Method and apparatus for providing on demand services in a subscriber system

A method of providing on demand services in a subscriber system having a plurality of on demand channels distributed over a network to a multiplicity of subscribers, at least one of which on demand channels can be accessed by authorized subscribers, said method comprising the steps of:

• digitizing analog program information to form program files wherein said analog program information has a video component and a stereo audio component;
• encoding said stereo audio component in a BTSC stereo format before said program information is digitized;
• storing said program files in a memory to form a library of program files which can be accessed on demand by the authorized subscribers;
• retrieving a selected program file from said program library in response to a subscriber request from an authorized subscriber;
• converting said selected program file to an analog program signal at a time requested in the subscriber request;
• and
• modulating said analog program signal onto one of said plurality of on demand channels which the subscriber making the request can access.

An on demand services feature for a subscription system including a plurality of scheduled channels and a plurality of on demand channels which are transmitted over a distribution network to a plurality of subscribers, said on demand feature comprising:

• a source of analog program information which provides video baseband information and associated audio baseband information as programs;
• means for digitizing said video baseband information of a program;
• means for scrambling said video baseband information before digitizing it with said video digitizing means, wherein said means for scrambling includes means for scrambling the horizontal synchronizing interval of at least one horizontal line of said video signal;
• means for digitizing said audio baseband information of a program;
• means for storing said digital video information and said digital audio information in a program file of a digital library;
• means for retrieving identified program files of said digital library in response to a subscriber request;
• means for converting said retrieved program file into an analog baseband video signal and an analog baseband audio signal;
• and
• means for modulating said analog baseband video and audio signals onto one of said demand channels.

An on demand services feature for a subscription system including a plurality of scheduled channels and a plurality of on demand channels which are transmitted over a distribution network to a plurality of subscribers, said on demand feature comprising:

• a source of analog program information which provides video baseband information and associated audio baseband information as programs;
• wherein said audio baseband information includes a first stereo channel and a second stereo channel;
• means for encoding said first and second stereo audio channels into a BTSC format baseband audio signal;
• means for digitizing said video baseband information of a program;
• means for scrambling said video baseband information before digitizing it with said video digitizing means comprising means for scrambling the active video portion and the horizontal synchronizing interval of at least one horizontal line of said video signal and means for generating descrambling information in the form of pulses which carry information representative of the mode and timing of the scrambling of the video signal;
• means for digitizing said audio baseband information of a program;
• means for storing said digital video information and said digital audio information in a program file of a digital library;
• means for retrieving identified program files of said digital library in response to a subscriber request;
• means for converting said retrieved program file into an analog baseband video signal and an analog baseband audio signal;
• and
• means for modulating said analog baseband video and audio signals onto one of said on demand channels.

An on demand services feature for a subscription system including a plurality of scheduled channels and a plurality of on demand channels which are transmitted over a distribution network to a plurality of subscribers, said on demand feature comprising:

• a source of analog program information which includes a video signal and at least first and second associated signals;
• means for digitizing said analog program information into program data files having at least video data blocks and first and second data blocks, wherein each data block corresponds to the analog information of the respective converted signal;
• means for storing said program data files in a memory to form a digital library of program data files;
• means for retrieving identified program data files of said digital library in response to a subscriber request;
• means for converting at least one of said video, first associated, and second associated data blocks into an analog signal in response to subscriber selection signal;
• and
• means for modulating said analog signal onto one of said on demand channels.

A method of providing on demand video programs with alternate language selection, comprising the steps of:

• digitizing a scrambled analog video signal;
• digitizing a first audio signal associated with the video signal which has been produced in a first language;
• digitizing a second audio signal associated with the video signal which has been produced in a second language;
• storing said digitized video, first audio and second audio signals in program data files in a memory to form a digital library of program data files;
• retrieving identified program data files of said digital library in response to a subscriber request identifying the respective program data file and one of said first and second audio signals;
• transmitting the identified program data file including the video signal and the selected audio signal to the subscriber making the request.

A system for the storage and retrieval of program signals, said system comprising:

• a source of scrambled analog program information wherein said scrambled analog program information has a scrambled video component and a stereo audio component;
• means for selectively digitizing said scrambled analog program information into program data files;
• means for encoding the stereo audio component into a BTSC format signal before the scrambled analog program information is digitized;
• means for storing said program data files in a memory;
• means for retrieving a program data file;
• means for converting said retrieved program data file into scrambled analog program information;
• and
• said conversion means converts said retrieved program data file into scrambled analog program information with a BTSC format stereo audio component.

A system for the storage and retrieval of program information, said system comprising:

• a source of analog program information including a stereo audio component;
• means for encoding said stereo audio component into a BTSC format signal;
• means for selectively digitizing said analog program information into program data files;
• means for storing said program data files in a memory;
• means for retrieving a program data file;
• and
• means for converting said retrieved program data file into analog program information with a BTSC format stereo audio component.

A services feature for a subscription system including a plurality of channels which are transmitted over a distribution network to a plurality of subscribers, said services feature comprising:

• a source of analog program information which provides video baseband information and associated audio baseband information as programs;
• means for scrambling said video baseband information of a program, wherein said means for scrambling includes means for scrambling the horizontal synchronizing interval of at least one horizontal line of said baseband video signal;
• means for digitizing said video baseband information of a program;
• means for digitizing said audio baseband information of a program;
• means for storing said digital video information and said digital audio information in a program file of a digital library;
• means for retrieving identified program files of said digital library in response to a subscriber request;
• means for converting said retrieved program file into an analog baseband video signal and an analog baseband audio signal;
• and
• means for modulating said analog baseband video and audio signals onto one of said channels.