Modifying Accompanying Audio Signal Patents (Class 380/236)
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Patent number: 7475246Abstract: A local content server system (LCS) for creating a secure environment for digital content is disclosed, which system comprises: a communications port in communication for connecting the LCS via a network to at least one Secure Electronic Content Distributor (SECD), which SECD is capable of storing a plurality of data sets, is capable of receiving a request to transfer at least one content data set, and is capable of transmitting the at least one content data set in a secured transmission; a rewritable storage medium whereby content received from outside the LCS may be stored and retrieved; a domain processor that imposes rules and procedures for content being transferred between the LCS and devices outside the LCS, and a programmable address module which can be programmed with an identification code uniquely associated with the LCS. The LCS is provided with rules and procedures for accepting and transmitting content data.Type: GrantFiled: August 4, 2000Date of Patent: January 6, 2009Assignee: Blue Spike, Inc.Inventors: Scott A. Moskowitz, Michael Berry
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Patent number: 7457415Abstract: A method and apparatus for securing and, optionally, distributing an information stream by divided the information stream into a collection of segments and compressing the segments, rearranging the order of the segments and encrypting the segments.Type: GrantFiled: October 30, 1998Date of Patent: November 25, 2008Assignee: Akikaze Technologies, LLCInventors: Glenn Arthur Reitmeier, Michael Tinker
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Patent number: 7424739Abstract: The present invention provides for validating that one or more modules reside on the same machine. When a second module wishes to establish communication with a first module, a shared memory that is accessible by the modules—but inaccessible by modules outside the machine—is used to store random data. The first module listens on a transport address corresponding to the random data for communication activity. The second module retrieves the random data from the shared memory, and then uses this data for determining the appropriate transport address to send information to when establishing the communication with the first module.Type: GrantFiled: October 29, 2004Date of Patent: September 9, 2008Assignee: Microaoft CorporationInventor: Janiv Pessach
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Patent number: 7412547Abstract: An apparatus, system and method of distributed processing are disclosed. The apparatus, system, and method communicate a software process from a driver device through a peripheral input/output channel to a processing device. The driver device and the processing device execute a common instruction set. The processing device executes the software process, reducing the processing demand on the driver device. The processing device may interface with a peripheral device through the peripheral input/output channel. In addition, the processing device communicates results data through the peripheral input/output channel in an isochronous transfer to the driver device.Type: GrantFiled: December 23, 2003Date of Patent: August 12, 2008Assignee: Lenovo Pte LtdInventors: Kevin Michael Reinberg, Richard Joseph Zabelicky
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Patent number: 7397920Abstract: Data input to an encrypting/decoding portion are input to an erroneous decoding detector. The erroneous decoding detector judges whether the data input are correctly decoded or not. For example, if it is judged that audio data input are not correctly decoded, the erroneous decoding detector does not output the audio data or outputs data indicating silence, thereby executing mute processing.Type: GrantFiled: February 8, 2002Date of Patent: July 8, 2008Assignee: Sony CorporationInventor: Ichiro Hamada
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Patent number: 7370204Abstract: By a program process, CPU 31 embeds a watermark data into a waveform data stored in wave memory 41a. The program includes a step for detecting a characterizing part (attack part and loop part) of a waveform data that represents a waveform of a musical tone where the characterizing part represents characteristics of the musical tone, and a step for embedding a watermark data into a part of the waveform data excluding the detected characterizing part. Further, CPU 31 can also extract the watermark data by a program process including a step for detecting the characterizing part and a step for extracting the watermark data embedded in a part excluding the detected characterizing part. Thus, from waveform data including a watermark data, natural musical tones can be reproduced without deteriorating the characteristics of the musical tones at the time of reproduction.Type: GrantFiled: February 11, 2003Date of Patent: May 6, 2008Assignee: Yamaha CorporationInventor: Yasuhiro Kawano
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Patent number: 7319756Abstract: Coding of an audio signal (x) is provided where the coded bitstream (AS) comprises a parametric representation of the audio signal. One component of the parametric representation comprises tracks of linked sinusoidal components (CS) where subsequently linked components are coded differentially from parameters of linked signal components already determined. The coder scrambles (18) the differentially encoded frequency and/or amplitude values by mapping the differential values onto other differential values (CSe). By modifying these values, the bit-stream is still decode-able but results in tracks with random frequency and/or amplitude variation. Consequently, the signal will be degraded.Type: GrantFiled: April 16, 2002Date of Patent: January 15, 2008Assignee: Koninklijke Philips Electronics N.V.Inventors: Arnoldus Werner Johannes Oomen, Leon Maria Van De Kerkhof
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Patent number: 7230898Abstract: This invention relates to a reproducing apparatus compatible with a storage medium storing copyright-protected and copyright-unprotected files, the reproducing apparatus being capable of reproducing any one of the files stored on the medium, the reproducing apparatus comprising: demodulating means for demodulating any one of the copyright-protected files in one way and any one of the copyright-unprotected files in a different way; selective operation executing means operated to select either any one of the copyright-protected files or any one of the copyright-unprotected files as a file to be reproduced; and controlling means for causing the demodulating means to select one of the two different ways of demodulation depending on whether a copyright-protected file or a copyright-unprotected file has been selected by operation of the selective operation executing means.Type: GrantFiled: September 1, 2000Date of Patent: June 12, 2007Assignee: Sony CorporationInventors: Teppei Yokota, Nobuyuki Kihara
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Patent number: 7146008Abstract: A digitally encrypted audio signal may be transmitted with an analog television signal. Access to the analog television video signal may be controlled by using graphics overlay techniques. The use of digital encryption techniques on the audio channel prevents improper interception.Type: GrantFiled: June 16, 2000Date of Patent: December 5, 2006Assignee: Intel CaliforniaInventors: Eric C. Hannah, Benjamin M. Cahill, III
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Patent number: 7146007Abstract: An apparatus and method thereof for providing a secure path for a digital signal in an intelligent transceiver such as a bi-directional set-top box. A digital signal (e.g., a broadcast signal or a signal received via a cable modem) is received by the intelligent transceiver at a front-end device (comprising, for example, a tuner). The digital signal is descrambled (if it is scrambled) and encrypted (if it is not encrypted) by a first functional block (e.g., an interface card or point of deployment) coupled to the front-end device. Coupled to the front-end device via the first functional block is a second functional block for processing (e.g., decoding) audio and/or visual content within the digital signal. Integrated into the second functional block is a decryption engine for decrypting encrypted signals. Signals from the front-end device are received via the first functional block by the decryption engine integral to the second functional block.Type: GrantFiled: March 29, 2000Date of Patent: December 5, 2006Assignees: Sony Corporation, Sony Electronics, Inc.Inventors: Jun Maruo, Atsushi Kagami
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Patent number: 7124444Abstract: A method of converting audio data encrypted for anti-piracy and copyright protection to a suitable format so that the data can be played in a portable device. A computer first decrypts the encrypted audio data and inserts information for setting equalizer, then encrypts the audio data lightly with the information for setting equalizer and transmits the data to a portable device. The portable device sets equalizer suitable to the lightly-encrypted audio data using the information for setting equalizer inserted by the computer, then decrypts the lightly-encrypted audio data, and outputs the decrypted audio data while amplifying or attenuating audio data for each band according to the set equalizer. Therefore, heavily encrypted audio data can be playable in a portable device with relatively low computing power and, by setting equalizer mode suitable to a music genre, the audio data can be conveyed to a listener authentically.Type: GrantFiled: April 23, 2002Date of Patent: October 17, 2006Assignee: LG Electronics Inc.Inventor: Won Jun Yang
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Patent number: 7035700Abstract: Method and apparatus for embedding binary data in audio signals. The magnitude of the power spectrum at the perceptual holes of each frame of a host speech utterance, may be altered so as to embed digital data. The phase spectrum at perceptually masked spectral points of each frame of a host speech utterance, may also be altered so as to embed digital data.Type: GrantFiled: March 13, 2002Date of Patent: April 25, 2006Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Kaliappan Gopalan, Daniel S. Benincasa
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Patent number: 7020286Abstract: A system for modulating and demodulating signals that provides a new class of signal modulators and their corresponding demodulators. The modulation scheme embeds in an information signal a carrier signal by modulating the oscillatory rate of the carrier signal. The invention generalizes the possible carrier signals to any signal which can be generated by a dynamical system that have a known exponentially convergent observer, as in certain chaotic systems.Type: GrantFiled: February 15, 2002Date of Patent: March 28, 2006Assignee: Massachusetts Institute of TechnologyInventors: Wade P. Torres, Alan V. Oppenheim, Rodolfo R. Rosales
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Patent number: 6990198Abstract: An apparatus and a method for securing a communication information in a CDMA communication system are disclosed. The method of the invention comprises the steps of encoding a input analog signal as an information bit having a predetermined size and generating a vocoder packet information bit, and encrypting said encoded vocoder packet information bit using a block cipher and a security key, and adding a frame quality indicator and the encoder tail bits to the encrypted vocoder packet information bit and configuring it as a CDMA frame, and transmitting the CDMA frame which passes a convolutional encoder, interleaver, and modulator in sequence, to a base station through an assigned frequency band.Type: GrantFiled: May 24, 2001Date of Patent: January 24, 2006Assignee: Great World Wide Ltd.Inventor: Kiho Kim
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Patent number: 6985590Abstract: The present invention provides a method and a system with which information embedded in compressed digital audio data can be directly operated. An embodiment of the system for embedding additional information in compressed audio data includes: means for extracting MDCT (Modified Discrete Cosine Transform) coefficients from the compressed audio data; means for employing the MDCT coefficients to calculate a frequency component for the compressed audio data; means for embedding additional information in the frequency component obtained in a frequency domain; means for transforming into MDCT coefficients the frequency component in which the additional information is embedded; and means for using the MDCT coefficients, in which the additional information is embedded, to generate compressed audio data.Type: GrantFiled: December 20, 2000Date of Patent: January 10, 2006Assignee: International Business Machines CorporationInventors: Ryuki Tachibana, Shuhichi Shimizu, Seiji Kobayashi
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Patent number: 6879652Abstract: An encoder transforms at least a portion of a signal, counts the resulting transform coefficients having a zero value, and encodes the signal with the zero count. A decoder decodes the signal in order to recover the zero count. The decoder may also determine its own zero count of the signal as received and may compare the zero count that it determines to the recovered zero count. The decoder may be arranged to detect compression/decompression based upon results from the comparison, and/or the decoder may be arranged to prevent use of a device based upon results from the comparison.Type: GrantFiled: July 14, 2000Date of Patent: April 12, 2005Assignee: Nielsen Media Research, Inc.Inventor: Venugopal Srinivasan
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Patent number: 6597789Abstract: Conventional decoding systems for scrambled audio-visual signals are improved by providing a dual-side local oscillator that functions as a high-side oscillator if the incoming RF signal is unscrambled and as a low-side oscillator if the incoming RF signal is scrambled. The result is that the unscrambled signal is reversed from an audio-over-video transmission configuration to an IF signal with a video-over-audio configuration, and a scrambled signal is maintained in a video-over-audio configuration, the video-over-audio configuration being the configuration required for proper reception and use of the signal by a television set. To function as both a high- and low-side oscillator, the dual-side oscillator has independent voltage control and does not follow the tracking filter associated with the tuner.Type: GrantFiled: December 17, 1998Date of Patent: July 22, 2003Assignee: General Instrument CorporationInventor: Joseph B. Glaab
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Publication number: 20030099356Abstract: Transmission of an audio signal is performed alternately in a first and a second condition in precisely timed sequence. In the first condition, the audio signal is inverted in frequency spectrum. In the second condition, the audio signal is normal. Due to this, a cryptographic apparatus is improved in security in communication. in a radio communication system linked to a radio network for transmitting an audio signal having been inverted in frequency spectrum to render the signal unintelligible, there are provided: a transmitter-side frequency spectrum inversion/non-inversion circuit including a frequency spectrum inversion circuit; a CPU for generating a control signal; a transmitter-side frequency spectrum inversion/non-inversion change-over switch; and, a sub-carrier oscillator. The CPU controls both the frequency spectrum inversion/non-inversion switch and the sub-carrier transmitter.Type: ApplicationFiled: December 26, 2001Publication date: May 29, 2003Inventors: Shouji Fujino, Hiroyuki Hakoda
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Patent number: 6571144Abstract: The foregoing problems are solved and a technical advance is achieved by a computer-implemented system for providing a digital watermark in an audio signal. In a preferred embodiment, a audio file, such as a .WAV file, representing an audio signal to be watermarked is preprocessed using an algorithm of the present invention herein referred to as the “PAWS algorithm” to determine and log the location and number of opportunities that exist for inserting a watermark into the audio signal such that it will be masked by the audio signal. The user can adjust certain parameters of the PAWS algorithm before the audio file is processed. A/B/X testing between the original and watermarked files is also supported to allow the user to undo or re-encode the watermark, if desired.Type: GrantFiled: October 20, 1999Date of Patent: May 27, 2003Assignee: Intel CorporationInventors: Donald W. Moses, Robert W. Moses
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Publication number: 20030088327Abstract: A narrow-band audio signal (9) contains information, present as recognisable distortions, for processing the signal into a wide-band signal.Type: ApplicationFiled: October 22, 2002Publication date: May 8, 2003Inventors: Rakesh Taori, Andreas Johannes Gerrits, Robert Johannes Sluijter
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Publication number: 20030081780Abstract: The present invention provides a system and method for introducing white noises into a digital audio signal so that there is progressive and cumulative degradation in audio quality after each successive reproduction of the audio sound signal in a fashion analogous to analog audio reproduction. The invention provides a white noise generator, and a digital entroping unit. In a preferred embodiment, the white noise generator is implemented by a hardware random number generator. The digital entroping unit controls the magnitude of white noise desired based on a random number generated by the random number generator, and adds the white noise to the input audio sound signal to produce a degraded audio sound signal. The magnitude of white noise can be controlled by using various masking and formatting of random number data.Type: ApplicationFiled: October 31, 2001Publication date: May 1, 2003Inventor: Jason Seung-Min Kim
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Publication number: 20030068043Abstract: The present invention provides a method of embedding watermarking data in an audio signal, comprising the steps of: incorporating watermarking information into said audio signal, sectioning said signal into at least two sections, marking at least one said section whereby said sections may be identified, generating distortion in one said section of said signal in a manner recoverable by a key obtainable from at least one other said section, and appending said distorted section to said at least one other section to form a composite signal comprising a distorted section and at least one undistorted section. The present invention is particularly useful for enabling advertisements and or trial listening sections to be added to an audio file in such a manner that they include the key for recovering a distorted section. If an attempt is made to remove the advertisement or trial section, then the key would be lost.Type: ApplicationFiled: October 1, 2001Publication date: April 10, 2003Inventors: Kar Yan Tam, Kai Fung Tsang, Sai Ho Kwok, Shing Chi Cheung
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Publication number: 20020184505Abstract: An implementation of a technology is described herein for recognizing the audio content of digital signals. The technology determines one or more hash values for the original audio content of a digital signal. In one implementation described herein, audio content recognition facilitates identification of the original audio content and other audio content that is substantially perceptually same to the original audio content. In another implementation described herein, audio content recognition facilitates semantic categorization of such original content so that it may be grouped with other audio works in the same semantic category. This abstract itself is not intended to limit the scope of this patent. The scope of the present invention is pointed out in the appending claims.Type: ApplicationFiled: April 24, 2001Publication date: December 5, 2002Inventors: M. Kivanc Mihcak, Ramarathnam Venkatesan
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Publication number: 20020172364Abstract: A method and apparatus for controlling a discontinuous transmission process. Audio information is digitized and provided to a vocoder. A voice activity level is determined from the digitized audio signal, and if voice activity is present, active vocoder frames are generated at a predetermined output rate. If voice activity is not detected, inactive vocoder frames are generated. During transitions between periods of speech activity and speech inactivity, transition frames are generated, the transition frames comprising background noise information.Type: ApplicationFiled: December 19, 2000Publication date: November 21, 2002Inventor: Anthony Mauro
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Publication number: 20020154775Abstract: A method of converting audio data encrypted for anti-piracy and copyright protection to a suitable format so that the data can be played in a portable device. A computer first decrypts the encrypted audio data and inserts information for setting equalizer, then encrypts the audio data lightly with the information for setting equalizer and transmits the data to a portable device. The portable device sets equalizer suitable to the lightly-encrypted audio data using the information for setting equalizer inserted by the computer, then decrypts the lightly-encrypted audio data, and outputs the decrypted audio data while amplifying or attenuating audio data for each band according to the set equalizer. Therefore, heavily encrypted audio data can be playable in a portable device with relatively low computing power and, by setting equalizer mode suitable to a music genre, the audio data can be conveyed to a listener authentically.Type: ApplicationFiled: April 23, 2002Publication date: October 24, 2002Applicant: LG Electronics Inc.Inventor: Won Jun Yang
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Publication number: 20020154773Abstract: A tunneling system includes an encoding module, which is typically located in the production studio, and a decoding module, which is typically located in the entertainment venue. The encoding module is configured to incorporate DMX codes into an Audio Engineering Society (AES) digital audio stream to provide additional scenes, props, special effects, lights, sounds, and music in the entertainment venue. The DMX codes are typically incorporated into the AES digital audio stream so that they are synchronized with the performance recorded on the digital video stream. The encoding module is used to add, embed or record the AES digital audio stream with DMX codes, e.g., lighting data or queues, etc., which control the equipment in the entertainment venue. The recording module is used to make the standard AES/European Broadcasting Union (EBU) audio channels hold codes such as lighting data to enhance the entertainment experience.Type: ApplicationFiled: February 26, 2002Publication date: October 24, 2002Inventors: Gary Standard, Carl McMillan, Gregg Whitaker, Lou Weiss, Jeff Long, Russ Standard, Lee Standard
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Publication number: 20020154774Abstract: Coding of an audio signal (x) is provided where the coded bitstream (AS) comprises a parametric representation of the audio signal. One component of the parametric representation comprises tracks of linked sinusoidal components (CS) where subsequently linked components are coded differentially from parameters of linked signal components already determined. The coder scrambles (18) the differentially encoded frequency and/or amplitude values by mapping the differential values onto other differential values (CSe). By modifying these values, the bit-stream is still decode-able but results in tracks with random frequency and/or amplitude variation. Consequently, the signal will be degraded.Type: ApplicationFiled: April 16, 2002Publication date: October 24, 2002Inventors: Arnoldus Werner Johannes Oomen, Leon Maria Van De Kerkhof
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Publication number: 20020087863Abstract: In the apparatus and method for a watermark embedding and detection through a linear prediction analysis, and a record medium capable of being read through a computer having a writing of a program to realize the inventive method, in which a quality of a signal does not drop, even after an imbedding of a watermark by using a signal based on a changed shape of an original signal through a use of a linear prediction analysis, with a watermark signal to be imbedded in a digital signal, but also the watermark signal containing copyright information can be detected even though an optional attack is applied thereto.Type: ApplicationFiled: April 13, 2001Publication date: July 4, 2002Inventors: Jong-Won Seok, Jin-Woo Hong, Jin-Heung Lee
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Publication number: 20020080963Abstract: Data input to an encrypting/decoding portion are input to an erroneous decoding detector. The erroneous decoding detector judges whether the data input are correctly decoded or not. For example, if it is judged that audio data input are not correctly decoded, the erroneous decoding detector does not output the audio data or outputs data indicating silence, thereby executing mute processing.Type: ApplicationFiled: February 8, 2002Publication date: June 27, 2002Inventor: Ichiro Hamada
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Publication number: 20020006203Abstract: The present invention provides a method and a system with which information embedded in compressed digital audio data can be directly operated. An embodiment of the system for embedding additional information in compressed audio data includes: means for extracting MDCT (Modified Discrete Cosine Transform) coefficients from the compressed audio data; means for employing the MDCT coefficients to calculate a frequency component for the compressed audio data; means for embedding additional information in the frequency component obtained in a frequency domain; means for transforming into MDCT coefficients the frequency component in which the additional information is embedded; and means for using the MDCT coefficients, in which the additional information is embedded, to generate compressed audio data.Type: ApplicationFiled: December 20, 2000Publication date: January 17, 2002Inventors: Ryuki Tachibana, Shuhichi Shimizu, Seiji Kobayashi
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Patent number: 6310957Abstract: Apparatus for interdicting television channels of a cable television system comprises a plurality of oscillators dedicated to jamming the audio portion of television channels to be interdicted, and a further plurality of different oscillators dedicated to jamming the video portion of television channels to be interdicted. The number of jamming oscillators for jamming the audio is less than or equal to the number of jamming oscillators for jamming the video. The hopping rate for video jamming is greatly in excess of the hopping rate for audio jamming. On the other hand, the dwell time for audio jamming is greatly in excess of the dwell time for video jamming. At least two levels of jamming effectiveness of both audio and video portions can be addressably controlled from the headend of a system including such interdiction apparatus.Type: GrantFiled: November 4, 1997Date of Patent: October 30, 2001Assignee: AT&T Corp.Inventors: Michael Wyndham Heller, Jack Elden James, Byron Lynn Johnson, Ronald Lee Katz, Stephen Gratzer McWilliams
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Patent number: 6222924Abstract: To prevent unauthorized reception, storage, copying and reproduction of digital media objects it is defined in addition to a scrambled broadcast format a scrambled storage format which is different from the broadcast format. A user's terminal equipment cannot receive, store or reproduce protected objects without a key which is advantageously a bit sequence stored on a portable memory medium and which can be different according to the type of use it gives entitlement to. To prevent the storing and later reproduction as such of data in the broadcast format, a time stamp is included in the broadcast format representing the time of broadcasting. A playback device cannot reproduce a broadcast-format object if the reproduction time differs from the time stamp included in the broadcast format. The reproduction time is advantageously read from a real time clock of a portable memory medium.Type: GrantFiled: August 18, 1998Date of Patent: April 24, 2001Assignee: Oy Nokia ABInventor: Ari Salomäki
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Patent number: 6185687Abstract: A signal reproducing apparatus for prohibiting copying or unauthorized use. The apparatus includes a copying management information decision circuit 19 for discriminating the state of the copying management information read out from each header of a data sector and within the TOC, a protect signal generating circuit 20 for generating a protect signal based on the discrimination signal and a mixing circuit 24 for mixing a protect signal in a vertical blanking period of an analog video signal D/A converted from digital video data reproduced from an optical disc D. The apparatus also includes a descrambling circuit 31 for descrambling the digital data based on the copying management information and a scrambling circuit 32 for descrambling the digital data. The apparatus enables prohibition of unauthorized analog copying and digital copying, inhibition of serial generational copying and prohibition of unauthorized analog and digital copying simultaneously.Type: GrantFiled: August 19, 1999Date of Patent: February 6, 2001Assignee: Sony CorporationInventors: Yoichiro Sako, Shigeyuki Yoneyama
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Patent number: 6091822Abstract: A technique is disclosed for preventing unauthorized playback of scrambled video/audio signals recorded on, for example, a video tape cassette, which technique includes several cooperating processes and apparatus which further prevent the playback of recorded video/audio when the playback apparatus is in a still or pause mode of operation. The technique includes selected combinations of processes of inverting and re-clamping the luminance component of the video signal just prior to FM modulation; blanking an overscan portion, or portions, of the video signal and adding a video retrace signal to the overscan portion(s); inverting the normal control track signal and position modulating the normally unused edge; and selectively scrambling the audio signal and recording the scrambled audio signal in an audio track or in a Hi-Fi track. A selected user specific authorization code is recording in and recovered from the audio track.Type: GrantFiled: January 8, 1998Date of Patent: July 18, 2000Assignee: Macrovision CorporationInventors: Andrew B. Mellows, John O. Ryan, William J. Wrobleski, Ronald Quan, Gerow D. Brill
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Patent number: 6078668Abstract: An apparatus and method for concealing data bursts in an analog scrambler using audio repetition. What otherwise would be periodic data bursts appearing at the audio output are replaced with samples from audio portions of the multiplexed signal. Preferably the replaced audio samples come from immediately past portions of the audio of the signal. The data bursts are therefore effectively concealed from the audio output which improves on the degradation of audio otherwise caused by the data bursts that are mixed in periodically with the audio portions of the signal.Type: GrantFiled: August 7, 1996Date of Patent: June 20, 2000Assignee: Transcrypt International, Inc.Inventor: Steven P. Poulsen
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Patent number: 6055315Abstract: A scrambling system for a cable television system in which a group of channel frequencies are reused over a plurality of service areas includes an access controller, an encoder and a plurality of simplified scrambling units. Each service area receives different television signals on the group of channel frequencies. The access controller provides signal authorization information for a given channel frequency to a plurality of receiver/decoders located in the different services areas. The access controller also provides descrambling information corresponding to the signal authorization information to the encoder for the given channel frequency. The encoder produces a conditional access code by placing the descrambling information into a scrambled reference signal. An extracting unit removes the conditional access code from the scrambled reference signal and distributes the conditional access code to each of the simplified scrambling units operating at the given channel frequency.Type: GrantFiled: December 7, 1998Date of Patent: April 25, 2000Assignee: ICTV, Inc.Inventors: John F. Doyle, Stephen C. Snell, Timothy Dunn