Asynchronous copy protection detector

• US 7,599,604 B2
• Filed: 06/13/2002
• Issued: 10/06/2009
• Est. Priority Date: 12/14/2001
• Status: Expired due to Fees

• Current Assignee: InterDigital Madison Patent Holdings (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Rumreich, Mark Francis, Hague, John Alan
• Primary Examiner(s): Tran; Thai
• Assistant Examiner(s): Dang; Hung Q
• Application Number:
  US10/170,955
• Publication Number:
  US 20030113101A1
• Time in Patent Office: 2,672 Days
• Field of Search: 386/66, 386/1, 386/94, 386/60, 386/84, 386/95, 380/218, 380/221, 380/203, 380/204, 380/224, 348/476, 348/478, 348/465, 348/525
• US Class Current: 386/252
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00615 said format change concerning the logical format of the recording medium, e.g. the structure of sectors, blocks, or frames
• CPC Class Codes: G11B 23/28 Indicating or preventing prior or unauthorised use, e.g. cassettes with sealing or locking means, write-protect devices for discs write-protect devices for tapes G11B23/042, G11B23/08714; dummy cassettes for locking in the drive G11B33/005
• CPC Class Codes: H04N 2005/91314 the copy protection signal being a pulse signal inserted in blanking intervals of the video signal, e.g. pseudo-AGC pulses, pseudo-sync pulses
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection

Abstract

A video system (100) includes detection circuitry (200A-200C) operative to detect pseudo-synchronization pulses within a composite synchronization signal in dependence upon at least one timing signal. Timing circuitry (200D-200F) is operative to generate the at least one timing signal without utilizing synchronization information within the composite synchronization signal.

Claims

1. A video system, comprising:

detection circuitry operative to detect pseudo-synchronization pulses associated with a copy protection scheme within a composite synchronization signal in dependence upon at least two timing signals,

wherein detection of said pseudo-synchronization pulses associated with a copy protection scheme by said detection circuitry is independent of timing signals generated utilizing synchronization information within the composite synchronization signal, and

wherein said detection circuitry comprises circuitry to;

subsample said composite synchronization signal to create a subsampled signal;

perform matched filtering on said subsampled signal; and

further process said matched filtered subsampled signal using said at least two timing signals to generate a signal indicating the presence of said pseudo-synchronization pulses associated with a copy protection scheme; and

timing circuitry operative to generate the at least two timing signals;

wherein the at least two timing signals are generated independently of said synchronization information within the composite synchronization signal.

2. The video system of claim 1, wherein the detection circuitry includes a filter operative to detect at least one predetermined bit pattern representative of the pseudo-synchronization pulses associated with a copy protection scheme.

3. The video system of claim 1, wherein the detection circuitry is operative to detect pseudo-synchronization pulses associated with a copy protection scheme in each of a plurality of consecutive lines of a video field.

4. The video system of claim 1, wherein one of the timing signals approximates an interval corresponding to one line of a video field.

5. The video system of claim 4, wherein another of the timing signals approximates an interval corresponding to a plurality of video fields.

6. The video system of claim 1, wherein one of the timing signals approximates an interval corresponding to a plurality of video fields.

7. An asynchronous detector, comprising:

detecting means for detecting pseudo-synchronization pulses associated with a copy protection scheme within a composite synchronization signal in dependence upon at least two timing signals, wherein detection of said pseudo-synchronization pulses associated with a copy protection scheme by said detecting means is independent of timing signals generated utilizing synchronization information within the composite synchronization signal, and wherein said detecting means comprises;

means for subsampling said composite synchronization signal to create a subsampled signal;

means for performing matched filtering on said subsampled signal; and

means for further processing said matched filtered subsampled signal using said at least two timing signals to generate a signal indicating the presence of said pseudo-synchronization pulses associated with a copy protection scheme; and

means for generating the at least two timing signals;

wherein the at least two timing signals are generated independently of said synchronization information within the composite synchronization signal.

8. The asynchronous detector of claim 7, wherein the detecting means includes means for detecting at least one predetermined bit pattern representative of the pseudo-synchronization pulses associated with a copy protection scheme.

9. The asynchronous detector of claim 7, wherein the detecting means detects pseudo-synchronization pulses associated with a copy protection scheme in each of a plurality of consecutive lines of a video field.

10. The asynchronous detector of claim 7, wherein one of the timing signals approximates an interval corresponding to one line of a video field.

11. The asynchronous detector of claim 10, wherein another of the timing signals approximates an interval corresponding to a plurality of video fields.

12. The asynchronous detector of claim 7, wherein one of the timing signals approximates an interval corresponding to a plurality of video fields.

13. A method for asynchronously detecting a copy protection scheme in a video system, comprising steps of:

detecting pseudo-synchronization pulses associated with the copy protection scheme within a composite synchronization signal in dependence upon at least two timing signals, wherein detection of said pseudo-synchronization pulses associated with a copy protection scheme by said detection circuitry is independent of timing signals generated utilizing synchronization information within the composite synchronization signal, and wherein said detecting comprises;

subsampling said composite synchronization signal to create a subsampled signal;

performing matched filtering on said subsampled signal; and

further processing said matched filtered subsampled signal using said at least two timing signals to generate a signal indicating the presence of said pseudo-synchronization pulses associated with a copy protection scheme; and

generating the at least two timing signals independently of said synchronization information within the composite synchronization signal.

14. The method of claim 13, wherein the detecting step comprises detecting at least one predetermined bit pattern representative of the pseudo-synchronization pulses associated with a copy protection scheme.

15. The method of claim 13, wherein the detecting step comprises detecting pseudo-synchronization pulses associated with a copy protection scheme in each of a plurality of consecutive lines of a video field.

16. The method of claim 13, wherein one of the timing signals approximates an interval corresponding to one line of a video field.

17. The method of claim 16, wherein another of the timing signals-approximates an interval corresponding to a plurality of video fields.

18. The method of claim 13, wherein one of the timing signals approximates an interval corresponding to a plurality of video fields.