Use subcode channel to prevent CD audio frequency piracy
The cross reference of related application
The application is the common unsettled U.S. Patent application 09/549 of application on April 14th, 2000,820 subsequent application, U.S. Patent application 09/549,820 is U.S. Patent applications 09/370 of application on August 9th, 1999,813 subsequent application, U.S. Patent application 09/370,813 is subsequent application of the U.S. Patent application 09/175,255 of application on October 20th, 1998.The assignee that these all applications all transfer present patent application, and be incorporated in herein as a reference.
Invention field
The present invention relates generally to the protection of Intellectual Property Rights measure, and specifically prevent the audio frequency of recording, the piracy of computer-readable medium.
Background of invention
Compact disk (CD) disc is a device that preferably is suitable for distributed digital loop recording and computer software.CD audio record almost generally makes according to the standard 908 of International Electrotechnical Commission (IEC) (EEC), and this standard 908 is called " optical disc digital audio system " (1987, Switzerland, Geneva), and it is incorporated in herein as a reference.This 908 standard also claims Red Data Book, stipulates that how many voice datas are encoded and are recorded on the disk, makes these data be used standard digital decoding chip and plays.Different standards is applicable to other data type, and such as computer software, this computer software also can be recorded on the CD.For example, a plurality of period discs of blue book standard code, it is combining audio and other data on single disk.
The music CD of master is by having the molded plastic blank disc production of master slug, and this molded plastic blank disc is to use expensive special equipment to produce.Alternatively, a recordable CD (CDR) can be made according to user's requirement by the factory of authorizing.Because laser disc equipment expensive, consider that recently the CD disc will relatively maintain secrecy with anti-piracy.Variation has taken place in these situations recently, has become and can utilize for the user as the laser disc equipment and the read/write medium of cheapness.Therefore, be easy to use the conventional personal computer that has read/write CD driver now, perhaps read driver and a write driver goes to carry out the accurately digital copy of all types of CD with one.This CD content is read by computer byte of a byte from the original cd of typically legal purchase, writes then to blank disc CD, duplicates so that carry out piracy.Similarly clone method can use other medium, such as digital video disks (DVD).For disc and software industry because such piracy is duplicated the financial loss estimation of generation at more than one hundred million dollars.
It is the digital audio output that provides via many CD Player that another kind is used for the common method that piracy duplicates, and exports such as S/PDIF (Sony/Philips digital interconnect form).These output formats are by IEC standard 958 regulations, and this IEC standard 958 is called " digital audio interface " (1993, Switzerland, Geneva), and it is incorporated in herein as a reference.This S/PDIF output can be used legally, removes to connect transducer, loud speaker and other the acoustic component of CD Player to high-quality.On the other hand, because the audio content of this CD of its bitwise copy, the output of this S/PDIF also is used for carrying out piracy in the piracy use easily.Except this audio content, these S/PDIF data comprise a subcode, and this subcode is called as periodical copy management system (SCMS) subcode, and whether this Data Source is original record or copy in its expression.According to SCMS, commercial available tape deck hypothesis does not allow the user to remove recorded voice from the S/PDIF data flow that is labeled as copy.But, be easy to be bypassed for this safeguard measure of pirate plagiarist.
Summary of the invention
A purpose of some aspect of the present invention is, the method and apparatus that improves the piracy that is used to prevent the computer-readable medium recorded is provided.
Another purpose of some aspect of the present invention is to be provided for producing the method and apparatus that piracy is had the compact disk of drag.
Another purpose of some aspect of the present invention is, the method and apparatus of the digital copy that is provided for preventing that disc is illegal.
In a preferred embodiment of the invention, by at subcode channel, preferably change preventing to be recorded in a signal on the original storage medium in the Q channel by piracy.For this purpose, a data writing unit comprises a coding module, its received audio signal and according to these signals of standard 908 coding of International Electrotechnical Commission (IEC) (EEC).The modification insert module of this data write unit by insert a modification in the subcode Q of this code signal channel, changes this encoded signals.A logging modle of this data write unit is the signal of this change of record on this storage medium subsequently, and this storage medium typically comprises compact disk (CD).
Preferably, though according to standard 908, perhaps according to the equipment standard of using in CD drive, the signal of this change is wrong, yet does not hinder this audio signal according to the broadcast of record from original medium.Therefore, this original cd can be carried out in the mode that not influenced by this change substantially.On the contrary, when attempting to make the piracy of this CD, this change causes irrecoverable error basically.This mistake shows that in itself duplicating at all that perhaps this is illegal can not produce, and perhaps this copy is destroyed, reflects that in so a kind of mode it is out of use basically.Preferably, the software that resides in the mandate in this data write unit or other the hardware can duplicate this CD, the feasible influence that is not subjected to this change, and duplicating also of mandate can be played.
In some preferred embodiment of the present invention, this is revised insert module and inserts this modification by the regulation amendment record in the absolute or relative track time of the audio signal on the CD in subcode Q channel.Known CD copy step relies on the non-destruction magnetic track time in this field, therefore can not use the piracy of the CD of these embodiment formulations of the present invention.Optionally, this master magnetic track time is stored on the position of original cd by the subcode channel reservation of standard 908 regulations.The propagation software of authorizing is retrieved this master magnetic track time from this predetermined position, and therefore can carry out the abundant function copy of original cd.
Alternatively or in addition, insert this modification by on this disk, increasing one or more additional time periods (session), this disk has a magnetic track that import to point in the program area of very first time section, and comprises that specific pattern removes to hinder uncommitted computer and read this time period.
Further alternatively or in addition, this modification insert module is recorded in the modified index amount that this CD goes up the audio signal magnetic track by regulation, inserts this modification in this subcode Q channel.Known CD copy step relies on non-destruction magnetic track index (index) in this field, therefore can not use the piracy of the CD of these embodiment formulations of the present invention.Optionally, this original track index is stored on the position of original cd by the subcode channel reservation of standard 908 regulations.The propagation software of authorizing from the disk should be predetermined the position or retrieve this original track index from second time period, and therefore can carry out the abundant function copy of original CD.
Preferably; for the personal computer (PC) that allows to authorize goes to play the disc content of protection; this original content is protected by digital rectification management (DRM) technology, typically by compression (using any suitable form known in the art, such as MP3 or VQF) and this content of encryption.These ciphered data are stored in hiding mode to conventional CD-ROM drive software, for example in the subcode channel position of reserving, paralysis zone or export area, perhaps second time period on this CD.These data can only be passed through the decrypted and broadcast of software of use authority, and the software of this mandate preferably was stored in second time period.
In addition preferably, this modification that is inserted among this CD reaches the degree that causes that S/PDIF output changes or other the numeral output that is produced by CD Player changes, and wherein CD Player is play the CD of this protection.The voice playing that this variation in this numeral output does not hinder laser disc by the equipment of compatibility, this compatible equipment is such as the audio tweeter that has digital-to-analog converter.But, the piracy that this variation uses numeral output to prevent this CD content, for example, this numeral output inputs to register as numeral.
Optionally, this modification in being inserted in subcode channel, another modification is used as additional piracy obstruction and intentionally is inserted in this voice data.This modification is inserted on this disk with a kind of like this method so that auxiliary data, auxiliary data are such as error detection code, it is provided by 908 standards (perhaps other applicable standard), can make CD Player during playing or proofread and correct or hide this modification, perhaps fully ignore them.But when a piracy is when being made of medium, these auxiliary data are invalid in overcome the modification of having a mind in original medium, and irrecoverable error basically appears in the result in duplicating.The method that is used to insert such modification has been described in above-mentioned U.S. Patent application 09/175,255 and 09/370,813.
Therefore, according to the preferred embodiments of the present invention, provide a kind of and be used to protect the data that are recorded on the original storage medium, in case the method for using illegal data taking equipment to duplicate, this method comprises:
Reception is according to standard 908 coded datas of International Electrotechnical Commission (IEC);
Change the part of this coded data, in the subcode Q of these data channel, to insert a modification, make that the data of this change are inconsistent with the enforcement of the standard of using 908 in data taking equipment, but do not hinder broadcast according to these data of record on it; With
These data of record on this original storage medium, the data that comprise this change, an operation of playing these record data is not moved not to be subjected to these data to change the mode that influences basically whereby, but occurs irrecoverable error basically in the piracy of original storage medium.
Preferably, this medium comprises compact disk, and these data comprise digital audio-frequency data.
In a preferred embodiment, change these data and be included in absolute time of modification in the data that are recorded on this medium.Preferably, a correction absolute time is stored in the subcode bits of reserving on this medium.Preferably, revise this absolute time and comprise absolute time in a plurality of successive modules that change the magnetic track be recorded in selection.
In a further advantageous embodiment, change these data and comprise the absolute time that need not to change in the subcode Q channel that is recorded in one or more modules, one or more modules of duplicating these data on this storage medium are to new position.
In another preferred embodiment, change these data and comprise the vertex degree that is modified in the magnetic track that is recorded in data on this medium.Preferably, this method is included in correction index of storage in the subcode bits of reserving on this medium.
In another preferred embodiment, change these data and comprise that producing a plurality of time periods records, comprise one or more audio frequency and data time section, wherein this modification in subcode Q channel is inserted into one or more data and audio frequency in the time period.Preferably, produce these a plurality of time period records and comprise that the one or more magnetic tracks that were positioned at for the first audio frequency time period on this medium are pointed in this importing to importing of a time period generation.Alternatively or in addition, produce these a plurality of time periods records and comprise a time period is produced an importing that it comprises the track number of Duoing than this standard code.Further alternatively or in addition, produce these a plurality of time periods records and comprise a time period is produced an importing that it represents that this recording medium is shorter than its reality.Further alternatively or in addition, produce the absolute time that begins to insert a modification that these a plurality of time periods records are included in a time period.Again further alternatively or in addition, produce these a plurality of time periods records and comprise and producing a plurality of time periods that at least wherein two are identified as audio signal.
In a preferred embodiment, write down these data and be included in data on this medium and compress in the time period and store this data, for the usefulness of the authorized copy of carrying out this medium.
In a further advantageous embodiment, this coded data comprises coding audio data, and this method comprises a part that changes this coding audio data, make that the data of this change are inconsistent with the enforcement of the standard of using 908 in this data taking equipment, wherein these data of record comprise the data that record is auxiliary on this medium, should auxiliary data use in operation by processor, go part operation to this change of coding audio data, the feasible mode that influences with the change that is not subjected to this coding audio data is basically operated played data, but should auxiliary data be invalid to duplicating these data when the part of this change of correction coding voice data, result's this change in pirate this original medium causes further irrecoverable error basically.
Preferably, this auxiliary data comprises error detection code.
According to the preferred embodiments of the present invention, a kind of data that are recorded on the original storage medium that are used to protect further are provided, with anti-piracy method, this method comprises:
Reception is according to standard 908 coded datas of International Electrotechnical Commission (IEC);
A part that changes this coded data is to insert a modification in these data, make that the numeral output of data of this change will be inconsistent with the equipment such as the digital outputting standard of the standard 958 of International Electrotechnical Commission (IEC), but this modification does not hinder the broadcast according to these data that write down on it; With
These data of record on this original storage medium, the data that comprise this change, an operation of playing these record data does not move not to be subjected to the mode of the influence of this data modification basically whereby, but be based on this numeral output, irrecoverable error basically in the piracy of original storage medium, occurs.
Preferably, change coded data and partly comprise the one or more control bits of change in coded data, this control bit is duplicated in this numeral output.In addition or alternatively, change this coded data and partly be included in a frame coded data inner conversion voice data position.
According to the preferred embodiments of the present invention, also provide a kind of and be used to protect the data that are recorded on the original data storage medium, in case the device that uses illegal data taking equipment to duplicate, this device comprises:
An encoder is applicable to receive the data flow be used to be recorded on the medium, and according to standard 908 these data of coding of International Electrotechnical Commission (IEC);
A sub-code generator, play a part to revise a change coded data part by in the subcode Q of these data channel, inserting one, make that the data of this change are inconsistent with the enforcement of the standard of using 908 in data taking equipment, but do not hinder broadcast according to these data of record on it; With
8 to 14 (EFM) modulators, connect and go to modulate the data that are used to be recorded in this change on this original storage medium, play the record data operation whereby and do not move, but in pirate this original storage medium, irrecoverable error basically occurs not to be subjected to these data to change the mode that influences basically.
In a preferred embodiment, this device comprises a data time period generator, play a part to provide the data time section to be used to be recorded in this original storage medium to EFM, make these data that are recorded on the medium comprise a plurality of time period data, and this defective in subcode Q channel is inserted at least one of a plurality of time periods.
According to a preferred embodiment of the present invention, provide a kind of in addition for the data storage medium that duplicates drag that uses illegal read-out device, store media data thereon according to standard 908 codings of International Electrotechnical Commission (IEC), be changed by in the subcode Q of these data channel, inserting a part of revising coded data, make that the enforcement of the standard 908 that the data of this change are identified as and use is inconsistent in data taking equipment, but do not hinder the broadcast of writing down these data according to it, an operation of playing these record data does not move not to be subjected to these data to change the mode that influences basically whereby, but has irrecoverable error basically in the piracy of this original storage medium.
Invention will be more fully understood from the DETAILED DESCRIPTION OF THE PREFERRED of carrying out together below in conjunction with accompanying drawing, wherein:
Brief description of drawings
Fig. 1 be one according to the cutaway view of recording the compact disk (CD) of convention known in the art;
Fig. 2 is one and illustrates according to the preferred embodiments of the present invention, is used to produce anti-schematic block diagram of duplicating the device of CD;
Fig. 3 is one and writes schematic diagram to the data structure details of CD according to the convention of recording known in the art; With
Fig. 4 be one according to the preferred embodiments of the present invention, schematically illustrate for prevent pirate on CD the block diagram of copy data.
DETAILED DESCRIPTION OF THE PREFERRED
With reference now to Fig. 1,, it is the simple cutaway view of an audio frequency compact disk (CD) 20, and the general layout of recording this disk of convention according to well known in the art is shown.An information area 22 comprises an importing (LI) zone 24, one program areas (PA) 26 and derivation (LO) zone 28.The information area 22 is outwards developed with the expansion helix, and comprises the recorded content that CD 20 is all.Both comprise P and Q channel ingress area 24 and export area 28, and it is included in time and the magnetic track information that uses during CD plays.Program area 26 is by forming up to the audio-frequency information (for example, music) of 99 magnetic tracks and the subcode information of following.
The preferred embodiments of the present invention provide in order to stop piracy to be duplicated, and are used for revising a plurality of different, the complementary method of CD 20 data.Be described in more detail below a plurality of this embodiment.Generally speaking, this modification is divided into following classification:
Conventional magnetic disk modification-for example, on an audio frequency CD, record the some time section.Usually increase the conflict pointer by the importing in second time period, this second time period can be used for misleading personal computer (PC), and it duplicates middle use piracy usually.Preferably, the time period at the end on this CD is a data time section that comprises the compressed format music.Preferably, this music is encrypted and/or use the digital packaging technology (also to be called the coding of digital copyright management-DRM), so that can directly play from this disk, can download and play from a privileged user's disk by security software.
Preferably, as what in above-mentioned U.S. Patent application 09/370,813, describe, revise this voice data by inserting noise.
Revise this subcode information, especially in the Q channel.These modifications can comprise, for example, change absolute or relative time, the index pointer, and contents table (TOC) information (list too much or magnetic track, perhaps the misleading pointer between a plurality of time periods) very little, control byte is revised, pre-gap length control.Other above-mentioned modification is conspicuous to those skilled in the art.
To being recorded in the rudimentary modification that CD goes up bit architecture.Being modified in the above-mentioned U.S. Patent application of mentioning 09/175,255 and 09/370,813 like this described in detail.They usually be included in CD upper record order, cause hardware error in some CD drive that PC uses, prevent that perhaps them from distorting the voice data of mistake.Alternatively or in addition, bit sequence can be recorded on this CD, it does not appear in 8 to 14 (EFM) lookup table with the routine of 908 canonical representations.
The needs that depend on application, these modifications can be with different being used in combination in CD 20.
Fig. 2 is one and illustrates according to the preferred embodiments of the present invention, is used to produce the schematic block diagram of the device 40 that resists the CD that duplicates.This primary sound or analogue audio frequency are converted into the number format that is suitable for encoding on disk, make this information can be subsequently standard player by an audio frequency CD 20 be played (decoding).In the phase I of coding, produce digital bit stream, the simulated audio signal that its expression is continuous.This analog signal is converted into the discrete digital sampling by an analog to digital (A/D) transducer 30.
In order to detect and error correction during playing, parity check bit is increased to this bit stream.Error correction encoder 32 utilizes the normally used Reed-Solomon code coding (CIRC) that interweaves mutually this numerical data of going to resequence.Per 32 bytes of 36 pairs of error correction audio frequency of subcode generator just increase a byte subcode.The content of the subcode channel that this 908 standard code was increased in this stage.But subcode generator 36 changes this standard subcode in such a way, i.e. the broadcast that this CD is common is uninfluenced substantially, but piracy is prevented from.Especially, this change does not damage the integrality of this bit stream, and does not produce the CIRC mistake on this disk.The method of above-mentioned change is described hereinafter.
The device 40 that illustrates equally comprises a selectable data time section generator 37, and for the usefulness that produces a plurality of time period disks, it comprises audio frequency and data time section.As describing hereinafter, this time period is configured to make and stops uncommitted computer to read this CD.An audio compressor 35 optionally is provided, has been contained in such input of audio frequency in the time period disk more than with the coding form compressed package.
Known in this field, 16 words of standard of speech data are mapped as 2 14 " optics " symbols, and record at this and to comprise in additional information such as Play Control and Presentation Function.The output of the output of one 8 to 14 modulator (EFM), 34 composition error correcting coders 32 and the output of subcode generator 36 and data time section generator 37.Every of coded data is preferably used laser beam recorder (LBR) 38 physically to be scribed at the stamper that is used to produce CD 20, to produce a series of precise and tiny concave points on this stamper.Alternatively, special-purpose cd-rom recorder 39 is used for directly going up at recordable CD (CDR) producing CD 20.
Fig. 3 is the schematic diagram of a data structure details that is received by EFM modulator 34 according to this 908 standard.The data module 58 that is used to be recorded on the CD comprises 98 frames, and each frame origin comes from 32 byte datas or symbol and one 8 " subcode " words formations of encoder 32 (perhaps deriving from data time section generator 37).8 of in each subcode word these are called P, Q, R, S, T, U, V and W respectively.
This Q the position that derives from 98 successive frames is called subcode Q channel 64 by stack up.This subcode Q channel comprises program and timing information, comprises sync bit S0 and S1,4 control bits, 4 bit address positions, 72 bit data positions, and 16 cyclic redundancy check (CRC) code (CRCC).In ingress area 24, this 72 bit data position comprises relative time (read time, perhaps tracking time) data 74 and track location, in program area 26, stores relative time and absolute time (A time, perhaps disk time) data simultaneously.This relative time that is used for each module is represented to begin to the duration of the beginning of this module from current magnetic track.This absolute time represents that from the program area 26 began to the duration of the beginning of this module.Time is that unit is measured with minute, second and frame, has 75 time frames (being different from 98 Frames in a module) in wherein in one second.This Q channel also comprises a track number (TNO), and is also referred to as vertex degree in the magnetic track index.In ingress area 24, this Q channel carries a contents table (TOC).
Tabulation I below schematically illustrates the variation according to the absolute time value of the preferred embodiments of the present invention subcode Q channel 64.In the typical case's coding according to the CD 20 of standard 908, absolute time originates in the beginning of program area 26, and is increased to the end of export area 28 linearly.In order to guarantee replicating original audio frequency glibly, and guarantee the simultaneity of time between frame of recording and the frame play later, use this absolute time as pointer at the known propagation software in this field.Preferably, a modification is inserted into the absolute time value of subcode Q channel, as in the tabulation shown in " change " row, therefore good as if increased the speed of time by this magnetic track.
Tabulation I
Original time | The time that changes |
Minute | Second | Frame | Minute | Second | Frame |
0 (beginning magnetic track) | ????0 | ????0 | ????0 | ????0 | ????0 |
????0 | ????0 | ????1 | ????0 | ????0 | ????2 |
????0 | ????0 | ????2 | ????0 | ????0 | ????4 |
????0 | ????0 | ????3 | ????0 | ????0 | ????6 |
????0 | ????0 | ????4 | ????0 | ????0 | ????7 |
????0 | ????0 | ????5 | ????0 | ????0 | ????8 |
????... | ????... | ????... | ?... | ????... | ????... |
????0 | ????0 | ????71 | ?0 | ????0 | ????74 |
????0 | ????0 | ????72 | ?0 | ????1 | ????0 |
????... | ????... | ????... | ?... | ????... | ????... |
5 (terminal magnetic tracks) | ????30 | ????42 | ?5 | ????36 | ????20 |
5 (pauses) | ????30 | ????43 | ?5 | ????30 | ????43 |
???5 | ????30 | ????44 | ?5 | ????30 | ????44 |
???... | ????... | ????... | ?... | ????... | ????... |
This absolute time that the is used for original CD 20 preferably module of the several successive outside per 150 continuous modules increases, and the paralysis zone between magnetic track recovers normal, shown in above-mentioned tabulation, plays so as not to influencing audio stereo unfriendly.The standard CD player will not be subjected to the influence of these deliberate absolute time distortions.But CD 20 uncommitted duplicating will comprise the music discontinuity, and for example, in above-mentioned tabulation, absolute time jumps to frame 4 from frame 2 and jumps to frame 6.This consequential signal that duplicates on this CD will have a series of constant amplitudes, audible, distortion and common ear-piercing sound.
Optionally, this original correction absolute time information is stored in the predetermined position of subcode R-W channel (Fig. 3), and it is unallocated at present according to standard 908.The software of authorizing can carry out replicating original CD 20 by the data that visit is stored in the R-W channel.
Alternatively, except inserting in this absolute time the modification, by changing vertex degree (indes) and/or mode value, the modification that produces audible effect in uncommitted duplicating is inserted in the subcode Q channel 64.Be similar to this absolute magnetic track time, this vertex degree provides a series of " checkpoints " in magnetic track.Revise the point index for one and in a uncommitted CD 20 duplicates, will cause noiseless zone, but can not influence the broadcast of original CD.Optionally, as mentioned above, this correction index is stored in the R-W channel, and the software of authorizing can duplicate this original CD by this index of retrieval from these channels.
Preferably, being inserted in modification among this CD reaches and causes that in numeral output such as the degree that changes in the S/PDIF output, this S/PDIF output is produced by CD Player, plays the CD of this protection therein.This digital output data stream comprises 32 words of a sequence, is called as subframe, and each subframe is carried voice data between 16 and 24 together in company with preamble (preamble) and control bit.A control bit in each subframe is a subcode bits, is similar to the subcode bits in each frames of data on this CD.This subcode bits in the piece of one 192 frames in the S/PDIF data flow (typically 384 subframes) is carried at the most contents that CD goes up this subcode Q channel of playing, comprises control byte, track number and time.Preferably, be inserted in that this modification in the Q channel reaches the degree that is carried to the S/PDIF data on the disk.Do not hinder the voice playing of laser disc by loud speaker and other compatible equipment though these are revised, they use numeral output to stop the piracy of this CD content really.
As with aforesaid IEC 958 standard declarations, this S/PDIF signal comprises four control bytes of duplicating from this CD.Therefore, in the embodiment of a replacement of the present invention, these control bytes are used to stop the piracy of this audio content.For this purpose, according to the Red Data Book standard, record this control byte on this CD, this tracking mode is set to for " data " of a plurality of modules with repetitive cycling, typically between one and ten modules.Recomputate this CRCC then, make to stand in that this control byte is effective on the data accuracy position.But, be when making when recording by the S/PDIF of CD Player output, this control byte is provided with and will will typically cause noiseless or " noise made in coughing or vomiting clatter " sound occurring in the audio stream as a result.
In the embodiment of another replacement, to record in order to defeat uncommitted CD content, these positions in the S/PDIF envelope are moved or in other words handle (manipulate).Be sent to when digital-to-analog converter is used for voice playing when these 32 in the S/PDIF subframe, this transducer adopts all 32, and plays this audio frequency no matter should move.But digital recorder will be concentrated at the seat of given subframe and seek this voice data, and in the subclass of another and this voice data non-intersect (adjoint) this control data of searching, to be assumed to be according to standard to these data here.Therefore, handle this order and can hinder register, still can make voice playing simultaneously.
Fig. 4 be one according to the preferred embodiments of the present invention, schematically illustrate the block diagram that uses data time section generator 37 to be used to stop the pirate another kind of method of CD.Although an audio frequency CD only has the single time period 90, the device 40 with time period generator 37 can produce the CD with a plurality of time periods, for example comprises one or more audio frequency time periods 100 and at least one data time section 102.Read-only first time period on a plurality of time period CD of audio frequency CD Player, in this example, be the time period 100, and ignore remaining.DVD player reads, and also recognizes data time section 102, but audio plays time period 100 still.Therefore but when this CD was inserted into CD_ROM, computer can be visited any time period, will make computer become chaotic by the modification that is embedded in second or the later time section.Therefore, present embodiment is by inserting the subcode Q channel operation of conflict data to data time period 102 or additional audio frequency time period after the time period at first audio frequency.Preferably, outside three or the above time period altogether on this disk, at least also there are two audio frequency time periods.
Preferably, the data of modification also are inserted into the audio frequency time period 100.This modification is introduced in such a way, that is, the auxiliary data on the dish that is provided by 908 standards (or other standard) can make CD Player during playing or proofread and correct or hide this modification or fully ignore them as Reed-Solomon code coding (CIRC) error detection code that interweaves mutually.But when a piracy is when being made of medium, these auxiliary data are invalid overcoming aspect the modification of having a mind in original medium, and irrecoverable error in fact appears in the result in duplicating.The method that is used to insert such modification has been described in above-mentioned U.S. Patent application 09/175,255 and 09/370,813.
Although this is modified in subcode channel and/or the voice data, an audio frequency CD Player will be without any the audio signal of reappearing on this dish difficultly.But a computer CD driver will will be disturbed by the data (perhaps by both) in a plurality of time periods on this CD or modification in the audio frequency time period 100, and can not load or play this disk, say nothing of and duplicate it.
Preferably insert at audio frequency that increases and/or the modification in the data time section by one or more array structures down:
Produce the importing of the magnetic track of the program area that a sensing is arranged in first time period.
Produce a importing with the more track number that is allowed than 908 standards.
Revise this importing and remove to simulate short CD.
Be modified in the absolute time of this time period when beginning.
According to these methods, the II that tabulates below is described in the variation of carrying out in the subcode Q channel of a plurality of time period CD, so that need not to hinder voice playing to stop computer to duplicate this audio content.First time period on this CD is an audio frequency time period that meets this Red Data Book standard, and this second can be audio frequency or data time section with the later time section simultaneously, based on aforesaid this blue book.
Tabulation II
Time period | Standard | Revise |
1 | Import (2 -3 minutes) | Increase pointer B0 and C0 and give second and the 3rd time period, each blue book form. |
Pause length 2 seconds | Use different pre-gap (pregap) length, each blue book form preferably is set to the value between 1 and 3 second. |
The accurate A time | With the value of non-zero, for example, 10 seconds starting A time, the beginning of the disk that is used for computer CD driver of deshielding |
2 | Audio track | Audio track length 4 seconds (each Red Data Book minimum time) |
3 | Import (1 minute) audio track | Point to 99 non-existent data tracks at time 00:02 TOC and revise that to derive pointers (A2) be Value Data track length 4 seconds between 00:01 and 00:07, add to be filled to total CD length |
Result as these variations, computer CD-ROM or DVD-ROM driver, in case this subcode Q channel data in the time for reading section 3 will or fail to install up hill and dale this CD, perhaps will enter a searching and be listed in the endless loop that this TOC goes up non-existent data track.If this driver successful access time period 1 obtains this normal audio content, still might be confused by 1 second pre-gap (it exceeds outside this Red Data Book specification requirement) and the A time of twisting.But CD audio frequency and DVD player will not be subjected to the influence of these variations basically.In this, the time period 2 is important, owing to there is not it, some complys with the DVD player of blue book may refuse to install this CD.The special modification that should be appreciated that indication in this tabulation is listed by way of example.Optionally the time value and the modification of other parameters and the combination of setting will be conspicuous to those skilled in the art.
Preferably, for the personal computer (PC) that allows to authorize is play shielded disc content, this original content is compressed (using any suitable form known in the art, such as MP3 or VQF) by audio compressor 35 (Fig. 2) and encrypts.These ciphered data are used the storage of " digital packaging (digital-wrapper) " method, make that these data are hidden from the CD-ROM drive software of routine.For example, these data can be stored in the subcode channel position of aforesaid this reservation, and perhaps data on this CD are in the time period, perhaps in importing, derivation or paralysis zone.These data are can be only decrypted and play by the software of use authority, and the software of this mandate preferably also was stored in this second time period, and was available to suitable permitted user and/or equipment only.If its information source is not original CD, if perhaps distribute and use these data destroyed, the software of this mandate will stop the decoding of data.
Should be appreciated that aforesaid preferred embodiment is quoted as proof by way of example, and the present invention be not limited to illustrate especially and above-described those.In a single day on the contrary, scope of the present invention is included in the combination and the sub-portfolio of above-described various characteristics, and reads explanation above, the person skilled in the art can remember its variation and modification, and this explanation is open in the prior art.