Add Wasapi audio backend

WASAPI is a Windows audio backend for low latency audio.
This backend works for WinRT as well as classic desktop apps.

Task-number: QTBUG-42287
Change-Id: I7a1b7b103b64fadc50a9955a9d59443791f6d026
Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>

1 files changed, 118 insertions, 0 deletions

diff --git a/src/plugins/wasapi/qwasapiaudiooutput.h b/src/plugins/wasapi/qwasapiaudiooutput.h
new file mode 100644
index 000000000..4575c8672
--- /dev/null
+++ b/src/plugins/wasapi/qwasapiaudiooutput.h
@@ -0,0 +1,118 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd and/or its subsidiary(-ies).
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QAUDIOOUTPUTWASAPI_H
+#define QAUDIOOUTPUTWASAPI_H
+
+#include <QtCore/QLoggingCategory>
+#include <QtCore/QMutex>
+#include <QtCore/QTime>
+#include <QtMultimedia/QAbstractAudioOutput>
+#include <QtMultimedia/QAudio>
+
+#include <QReadWriteLock>
+#include <wrl.h>
+
+struct IAudioRenderClient;
+struct IAudioStreamVolume;
+
+QT_BEGIN_NAMESPACE
+
+class AudioInterface;
+class WasapiOutputDevicePrivate;
+class QWasapiProcessThread;
+
+Q_DECLARE_LOGGING_CATEGORY(lcMmAudioOutput)
+
+class QWasapiAudioOutput : public QAbstractAudioOutput
+{
+    Q_OBJECT
+public:
+    explicit QWasapiAudioOutput(const QByteArray &device);
+    ~QWasapiAudioOutput();
+
+    void start(QIODevice* device) Q_DECL_OVERRIDE;
+    QIODevice* start() Q_DECL_OVERRIDE;
+    void stop() Q_DECL_OVERRIDE;
+    void reset() Q_DECL_OVERRIDE;
+    void suspend() Q_DECL_OVERRIDE;
+    void resume() Q_DECL_OVERRIDE;
+    int bytesFree() const Q_DECL_OVERRIDE;
+    int periodSize() const Q_DECL_OVERRIDE;
+    void setBufferSize(int value) Q_DECL_OVERRIDE;
+    int bufferSize() const Q_DECL_OVERRIDE;
+    void setNotifyInterval(int milliSeconds) Q_DECL_OVERRIDE;
+    int notifyInterval() const Q_DECL_OVERRIDE;
+    qint64 processedUSecs() const Q_DECL_OVERRIDE;
+    qint64 elapsedUSecs() const Q_DECL_OVERRIDE;
+    QAudio::Error error() const Q_DECL_OVERRIDE;
+    QAudio::State state() const Q_DECL_OVERRIDE;
+    void setFormat(const QAudioFormat& fmt) Q_DECL_OVERRIDE;
+    QAudioFormat format() const Q_DECL_OVERRIDE;
+    void setVolume(qreal) Q_DECL_OVERRIDE;
+    qreal volume() const Q_DECL_OVERRIDE;
+
+    void process();
+private:
+    bool initStart(bool pull);
+    friend class WasapiOutputDevicePrivate;
+    friend class WasapiOutputPrivate;
+    QByteArray m_deviceName;
+    Microsoft::WRL::ComPtr<AudioInterface> m_interface;
+    Microsoft::WRL::ComPtr<IAudioRenderClient> m_renderer;
+#if defined(CLASSIC_APP_BUILD) || _MSC_VER >= 1900
+    Microsoft::WRL::ComPtr<IAudioStreamVolume> m_volumeControl;
+    qreal m_volumeCache;
+#endif
+    QMutex m_mutex;
+    QAudio::State m_currentState;
+    QAudio::Error m_currentError;
+    QAudioFormat m_currentFormat;
+    qint64 m_bytesProcessed;
+    QTime m_openTime;
+    int m_openTimeOffset;
+    int m_interval;
+    bool m_pullMode;
+    quint32 m_bufferFrames;
+    quint32 m_bufferBytes;
+    HANDLE m_event;
+    QWasapiProcessThread *m_eventThread;
+    QIODevice *m_eventDevice;
+};
+
+QT_END_NAMESPACE
+
+#endif