include/AudioDummy.h

   1 /*
   2  * AudioDummy.h - dummy audio-device
   3  *
   4  * Copyright (c) 2004-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
   5  *
   6  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public
  19  * License along with this program (see COPYING); if not, write to the
  20  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  * Boston, MA 02110-1301 USA.
  22  *
  23  */
  24
  25 #ifndef _AUDIO_DUMMY_H
  26 #define _AUDIO_DUMMY_H
  27
  28 #include "AudioBackend.h"
  29 #include "Cpu.h"
  30 #include "MicroTimer.h"
  31
  32
  33 class AudioDummy : public AudioBackend, public QThread
  34 {
  35 public:
  36         AudioDummy( bool & _success_ful, AudioOutputContext * context ) :
  37                 AudioBackend( DEFAULT_CHANNELS, context )
  38         {
  39                 _success_ful = true;
  40         }
  41
  42         virtual ~AudioDummy()
  43         {
  44                 stopProcessing();
  45         }
  46
  47         inline static QString name()
  48         {
  49                 return QT_TRANSLATE_NOOP( "setupWidget", "Dummy (no sound output)" );
  50         }
  51
  52
  53         class setupWidget : public AudioBackend::setupWidget
  54         {
  55         public:
  56                 setupWidget( QWidget * _parent ) :
  57                         AudioBackend::setupWidget( AudioDummy::name(), _parent )
  58                 {
  59                 }
  60
  61                 virtual ~setupWidget()
  62                 {
  63                 }
  64
  65                 virtual void saveSettings()
  66                 {
  67                 }
  68
  69                 virtual void show()
  70                 {
  71                         parentWidget()->hide();
  72                         QWidget::show();
  73                 }
  74
  75         } ;
  76
  77
  78 private:
  79         virtual void startProcessing()
  80         {
  81                 start();
  82         }
  83
  84         virtual void stopProcessing()
  85         {
  86                 if( isRunning() )
  87                 {
  88                         wait( 1000 );
  89                         terminate();
  90                 }
  91         }
  92
  93         virtual void run()
  94         {
  95                 MicroTimer timer;
  96                 sampleFrameA * buf = CPU::allocFrames( mixer()->framesPerPeriod() );
  97                 while( true )
  98                 {
  99                         timer.reset();
 100                         int frames = getNextBuffer( buf );
 101                         if( frames == 0 )
 102                         {
 103                                 break;
 104                         }
 105
 106                         const Sint32 microseconds = static_cast<Sint32>(
 107                                         mixer()->framesPerPeriod() * 1000000.0f /
 108                                                 mixer()->processingSampleRate() - timer.elapsed() );
 109                         if( microseconds > 0 )
 110                         {
 111                                 usleep( microseconds );
 112                         }
 113                 }
 114                 CPU::freeFrames( buf );
 115         }
 116
 117 } ;
 118
 119
 120 #endif