From d1230c292e39283aaef66d405d23be3b6f7afb62 Mon Sep 17 00:00:00 2001
From: jpark37 <jpark37@users.noreply.github.com>
Date: Mon, 27 Sep 2021 12:17:57 -0700
Subject: [PATCH] win-wasapi: Register capture thread with MMCSS

Ensure audio gets more priority to help prevent glitching.
---
 plugins/win-wasapi/CMakeLists.txt | 1 +
 plugins/win-wasapi/win-wasapi.cpp | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/plugins/win-wasapi/CMakeLists.txt b/plugins/win-wasapi/CMakeLists.txt
index 387efb608..4a5542960 100644
--- a/plugins/win-wasapi/CMakeLists.txt
+++ b/plugins/win-wasapi/CMakeLists.txt
@@ -15,6 +15,7 @@ add_library(win-wasapi MODULE
 	${win-wasapi_SOURCES}
 	${win-wasapi_HEADERS})
 target_link_libraries(win-wasapi
+	Avrt
 	libobs)
 set_target_properties(win-wasapi PROPERTIES FOLDER "plugins")
 
diff --git a/plugins/win-wasapi/win-wasapi.cpp b/plugins/win-wasapi/win-wasapi.cpp
index 03597f7e1..801fd9c10 100644
--- a/plugins/win-wasapi/win-wasapi.cpp
+++ b/plugins/win-wasapi/win-wasapi.cpp
@@ -13,6 +13,8 @@
 #include <atomic>
 #include <cinttypes>
 
+#include <avrt.h>
+
 using namespace std;
 
 #define OPT_DEVICE_ID "device_id"
@@ -577,6 +579,9 @@ DWORD WINAPI WASAPISource::CaptureThread(LPVOID param)
 		     hr);
 	}
 
+	DWORD unused = 0;
+	const HANDLE handle = AvSetMmThreadCharacteristics(L"Audio", &unused);
+
 	WASAPISource *source = (WASAPISource *)param;
 
 	const HANDLE inactive_sigs[] = {
@@ -684,6 +689,9 @@ DWORD WINAPI WASAPISource::CaptureThread(LPVOID param)
 		}
 	}
 
+	if (handle)
+		AvRevertMmThreadCharacteristics(handle);
+
 	if (com_initialized)
 		CoUninitialize();