PlayBack-Qt.h

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/***************************************************************************
          PlayBack-Qt.h  -  playback device for Qt Multimedia
                             -------------------
    begin                : Thu Nov 12 2015
    copyright            : (C) 2015 by Thomas Eschenbacher
    email                : Thomas.Eschenbacher@gmx.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef PLAY_BACK_QT_H
#define PLAY_BACK_QT_H

#include "config.h"
#ifdef HAVE_QT_AUDIO_SUPPORT

#include <QAudio>
#include <QAudioDeviceInfo>
#include <QByteArray>
#include <QIODevice>
#include <QList>
#include <QMap>
#include <QMutex>
#include <QObject>
#include <QQueue>
#include <QSemaphore>
#include <QString>

#include "libkwave/PlayBackDevice.h"
#include "libkwave/SampleArray.h"

class QAudioOutput;
class QIODevice;

namespace Kwave
{

    class SampleEncoder;

    class PlayBackQt: public QObject,
                      public Kwave::PlayBackDevice
    {
        Q_OBJECT
    public:

        PlayBackQt();

        virtual ~PlayBackQt() Q_DECL_OVERRIDE;

        virtual QString open(const QString &device, double rate,
                             unsigned int channels, unsigned int bits,
                             unsigned int bufbase) Q_DECL_OVERRIDE;

        virtual int write(const Kwave::SampleArray &samples) Q_DECL_OVERRIDE;

        virtual int close() Q_DECL_OVERRIDE;

        virtual QStringList supportedDevices() Q_DECL_OVERRIDE;

        virtual QString fileFilter() Q_DECL_OVERRIDE;

        virtual QList<unsigned int> supportedBits(const QString &device)
            Q_DECL_OVERRIDE;

        virtual int detectChannels(const QString &device,
                                   unsigned int &min, unsigned int &max)
            Q_DECL_OVERRIDE;

    private slots:

        void stateChanged(QAudio::State state);

    private:

        void createEncoder(const QAudioFormat &format);

        void scanDevices();

        QAudioDeviceInfo deviceInfo(const QString &device) const;

    private:

        class Buffer : public QIODevice
        {
        public:
            Buffer();

            virtual ~Buffer() Q_DECL_OVERRIDE;

            void start(unsigned int buf_size, int timeout);

            void setTimeout(int timeout);

            void drain(QByteArray &padding);

            void stop();

            virtual qint64 readData(char *data, qint64 len) Q_DECL_OVERRIDE;

            virtual qint64 writeData(const char *data, qint64 len)
                Q_DECL_OVERRIDE;

            virtual qint64 bytesAvailable() const Q_DECL_OVERRIDE;

        private:

            QMutex m_lock;

            QSemaphore m_sem_free;

            QSemaphore m_sem_filled;

            QQueue<char> m_raw_buffer;

            int m_timeout;

            QByteArray m_pad_data;

            int m_pad_ofs;
        };

    private:

        QMutex m_lock;

        QMap<QString, QString> m_device_name_map;

        QList<QAudioDeviceInfo> m_available_devices;

        QAudioOutput *m_output;

        unsigned int m_buffer_size;

        Kwave::SampleEncoder *m_encoder;

        Kwave::PlayBackQt::Buffer m_buffer;
    };
}

#endif /* HAVE_QT_AUDIO_SUPPORT */

#endif /* PLAY_BACK_QT_H */

//***************************************************************************
//***************************************************************************