Conditional access method and apparatus for simultaneously handling multiple television programmes

An audio/video content receiver comprising:

• a content decoder capable of decoding an audio/video programme from a packetized data stream by using data packets defining decryption information;
• a tuner arrangement configured to receive encoded audio/video content as a packetized data stream comprising one or more programmes having data packets identified by respective sets of one or more packet identifiers and comprising identification data mapping programmes to respective sets of the packet identifiers;
• a selector configured to select data packets from the packetized data stream for a required programme according to the set of packet identifiers defined by the identification data for that stream in respect of the required programme and to select further data packets from the packetized data stream from which a programme is selected which have packet identifiers not included in the identification data for that packetized data stream;
• and
• a composite packetized stream generator configured to generate a composite packetized data stream from the selected packets and to generate a composite stream identification data indicating packet identifiers of packets included in the composite packetized data stream;
• the content decoder being configured to receive the composite packetized data stream from the composite packetized stream generator for decoding the programme from the composite packetized data stream according to the packet identifiers in the composite stream identification data.