Method of constructing MPEG program streams from encrypted MPEG transport streams

A receiver for an encrypted MPEG transport stream, comprising:

• a transport stream de-multiplexer and decryptor adapted to receive the encrypted MPEG transport stream, said transport stream de-multiplexer and decryptor further adapted to convert said encrypted MPEG transport stream into a first video elementary stream and a first audio elementary stream, said first video elementary stream and said first audio elementary stream being received by an audio and video decoder and presenter, said audio and video decoder and presenter adapted to output a playable signal based on said first video and audio elementary streams;
• a program stream constructor adapted to receive the encrypted MPEG transport stream, said program stream constructor further adapted to construct and to output an encrypted MPEG compliant modified program stream from the encrypted MPEG transport stream, said encrypted MPEG compliant modified program stream comprised of packs of MPEG packetized elementary stream data structures;
• a storage subsystem adapted to store said encrypted MPEG compliant modified program stream;
• and
• a program stream de-multiplexer and decryptor adapted to retrieve said encrypted MPEG compliant modified program stream, said program stream de-multiplexer and decryptor further adapted to convert said encrypted MPEG compliant modified program stream into a second video elementary stream and a second audio elementary stream, said second video elementary stream and said second audio elementary stream being received by said audio and video decoder and presenter further adapted to output said playable signal based on said second video and audio elementary streams.

A method for creating an MPEG program stream comprising:

• extracting a program map table from an encrypted MPEG transport stream and creating a program stream map stream in a MPEG packetized elementary stream data structure;
• extracting a conditional access table from the encrypted MPEG transport stream and creating a conditional access stream in the MPEG packetized elementary stream data structure;
• extracting a program stream directory from the encrypted MPEG transport stream and creating a program stream directory stream in the MPEG packetized elementary stream data structure;
• determining the packet IDs of all transport stream packets of a single selected program;
• extracting an entitlement management message from the encrypted MPEG transport stream and creating an entitlement management message stream in the MPEG packetized elementary stream data structure;
• after creating said entitlement management message stream, extracting and selecting from the encrypted MPEG transport stream video packets, packets from one or more audio channel and an entitlement control message, said video packets, said one or more audio channel packets and said entitlement control message packet having packet IDs belonging to said single selected program and creating respectively from the selected video, audio channel, entitlement control message into an encrypted video stream, one or more encrypted audio channel streams and an entitlement control message stream in separate MPEG packetized elementary stream data structures, each MPEG packetized elementary stream data structure containing only one stream type and each audio MPEG packetized elementary stream data structure containing only one audio channel;
• and
• assembling said program stream map stream, said conditional access table stream, said program stream directory, said entitlement management message stream, said encrypted video stream, said encrypted audio channel streams and said entitlement control message stream into an encrypted MPEG compliant modified program stream.