Patent ID: 8427584

Claim:
An output device to output an image and/or a sound based on a signal input from one of a plurality of external devices connected to the output device, the external devices including a High-Definition Multimedia Interface (HDMI) source device to output an HDMI signal to the output device, the output device comprising: an instruction section to perform an instruction for adjusting sound volume of the sound to be output from the output device; an adjustment section to adjust the sound volume of the sound to be output in accordance with the instruction from the instruction section; a judgment section to judge whether a header of an Audio InfoFrame exists in InfoFrame data in the HDMI signal input from the HDMI source device or not; and an invalidation section to invalidate the instruction from the instruction section so that the previously set sound volume is maintained during a period from when the judgment section judges that the header of the Audio InfoFrame does not exist to when the judgment section judges that the header exists.