+++ b/miniaudio.h
@@ -20925,11 +20925,14 @@ typedef struct
     #pragma GCC diagnostic pop
 #endif
 
+#define MA_VIRTUAL_AUDIO_DEVICE_PROCESS_LOOPBACK L"VAD\\Process_Loopback"
+
 static ma_result ma_context_get_IAudioClient__wasapi(ma_context* pContext, ma_device_type deviceType, const ma_device_id* pDeviceID, ma_uint32 loopbackProcessID, ma_bool32 loopbackProcessExclude, ma_IAudioClient** ppAudioClient, ma_WASAPIDeviceInterface** ppDeviceInterface)
 {
     MA_AUDIOCLIENT_ACTIVATION_PARAMS audioclientActivationParams;
     PROPVARIANT activationParams;
     PROPVARIANT* pActivationParams = NULL;
+    ma_device_id virtualDeviceID;
 
     /* Activation parameters specific to loopback mode. */
     if (deviceType == ma_device_type_loopback && loopbackProcessID != 0) {
@@ -20942,8 +20945,11 @@ static ma_result ma_context_get_IAudioClient__wasapi(ma_context* pContext, ma_de
         activationParams.vt             = VT_BLOB;
         activationParams.blob.cbSize    = sizeof(audioclientActivationParams);
         activationParams.blob.pBlobData = (BYTE*)&audioclientActivationParams;
-
         pActivationParams = &activationParams;
+
+        /* When requesting a specific device ID we need to use a special device ID. */
+        MA_COPY_MEMORY(virtualDeviceID.wasapi, MA_VIRTUAL_AUDIO_DEVICE_PROCESS_LOOPBACK, (wcslen(MA_VIRTUAL_AUDIO_DEVICE_PROCESS_LOOPBACK) + 1) * sizeof(wchar_t)); /* +1 for the null terminator. */
+        pDeviceID = &virtualDeviceID;
     } else {
         pActivationParams = NULL;   /* No activation parameters required. */
     }