PURPOSE: To control the reproduction output of a sub-video image according to the recognition result by recognizing the language of a voice signal through voice when service information recorded in a recording medium is reproduced in the controller having the reproduction function of the recording medium capable of recording the service information comprising a main video image, a sub-video image synchronous with the main video image and audio signals of plural channels.

CONSTITUTION: A voice recognition section (RECO) 17 receives voice information reproduced and outputted from an audio signal output section 14e to recognize the classification of a language based on extraction of characteristic of utterance of a human voice signal or the like and provides the output of information being the result of kind recognition to a discrimination section (JUDGE) 18. Upon the receipt of the language classification recognition result from the voice recognition section (RECO) 17, the discrimination section (JUDGE) 18 controls the sub-picture decoder (SP-DEC) 14b of an MPEG decoder section (MPEG2-DEC) 14 to control the reproduction output of a caption.