text: #include "dvd_player.h"
  
  DVDPlayer::DVDPlayer (Amplifier *amp)
  {
      this->amp = amp;
      this->is_on = false;
      this->is_surround = false;
  }
  
  void DVDPlayer::on ()
  {
      printf("[DVDPlayer] ON!\n");
      this->is_on = true;
  }
  
  void DVDPlayer::off ()
  {
      printf("[DVDPlayer] OFF!\n");
      this->is_on = false;
  }
  
  void DVDPlayer::play (std::string name)
  {
      printf("[DVDPlayer] Playing '%s'!\n",name.c_str());
  }
  
  void DVDPlayer::pause ()
  {
      printf("[DVDPlayer] PAUSE!\n");
  }
  
  void DVDPlayer::stop ()
  {
      printf("[DVDPlayer] STOP!\n");
  }
  
  void DVDPlayer::eject ()
  {
      printf("[DVDPlayer] EJECT!\n");
  }
  
  void DVDPlayer::setSurroundAudio ()
  {
      this->is_surround = true;
  }
  
  void DVDPlayer::setTwoChannelAudio ()
  {
      this->is_surround = false;
  }