AudioDevice.h

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/*
 * AudioDevice.h - base-class for audio-devices, used by LMMS audio engine
 *
 * Copyright (c) 2004-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef LMMS_AUDIO_DEVICE_H
#define LMMS_AUDIO_DEVICE_H
 
#include <QMutex>
#include <samplerate.h>
 
#include "LmmsTypes.h"
 
class QThread;
 
namespace lmms
{
 
class AudioEngine;
class AudioBusHandle;
class SampleFrame;
 
 
class AudioDevice
{
public:
        AudioDevice( const ch_cnt_t _channels, AudioEngine* audioEngine );
        virtual ~AudioDevice();
 
        // if audio-driver supports ports, classes inheriting AudioBusHandle
        // (e.g. channel-tracks) can register themselves for making
        // audio-driver able to collect their individual output and provide
        // them at a specific port - currently only supported by JACK
        virtual void registerPort(AudioBusHandle* port);
        virtual void unregisterPort(AudioBusHandle* port);
        virtual void renamePort(AudioBusHandle* port);
 
        inline bool supportsCapture() const
        {
                return m_supportsCapture;
        }
 
        inline sample_rate_t sampleRate() const
        {
                return m_sampleRate;
        }
 
        void startProcessing();
 
        void stopProcessing();
 
        bool isRunning() const { return m_running.test(std::memory_order_acquire); }
 
protected:
        // convert a given audio-buffer to a buffer in signed 16-bit samples
        // returns num of bytes in outbuf
        int convertToS16(const SampleFrame* _ab, const f_cnt_t _frames, int_sample_t* _output_buffer,
                const bool _convert_endian = false);
 
        // clear given signed-int-16-buffer
        void clearS16Buffer(int_sample_t* _outbuf, const f_cnt_t _frames);
 
        ch_cnt_t channels() const { return m_channels; }
 
        AudioEngine* audioEngine() { return m_audioEngine; }
 
        void setSampleRate(const sample_rate_t _new_sr) { m_sampleRate = _new_sr; }
        void setChannels(const ch_cnt_t channels) { m_channels = channels; }
 
        static void stopProcessingThread( QThread * thread );
protected:
        bool m_supportsCapture;
 
private:
        virtual void startProcessingImpl() = 0;
        virtual void stopProcessingImpl() = 0;
 
        sample_rate_t m_sampleRate;
        ch_cnt_t m_channels;
        AudioEngine* m_audioEngine = nullptr;
        std::atomic_flag m_running = ATOMIC_FLAG_INIT;
};
 
} // namespace lmms
 
#endif // LMMS_AUDIO_DEVICE_H