Signal processing not specific to the method of recording or reproducing Circuits therefor

GPHYSICS G11Information storage G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER

G11B20/00Signal processing not specific to the method of recording or reproducing Circuits therefor

G11B20/00007Time or data compression or expansion G11B20/00086Circuits for prevention of unauthorised reproduction or copying G11B20/00094involving measures which result in a restriction to authorised record carriers G11B20/00101the original record carrier having a larger recording capacity than the potential target medium G11B20/00108wherein original, non-rewritable record carriers are recognised by trying to erase recorded data G11B20/00115wherein the record carrier stores a unique medium identifier G11B20/00123the record carrier being identified by recognising some of its unique characteristics G11B20/0013wherein the measure concerns not the entire record carrier, but a specific physical or logical area of one or more record carriers G11B20/00137involving measures which result in a restriction to contents recorded on or reproduced from a record carrier to authorised users G11B20/00144involving a user identifier G11B20/00152involving a password G11B20/00159Parental control systems G11B20/00166involving measures which result in a restriction to authorised contents recorded on or reproduced from a record carrier G11B20/00173wherein the origin of the content is checked G11B20/00181using a content identifier G11B20/00188involving measures which result in a restriction to authorised devices recording or reproducing contents to/from a record carrier G11B20/00195using a device identifier associated with the player or recorder G11B20/00202wherein the copy protection scheme builds on multi-session recording G11B20/0021involving encryption or decryption of contents recorded on or reproduced from a record carrier G11B20/00217the cryptographic key used for encryption and/or decryption of contents recorded on or reproduced from the record carrier being read from a specific source G11B20/00224wherein the key is obtained from a remote server G11B20/00231wherein the key is obtained from a local external medium G11B20/00239wherein the key is provided by a software application accessing the medium G11B20/00246wherein the key is obtained from a local device G11B20/00253wherein the key is stored on the record carrier G11B20/0026the key being stored as a barcode G11B20/00268said barcode being recorded in a burst cutting area [BCA] G11B20/00275the key being stored on a chip attached to the record carrier G11B20/00282the key being stored in the content area G11B20/00289wherein the key is stored as a watermark G11B20/00297the key being stored in a management area G11B20/00304the key being stored in the lead-in area [LIA] G11B20/00311the key being stored in the lead-out area [LOA] G11B20/00318the key being stored in the TOC G11B20/00326the key being embossed on the record carrier G11B20/00333the key being stored in header data G11B20/0034the key being stored as a hologram G11B20/00347wherein the medium identifier is used as a key G11B20/00355the record carrier having a label that provides the key G11B20/00362the key being obtained from a media key block [MKB] G11B20/00369wherein a first key, which is usually stored on a hidden channel G11B20/00376the key being stored by varying the pit format G11B20/00384the key being derived from a physical signature of the record carrier G11B20/00391the key being stored in subcodes G11B20/00398the key being stored in sync patterns G11B20/00405the key being stored by varying characteristics of the recording track G11B20/00413wherein the key is input by a user G11B20/0042the copy protection scheme being related to a specific access protection standard G11B20/00427advanced access content system [AACS] G11B20/00434content protection for pre-recorded media [CPPM] G11B20/00442content protection for recordable media [CPRM] G11B20/00449content scrambling system [CSS] G11B20/00456digital transmission content protection [DTCP] G11B20/00463high-bandwidth digital content protection [HDCP] G11B20/00471video content protection system [VCPS] G11B20/00478wherein contents are decrypted and re-encrypted with a different key when being copied from/to a record carrier G11B20/00485characterised by a specific kind of data which is encrypted and recorded on and/or reproduced from the record carrier G11B20/00492wherein content or user data is encrypted G11B20/005wherein only some specific parts of the content are encrypted G11B20/00507wherein consecutive physical data units of the record carrier are encrypted with separate encryption keys G11B20/00514wherein the entire content is encrypted with the same key G11B20/00521wherein each session of a multisession recording medium is encrypted with a separate encryption key G11B20/00528wherein each title is encrypted with a separate encryption key for each title G11B20/00536wherein encrypted content data is subjected to a further, iterated encryption G11B20/00543wherein external data is encrypted G11B20/0055wherein license data is encrypted G11B20/00557wherein further management data is encrypted G11B20/00565wherein parity data is encrypted G11B20/00572involving measures which change the format of the recording medium G11B20/00579said format change concerning the data encoding, e.g., modulation schemes violating run-length constraints, causing excessive DC content, or involving uncommon codewords or sync patterns G11B20/00586said format change concerning the physical format of the recording medium G11B20/00594wherein the shape of recording marks is altered G11B20/00601wherein properties of tracks are altered, e.g., by changing the wobble pattern or the track pitch, or by adding interruptions or eccentricity G11B20/00608wherein the material that the record carrier is made of is altered G11B20/00615said format change concerning the logical format of the recording medium G11B20/00623wherein the modification to the logical format directly concerns user data G11B20/0063wherein the modification to the logical format mainly concerns management data, e.g., by changing the format of the TOC or the subcode G11B20/00637said management data being address data G11B20/00644the address data format being such that there are overlapping address ranges G11B20/00652the address data being scrambled so that ascending address values do not reflect the physical order of data blocks G11B20/00659involving a control step which is implemented as an executable file stored on the record carrier G11B20/00666involving a step of erasing or nullifying data G11B20/00673wherein the erased or nullified data include a cryptographic key G11B20/00681involving measures which prevent a specific kind of data access G11B20/00688said measures preventing that a usable copy of recorded data can be made on another medium G11B20/00695said measures preventing that data are read from the recording medium G11B20/00702said measures preventing that data are recorded on the recording medium G11B20/0071involving a purchase action G11B20/00717wherein accounting and payment are postponed G11B20/00724wherein a prepaid credit balance is registered on the recording medium G11B20/00731involving a digital rights management system for enforcing a usage restriction G11B20/00739wherein the usage restriction is associated with a specific geographical region G11B20/00746wherein the usage restriction can be expressed as a specific number G11B20/00753wherein the usage restriction limits the number of copies that can be made G11B20/0076wherein the copy frequency G11B20/00768wherein copy control information is used G11B20/00775wherein said copy control information is encoded in an encryption mode indicator [EMI] G11B20/00782wherein the usage restriction limits the number of times a program can be installed G11B20/00789wherein the usage restriction limits the number of functional copies, which can be accessed at a time G11B20/00797wherein the usage restriction limits the number of times a content can be reproduced G11B20/00804wherein the usage restriction limits the number of users or devices that are allowed to access a given content G11B20/00811wherein said number is encoded as a cryptographic token or ticket G11B20/00818wherein the usage restriction limits the signal quality G11B20/00826wherein a spoiler signal is added to degrade the signal quality G11B20/00833wherein the usage restriction limits the data access speed G11B20/0084wherein the usage restriction can be expressed as a specific time or date G11B20/00847wherein the usage restriction is defined by a licence file G11B20/00855involving a step of exchanging information with a remote server G11B20/00862wherein the remote server can grant the permission to use a content G11B20/00869wherein the remote server can deliver the content to a receiving device G11B20/00876wherein physical copy protection means are attached to the medium G11B20/00884involving a watermark G11B20/00891embedded in audio data G11B20/00898based on a hash function G11B20/00905multiple watermarks used in combination G11B20/00913based on a spread spectrum technique G11B20/0092involving measures which are linked to media defects or read/write errors G11B20/00927wherein said defects or errors are generated on purpose G11B20/00934said intentional errors occurring because of corrupted address information G11B20/00942said intentional errors occurring due to an invalid playback path or program chain G11B20/00949said intentional errors occurring due to bad sectors, which are either physically destroyed or which are declared defective in the defect management information G11B20/00956said intentional errors occurring due to an invalid TOC G11B20/00963wherein said defects or errors are not generated on purpose G11B20/00971involving measures for monitoring the industrial media production and distribution channels G11B20/00978wherein the record carrier stores a trial version of a content G11B20/00985the trial version being of lower quality than the original version G11B20/00992Circuits for stereophonic or quadraphonic recording or reproducing G11B20/02Analogue recording or reproducing G11B20/025Error detection or correction G11B20/04Direct recording or reproducing G11B20/06Angle-modulation recording G11B20/08Pulse-modulation recording or reproducing G11B20/10Digital recording or reproducing G11B20/10009Improvement or modification of read or write signals G11B20/10018analog processing for digital recording or reproduction G11B20/10027adjusting the signal strength during recording or reproduction G11B20/10037A/D conversion, D/A conversion, sampling, slicing and digital quantisation or adjusting parameters thereof G11B20/10046filtering or equalising G11B20/10055using partial response filtering when writing the signal to the medium or reading it therefrom G11B20/10064EEPR4 or E2PR4 G11B20/10074EPR4 G11B20/10083PR1 or PR(1,1,) G11B20/10092partial response PR(1,1,1,1) G11B20/10101PR2 or PR(1,2,1) G11B20/10111partial response PR(1,2,2,1) G11B20/1012partial response PR(1,2,2,2,1) G11B20/10129partial response PR(1,2,3,3,2,1) G11B20/10138partial response PR (2,3,3,2) G11B20/10148partial response PR(1,3,3,1) G11B20/10157PR3 or PR(2,1,-1) G11B20/10166partial response PR(3,4,4,3) G11B20/10175PR4, PR(1,0,-1) G11B20/10185PR5 or PR(-1,0,2,0,-1) G11B20/10194using predistortion during writing G11B20/10203baseline correction G11B20/10212compensation for data shift ( G11B20/10222clock-related aspects G11B20/10231wherein an asynchronous, free-running clock is used; Interpolation of sampled signals G11B20/1024wherein a phase-locked loop [PLL] is used G11B20/1025the PLL being discrete time or digital PLL G11B20/10259simultaneous timing recovery for multiple parallel tracks G11B20/10268bit detection or demodulation methods G11B20/10277the demodulation process being specifically adapted to partial response channels G11B20/10287using probabilistic methods G11B20/10296using the Viterbi algorithm G11B20/10305signal quality assessment G11B20/10314amplitude of the recorded or reproduced signal G11B20/10324asymmetry of the recorded or reproduced waveform G11B20/10333wherein the asymmetry is linked to domain bloom G11B20/10342sub-information or auxiliary signals different from the normal recording marks G11B20/10351baseline shift, DC content, bias G11B20/10361digital demodulation process G11B20/1037based on hard decisions G11B20/10379based on soft decisions G11B20/10388control of the read or write heads G11B20/10398jitter, timing deviations or phase and frequency errors G11B20/10407by verifying the timing of signal transitions G11B20/10416by verifying the timing of peak values G11B20/10425by counting out-of-lock events of a PLL G11B20/10435by verifying the timing of predetermined signal patterns G11B20/10444by verifying the timing of zero crossings G11B20/10453physical shape of recording marks G11B20/10462consistency with a reference waveform in a given time period G11B20/10472derived from statistics of other quality measures G11B20/10481optimisation methods G11B20/1049using closed-form solutions G11B20/105selecting parameter values from a plurality of predetermined settings G11B20/10509iterative methods G11B20/10518using neural networks G11B20/10527Audio or video recording; Data buffering arrangements G11B20/12Formatting G11B20/1201on tapes G11B20/1202with longitudinal tracks only G11B20/1204for continuous data G11B20/1205for discontinuous data G11B20/1207with transverse tracks only G11B20/1208for continuous data G11B20/1209for discontinuous data G11B20/1211with different data track configurations G11B20/1212for continuous data G11B20/1214for discontinuous data G11B20/1215on cards G11B20/1217on discs G11B20/1251for continuous data G11B20/1252for discontinuous data G11B20/1254for mixed data G11B20/1258where blocks are arranged within multiple radial zones G11B20/1261on films G11B20/1262with more than one format/standard G11B20/14using self-clocking codes G11B20/1403characterised by the use of two levels G11B20/1407code representation depending on a single bit G11B20/1411conversion to or from pulse width coding G11B20/1415conversion to or from pulse frequency coding G11B20/1419to or from biphase level coding, i.e. to or from codes where a one is coded as a transition from a high to a low level during the middle of a bit cell and a zero is encoded as a transition from a low to a high level during the middle of a bit cell or vice versa G11B20/1423Code representation depending on subsequent bits G11B20/1426conversion to or from block codes or representations thereof G11B20/1488characterised by the use of three levels G11B20/1492two levels are symmetric, in respect of the sign to the third level which is "zero" G11B20/1496characterised by the use of more than three levels G11B20/16using non self-clocking codes G11B20/18Error detection or correction Testing G11B20/1803by redundancy in data representation G11B20/1806Pulse code modulation systems for audio signals G11B20/1809by interleaving G11B20/1813by adding special bits or symbols to the coded information G11B20/1816Testing G11B20/182using test patterns G11B20/1833by adding special lists or symbols to the coded information G11B20/1866by interleaving G11B20/1876Interpolating methods G11B20/1879Direct read-after-write methods G11B20/1883Methods for assignment of alternate areas for defective areas G11B20/1886with tapes G11B20/1889with discs G11B20/20for correction of skew for multitrack recording G11B20/22for reducing distortions G11B20/225for reducing wow or flutter G11B20/24for reducing noise