virtual bool TransmitSystemAudioModeStatus(cec_logical_address dest);
virtual uint8_t VolumeUp(void);
virtual uint8_t VolumeDown(void);
virtual uint8_t MuteAudio(void);
virtual bool TransmitSystemAudioModeStatus(cec_logical_address dest);
virtual uint8_t VolumeUp(void);
virtual uint8_t VolumeDown(void);
virtual uint8_t MuteAudio(void);