qtmobility/src/multimedia/audio/qaudiooutput_alsa_p.cpp
changeset 14 6fbed849b4f4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/qtmobility/src/multimedia/audio/qaudiooutput_alsa_p.cpp	Wed Jun 23 19:08:38 2010 +0300
@@ -0,0 +1,795 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Mobility Components.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** 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, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  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.
+//
+// We mean it.
+//
+
+#include <QtCore/qcoreapplication.h>
+#include "qaudiooutput_alsa_p.h"
+#include "qaudiodeviceinfo_alsa_p.h"
+
+QT_BEGIN_NAMESPACE
+
+//#define DEBUG_AUDIO 1
+
+QAudioOutputPrivate::QAudioOutputPrivate(const QByteArray &device)
+{
+    bytesAvailable = 0;
+    handle = 0;
+    ahandler = 0;
+    access = SND_PCM_ACCESS_RW_INTERLEAVED;
+    pcmformat = SND_PCM_FORMAT_S16;
+    buffer_frames = 0;
+    period_frames = 0;
+    buffer_size = 0;
+    period_size = 0;
+    buffer_time = 100000;
+    period_time = 20000;
+    totalTimeValue = 0;
+    intervalTime = 1000;
+    audioBuffer = 0;
+    errorState = QAudio::NoError;
+    deviceState = QAudio::StoppedState;
+    audioSource = 0;
+    pullMode = true;
+    resuming = false;
+    opened = false;
+
+    m_device = device;
+
+    timer = new QTimer(this);
+    connect(timer,SIGNAL(timeout()),SLOT(userFeed()));
+}
+
+QAudioOutputPrivate::~QAudioOutputPrivate()
+{
+    close();
+    disconnect(timer, SIGNAL(timeout()));
+    QCoreApplication::processEvents();
+    delete timer;
+}
+
+QAudio::Error QAudioOutputPrivate::error() const
+{
+    return errorState;
+}
+
+QAudio::State QAudioOutputPrivate::state() const
+{
+    return deviceState;
+}
+
+void QAudioOutputPrivate::async_callback(snd_async_handler_t *ahandler)
+{
+    QAudioOutputPrivate* audioOut;
+
+    audioOut = static_cast<QAudioOutputPrivate*>
+        (snd_async_handler_get_callback_private(ahandler));
+
+    if((audioOut->deviceState==QAudio::ActiveState)||(audioOut->resuming))
+        audioOut->feedback();
+}
+
+int QAudioOutputPrivate::xrun_recovery(int err)
+{
+    int  count = 0;
+    bool reset = false;
+
+    if(err == -EPIPE) {
+        errorState = QAudio::UnderrunError;
+        emit errorChanged(errorState);
+        err = snd_pcm_prepare(handle);
+        if(err < 0)
+            reset = true;
+
+    } else if((err == -ESTRPIPE)||(err == -EIO)) {
+        errorState = QAudio::IOError;
+        emit errorChanged(errorState);
+        while((err = snd_pcm_resume(handle)) == -EAGAIN){
+            usleep(100);
+            count++;
+            if(count > 5) {
+                reset = true;
+                break;
+            }
+        }
+        if(err < 0) {
+            err = snd_pcm_prepare(handle);
+            if(err < 0)
+                reset = true;
+        }
+    }
+    if(reset) {
+        close();
+        open();
+        snd_pcm_prepare(handle);
+        return 0;
+    }
+    return err;
+}
+
+int QAudioOutputPrivate::setFormat()
+{
+    snd_pcm_format_t pcmformat = SND_PCM_FORMAT_S16;
+
+    if(settings.sampleSize() == 8) {
+        pcmformat = SND_PCM_FORMAT_U8;
+
+    } else if(settings.sampleSize() == 16) {
+        if(settings.sampleType() == QAudioFormat::SignedInt) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_S16_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_S16_BE;
+        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_U16_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_U16_BE;
+        }
+    } else if(settings.sampleSize() == 24) {
+        if(settings.sampleType() == QAudioFormat::SignedInt) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_S24_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_S24_BE;
+        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_U24_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_U24_BE;
+        }
+    } else if(settings.sampleSize() == 32) {
+        if(settings.sampleType() == QAudioFormat::SignedInt) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_S32_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_S32_BE;
+        } else if(settings.sampleType() == QAudioFormat::UnSignedInt) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_U32_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_U32_BE;
+        } else if(settings.sampleType() == QAudioFormat::Float) {
+            if(settings.byteOrder() == QAudioFormat::LittleEndian)
+                pcmformat = SND_PCM_FORMAT_FLOAT_LE;
+            else
+                pcmformat = SND_PCM_FORMAT_FLOAT_BE;
+        }
+    } else if(settings.sampleSize() == 64) {
+        if(settings.byteOrder() == QAudioFormat::LittleEndian)
+            pcmformat = SND_PCM_FORMAT_FLOAT64_LE;
+        else
+            pcmformat = SND_PCM_FORMAT_FLOAT64_BE;
+    }
+
+    return snd_pcm_hw_params_set_format( handle, hwparams, pcmformat);
+}
+
+void QAudioOutputPrivate::start(QIODevice* device)
+{
+    if(deviceState != QAudio::StoppedState)
+        deviceState = QAudio::StoppedState;
+
+    errorState = QAudio::NoError;
+
+    // Handle change of mode
+    if(audioSource && !pullMode)
+        delete audioSource;
+
+    close();
+
+    pullMode = true;
+    audioSource = device;
+
+    deviceState = QAudio::ActiveState;
+
+    open();
+
+    emit stateChanged(deviceState);
+}
+
+QIODevice* QAudioOutputPrivate::start()
+{
+    if(deviceState != QAudio::StoppedState)
+        deviceState = QAudio::StoppedState;
+
+    errorState = QAudio::NoError;
+
+    // Handle change of mode
+    if(audioSource && !pullMode)
+        delete audioSource;
+
+    close();
+
+    audioSource = new OutputPrivate(this);
+    audioSource->open(QIODevice::WriteOnly|QIODevice::Unbuffered);
+    pullMode = false;
+
+    deviceState = QAudio::IdleState;
+
+    open();
+
+    emit stateChanged(deviceState);
+
+    return audioSource;
+}
+
+void QAudioOutputPrivate::stop()
+{
+    if(deviceState == QAudio::StoppedState)
+        return;
+    errorState = QAudio::NoError;
+    deviceState = QAudio::StoppedState;
+    close();
+    emit stateChanged(deviceState);
+}
+
+bool QAudioOutputPrivate::open()
+{
+    if(opened)
+        return true;
+
+#ifdef DEBUG_AUDIO
+    QTime now(QTime::currentTime());
+    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :open()";
+#endif
+    timeStamp.restart();
+    elapsedTimeOffset = 0;
+
+    int dir;
+    int err=-1;
+    int count=0;
+    unsigned int freakuency=settings.frequency();
+
+    QString dev = QString(QLatin1String(m_device.constData()));
+    QList<QByteArray> devices = QAudioDeviceInfoInternal::availableDevices(QAudio::AudioOutput);
+    if(dev.compare(QLatin1String("default")) == 0) {
+#if(SND_LIB_MAJOR == 1 && SND_LIB_MINOR == 0 && SND_LIB_SUBMINOR >= 14)
+        dev = QLatin1String(devices.first());
+#else
+        dev = QLatin1String("hw:0,0");
+#endif
+    } else {
+#if(SND_LIB_MAJOR == 1 && SND_LIB_MINOR == 0 && SND_LIB_SUBMINOR >= 14)
+        dev = QLatin1String(m_device);
+#else
+        int idx = 0;
+        char *name;
+
+        QString shortName = QLatin1String(m_device.mid(m_device.indexOf('=',0)+1).constData());
+
+	while(snd_card_get_name(idx,&name) == 0) {
+            if(qstrncmp(shortName.toLocal8Bit().constData(),name,shortName.length()) == 0)
+                break;
+            idx++;
+	}
+        dev = QString(QLatin1String("hw:%1,0")).arg(idx);
+#endif
+    }
+
+    // Step 1: try and open the device
+    while((count < 5) && (err < 0)) {
+        err=snd_pcm_open(&handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_PLAYBACK,0);
+        if(err < 0)
+            count++;
+    }
+    if (( err < 0)||(handle == 0)) {
+        errorState = QAudio::OpenError;
+        emit errorChanged(errorState);
+        deviceState = QAudio::StoppedState;
+        return false;
+    }
+    snd_pcm_nonblock( handle, 0 );
+
+    // Step 2: Set the desired HW parameters.
+    snd_pcm_hw_params_alloca( &hwparams );
+
+    bool fatal = false;
+    QString errMessage;
+    unsigned int chunks = 8;
+
+    err = snd_pcm_hw_params_any( handle, hwparams );
+    if ( err < 0 ) {
+        fatal = true;
+        errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_any: err = %1").arg(err);
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_rate_resample( handle, hwparams, 1 );
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_rate_resample: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_access( handle, hwparams, access );
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_access: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = setFormat();
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_format: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_channels( handle, hwparams, (unsigned int)settings.channels() );
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_channels: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_rate_near( handle, hwparams, &freakuency, 0 );
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_rate_near: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        unsigned int maxBufferTime = 0;
+        unsigned int minBufferTime = 0;
+        unsigned int maxPeriodTime = 0;
+        unsigned int minPeriodTime = 0;
+
+        err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &maxBufferTime, &dir);
+        if ( err >= 0)
+            err = snd_pcm_hw_params_get_buffer_time_min(hwparams, &minBufferTime, &dir);
+        if ( err >= 0)
+            err = snd_pcm_hw_params_get_period_time_max(hwparams, &maxPeriodTime, &dir);
+        if ( err >= 0)
+            err = snd_pcm_hw_params_get_period_time_min(hwparams, &minPeriodTime, &dir);
+
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: buffer/period min and max: err = %1").arg(err);
+        } else {
+            if (maxBufferTime < buffer_time || buffer_time < minBufferTime || maxPeriodTime < period_time || minPeriodTime > period_time) {
+#ifdef DEBUG_AUDIO
+                qDebug()<<"defaults out of range";
+                qDebug()<<"pmin="<<minPeriodTime<<", pmax="<<maxPeriodTime<<", bmin="<<minBufferTime<<", bmax="<<maxBufferTime;
+#endif
+                period_time = minPeriodTime;
+                if (period_time*4 <= maxBufferTime) {
+                    // Use 4 periods if possible
+                    buffer_time = period_time*4;
+                    chunks = 4;
+                } else if (period_time*2 <= maxBufferTime) {
+                    // Use 2 periods if possible
+                    buffer_time = period_time*2;
+                    chunks = 2;
+                } else {
+                    qWarning()<<"QAudioOutput: alsa only supports single period!";
+                    fatal = true;
+                }
+#ifdef DEBUG_AUDIO
+                qDebug()<<"used: buffer_time="<<buffer_time<<", period_time="<<period_time;
+#endif
+            }
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_buffer_time_near(handle, hwparams, &buffer_time, &dir);
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_buffer_time_near: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_period_time_near(handle, hwparams, &period_time, &dir);
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_period_time_near: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params_set_periods_near(handle, hwparams, &chunks, &dir);
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params_set_periods_near: err = %1").arg(err);
+        }
+    }
+    if ( !fatal ) {
+        err = snd_pcm_hw_params(handle, hwparams);
+        if ( err < 0 ) {
+            fatal = true;
+            errMessage = QString::fromLatin1("QAudioOutput: snd_pcm_hw_params: err = %1").arg(err);
+        }
+    }
+    if( err < 0) {
+        qWarning()<<errMessage;
+        errorState = QAudio::OpenError;
+        emit errorChanged(errorState);
+        deviceState = QAudio::StoppedState;
+        return false;
+    }
+    snd_pcm_hw_params_get_buffer_size(hwparams,&buffer_frames);
+    buffer_size = snd_pcm_frames_to_bytes(handle,buffer_frames);
+    snd_pcm_hw_params_get_period_size(hwparams,&period_frames, &dir);
+    period_size = snd_pcm_frames_to_bytes(handle,period_frames);
+    snd_pcm_hw_params_get_buffer_time(hwparams,&buffer_time, &dir);
+    snd_pcm_hw_params_get_period_time(hwparams,&period_time, &dir);
+
+    // Step 3: Set the desired SW parameters.
+    snd_pcm_sw_params_t *swparams;
+    snd_pcm_sw_params_alloca(&swparams);
+    snd_pcm_sw_params_current(handle, swparams);
+    snd_pcm_sw_params_set_start_threshold(handle,swparams,period_frames);
+    snd_pcm_sw_params_set_stop_threshold(handle,swparams,buffer_frames);
+    snd_pcm_sw_params_set_avail_min(handle, swparams,period_frames);
+    snd_pcm_sw_params(handle, swparams);
+
+    // Step 4: Prepare audio
+    if(audioBuffer == 0)
+        audioBuffer = new char[snd_pcm_frames_to_bytes(handle,buffer_frames)];
+    snd_pcm_prepare( handle );
+    snd_pcm_start(handle);
+
+    // Step 5: Setup callback and timer fallback
+    snd_async_add_pcm_handler(&ahandler, handle, async_callback, this);
+    bytesAvailable = bytesFree();
+
+    // Step 6: Start audio processing
+    timer->start(period_time/1000);
+
+    clockStamp.restart();
+    timeStamp.restart();
+    elapsedTimeOffset = 0;
+    errorState  = QAudio::NoError;
+    totalTimeValue = 0;
+    opened = true;
+
+    return true;
+}
+
+void QAudioOutputPrivate::close()
+{
+    timer->stop();
+
+    if ( handle ) {
+        snd_pcm_drain( handle );
+        snd_pcm_close( handle );
+        handle = 0;
+        delete [] audioBuffer;
+        audioBuffer=0;
+    }
+    if(!pullMode && audioSource) {
+        delete audioSource;
+        audioSource = 0;
+    }
+    opened = false;
+}
+
+int QAudioOutputPrivate::bytesFree() const
+{
+    if(resuming)
+        return period_size;
+
+    if(deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
+        return 0;
+    int frames = snd_pcm_avail_update(handle);
+    if((int)frames > (int)buffer_frames)
+        frames = buffer_frames;
+
+    return snd_pcm_frames_to_bytes(handle, frames);
+}
+
+qint64 QAudioOutputPrivate::write( const char *data, qint64 len )
+{
+    // Write out some audio data
+    if ( !handle )
+        return 0;
+#ifdef DEBUG_AUDIO
+    qDebug()<<"frames to write out = "<<
+        snd_pcm_bytes_to_frames( handle, (int)len )<<" ("<<len<<") bytes";
+#endif
+    int frames, err;
+    int space = bytesFree();
+    if(len < space) {
+        // Just write it
+        frames = snd_pcm_bytes_to_frames( handle, (int)len );
+        err = snd_pcm_writei( handle, data, frames );
+    } else {
+        // Only write space worth
+        frames = snd_pcm_bytes_to_frames( handle, (int)space );
+        err = snd_pcm_writei( handle, data, frames );
+    }
+    if(err > 0) {
+        totalTimeValue += err;
+        resuming = false;
+        errorState = QAudio::NoError;
+        if (deviceState != QAudio::ActiveState) {
+            deviceState = QAudio::ActiveState;
+            emit stateChanged(deviceState);
+        }
+        return snd_pcm_frames_to_bytes( handle, err );
+    } else
+        err = xrun_recovery(err);
+
+    if(err < 0) {
+        close();
+        errorState = QAudio::FatalError;
+        emit errorChanged(errorState);
+        deviceState = QAudio::StoppedState;
+        emit stateChanged(deviceState);
+    }
+    return 0;
+}
+
+int QAudioOutputPrivate::periodSize() const
+{
+    return period_size;
+}
+
+void QAudioOutputPrivate::setBufferSize(int value)
+{
+    if(deviceState == QAudio::StoppedState)
+        buffer_size = value;
+}
+
+int QAudioOutputPrivate::bufferSize() const
+{
+    return buffer_size;
+}
+
+void QAudioOutputPrivate::setNotifyInterval(int ms)
+{
+    intervalTime = qMax(0, ms);
+}
+
+int QAudioOutputPrivate::notifyInterval() const
+{
+    return intervalTime;
+}
+
+qint64 QAudioOutputPrivate::processedUSecs() const
+{
+    return qint64(1000000) * totalTimeValue / settings.frequency();
+}
+
+void QAudioOutputPrivate::resume()
+{
+    if(deviceState == QAudio::SuspendedState) {
+        int err = 0;
+
+        if(handle) {
+            err = snd_pcm_prepare( handle );
+            if(err < 0)
+                xrun_recovery(err);
+
+            err = snd_pcm_start(handle);
+            if(err < 0)
+                xrun_recovery(err);
+
+            bytesAvailable = (int)snd_pcm_frames_to_bytes(handle, buffer_frames);
+        }
+        resuming = true;
+
+        deviceState = QAudio::ActiveState;
+
+        errorState = QAudio::NoError;
+        timer->start(period_time/1000);
+        emit stateChanged(deviceState);
+    }
+}
+
+void QAudioOutputPrivate::setFormat(const QAudioFormat& fmt)
+{
+    if (deviceState == QAudio::StoppedState)
+        settings = fmt;
+}
+
+QAudioFormat QAudioOutputPrivate::format() const
+{
+    return settings;
+}
+
+void QAudioOutputPrivate::suspend()
+{
+    if(deviceState == QAudio::ActiveState || deviceState == QAudio::IdleState || resuming) {
+        timer->stop();
+        deviceState = QAudio::SuspendedState;
+        errorState = QAudio::NoError;
+        emit stateChanged(deviceState);
+    }
+}
+
+void QAudioOutputPrivate::userFeed()
+{
+    if(deviceState == QAudio::StoppedState || deviceState == QAudio::SuspendedState)
+        return;
+#ifdef DEBUG_AUDIO
+    QTime now(QTime::currentTime());
+    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :userFeed() OUT";
+#endif
+    if(deviceState ==  QAudio::IdleState)
+        bytesAvailable = bytesFree();
+
+    deviceReady();
+}
+
+void QAudioOutputPrivate::feedback()
+{
+    updateAvailable();
+}
+
+
+void QAudioOutputPrivate::updateAvailable()
+{
+#ifdef DEBUG_AUDIO
+    QTime now(QTime::currentTime());
+    qDebug()<<now.second()<<"s "<<now.msec()<<"ms :updateAvailable()";
+#endif
+    bytesAvailable = bytesFree();
+}
+
+bool QAudioOutputPrivate::deviceReady()
+{
+    if(pullMode) {
+        int l = 0;
+        int chunks = bytesAvailable/period_size;
+        if(chunks==0) {
+            bytesAvailable = bytesFree();
+            return false;
+        }
+#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 ="<<period_size*chunks;
+#endif
+        int input = period_frames*chunks;
+        if(input > (int)buffer_frames)
+            input = buffer_frames;
+        l = audioSource->read(audioBuffer,snd_pcm_frames_to_bytes(handle, input));
+        if(l > 0) {
+            // Got some data to output
+            if(deviceState != QAudio::ActiveState)
+                return true;
+            qint64 bytesWritten = write(audioBuffer,l);
+            if (bytesWritten != l)
+                audioSource->seek(audioSource->pos()-(l-bytesWritten));
+            bytesAvailable = bytesFree();
+
+        } else if(l == 0) {
+            // Did not get any data to output
+            bytesAvailable = bytesFree();
+            if(bytesAvailable > snd_pcm_frames_to_bytes(handle, buffer_frames-period_frames)) {
+                // Underrun
+                if (deviceState != QAudio::IdleState) {
+                    errorState = QAudio::UnderrunError;
+                    emit errorChanged(errorState);
+                    deviceState = QAudio::IdleState;
+                    emit stateChanged(deviceState);
+                }
+            }
+
+        } else if(l < 0) {
+            close();
+            deviceState = QAudio::StoppedState;
+            errorState = QAudio::IOError;
+            emit errorChanged(errorState);
+            emit stateChanged(deviceState);
+        }
+    } else {
+        bytesAvailable = bytesFree();
+        if(bytesAvailable > snd_pcm_frames_to_bytes(handle, buffer_frames-period_frames)) {
+            // Underrun
+            if (deviceState != QAudio::IdleState) {
+                errorState = QAudio::UnderrunError;
+                emit errorChanged(errorState);
+                deviceState = QAudio::IdleState;
+                emit stateChanged(deviceState);
+            }
+        }
+    }
+
+    if(deviceState != QAudio::ActiveState)
+        return true;
+
+    if(intervalTime && (timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
+        emit notify();
+        elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
+        timeStamp.restart();
+    }
+    return true;
+}
+
+qint64 QAudioOutputPrivate::elapsedUSecs() const
+{
+    if (deviceState == QAudio::StoppedState)
+        return 0;
+
+    return clockStamp.elapsed()*1000;
+}
+
+void QAudioOutputPrivate::reset()
+{
+    if(handle)
+        snd_pcm_reset(handle);
+
+    stop();
+}
+
+OutputPrivate::OutputPrivate(QAudioOutputPrivate* audio)
+{
+    audioDevice = qobject_cast<QAudioOutputPrivate*>(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)) {
+        while(written < len) {
+            int chunk = audioDevice->write(data+written,(len-written));
+            if(chunk <= 0)
+                retry++;
+            written+=chunk;
+            if(retry > 10)
+                return written;
+        }
+    }
+    return written;
+
+}
+
+QT_END_NAMESPACE