From 3ceee008f396b1355a32cf434c110cc00707aeaf Mon Sep 17 00:00:00 2001
From: ns6089 <61738816+ns6089@users.noreply.github.com>
Date: Wed, 16 Aug 2023 02:13:31 +0300
Subject: [PATCH] Use MMCSS task in audio capture thread

---
 CMakeLists.txt                 |  1 +
 src/platform/windows/audio.cpp | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7a13b46f..3fa910ef 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -204,6 +204,7 @@ if(WIN32)
             dwmapi
             userenv
             synchronization.lib
+            avrt
             ${CURL_STATIC_LIBRARIES})
 
     set_source_files_properties(third-party/ViGEmClient/src/ViGEmClient.cpp
diff --git a/src/platform/windows/audio.cpp b/src/platform/windows/audio.cpp
index 1f794e24..b10e6a7c 100644
--- a/src/platform/windows/audio.cpp
+++ b/src/platform/windows/audio.cpp
@@ -13,6 +13,8 @@
 
 #include <newdev.h>
 
+#include <avrt.h>
+
 #include "src/config.h"
 #include "src/main.h"
 #include "src/platform/common.h"
@@ -449,6 +451,14 @@ namespace platf::audio {
         return -1;
       }
 
+      {
+        DWORD task_index = 0;
+        mmcss_task_handle = AvSetMmThreadCharacteristics("Pro Audio", &task_index);
+        if (!mmcss_task_handle) {
+          BOOST_LOG(error) << "Couldn't associate audio capture thread with Pro Audio MMCSS task [0x" << util::hex(GetLastError()).to_string_view() << ']';
+        }
+      }
+
       status = audio_client->Start();
       if (FAILED(status)) {
         BOOST_LOG(error) << "Couldn't start recording [0x"sv << util::hex(status).to_string_view() << ']';
@@ -467,6 +477,10 @@ namespace platf::audio {
       if (audio_client) {
         audio_client->Stop();
       }
+
+      if (mmcss_task_handle) {
+        AvRevertMmThreadCharacteristics(mmcss_task_handle);
+      }
     }
 
   private:
@@ -571,6 +585,8 @@ namespace platf::audio {
     util::buffer_t<std::int16_t> sample_buf;
     std::int16_t *sample_buf_pos;
     int channels;
+
+    HANDLE mmcss_task_handle = NULL;
   };
 
   class audio_control_t: public ::platf::audio_control_t {