AudioDummy.h

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/*
 * AudioDummy.h - dummy audio-device
 *
 * 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_DUMMY_H
#define LMMS_AUDIO_DUMMY_H
 
#include "AudioDevice.h"
#include "AudioDeviceSetupWidget.h"
#include "AudioEngine.h"
#include "MicroTimer.h"
 
namespace lmms
{
 
class AudioDummy : public QThread, public AudioDevice
{
        Q_OBJECT
public:
        AudioDummy( bool & _success_ful, AudioEngine* audioEngine ) :
                AudioDevice( DEFAULT_CHANNELS, audioEngine )
        {
                _success_ful = true;
        }
 
        ~AudioDummy() override
        {
                stopProcessing();
        }
 
        inline static QString name()
        {
                return QT_TRANSLATE_NOOP( "AudioDeviceSetupWidget", "Dummy (no sound output)" );
        }
 
 
        class setupWidget : public gui::AudioDeviceSetupWidget
        {
        public:
                setupWidget( QWidget * _parent ) :
                        gui::AudioDeviceSetupWidget( AudioDummy::name(), _parent )
                {
                }
 
                ~setupWidget() override = default;
 
                void saveSettings() override
                {
                }
 
                void show() override
                {
                        parentWidget()->hide();
                        QWidget::show();
                }
 
        } ;
 
 
private:
        void startProcessing() override
        {
                start();
        }
 
        void stopProcessing() override
        {
                stopProcessingThread( this );
        }
 
        void run() override
        {
                MicroTimer timer;
                while( true )
                {
                        timer.reset();
                        const SampleFrame* b = audioEngine()->nextBuffer();
                        if( !b )
                        {
                                break;
                        }
                        if( audioEngine()->hasFifoWriter() )
                        {
                                delete[] b;
                        }
 
                        const int microseconds = static_cast<int>( audioEngine()->framesPerPeriod() * 1000000.0f / audioEngine()->outputSampleRate() - timer.elapsed() );
                        if( microseconds > 0 )
                        {
                                usleep( microseconds );
                        }
                }
        }
 
} ;
 
} // namespace lmms
 
#endif // LMMS_AUDIO_DUMMY_H