Video scene change detection

A method of partially dual encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice wherein the video slice contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• encrypting the packets identified as being of the specified packet type using a second encryption method to produce second encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal.

A selective encryption encoder, comprising:

• a packet identifier that identifies packets of a specified packet type, the specified packet type comprising packets carrying data representing a video slice wherein the video slice contains a larger amount of data than a threshold amount of data;
• a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;
• means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;
• and
• a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

A method of partially encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice wherein the video slice contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

A method of partially dual encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice wherein a preceding video slice contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• encrypting the packets identified as being of the specified packet type using a second encryption method to produce second encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal.

A selective encryption encoder, comprising:

• a packet identifier that identifies packets of a specified packet type, the specified packet type comprising packets carrying data representing a video slice wherein a preceding video slice contains a larger amount of data than a threshold amount of data;
• a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;
• means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;
• and
• a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

A method of partially encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice wherein a preceding video slice contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

A method of partially dual encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice header for a video slice that contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• encrypting the packets identified as being of the specified packet type using a second encryption method to produce second encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal.

A selective encryption encoder, comprising:

• a packet identifier that identifies packets of a specified packet type, the specified packet type comprising packets carrying data representing a video slice header for a video slice that contains a larger amount of data than a threshold amount of data;
• a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;
• means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;
• a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

A method of partially encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice header for a video slice that contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

A method of partially dual encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice header for a slice following a preceding video slice that contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• encrypting the packets identified as being of the specified packet type using a second encryption method to produce second encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal.

A selective encryption encoder, comprising:

• a packet identifier that identifies packets of a specified packet type, the specified packet type comprising packets carrying data representing a video slice header for a slice following a preceding video slice that contains a larger amount of data than a threshold amount of data;
• a packet duplicator that duplicates the identified packets to produce first and second sets of the identified packets;
• means for sending and receiving packets to and from a primary encryption encoder to encrypt the first set of identified packets under a first encryption method;
• a secondary encrypter for encrypting the second set of identified packets under a second encryption method.

A method of partially encrypting a digital video signal, comprising:

• examining unencrypted packets of data in the digital video signal to identify a specified packet type, the specified packet type comprising packets carrying data representing a video slice header for a slice following a preceding video slice that contains a larger amount of data than a threshold amount of data;
• encrypting packets identified as being of the specified packet type using a first encryption method to produce first encrypted packets;
• and
• replacing the unencrypted packets of the specified packet type with the first encrypted packets in the digital video signal to produce a partially encrypted video signal.

A television set-top box, comprising:

• a receiver receiving a digital television signal comprising:
• a plurality of unencrypted packets;
• and
• a plurality of encrypted packets, wherein certain of the encrypted packets carry data representing a first image associated with the scene change;
• a decrypter that decrypts the encrypted packets;
• and
• a decoder that decodes the unencrypted packets and the decrypted packets to produce a signal suitable for play on a television set.

A selective encryption decoder, for decrypting and decoding a selectively encrypted digital video signal, comprising:

• a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets carry data representing a first image associated with the scene change;
• the unencrypted packets having a first packet identifier (PID) and the encrypted packets having a second packet identifier (PID);
• a decrypter receiving the encrypted packets having the second PID and decrypting the encrypted packets using a first encryption method to produce decrypted packets;
• a PID remapper that changes at least one of the first and second PIDs so that the unencrypted packets and the decrypted packets have the same PID;
• and
• a decoder that decodes the unencrypted and decrypted packets to produce a decoded video signal.

A method of decrypting and decoding a selectively encrypted digital video signal, comprising:

• receiving packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets carry data representing a first image associated with the scene change;
• the unencrypted packets having a first packet identifier (PID) and the encrypted packets having a second packet identifier (PID);
• decrypting the encrypted packets having the second PID to produce decrypted packets;
• remapping at least one of the first and second PIDs so that the unencrypted packets and the decrypted packets have the same PID;
• and
• decoding the unencrypted and decrypted packets to produce a decoded video signal.

A computer readable medium that carries instructions that when executes on a programmed processor to facilitate operation of a video receiver device to decrypt and decode a selectively encoded digital video signal wherein the instructions comprise:

• a code segment that controls a demultiplexer that receives packets of digital video, certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets carry data representing a first image associated with the scene change, the unencrypted packets having a first packet identifier (PID) and the encrypted packets having a second packet identifier (PID);
• a code segment that controls decryption of the encrypted packets to produce decrypted packets;
• a code segment that controls remapping at least one of the first and second PIDs so that the unencrypted packets and the decrypted packets have the same PID;
• and
• a code segment that controls decoding the unencrypted and decrypted packets to produce a decoded video signal.

A selectively encrypted digital video signal embodied in a carrier wave, comprising:

• a stream of packets of video data, wherein the stream of packets when not encrypted represent a segment of video content;
• certain of the packets being unencrypted and certain of the packets being encrypted, wherein certain of the encrypted packets carry data representing a first image associated with the scene change;
• a first segment of code that identifies the unencrypted packets by a first packet identifier (PID);
• and
• a second segment of code that identifies the encrypted packets by a second packet identifier (PID).

A selectively encrypted digital video signal embodied in a computer readable medium, comprising:

• a sequence of packets of video data, wherein the sequence of packets when not encrypted represent a segment of video content;
• wherein certain of the packets are unencrypted;
• wherein certain of the packets have been produced by decrypting encrypted packets;
• wherein certain of the encrypted packets carry data representing a first image associated with the scene change;
• and
• a segment of code that identifies the unencrypted packets by a first packet identifier (PID);
• and
• a segment of code that identifies the encrypted packets by a second packet identifier (PID).