CA2235099A1 - Method and apparatus for scrambling and descrambling of video signals with edge fill - Google Patents

Method and apparatus for scrambling and descrambling of video signals with edge fill

Info

Publication number
CA2235099A1
CA2235099A1 CA 2235099 CA2235099A CA2235099A1 CA 2235099 A1 CA2235099 A1 CA 2235099A1 CA 2235099 CA2235099 CA 2235099 CA 2235099 A CA2235099 A CA 2235099A CA 2235099 A1 CA2235099 A1 CA 2235099A1
Authority
CA
Canada
Prior art keywords
video
location
scrambling
sync signal
active
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA 2235099
Other languages
French (fr)
Other versions
CA2235099C (en
Inventor
John O. Ryan
Ronald Quan
James R. Holzgrafe
Peter J. Wonfor
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rovi Corp
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority claimed from CA002082675A external-priority patent/CA2082675C/en
Publication of CA2235099A1 publication Critical patent/CA2235099A1/en
Application granted granted Critical
Publication of CA2235099C publication Critical patent/CA2235099C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

METHOD AND APPARATUS FOR SCRAMBLING AND DESCRAMBLING
OF VIDEO SIGNALS WITH EDGE FILL

A video-scrambling system induces a random wobble i.e., time shifting, in the location of active portion of the video frame, without affecting the horizontal sync signal and colorburst in each video line, thus providing both security and concealment. The security is enhanced by filling in the gap between the nominal beginning of active video and the actual beginning of active video with a synthesized video signal which replicates the adjacent active video using a digitally generated filling pattern.
Also, a random noise overlay further conceals the location of the gap. Additional concealment is provided by wiggling in time the location of the horizontal sync signal using one or two frequencies and also by randomly altering the location of the vertical sync signal. The NTSC digital encoding in accordance with the invention is simplified by using only two channels, chrominance and luminance, and by a heterodyne circuit for chrominance stability. NTSC encoding is enhanced by providing detail normally lost, by use of the chroma channel.
Additionally, a non-standard video signal may be provided with a portion of the colorburst on the front porch of the horizontal blanking, thus allowing use of a relatively simple decoder.
CA002235099A 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill Expired - Fee Related CA2235099C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US79589091A 1991-11-19 1991-11-19
US795,890 1991-11-19
CA002082675A CA2082675C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
CA002082675A Division CA2082675C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill

Publications (2)

Publication Number Publication Date
CA2235099A1 true CA2235099A1 (en) 1993-05-20
CA2235099C CA2235099C (en) 2000-01-25

Family

ID=25675660

Family Applications (5)

Application Number Title Priority Date Filing Date
CA002235100A Expired - Fee Related CA2235100C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235102A Expired - Fee Related CA2235102C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235101A Expired - Fee Related CA2235101C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235097A Expired - Fee Related CA2235097C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235099A Expired - Fee Related CA2235099C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill

Family Applications Before (4)

Application Number Title Priority Date Filing Date
CA002235100A Expired - Fee Related CA2235100C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235102A Expired - Fee Related CA2235102C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235101A Expired - Fee Related CA2235101C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill
CA002235097A Expired - Fee Related CA2235097C (en) 1991-11-19 1992-11-12 Method and apparatus for scrambling and descrambling of video signals with edge fill

Country Status (1)

Country Link
CA (5) CA2235100C (en)

Also Published As

Publication number Publication date
CA2235102A1 (en) 1993-05-20
CA2235101A1 (en) 1993-05-20
CA2235097C (en) 2000-02-29
CA2235100A1 (en) 1993-05-20
CA2235099C (en) 2000-01-25
CA2235097A1 (en) 1993-05-20
CA2235100C (en) 2000-01-25
CA2235102C (en) 2000-01-25
CA2235101C (en) 2001-07-17

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Effective date: 20041112