Move win32 and Alsa audio backends into plugins.

Change-Id: I9835cf5ee97900569f26421a19543b485e933051
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>

src/plugins/windowsaudio/qwindowsaudiooutput.cpp

@@ -0,0 +1,762 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of other Qt classes.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// INTERNAL USE ONLY: Do NOT use for any other purpose.
+//
+
+#include "qwindowsaudiooutput.h"
+#include <QtEndian>
+
+#ifndef SPEAKER_FRONT_LEFT
+    #define SPEAKER_FRONT_LEFT            0x00000001
+    #define SPEAKER_FRONT_RIGHT           0x00000002
+    #define SPEAKER_FRONT_CENTER          0x00000004
+    #define SPEAKER_LOW_FREQUENCY         0x00000008
+    #define SPEAKER_BACK_LEFT             0x00000010
+    #define SPEAKER_BACK_RIGHT            0x00000020
+    #define SPEAKER_FRONT_LEFT_OF_CENTER  0x00000040
+    #define SPEAKER_FRONT_RIGHT_OF_CENTER 0x00000080
+    #define SPEAKER_BACK_CENTER           0x00000100
+    #define SPEAKER_SIDE_LEFT             0x00000200
+    #define SPEAKER_SIDE_RIGHT            0x00000400
+    #define SPEAKER_TOP_CENTER            0x00000800
+    #define SPEAKER_TOP_FRONT_LEFT        0x00001000
+    #define SPEAKER_TOP_FRONT_CENTER      0x00002000
+    #define SPEAKER_TOP_FRONT_RIGHT       0x00004000
+    #define SPEAKER_TOP_BACK_LEFT         0x00008000
+    #define SPEAKER_TOP_BACK_CENTER       0x00010000
+    #define SPEAKER_TOP_BACK_RIGHT        0x00020000
+    #define SPEAKER_RESERVED              0x7FFC0000
+    #define SPEAKER_ALL                   0x80000000
+#endif
+
+#ifndef _WAVEFORMATEXTENSIBLE_
+
+    #define _WAVEFORMATEXTENSIBLE_
+    typedef struct
+    {
+        WAVEFORMATEX Format;          // Base WAVEFORMATEX data
+        union
+        {
+            WORD wValidBitsPerSample; // Valid bits in each sample container
+            WORD wSamplesPerBlock;    // Samples per block of audio data; valid
+                                      // if wBitsPerSample=0 (but rarely used).
+            WORD wReserved;           // Zero if neither case above applies.
+        } Samples;
+        DWORD dwChannelMask;          // Positions of the audio channels
+        GUID SubFormat;               // Format identifier GUID
+    } WAVEFORMATEXTENSIBLE, *PWAVEFORMATEXTENSIBLE, *LPPWAVEFORMATEXTENSIBLE;
+    typedef const WAVEFORMATEXTENSIBLE* LPCWAVEFORMATEXTENSIBLE;
+
+#endif
+
+#if !defined(WAVE_FORMAT_EXTENSIBLE)
+#define WAVE_FORMAT_EXTENSIBLE 0xFFFE
+#endif
+
+//#define DEBUG_AUDIO 1
+
+QT_BEGIN_NAMESPACE
+
+QWindowsAudioOutput::QWindowsAudioOutput(const QByteArray &device)
+{
+    bytesAvailable = 0;
+    buffer_size = 0;
+    period_size = 0;
+    m_device = device;
+    totalTimeValue = 0;
+    intervalTime = 1000;
+    audioBuffer = 0;
+    errorState = QAudio::NoError;
+    deviceState = QAudio::StoppedState;
+    audioSource = 0;
+    pullMode = true;
+    finished = false;
+    volumeCache = (qreal)1.;
+}
+
+QWindowsAudioOutput::~QWindowsAudioOutput()
+{
+    mutex.lock();
+    finished = true;
+    mutex.unlock();
+
+    close();
+}
+
+void CALLBACK QWindowsAudioOutput::waveOutProc( HWAVEOUT hWaveOut, UINT uMsg,
+        DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2 )
+{
+    Q_UNUSED(dwParam1)
+    Q_UNUSED(dwParam2)
+    Q_UNUSED(hWaveOut)
+
+    QWindowsAudioOutput* qAudio;
+    qAudio = (QWindowsAudioOutput*)(dwInstance);
+    if(!qAudio)
+        return;
+
+    QMutexLocker(&qAudio->mutex);
+
+    switch(uMsg) {
+        case WOM_OPEN:
+            qAudio->feedback();
+            break;
+        case WOM_CLOSE:
+            return;
+        case WOM_DONE:
+            if(qAudio->finished || qAudio->buffer_size == 0 || qAudio->period_size == 0) {
+                return;
+            }
+            qAudio->waveFreeBlockCount++;
+            if(qAudio->waveFreeBlockCount >= qAudio->buffer_size/qAudio->period_size)
+                qAudio->waveFreeBlockCount = qAudio->buffer_size/qAudio->period_size;
+            qAudio->feedback();
+            break;
+        default:
+            return;
+    }
+}
+
+WAVEHDR* QWindowsAudioOutput::allocateBlocks(int size, int count)
+{
+    int i;
+    unsigned char* buffer;
+    WAVEHDR* blocks;
+    DWORD totalBufferSize = (size + sizeof(WAVEHDR))*count;
+
+    if((buffer=(unsigned char*)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,
+                    totalBufferSize)) == 0) {
+        qWarning("QAudioOutput: Memory allocation error");
+        return 0;
+    }
+    blocks = (WAVEHDR*)buffer;
+    buffer += sizeof(WAVEHDR)*count;
+    for(i = 0; i < count; i++) {
+        blocks[i].dwBufferLength = size;
+        blocks[i].lpData = (LPSTR)buffer;
+        buffer += size;
+    }
+    return blocks;
+}
+
+void QWindowsAudioOutput::freeBlocks(WAVEHDR* blockArray)
+{
+    WAVEHDR* blocks = blockArray;
+
+    int count = buffer_size/period_size;
+
+    for(int i = 0; i < count; i++) {
+        waveOutUnprepareHeader(hWaveOut,blocks, sizeof(WAVEHDR));
+        blocks++;
+    }
+    HeapFree(GetProcessHeap(), 0, blockArray);
+}
+
+QAudioFormat QWindowsAudioOutput::format() const
+{
+    return settings;
+}
+
+void QWindowsAudioOutput::setFormat(const QAudioFormat& fmt)
+{
+    if (deviceState == QAudio::StoppedState)
+        settings = fmt;
+}
+
+void QWindowsAudioOutput::start(QIODevice* device)
+{
+    if(deviceState != QAudio::StoppedState)
+        close();
+
+    if(!pullMode && audioSource)
+        delete audioSource;
+
+    pullMode = true;
+    audioSource = device;
+
+    deviceState = QAudio::ActiveState;
+
+    if(!open())
+        return;
+
+    emit stateChanged(deviceState);
+}
+
+QIODevice* QWindowsAudioOutput::start()
+{
+    if(deviceState != QAudio::StoppedState)
+        close();
+
+    if(!pullMode && audioSource)
+        delete audioSource;
+
+    pullMode = false;
+    audioSource = new OutputPrivate(this);
+    audioSource->open(QIODevice::WriteOnly|QIODevice::Unbuffered);
+
+    deviceState = QAudio::IdleState;
+
+    if(!open())
+        return 0;
+
+    emit stateChanged(deviceState);
+
+    return audioSource;
+}
+
+void QWindowsAudioOutput::stop()
+{
+    if(deviceState == QAudio::StoppedState)
+        return;
+    close();
+    if(!pullMode && audioSource) {
+        delete audioSource;
+        audioSource = 0;
+    }
+    emit stateChanged(deviceState);
+}
+
+bool QWindowsAudioOutput::open()
+{
+#ifdef DEBUG_AUDIO
+    QTime now(QTime::currentTime());
+    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :open()";
+#endif
+
+    period_size = 0;
+
+    if (!settings.isValid()) {
+        qWarning("QAudioOutput: open error, invalid format.");
+    } else if (settings.channelCount() <= 0) {
+        qWarning("QAudioOutput: open error, invalid number of channels (%d).",
+                 settings.channelCount());
+    } else if (settings.sampleSize() <= 0) {
+        qWarning("QAudioOutput: open error, invalid sample size (%d).",
+                 settings.sampleSize());
+    } else if (settings.sampleRate() < 8000 || settings.sampleRate() > 96000) {
+        qWarning("QAudioOutput: open error, sample rate out of range (%d).", settings.sampleRate());
+    } else if (buffer_size == 0) {
+        // Default buffer size, 200ms, default period size is 40ms
+        buffer_size
+                = (settings.sampleRate()
+                * settings.channelCount()
+                * settings.sampleSize()
+                + 39) / 40;
+        period_size = buffer_size / 5;
+    } else {
+        period_size = buffer_size / 5;
+    }
+
+    if (period_size == 0) {
+        errorState = QAudio::OpenError;
+        deviceState = QAudio::StoppedState;
+        emit stateChanged(deviceState);
+        return false;
+    }
+
+    waveBlocks = allocateBlocks(period_size, buffer_size/period_size);
+
+    mutex.lock();
+    waveFreeBlockCount = buffer_size/period_size;
+    mutex.unlock();
+
+    waveCurrentBlock = 0;
+
+    if(audioBuffer == 0)
+        audioBuffer = new char[buffer_size];
+
+    timeStamp.restart();
+    elapsedTimeOffset = 0;
+
+    wfx.nSamplesPerSec = settings.sampleRate();
+    wfx.wBitsPerSample = settings.sampleSize();
+    wfx.nChannels = settings.channelCount();
+    wfx.cbSize = 0;
+
+    bool surround = false;
+
+    if (settings.channelCount() > 2)
+        surround = true;
+
+    wfx.wFormatTag = WAVE_FORMAT_PCM;
+    wfx.nBlockAlign = (wfx.wBitsPerSample >> 3) * wfx.nChannels;
+    wfx.nAvgBytesPerSec = wfx.nBlockAlign * wfx.nSamplesPerSec;
+
+    QDataStream ds(&m_device, QIODevice::ReadOnly);
+    quint32 deviceId;
+    ds >> deviceId;
+
+    if (!surround) {
+        if (waveOutOpen(&hWaveOut, UINT_PTR(deviceId), &wfx,
+                    (DWORD_PTR)&waveOutProc,
+                    (DWORD_PTR) this,
+                    CALLBACK_FUNCTION) != MMSYSERR_NOERROR) {
+            errorState = QAudio::OpenError;
+            deviceState = QAudio::StoppedState;
+            emit stateChanged(deviceState);
+            qWarning("QAudioOutput: open error");
+            return false;
+        }
+    } else {
+        WAVEFORMATEXTENSIBLE wfex;
+        wfex.Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
+        wfex.Format.nChannels = settings.channelCount();
+        wfex.Format.wBitsPerSample = settings.sampleSize();
+        wfex.Format.nSamplesPerSec = settings.sampleRate();
+        wfex.Format.nBlockAlign = wfex.Format.nChannels*wfex.Format.wBitsPerSample/8;
+        wfex.Format.nAvgBytesPerSec=wfex.Format.nSamplesPerSec*wfex.Format.nBlockAlign;
+        wfex.Samples.wValidBitsPerSample=wfex.Format.wBitsPerSample;
+        static const GUID _KSDATAFORMAT_SUBTYPE_PCM = {
+             0x00000001, 0x0000, 0x0010, {0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}};
+        wfex.SubFormat=_KSDATAFORMAT_SUBTYPE_PCM;
+        wfex.Format.cbSize=22;
+
+        wfex.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT;
+        if (settings.channelCount() >= 4)
+            wfex.dwChannelMask |= SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT;
+        if (settings.channelCount() >= 6)
+            wfex.dwChannelMask |= SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY;
+        if (settings.channelCount() == 8)
+            wfex.dwChannelMask |= SPEAKER_SIDE_LEFT | SPEAKER_SIDE_RIGHT;
+
+        if (waveOutOpen(&hWaveOut, UINT_PTR(deviceId), &wfex.Format,
+                    (DWORD_PTR)&waveOutProc,
+                    (DWORD_PTR) this,
+                    CALLBACK_FUNCTION) != MMSYSERR_NOERROR) {
+            errorState = QAudio::OpenError;
+            deviceState = QAudio::StoppedState;
+            emit stateChanged(deviceState);
+            qWarning("QAudioOutput: open error");
+            return false;
+        }
+    }
+
+    totalTimeValue = 0;
+    timeStampOpened.restart();
+    elapsedTimeOffset = 0;
+
+    setVolume(volumeCache);
+
+    errorState = QAudio::NoError;
+    if(pullMode) {
+        deviceState = QAudio::ActiveState;
+        QTimer::singleShot(10, this, SLOT(feedback()));
+    } else
+        deviceState = QAudio::IdleState;
+
+    return true;
+}
+
+void QWindowsAudioOutput::close()
+{
+    if(deviceState == QAudio::StoppedState)
+        return;
+
+    deviceState = QAudio::StoppedState;
+    errorState = QAudio::NoError;
+    int delay = (buffer_size-bytesFree())*1000/(settings.sampleRate()
+                  *settings.channelCount()*(settings.sampleSize()/8));
+    waveOutReset(hWaveOut);
+    Sleep(delay+10);
+
+    freeBlocks(waveBlocks);
+    waveOutClose(hWaveOut);
+    delete [] audioBuffer;
+    audioBuffer = 0;
+    buffer_size = 0;
+}
+
+int QWindowsAudioOutput::bytesFree() const
+{
+    int buf;
+    buf = waveFreeBlockCount*period_size;
+
+    return buf;
+}
+
+int QWindowsAudioOutput::periodSize() const
+{
+    return period_size;
+}
+
+void QWindowsAudioOutput::setBufferSize(int value)
+{
+    if(deviceState == QAudio::StoppedState)
+        buffer_size = value;
+}
+
+int QWindowsAudioOutput::bufferSize() const
+{
+    return buffer_size;
+}
+
+void QWindowsAudioOutput::setNotifyInterval(int ms)
+{
+    intervalTime = qMax(0, ms);
+}
+
+int QWindowsAudioOutput::notifyInterval() const
+{
+    return intervalTime;
+}
+
+qint64 QWindowsAudioOutput::processedUSecs() const
+{
+    if (deviceState == QAudio::StoppedState)
+        return 0;
+    qint64 result = qint64(1000000) * totalTimeValue /
+        (settings.channelCount()*(settings.sampleSize()/8)) /
+        settings.sampleRate();
+
+    return result;
+}
+
+qint64 QWindowsAudioOutput::write( const char *data, qint64 len )
+{
+    // Write out some audio data
+    if (deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
+        return 0;
+
+    char* p = (char*)data;
+    int l = (int)len;
+
+    QByteArray reverse;
+    if (settings.byteOrder() == QAudioFormat::BigEndian) {
+
+        switch (settings.sampleSize()) {
+            case 8:
+                // No need to convert
+                break;
+
+            case 16:
+                reverse.resize(l);
+                for (qint64 i = 0; i < (l >> 1); i++)
+                    *((qint16*)reverse.data() + i) = qFromBigEndian(*((qint16*)data + i));
+                p = reverse.data();
+                break;
+
+            case 32:
+                reverse.resize(l);
+                for (qint64 i = 0; i < (l >> 2); i++)
+                    *((qint32*)reverse.data() + i) = qFromBigEndian(*((qint32*)data + i));
+                p = reverse.data();
+                break;
+        }
+    }
+
+    WAVEHDR* current;
+    int remain;
+    current = &waveBlocks[waveCurrentBlock];
+    while(l > 0) {
+        mutex.lock();
+        if(waveFreeBlockCount==0) {
+            mutex.unlock();
+            break;
+        }
+        mutex.unlock();
+
+        if(current->dwFlags & WHDR_PREPARED)
+            waveOutUnprepareHeader(hWaveOut, current, sizeof(WAVEHDR));
+
+        if(l < period_size)
+            remain = l;
+        else
+            remain = period_size;
+        memcpy(current->lpData, p, remain);
+
+        l -= remain;
+        p += remain;
+        current->dwBufferLength = remain;
+        waveOutPrepareHeader(hWaveOut, current, sizeof(WAVEHDR));
+        waveOutWrite(hWaveOut, current, sizeof(WAVEHDR));
+
+        mutex.lock();
+        waveFreeBlockCount--;
+#ifdef DEBUG_AUDIO
+        qDebug("write out l=%d, waveFreeBlockCount=%d",
+                current->dwBufferLength,waveFreeBlockCount);
+#endif
+        mutex.unlock();
+
+        totalTimeValue += current->dwBufferLength;
+        waveCurrentBlock++;
+        waveCurrentBlock %= buffer_size/period_size;
+        current = &waveBlocks[waveCurrentBlock];
+        current->dwUser = 0;
+        errorState = QAudio::NoError;
+        if (deviceState != QAudio::ActiveState) {
+            deviceState = QAudio::ActiveState;
+            emit stateChanged(deviceState);
+        }
+    }
+    return (len-l);
+}
+
+void QWindowsAudioOutput::resume()
+{
+    if(deviceState == QAudio::SuspendedState) {
+        deviceState = QAudio::ActiveState;
+        errorState = QAudio::NoError;
+        waveOutRestart(hWaveOut);
+        QTimer::singleShot(10, this, SLOT(feedback()));
+        emit stateChanged(deviceState);
+    }
+}
+
+void QWindowsAudioOutput::suspend()
+{
+    if(deviceState == QAudio::ActiveState || deviceState == QAudio::IdleState) {
+        int delay = (buffer_size-bytesFree())*1000/(settings.sampleRate()
+                *settings.channelCount()*(settings.sampleSize()/8));
+        waveOutPause(hWaveOut);
+        Sleep(delay+10);
+        deviceState = QAudio::SuspendedState;
+        errorState = QAudio::NoError;
+        emit stateChanged(deviceState);
+    }
+}
+
+void QWindowsAudioOutput::feedback()
+{
+#ifdef DEBUG_AUDIO
+    QTime now(QTime::currentTime());
+    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :feedback()";
+#endif
+    bytesAvailable = bytesFree();
+
+    if(!(deviceState==QAudio::StoppedState||deviceState==QAudio::SuspendedState)) {
+        if(bytesAvailable >= period_size)
+            QMetaObject::invokeMethod(this, "deviceReady", Qt::QueuedConnection);
+    }
+}
+
+bool QWindowsAudioOutput::deviceReady()
+{
+    if(deviceState == QAudio::StoppedState || deviceState == QAudio::SuspendedState)
+        return false;
+
+    if(pullMode) {
+        int chunks = bytesAvailable/period_size;
+#ifdef DEBUG_AUDIO
+        qDebug()<<"deviceReady() avail="<<bytesAvailable<<" bytes, period size="<<period_size<<" bytes";
+        qDebug()<<"deviceReady() no. of chunks that can fit ="<<chunks<<", chunks in bytes ="<<chunks*period_size;
+#endif
+        bool startup = false;
+        if(totalTimeValue == 0)
+            startup = true;
+
+        bool full=false;
+
+        mutex.lock();
+        if (waveFreeBlockCount==0) full = true;
+        mutex.unlock();
+
+        if (full) {
+#ifdef DEBUG_AUDIO
+            qDebug() << "Skipping data as unable to write";
+#endif
+            if ((timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
+                emit notify();
+                elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
+                timeStamp.restart();
+            }
+            return true;
+        }
+
+        if(startup)
+            waveOutPause(hWaveOut);
+        int input = period_size*chunks;
+        int l = audioSource->read(audioBuffer,input);
+        if(l > 0) {
+            int out= write(audioBuffer,l);
+            if(out > 0) {
+                if (deviceState != QAudio::ActiveState) {
+                    deviceState = QAudio::ActiveState;
+                    emit stateChanged(deviceState);
+                }
+            }
+            if ( out < l) {
+                // Didn't write all data
+                audioSource->seek(audioSource->pos()-(l-out));
+            }
+            if (startup)
+                waveOutRestart(hWaveOut);
+        } else if(l == 0) {
+            bytesAvailable = bytesFree();
+
+            int check = 0;
+
+            mutex.lock();
+            check = waveFreeBlockCount;
+            mutex.unlock();
+
+            if(check == buffer_size/period_size) {
+                if (deviceState != QAudio::IdleState) {
+                    errorState = QAudio::UnderrunError;
+                    deviceState = QAudio::IdleState;
+                    emit stateChanged(deviceState);
+                }
+            }
+
+        } else if(l < 0) {
+            bytesAvailable = bytesFree();
+            if (errorState != QAudio::IOError)
+                errorState = QAudio::IOError;
+        }
+    } else {
+        int buffered;
+
+        mutex.lock();
+        buffered = waveFreeBlockCount;
+        mutex.unlock();
+
+        if (buffered >= buffer_size/period_size && deviceState == QAudio::ActiveState) {
+            if (deviceState != QAudio::IdleState) {
+                errorState = QAudio::UnderrunError;
+                deviceState = QAudio::IdleState;
+                emit stateChanged(deviceState);
+            }
+        }
+    }
+    if(deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
+        return true;
+
+    if(intervalTime && (timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
+        emit notify();
+        elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
+        timeStamp.restart();
+    }
+
+    return true;
+}
+
+qint64 QWindowsAudioOutput::elapsedUSecs() const
+{
+    if (deviceState == QAudio::StoppedState)
+        return 0;
+
+    return timeStampOpened.elapsed()*1000;
+}
+
+QAudio::Error QWindowsAudioOutput::error() const
+{
+    return errorState;
+}
+
+QAudio::State QWindowsAudioOutput::state() const
+{
+    return deviceState;
+}
+
+void QWindowsAudioOutput::setVolume(qreal v)
+{
+    const qreal normalizedVolume = qBound(qreal(0.0), v, qreal(1.0));
+    if (deviceState != QAudio::ActiveState) {
+        volumeCache = normalizedVolume;
+        return;
+    }
+    const quint16 scaled = normalizedVolume * 0xFFFF;
+    DWORD vol = MAKELONG(scaled, scaled);
+    MMRESULT res = waveOutSetVolume(hWaveOut, vol);
+    if (res == MMSYSERR_NOERROR)
+        volumeCache = normalizedVolume;
+}
+
+qreal QWindowsAudioOutput::volume() const
+{
+    return volumeCache;
+}
+
+void QWindowsAudioOutput::reset()
+{
+    close();
+}
+
+OutputPrivate::OutputPrivate(QWindowsAudioOutput* audio)
+{
+    audioDevice = qobject_cast<QWindowsAudioOutput*>(audio);
+}
+
+OutputPrivate::~OutputPrivate() {}
+
+qint64 OutputPrivate::readData( char* data, qint64 len)
+{
+    Q_UNUSED(data)
+    Q_UNUSED(len)
+
+    return 0;
+}
+
+qint64 OutputPrivate::writeData(const char* data, qint64 len)
+{
+    int retry = 0;
+    qint64 written = 0;
+
+    if((audioDevice->deviceState == QAudio::ActiveState)
+            ||(audioDevice->deviceState == QAudio::IdleState)) {
+        qint64 l = len;
+        while(written < l) {
+            int chunk = audioDevice->write(data+written,(l-written));
+            if(chunk <= 0)
+                retry++;
+            else
+                written+=chunk;
+
+            if(retry > 10)
+                return written;
+        }
+        audioDevice->deviceState = QAudio::ActiveState;
+    }
+    return written;
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qwindowsaudiooutput.cpp"