# US 5,706,346 A · Scrambling apparatus and descrambling apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,346 A - Document ID: US5706346A - Status: Granted - Kind: A - Application number: 08/321,757 - Filed: 1994-10-12 - Granted: 1998-01-06 - Earliest claimed: 1993-10-12 - Assignees: Matsushita Electric Industrial Co., Ltd. - Inventors: Noboru Katta; Hiroki Murakami; Susumu Ibaraki; Seiji Nakamura - Web page: https://patentgrep.com/patent/US5706346A ## CPC - 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)} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A scrambling apparatus has at least one of the following processing units: a signal inserting processor for inserting a dummy pattern indicating the quantization width in the compressed video data; a conversion processor for scrambling a signal specifying whether field or frame processing is used; a DCT coefficient conversion processor for scrambling a part of the code defining the DCT coefficient; an intra.sub.-- dc.sub.-- precision conversion processor for scrambling the intra.sub.-- dc.sub.-- precision signal; and an alternate.sub.-- scan conversion processor for scrambling the alternate .sub.-- scan signal. A descrambling apparatus reverses the conversion process on the video data scrambled by the scrambling apparatus to restore the video data to the original unscrambled state. ## Claims ### Claim 1 A scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambled digital video signal and a descrambling apparatus for descrambling the scrambled digital video signal to output the compression-coded digital video signal, said scrambling apparatus comprising: signal insertion means for inserting into the compression-coded digital video signal a signal identifying a quantization width at which an original video signal has been quantized into the compression-coded digital video signal to obtain the scrambled digital video signal; and said descrambling apparatus comprising: removing means for removing from the scrambled digital video signal the signal inserted into the compression-coded digital video signal by said signal insertion means. ### Claim 2 A scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambled digital video signal and a descrambling apparatus for descrambling the scrambled digital video signal to output the compression-coded digital video signal, said scrambling apparatus comprising: detecting means for detecting a predetermined position in said compression-coded digital video signal; dummy generation means for generating a dummy data which does not form an original part of said compression-coded digital video signal; and insertion means for inserting said dummy data at said predetermined position in said compression-coded digital video signal to obtain said scrambled digital video signal; and said descrambling apparatus comprising: dummy detection means for detecting said dummy data in said scrambled digital video signal; and removing means for removing the detected dummy data from said scrambled digital video signal to obtain said compression-coded digital video signal. ### Claim 3 (depends on 2) A scrambling system according to claim 2, wherein said descrambling apparatus further comprises detecting means for detecting a predetermined position in said scrambled digital video signal. ### Claim 4 (depends on 2) A scrambling system according to claim 2, wherein said scrambling apparatus further comprises: detecting means for detecting in said compression-coded digital video signal a predetermined code selected from a group of a first code identifying which one of a field processing and a frame processing is used in an orthogonal transform coded video signal, a second code identifying a coefficient of a DC component in the coefficient components after orthogonal transform coding in the orthogonal transform coded video data, and a third code identifying a scanning method when a DCT coefficient is coded by two-dimensional Huffman coding; and inversion means for inverting said detected predetermined code in said compression-coded video signal to obtain said scrambled digital video signal; and wherein said descrambling apparatus further comprises: detection means for detecting said inverted predetermined code in said scrambled digital video signal; and means for restoring said inverted predetermined code back to an original non-inverted state to obtain the compression-coded digital video signal. ### Claim 5 In a scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambled digital video signal and a descrambling apparatus for descrambling the scrambled digital video signal to output the compression-coded digital video signal, said scrambling apparatus comprising: detecting means for detecting a predetermined position in said compression-coded digital video signal; dummy generation means for generating a dummy data which does not form an original part of said compression-coded digital video signal; and insertion means for inserting said dummy data at said predetermined position in said compression-coded digital video signal to obtain said scrambled digital video signal. ### Claim 6 (depends on 5) A scrambling apparatus according to claim 5, wherein said dummy signal identifies a quantization width at which an original video signal has been quantized into the compression-coded digital video signal. ### Claim 7 (depends on 5) A scrambling apparatus according to claim 5, wherein said insertion means processes and inserts a signal identifying a quantization width at which an original video signal has heed quantized for each coefficient component in resultant orthogonal transform coded video data. ### Claim 8 (depends on 7) A scrambling apparatus according to claim 7, wherein the insertion means inserts a code identifying a quantization width of a coefficient component identifying an AC component in an orthogonal transform coded video data as a code identifying a value which is smaller than the quantization width value at which an original video signal has been quantized into the compression-coded digital video signal. ### Claim 9 (depends on 8) A scrambling apparatus according to claim 8, wherein the insertion means inserts a quantization matrix in the compression-coded digital video signal which conforms to the MPEG standard. ### Claim 10 (depends on 9) A scrambling apparatus according to claim 9, wherein the insertion means inserts a quantization matrix of which all components other than the component in line one and column one of the quantization matrix have a value of one. ### Claim 11 (depends on 9) A scrambling apparatus according to claim 9, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: any one component in line one other than the component at line one and column one identifying the quantization width of a high frequency signal of a horizontal component of the quantization matrix of the MPEG-standard video signal, and any one component in column one identifying the quantization width of a high frequency component of a vertical component having a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 12 (depends on 11) A scrambling apparatus according to claim 11, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: the component at line two and column one identifying the quantization width of the first order high frequency component of a vertical component of the quantization matrix of the MPEG-standard video signal, and the component at line one and column two identifying the quantization width of the first order high frequency component of a horizontal component, have a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the high frequency components other than the component at line one and column one have a value which is smaller than said actual coding quantization width. ### Claim 13 (depends on 5) A scrambling apparatus according to claim 5, wherein said insertion means inserts a selected quantization matrix code in said compression-coded digital video signal which conforms to the MPEG standard. ### Claim 14 (depends on 5) A scrambling apparatus according to claim 5, wherein the insertion means scrambles a quantization matrix code already present in the compression-coded digital video signal as an inserting pattern. ### Claim 15 (depends on 5) A scrambling apparatus according to claim 5, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: any one component in a line one other than the component at line one and column one of the quantization matrix of the MPEG-standard video signal has a value greater than the actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 16 (depends on 15) A scrambling apparatus according to claim 15, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: the component of line one and column two identifying the quantization width of a first order high frequency signal of a horizontal component of the quantization matrix of the MPEG-standard video signal has a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 17 (depends on 16) A scrambling apparatus according to claim 16, wherein the insertion means inserts a quantization matrix code wherein: the value of the component of line one and column two is 255; and the value of all components other than the components at line one and column two and at line one and column one is one. ### Claim 18 (depends on 15) A scrambling apparatus according to claim 15, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: the component of line one add column three identifying the quantization width of a second order high frequency signal of a horizontal component of the quantization matrix of the MPEG-standard video signal has a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 19 (depends on 18) A scrambling apparatus according to claim 18, wherein the insertion means inserts a quantization matrix code wherein: the value of the component at line one and column three is 255; and the value of all components other than the components at line one and column three and at line one and column one is one. ### Claim 20 (depends on 5) A scrambling apparatus according to claim 5, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: any one component in line one other than the component at line one and column one of the quantization matrix of the MPEG-standard video signal has a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 21 (depends on 20) A scrambling apparatus according to claim 20, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: the component at line two and column one identifying the quantization width of a first order high frequency signal of a vertical component of the quantization matrix of the MPEG-standard video signal has a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 22 (depends on 21) A scrambling apparatus according to claim 21, wherein the insertion means inserts a quantization matrix code wherein: the value of the component at line two is and column one is 255; and the value of all components other than the components at line two and column one and at line one and column one is one. ### Claim 23 (depends on 20) A scrambling apparatus according to claim 20, wherein the insertion means processes and inserts to the predetermined position in the compression-coded digital video signal a quantization matrix code wherein: the component at line three and column one identifying the quantization width of a second order high frequency signal of a vertical component of the quantization matrix of the MPEG-standard video signal has a value which is greater than an actual coding quantization width at which an original video signal has been quantized into the compression-coded digital video signal; and the other high frequency components have a value which is smaller than said actual coding quantization width. ### Claim 24 (depends on 23) A scrambling apparatus according to claim 23, wherein the insertion means inserts a quantization matrix code wherein: the value of the component at line three and column one is 255; and the value of all components other than the components at line three and column one and at line one and column one is one. ### Claim 25 (depends on 5) A scrambling apparatus according to claim 5, wherein the insertion means comprises an insertion position information generating means for generating a code identifying the inserted position of a quantization matrix inserted by the insertion means. ### Claim 26 (depends on 25) A scrambling apparatus according to claim 25, wherein the insertion position information generating means generates as position information inserted by the insertion means, a signal indicating insertion in the sequence header when the quantization matrix code is inserted in the sequence header, and a value of a temporal.sub.-- reference signal of the inserted signal when a quantization matrix code is inserted in the quant.sub.-- matrix.sub.-- extension. ### Claim 27 (depends on 5) A scrambling apparatus according to claim 5, wherein: the insertion means comprises pattern information generating means for generating a dummy data pattern of a quantization matrix code to be inserted by said insertion means. ### Claim 28 (depends on 5) A scrambling apparatus according to claim 5, further comprising: detecting means for detecting in said compression-coded digital video signal a predetermined code selected from a group of a first code identifying which one of a field processing and a frame processing is used in an orthogonal transform coded video signal, a second code identifying a coefficient of a DC component in the coefficient components after orthogonal transform coding in the orthogonal transform coded video data, and a third code identifying a scanning method when a DCT coefficient is coded by two-dimensional Huffman coding; and inversion means for inverting said detected predetermined code in said compression-coded video signal to obtain said scrambled digital video signal. ### Claim 29 (depends on 5) A scrambling apparatus according to claim 5, further comprising: detecting means for detecting a coefficient component in the orthogonal transform coded video signal; and scrambling means for scrambling the detected coefficient component. ### Claim 30 (depends on 29) A scrambling apparatus according to claim 29, wherein said scrambling means comprises: random number generation means for generating a random number relative to said detected coefficient component; and inversion means for inverting said coefficient component based on said generated random number to obtain said scrambled digital video signal. ### Claim 31 In a scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambled digital video signal and a descrambling apparatus for descrambling the scrambled digital video signal to output the compression-coded digital video signal, said descrambling apparatus comprising: dummy detection means for detecting a dummy data which does not form an original part of said compression-coded digital video signal and inserted in said scrambled digital video signal; and removing means for removing the detected dummy data from said scrambled digital video signal to obtain said compression-coded digital video signal. ### Claim 32 (depends on 31) A descrambling apparatus according to claim 31, wherein the dummy detection means detects a quantization matrix code existing in a position identified by an inserted position information. ### Claim 33 (depends on 32) A descrambling apparatus according to claim 32, wherein the dummy detection means detects a pattern of the quantization matrix code identified by the pattern recognition code of the inserted quantization matrix code. ### Claim 34 (depends on 31) A descrambling apparatus according to claim 31, further comprising: detecting means for detecting an inverted predetermined code in said compression-coded digital video signal, said inverted predetermined code selected from a group of a first code identifying which one of a field processing and a frame processing is used in an orthogonal transform coded video signal, a second code identifying a coefficient of a DC component in the coefficient components after orthogonal transform coding in the orthogonal transform coded video data, and a third code identifying a scanning method when a DCT coefficient is coded by two-dimensional Huffman coding; and means for restoring said inverted predetermined code back to an original non-inverted state to obtain the compression-coded digital video signal. ### Claim 35 A descrambling apparatus for descrambling a scrambled digital video signal obtained scrambling a compressed video signal conforming to the MPEG standard having various codes, said descrambling apparatus comprising: detecting means for denoting said various codes contained in said scrambled digital video signal; reproducing means for reproducing said compressed video signal; dummy detection means for detecting a dummy quantization matrix code inserted in said compression video signal; and means for inhibiting processing of said scrambled digital signal when said scrambled digital video signal matches said dummy quantization matrix code. ### Claim 36 A scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambled digital video signal and a descrambling apparatus for descrambling the scrambled digital video signal to output the compression-coded digital video signal, said scrambling apparatus comprising: detecting means for detecting in said compression-coded digital video signal a predetermined code selected from a group of a first code identifying which one of a field processing and a frame processing is used in an orthogonal transform coded video signal, a second code identifying a coefficient of a DC component in the coefficient components after orthogonal transform coding in the orthogonal transform coded video data, and a third code identifying a scanning method when a DCT coefficient is coded by two-dimensional Huffman coding; and inversion means for inverting said detected predetermined code in said compression-coded video signal to obtain said scrambled digital video signal; and said descrambling apparatus comprising: detection means for detecting said inverted predetermined code in said scrambled digital video signal; and means for restoring said inverted predetermined code back to an original non-inverted state to obtain the compression-coded digital video signal. ### Claim 37 A scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambling digital video signal and a descrambling apparatus for descrambling the scrambled video signal to output the compression-coded digital video signal, detecting means for detecting in said compression-coded digital video signal a predetermined code selected from a group of a first code identifying which one of a field processing and a frame processing is used in an orthogonal transform coded video signal, a second code identifying a coefficient of a DC component in the coefficient components after orthogonal transform coding in the orthogonal transform coded video data, and a third code identifying a scanning method when a DCT coefficient is coded by two-dimensional Huffman coding; and inversion means for inverting said detected predetermined code in said compression-coded video signal to obtain said scrambled digital video signal. ### Claim 38 A scrambling system comprising a scrambling apparatus for scrambling a compression-coded digital video signal to output a scrambling digital video signal and a descrambling apparatus for descrambling the scrambled video signal to output the compression-coded digital video signal, detection means for detecting an inverted predetermined code in said scrambled digital video signal, said inverted predetermined code selected from a group of a first code identifying which one of a field processing and a frame processing is used in an orthogonal transform coded video signal, a second code identifying a coefficient of a DC component in a coefficient components after orthogonal transform coding in the orthogonal transform coded video data, and a third code identifying a scanning method when a DCT coefficient is coded by two-dimensional Huffman coding; and means for restoring said inverted predetermined code back to an original non-inverted state to obtain the compression-coded digital video signal.