Low-latency AudioInputStream implementation based on WASAPI for Windows.

media/audio/win/avrt_wrapper_win.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// The avrt namespace encapsulates the details needed to support MMCSS.
+//
+// The Multimedia Class Scheduler service (MMCSS) enables multimedia
+// applications to ensure that their time-sensitive processing receives
+// prioritized access to CPU resources. This service enables multimedia
+// applications to utilize as much of the CPU as possible without denying
+// CPU resources to lower-priority applications.
+// MMCSS requires Windows Vista or higher and that the Avrt DLL is loaded.
+//
+// TODO(henrika): refactor and merge into existing thread implementation
+// for Windows to ensure that MMCSS can be enabled for all threads.
+//
+#ifndef MEDIA_AUDIO_WIN_AVRT_WRAPPER_WIN_H_
+#define MEDIA_AUDIO_WIN_AVRT_WRAPPER_WIN_H_
+
+#include <windows.h>
+#include <avrt.h>
+
+#include "base/basictypes.h"
+
+namespace avrt {
+
+// Loads the Avrt.dll which is available on Windows Vista and later.
+bool Initialize();
+
+// Function wrappers for the underlying MMCSS functions.
+bool AvRevertMmThreadCharacteristics(HANDLE avrt_handle);
+HANDLE AvSetMmThreadCharacteristics(const wchar_t* task_name,
+                                    DWORD* task_index);
+bool AvSetMmThreadPriority(HANDLE avrt_handle, AVRT_PRIORITY priority);
+
+}  // namespace avrt
+
+#endif  // MEDIA_AUDIO_WIN_AVRT_WRAPPER_WIN_H_
+