Playback device for optical recording medium. optical recording medium playback method, and playback program for optical recording medium

Abstract

To play back an optical disk requiring network connection, a playback device is provided, which has a function by which the network condition is evaluated before playing back a title. The playback device plays back the optical disk including programs connecting through the network to data-supplying sources; the playback device determines whether or not the network circuit is available; and when the network connection is not available depending on a network connection status or its memory amount, the playback device plays back with a non-network-ready mode.

1 . A playback device that, when playing back an MPEG-2 compressed and coded video stream recorded on a recording medium, obtains data necessary for the playback through a network, the playback device comprising:
 a network-connection-necessity determining unit that, when the video stream is played back, determines whether it is necessary to obtain the data through the network;   a network-circuit-information acquiring unit acquires network circuit information, which is information used as a basis for determining the necessity of obtaining the data through the network;   a system control unit that determines whether or not to connect to the network on the basis of an analysis result of the network circuit information outputted from the network-circuit-information acquiring unit and network-connection-requirement indication information outputted from the network-connection-necessity determining unit; and   a video decoder that, according to a determination signal from the system control unit, plays back the video stream using the data obtained through the network or plays back the video stream without obtaining the data,   wherein the video stream is an elementary stream composed of packets and to be accessed in units of GOPs, and   the video decoder performs random-access playback by connecting to a server through the network based on the determination signal and obtaining playback control information from the server.