Dynamic composition of pre-encrypted video on demand content

• US 7,346,163 B2
• Filed: 03/16/2004
• Issued: 03/18/2008
• Est. Priority Date: 10/31/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Agnihotri, Davender, Pedlow, JR., Leo M.
• Primary Examiner(s): Revak, Christopher
• Assistant Examiner(s): CHEN, SHIN HON
• Application Number:
  US10/802,007
• Publication Number:
  US 20050094808A1
• Time in Patent Office: 1,463 Days
• Field of Search: 380/210, 380/211, 380/212, 380/233, 380/240, 380/242, 380/37, 380/200, 380/239, 713/153, 713/160, 713/162, 713/176
• US Class Current: 380/210
• CPC Class Codes: G11B 27/005 Reproducing at a different information rate from the information rate of recording for television signals H04N5/783
• CPC Class Codes: G11B 27/322 used signal is digitally coded
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/23473 by pre-encrypting
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/2362 Generation or processing of Service Information [SI]
• CPC Class Codes: H04N 21/2387 Stream processing in response to a playback request from an end-user, e.g. for trick-play
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/8453 by locking or enabling a set of features, e.g. optional functionalities in an executable program
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/17336 Handling of requests in head-ends

Abstract

According to certain embodiments consistent with the present invention, a method of processing digital video content, wherein the digital video content comprises intra-coded frames and inter-coded frames, involves selecting a plurality of the intra-coded frames for encryption to produce selected frames; encrypting the selected frames under a first encryption algorithm to produce first encrypted frames; storing the inter-coded frames in a first file; and storing the intra-coded frames, whether encrypted under the first encryption algorithm or unencrypted, in a second file. For a multiple encryption embodiment consistent with the present invention, the method further involves duplicating the intra-coded frames; encrypting duplicates of the selected frames under a second encryption algorithm to produce second encrypted frames; storing the intra-coded frames, whether encrypted under the second encryption algorithm or unencrypted, in a third file. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Claims

1. A method of processing digital video content in a video-on-Demand (VOD) system, wherein the digital video content comprises unencrypted intra-coded frames and inter-coded frames, the method comprising:

duplicating the unencrypted intra-coded frames;

selecting a plurality of the unencrypted intra-coded frames for encryption to produce selected frames;

encrypting the selected frames under a first encryption algorithm to produce first encrypted frames;

encrypting the duplicates of the unencrypted selected frames under a second encryption algorithm to produce second encrypted frames;

storing the inter-coded frames in a first file;

storing the intra-coded frames, whether encrypted under the first encryption algorithm or unencrypted, in a second file; and

storing the duplicate intra-coded frames, whether encrypted under the second encryption algorithm or unencrypted, in a third file;

sending normal play content to a receiver compatible with the first encryption algorithm by multiplexing content from the first file with content from the second file,

sending trick play content to a receiver compatible with the first encryption algorithm by retrieving content only from the second file;

sending normal play content to a receiver compatible with the second encryption algorithm by multiplexing content from the first file with content from the third file,

sending trick play content to a receiver compatible with the second encryption algorithm by retrieving content only from the third file;

whereby, separate trick play files and multiple encrypted content files are combined.

2. The method according to claim 1, wherein the digital content comprises MPEG encoded digital content, and wherein the intra-coded frames comprise I-frames, and wherein the inter-coded frames comprise B-frames and P-frames.

3. The method according to claim 1, further comprising:

receiving a request from a subscriber terminal for the digital content;

determining whether the subscriber is enabled for decryption of content under the first encryption algorithm or the second encryption algorithm in order to determine which of the second and third files to use for sending normal play content and trick play content.

4. The method according to claim 3, wherein the content is retrieved from the first and third files in an order of sequential frames in the content for normal play content for a receiver compatible with the second encryption algorithm, and wherein the content is retrieved from the first and second files in an order of sequential frames in the content for normal play content for a receiver compatible with the first encryption algorithm.

5. The method according to claim 1, wherein the digital content comprises MPEG encoded digital content, and wherein the intra-coded frames comprise I-frames, and wherein the inter-coded frames comprise B-frames and P-frames.

6. An apparatus for processing digital video content, wherein the digital video content comprises intra-coded frames and inter-coded frames, the method comprising:

an encryption processor that duplicates the intra-coded frames and selects a plurality of the intra-coded frames for encryption to produce selected frames;

a first encrypter for encrypting the selected frames under a first encryption algorithm to produce first encrypted frames;

a second encrypter for encrypting the duplicates of the selected frames under a second encryption algorithm to produce second encrypted frames;

a file server that stores the inter-coded frames in a first file;

the file server further storing the intra-coded frames, whether encrypted under the first encryption algorithm or unencrypted, in a second file;

the file server further storing the intra-coded frames, whether encrypted under the second encryption algorithm or unencrypted, in a third file;

a session manager that receives a request from a subscriber terminal for the digital content, the session manager further determining whether the the subscriber is enabled for decryption of content under the first encryption algorithm or the second encryption algorithm;

a multiplexer operating under control of the session manager, the multiplexer operating to retrieve content from the file server to;

send normal play content to a receiver compatible with the first encryption algorithm by multiplexing content from the first file with content from the second file,

send trick play content to a receiver compatible with the first encryption algorithm by retrieving content only from the second file;

send normal play content to a receiver compatible with the second encryption algorithm by multiplexing content from the first file with content from the third file; and

send trick play content to a receiver compatible with the second encryption algorithm by retrieving content only from the third file; and

a transmitter that sends the content from the multiplexer to the subscriber terminal.

7. The apparatus according to claim 6, wherein the content is retrieved from the first and third files and the first and second files in an order of sequential frames in the content.

8. The apparatus according to claim 6, wherein the digital content comprises MPEG encoded digital content, and wherein the intra-coded frames comprise I-frames, and wherein the inter-coded frames comprise B-frames and P-frames.