A digital broadcast receiving apparatus, comprising:
- a scanning unit which scans a broadcast data of one or more sub channels included in a broadcast data of a physical channel in a digital broadcast wave;
- a channel information memory unit which stores the physical channel, a virtual channel, the sub channels, and scrambling information which indicates whether the sub channels are scrambled or not so as to refer the scrambling information to the sub channels;
- a scrambling judgment unit which judges whether the broadcast data of the sub channels, which is scanned by the scanning unit is scrambled or not;
- a memory control unit which stores a judgment result obtained by the scrambling judgment unit in the channel information memory unit as the scrambling information;
- and
- an updating unit which updates the scrambling information in the channel information memory unit by having the scanning unit scan only the physical channel that has a not-scrambled sub channel which is stored in the channel information memory unit and by executing the scrambling judgment unit and the memory control unit at a predetermined timing;
- wherein:
- when the judgment result obtained by the scrambling judgment unit indicates that all of the sub channels in the physical channel are scrambled, the memory control unit stores information that the sub channels are not scrambled as the scrambling information of a predetermined sub channel of the physical channel;
- and wherein the scrambling judgment unit comprises:
- a first judgment unit which judges whether the broadcast data of the sub channel, which is scanned by the scanning unit is scrambled or not by referring to each of a plurality of types of scrambling determination data used for judging whether the broadcast data is scrambled or not-scrambled, the scrambling information data being included in the broadcast data of the sub channel;
- a second judgment unit which judges whether the broadcast data is scrambled or not according to whether the broadcast data is decodable or not;
- and wherein the memory control unit comprises:
- a first memory control unit which stores information that the sub channel is not scrambled in the channel information memory unit when the first judgment unit judges that the broadcast data is not scrambled;
- a second memory control unit which stores information that the sub channel is not scrambled in the channel information memory unit when the second judgment unit judges that the broadcast data is decodable;
- a judgment unit which judges whether a judgment result obtained according to the first judgment unit by referring to one of the plurality of types of the scrambling determination data coincides with a judgment result obtained according to the second judgment unit or not;
- and
- a channel information memory control unit which makes the second memory control unit store the information in the channel information memory unit when the judgment unit judges that the judgment result obtained according to the first judgment unit does not coincide with the judgment result obtained according to the second judgment unit by referring to all of the types of the scrambling determination data, and makes the first memory control unit store the information in the channel information memory unit by referring to the one of the plurality of types of the scrambling determination data when the judgment unit judges that the judgment result obtained according to the first judgment unit by referring to the one of the plurality of types of scrambling determination data coincides with the judgment result obtained according to the second judgment unit.