A playback device judges whether a connected display device is equipped to display only interlaced video or both interlaced and progressive video. It equipped to display both interlaced and progressive video, a mode setting unit 15 sets an operation mode of the playback device to an image quality mode for interlaced signal output or a continuity mode for progressive signal output, according to a user selection received via a GUI. If continuity mode is set, the playback device decodes the video stream and performs progressive signal output.