Title of Invention	APPARATUS FOR AND METHOD OF RECORDING DIGITAL AUDIO/VIDEO SIGNALS
Abstract	A recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium has been proposed. The apparatus comprises writing means (21, 22,25) for recording the digital information signals and control means (20) for controlling the recording. The apparatus is capable of performing initialization, formatting and defect management of a rewritable medium. Further, the apparatus is capable of storing data in replacement areas instead of defect areas, which have been determined to be defective according to rules of the defect management. The control means (20) are adapted to re-record data from the replacement areas in the defect areas in order to improve playability of digital audio/video signals stored on the medium.

Title of Invention

APPARATUS FOR AND METHOD OF RECORDING DIGITAL AUDIO/VIDEO SIGNALS

Abstract

A recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium has been proposed. The apparatus comprises writing means (21, 22,25) for recording the digital information signals and control means (20) for controlling the recording. The apparatus is capable of performing initialization, formatting and defect management of a rewritable medium. Further, the apparatus is capable of storing data in replacement areas instead of defect areas, which have been determined to be defective according to rules of the defect management. The control means (20) are adapted to re-record data from the replacement areas in the defect areas in order to improve playability of digital audio/video signals stored on the medium.

Full Text	Apparatus for and method of recording digital audio/video signals The invention relates to a recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and corresponding replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the recording apparatus comprising input means for receiving the digital audio/video signals; recording means for recording the digital audio/video signals on the medium; reading means for reading digital audio/video signals recorded on the medium; output means for outputting the digital audio/video signals read; and control means for controlling recording the digital audio/video signals. The invention further relates to a reading apparatus-for reading digital audio/video signals from a removable rewritable disc like fording medium, the medium comprising a user area comprising user data represents by the digital audio/video signals, a table comprising a defect table, the defect table^6mprising a list of addresses of defeef areas in the user area and correspondingreplacgatfent areas on the medium, the re^diri^apparatus comprising . reading means forfeading digital^ullio/video siggafs recorded on the medium; output meaj^ror outouttiijg^e digital audi contro>6eans for controlling reading t}>e aigitai audio/video signals. TJe invention also relates to a mejhod of arranging digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprjgfnguser data represented by th^Qigital audio/video signals, a table area comprising a d§iect table, the defect table comprising a list of addresses of defect areas in the user area and ^corresponding replacement^as on the medium, the defect areas identified as defective according to predefined delect management rules. In addition, the invention relates to a method of reading digital audio/video signals from a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and corresponding replacement areas on the medium, the method comprising steps of reading the digital audio/video signals from the recording medium and outputtingthe digital audio/video signals read for processing. Further, the invention relates to a computer data system comprising a computer connected to a recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area for recording a defect table comprising a list of addresses of defect areas in the user area and corresponding replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the recording apparatus comprising input means connected to the computer for receiving the digital audio/video signals; recording means for recording the digital audio/video signals on the medium; reading means for reading digital audio/video signals recorded on the medium; output means for outputtingthe digital audio/video signals read to the computer; and control means for controlling recording th^dlgital audio/video signals. The invention also relates to a compjrt€r program product for arranging digital audio/video signals on a removable rewritabl^disc like recording medium. Recording modfa like optical referenced to with use of logical addresses defining addressing space. Partitioning of a recording medium allocates a space on the medium for storing data under control (according to rules) of a file system. At present, for example, DVD+RW discs are in use by Consumer Electronics (CE) devices and in the Personal Computer (PC) environment. In the CE environment DVD+RW discs are used mainly for recording digital video information according to a format of DVD Video Recording, commonly reffered to as DVD+VR. This means that there are defined specific allocation rules and set of files containing the video information itself and information about that video information such as title information, menu structures, etc. For example, in the DVD+VR format some files start at fixed addresses. Next to that, the (predefined) list of files has to be physically on a medium in a certain order. The PC environment is based on a different philosophy. There are, in principle, no allocation requirements. Specific applications may require some files to be present in a certain directory and applications will typically have their own data format to store information in files or to retrieve information from a file. This means that as long as there is free space available on a medium it is possible to add data files to that medium from all kinds of different applications. As an example, on a single disc th^could be multi-media files, text files and executable files all mixed with each other. Recently, more and more CE devices, li^^ideo players/recorders, have capability to seek through the file system infornmti^nonthe disc for files of a certain type that they can handle as well. Example of Airfare (mainly) JPEG files and also, already more and more, MP3 files. In the future ppsgibly more types of multi-media files will be supported in the CE world. Next to that^o new standards oiupeta-data are crepira (such as e.g. MPV or HighMAT) designedj#make it easier to mDYg/ngital conten£jb€tween PCs and home electronics device^g. by providing a»flftmon "look an^^el" in different environments. /The published international patent application WO 01 /22416 A1 discloses the recording'apparatus capable of performing initialization, formatting and defect management of Rewritable medium such as a CD-R^3isc. This is done to facilitate the use of CD-RW as a high-capacity floppy disc, so immediate writing or reading of files is possible. Such media are commonly referred to as Mount Rainier Rewritable (MRW) media, e.g. CD-MRW,DVD+MRW. Further, said recording apparatus makes it possible to store file system data of different file systems on one recording medium, so-called "bridge medium". This facilitates sharing of the bridge medium between different environments, e.g. the CE environment and the PC environment. A special part of a recording medium, called a general application area (GAA), is allocated for storing file system data of a file system used by other devices not capable of performing the defect management in line with WO 01/22416 Al. In the PC environment the most likely way of adding data to the bridge medium is by means of "drag-and-drop" technique. A user can then make the medium compatible with legacy players through the use of a compliance (bridge) application running on the PC. Basically, the application writes a second ("limited") file system data, called "CE-bridge", to the medium, using the suitable file system(s) and content pointers, such that a legacy "non-MRW" system can interpret these as content under its main file system. As a result, the CE-player will play the content that is referenced by this file system data, for which it has suitable content decoders. Examples of data stored on DVD+MRW discs in the PC environment are video, photo or audio data. If any defects are detected on a disc, the defect management^ applied. This could create a situation where some blocks of the playable multirpsdlacontent data are physically replaced to so-called Spare Area used by the defecps^nagement. In such a case, the data is still contiguous from a logical address point^view, however the data is not physically contiguous on the disc. Present DVD pl£iy€rs and recorders in the CE environment do not have any MRW capabiliti^&r^fhis means that they are not capable of reading MRW remapping tables to fincj^tit which blocks have been remapped to^he spare area. A further problem is cause$H5y the fact that navigation through DVQ>vl3eo data in video players is not base^moffsets within a file^isted in the filegyStem, but on so-called navigation packs^^fcW-PACKs, with/relSfrve offsets to aperfainpoint zero and other NAV-PACKs/piefefore, these present players and recojjlefs will not follow the remapping, but will by to read the data fi-om the defective^ It is an object of the invention to improve playback of multimedia content recorded on a medium with use of a defect management. This object is achieved, according to a first aspect of the invention, by a recording apparatus of the type described in the opening paragraph, characterized in that the control means are adapted to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area, to localize the replacement area according to the replacement area address, to localize the corresponding defect area according to the defect area address, to read the user data fiom the replacement area and to re-record the user data read in the defect area regardless of the defect management rules. This increases reliability of the content stored on the medium, as the defect area may contain good or partially good data after re-recording. In an embodiment of the recording apparatus, the control means are adapted to collect re-recording information related to re-recording of the user data read in the defect area, to include the re-recording information in the defect table and to record the defect table in the table area. This embodiment is advantageous in that provides information, which can be used to optimize access to and management of the content stored on the medium. In a further embodiment of the recording apparatus, the control meansjijre adapted to read user data re-recorded in the defect area, to compare the userjjataread fiom the defect area with the user data read fiom the corresponding replagertfent area and to include results of comparing in the re-recording informatioij^^Tiis provides a way of verifying how successful was the re-recording operatkrffand makes it possible to use this information while accessing data on the medparfiT In another embodimenpefthe recording apparatus, the cojjjol means are adapted to use status bits in th^d€rect table to includoj^ie re-recojdifig information in the defect table. This is effiptent way of ^Mng ttoAnfonnatipHr Apetfrdingto a secoi^sttect of thejntfention a reading apparatus of the type describedjurfhe opening paragraph is provijtedcharacterized in that the control means are adapted to monitor a speed of outputting the digital audio/video signals read, to read the defect table from the medium, to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area and to read the user data either from the replacement area or from the defect area corresponding to the replacement area in dependence on monitoring and speed requirements for the speed of outputting the digital audio/video signals read. This allows for optimizing the read-out of data from the medium. It is advantageous, if the control means of the reading apparatus are adapted to read the user data either from the replacement area or from the defect area in dependence on a re-recording information related to the user data in the defect area and the replacement area, the re-recording information comprised in the defect table. This further improves the read-out of the data. According to a third aspect of the invention a method of arranging digital audio/video signals on a removable rewritable disc like recording medium of the type described in the opening paragraph is provided characterized by searching the defect table for a replacement area address of a replacement area comprising the user data; searching the defect table for a defect area address of a defect area corresponding to the replacement area; localizing the replacement area according to the replacement area address; localizing the corresponding defect area according to the defect area address; reading the user data from the replacement area; re-recording the user data read in the defect area regardless of the defejef^ management rules. According to a forth aspect of the invention a methodp£feading digital audio/video signals from a removable rewritable disc like recording medium of the type described in the opening paragraph is provided characterised by monitoring aspeed of outputtingofthe digital audio/video signals reac^^ /l r i^\v reading the defect table froprtne medium; v> searching the defect t^bfe for a replacement area addrejs^f a replacement area comprising the user data; yS searchingtfie defect table for a defect area^ddress of a defect area correspondingto^le replacement area; reading the user data either froiuhe replacement area or from the defect area corrps^ondingto the replacement areajtf'aependence on the monitoring and speed -requirements for the speed of outputtingofthe digital audio/video signalsread. According to a fifth aspect of the invention a computer data system of the type described in the opening paragraph is provided, characterized in that the computer is adapted to control the>e6htrol means of the recording apparatus to perform the method as described in relation to the third aspect of the invention. According to a sixth aspect of the invention a computer program product for recording digital information signals is provided, which program is operative to cause a processor to perform the method as described in relation to the third aspect of the invention. These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which: Figure la shows a recording medium (top view), Figure lb shows a recording medium (cross section), Figure 2 shows a recording apparatus, in accordance with the invention, Figure 3 a shows a simplified layout of a non-MRW type of medium, Figure 3b shows a simplified layout of a MRW type of medium, Figure 4 shows a simple example of a re-recordingprocess, in accordance with the invention. Corresponding elements in different Figures have identical reference- numerals. A Figure 1 a shows an example of a receding medium 11 having aibrm of disc with a track 9 and a central hole 10. The track^oeing the position of the series of (to be) recorded marks representing digital infoafiation signals (data), is afranged in accordance with a spiral pattern of turns constitutm^substantiallyparallel trades on an information layer. The recording medium may be optfcally readable, called airoptical disc, and has an information layer of a recordable typz. Examples of a recorcjatfle disc are the CD-RW, and writable versions of DVD^uch as DVD+RW, andfllehigh density writable optical disc using blue lasers, calkd"Blu-ray Disc (BD). Digkm information signals (data) are represented on the infonp^uon layer by recording^nically detectable marks along the track, e.g. crystalline or ^morphous marks in phasp^hange material. The track 9 on the recordable type of recording medium is indicatedjay a pre-embossed track structure provided during manufacture of the blank recording^fiedium. The track structure is constituted, for example, by a pregroove 14, which enaj^s a read/write head to follow the track during scanning. The track structure comprises position information, e.g. addresses, for indication the location of units of information, usually called information blocks or packets. Figure 1 b is a cross-section taken along the line b-b of the recording medium 11 of the recordable type, in which a transparent substrate 15 is provided with a recording layer 16 and a protective layer 17. The protective layer 17 may comprise a further substrate layer, for example as in DVD where the recording layer is at a 0.6 mm substrate and a further substrate of 0.6 mm is bonded to the back side thereof. The pregroove 14maybe implemented as an indentation or an elevation of the substrate 15 material, or as a material property deviating from its surroundings. Figure 2 shows a recording apparatus for recording digital information signals a recording medium 11 such as CD-RW, DVD+RW or BD, in accordance with the invention. The apparatus is provided with writing means for scanning the track on the recording medium, which means include a drive unit 21 for rotating the recording medium 11, a head 22, and a positioning unit 25 for coarsely positioning the head 22 in the radial direction on the track. The head 22 comprises an optical system of a known type for generating a radiation beam 24 guided through optical elements focused to a radiation spot 23 on a track of the information layer of the recording medium. The radiation beam 24 is generated by a radiation source, e.g. a laser diode. The head further comprises (not shown) a focusing actuator for moving the focus of the radiation beam 24 along the optical axis of said beam and a tracking actuator for fine positioning of the spot 23 in a radial direction on the center of the track. The tracking actuator may comprise coils for radially moving an optical element or ma^^ ft w alternatively be arranged for changing the angle of a reflecting element. For^fmng digital I 1/ information signals (data) the radiation is controlled to create optically4€tectable marks in v, the recording layer. The marks may be in any optically readable fomi, e.g. in the form of areas with a reflection coefficient different from their surroprfaings, obtained when recording in materials such as dye, alloy or phase change materi^or in the form of areas witb^a direction of magnetization different from their sj^roundings, obtained wheirpe6ording in magneto-optical material. For reading, the^amation reflected by the inparcnation layer is detected by a detector of a usual type^g. a four-quadrant diod^ki'the head 22 for generating a read signal and further detector signals includipga tracking error and a focusing error signal for controllingafid tracking and focusing^dmators. The read signal is processed by read processing unitoO of a usual type including a demodulator, deformatter and output unit to retrieve Aefaigital information sign^(data). Hence retrieving means for reading informatiop^mclude the drive unit 2 L#fe head 22, the positioning unit 25 and the read processing unit 30. The apparatptfcomprises write processing means for processing the input digital information signals (data) to generate a write signal to drive the head 22, which means comprise an input unit 27, and modulator means comprising a formatter 28 and a modulator 29. The input digital information signals (data) may comprise for example real-time video and/or audio data or still images data. The input unit 27 processes the input data to units of information, which are passed to the formatter 28 for adding control data and formatting the data, e.g. by adding error correction codes (ECC) and/or interleaving. For computer applications units of information may be interfaced to the formatter 28 directly - in such case, as an option, the input unit 27 does not have to be present in the apparatus. The formatted data from the output of the formatter 28 is passed to the modulation unit 29, which comprises for example a channel coder, for generating a modulated signal, which drives the head 22. Further the modulation unit 29 comprises synchronizing means for including synchronizingpatterns in the modulated signal. The formatted units presented to the input of the modulation unit 29 comprise address information and are written to corresponding addressable locations on the recording medium under the control of control unit 20. Further, the apparatus comprises a control unit 20, which controls the recording and retrieving of information and may be arranged for receiving commands from a user or from a host computer. The control unit 20 is connected via control lines 26, e.g. a system bus, to said input unit 27, formatter 28 and modulator 29, to the read processing unit 30, and to the drive unit 21, and the positioning unit 25. The control unit 20 comprises control circuitry, for example a microprocessor, a program memory and control gates, for performing the procedures and functions according to the invention as described below. The control unit 20 may also be implemented as a state machine in logic circuits. The control unit 20 is capable of performing initialisation, formatting and defect management of a rewritable medium such as a DVp^KW disc. An example of simplified layout of such disc is shown in figure 3b^Ifcomprises lead-in area LI, lead-out area LO, a general application area GAA, a spare area SA (in this example cpmprising two sub-areas SA1 and SA2), a user area XJAfmd table atdftsMTA and SJ^C LI and LO contain mainly media read/write definitioja^uid adminia^rttondata. Thp^tfser area UA is used mainly for recording of data used forreal use$n@\aata related topdntent stored on a recording medium, such as user^Mm and first me'system data^tfmprising directory and file entries pointing to thejj«€r data according to rules of^irst file system. The general application area GAA can be used for storage of data th$tffoes not allow replacements by the defect management, such as application programs or device drivers that can handle defects, or file system data of additional file systems. The defect management is based on a main defect table MDT stored in a fnain table area MTA, a secondary defect table SDT stored in a secondary tabl^fea STA and replacement areas (packets) comprised in the spare area SA1, SA2. The secondary defect table is a copy of the main defect table; SDT contains the same information as MDT. STA is used as redundancy in case of issues with MTA, and for assuring that non-MRW PC-systems can use these tables for address remapper in order to logically construct the address space, compensating for the defect management reallocation (not interpretableby non-MRW drives). The main table area MTA is located within the lead-in area LI. Recording media with a layout of the type shown in figure 3b are commonly referred to as Mount Rainier Rewritable (MRW) media, e.g. CD-MRW or DVD+MRW, in contrast to "non-MRW" media with a layout as in example shown in figure 3a. In case of DVD+MRW recording media, GAA, S Al and SA2 have a size of 2,8 and 120 (or 504) MBytes, respectively. Based on the MRW definitions, it is possible to ensure that MRW media can be read by non-MRW capable drives, by installing a remapping driver on the PC. This remapping driver can be obtained easily, amongst other, by using GAA, such that the file system in GAA launches an application, which installs this driver or downloads it from the Internet. For convergence with non-MRW aware CE devices, the same or a different file system, (typically IS09660 or UDF) can be used for allowing addressing of the content typically recognized by CE devices. This is done by pointing to the multimedia content stored in UA of the MRW medium, using file system data stored in GAA, hereinafter alsc A referred to as second file system data, known by CE devices. There can be an extrafile \h^ system in GAA, dedicated to performing tasks related to the remapping drivepr / C* The defect management employs predefined rules for ctejl&fmining defective areas in UA, for organizing spare areas on a medium, for defining^5ircumstances under which data can be recorded/modified on the medium, generally, for'controlling storing informp#6n on the medium. A defect table contains information^yviiich can be used to perfajra-fne defect management. In particular, the defect table contains a list of defective area^packets), which have been determined to be defective duprfg verification or during usp/6f the medium, according to rules of the defect majMf^ment. For example, a paptfoilar area may be classified as a defective area, if readinj^dma recorded in it gives etro^Further, the defect table contains a list of repla^prfient areas (packets), reseryedto be used as replacements of defective areas. Defective and replacement area^are referred to by their addresses on the medium. Different flags or status bits v^ytkfn the defect table indicate characteristicsof those areas, e.g. usability for data recordpag/The defect table also contains information related to areas on the medium, where the defect management shall not be active, such as a size and position of GAA. After recording of DVD compliant video in the PC environment, there are few actions required before the MRW disc can be played in the (legacy) CE environment, as described in the introductorypart. These actions can be initiated automatically or via something like a "make convergent button" in a software application, or via a feature built inside the operating system functionality or via a user activated device function. The latter can be performed with help of a physical push button, a remote control, the user's voice or any other way the user may interact with the device. The control unit 20 is adapted to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area, to localize the replacement area according to the replacement area address, to localize the corresponding defect area according to the defect area address, to read the user data from the replacement area and to re-record the user data read in the defect area regardless of the defect management rules. Hereinafter, re-recording means attempting to record data stored in the replacement area at the original, defective location. The control unit 20 can perform these steps automatically as a default background operation of the apparatus or in response to the user's request as described above. Figure 4 shows a simple example of a re-recording process according to the invention. In figure 4a DVD compliant audio/video data 101 is recorded on a MRW disc^fitf a single defect area 102. During recording this defective location is replaced by ^y^ % replacement area 103 in the spare area 104. After re-recording is activated,^recorder reads j Ky remapped data from position 103 and then attempts to record this data^t its originaMc^tj^b1^ 102, as shown in figure 4b. \^/ This functionality of the control unit 20 kMsed on the following observ&tton. The MRW standard was defined with computer (kkfapplications in mind, where^m integrity is of the utmost importance. Acconiilig to the defect managementjalfes, user data is stored at a replacement location in th^g^are area instead of a particul^rtdefective) location, if a device can't be sure that awrtfe process at this location wiU^be successful. The same happens if write/read quality at the particular location is kg^than optimal to assure correct reading/writing at later stage in the device itself or in any other PC or CE device, which may be used for reading/writing this disc in the future. However, data recorded at the defective location may still be of a quality good enough for less sensitive applications, like in case of audio/video data. Moreover, rewriting information at the particular location might still be successful after the replacement is executed, for example as a result of using alternative recording parameters (\^rife strategy, laser power, servo tracking settings or simple retry strategies). Also, th^defective location might be readable giving no or less errors when read by a different device (e.g. by the CE device). In an embodiment, the control unit 20 is adapted to collect information related to re-recording of the user data, read from the replacement location, at the corresponding original (defective) location. This information is than included in the defect table and recorded on the medium. It should comprise at least a flag indicating that the defective location was recorded with the user data from the corresponding replacement location. In another embodiment, the control unit 20 is capable to verify results of re-recording the user data in the defect area (location). After the user data is re-recorded in the defect area, it is read from the defect area and compared with the user data read from the replacement area. The result of this comparison is included in the information related to re-recording. In the process of rewriting the replaced user data at the defective location, the MRW defect table is involved. For example, the various status bits in the defect tablei^n indicate one of the following situations: Status 1 ~ valid replacement of the user data; ■ a defective area that has not been recorded at it^6placement area; " a "free" entry, i.e. a replacement area usesjWe for future replacement; , j V/-" " a replacement area unusable for fut)j€replacement. 0 OAl^ Status 2 yS " the original (defective)^rfea has been recorded with the sapiejiarta as the replacement area or the origyaafarea contains the most recently wrkj^tfunformation (represented by binary5c00 according to the DVD+MRW specification); " thtfOTiginal area may contain different daja^s the replacement area corresponding to it (represented by binary xxOl according to the DVD+MRW specification). After re-recording the^er data from the replacement location at the original location, following cases, gjv^jv^s examples, can be indicated in the defect table (e.g. by using binary xxOl for ^tetfis 2 of the related entry in the defect table): " a case when such re-recording operation has been done, but no guaranties can be given with respect to quality of read-out performed by the receiving CE (other) device; " a read-out check by the MRW device after re-recording has given sufficient good results. In this case the MRW device may assume that next time the defective location is still readable and the replacement is a "preventive step" taken in order to recover the user data when the defective location gives problems, e.g. due to wear: " it is expected that a read-out by CE devices will provide good data and the replacement is a "preventive step" taken in order to recover the user data when the defective location gives problems, e.g. due to wear; " any other definition of strategy optimal for specific classes of devices or content types as described by the user, host or device, optimizing capability to stream the content in a specific environment. In an embodiment, the control unit 20 is capable of setting in the defect table status bits related to the defect area and the replacement area corresponding to it, representing one or more of the cases defined above. The entire process of re-recording the remapped data in the original area can be employed as one of actions started with the "make convergent button". As an example, this "button" can be a part of a special application in the PC environment executed after recording of DVD compliant video on the disc; the application that makes the DVD+MR^^ disc with its content playable in the (legacy) CE environment. . y^ The re-recording process can be performed also in a CE DVp^MRW ^ \^ recorder, i.e. the CE recorder with the MRW capability. Also, it can>tfperformed ^ immediately after recording of new audio/video data on a mejikim or at a later point in time, possibly by another recorder/device. The advantage ofpmorming the re-recording at the later point in time is that it can lead to good data^kuhe original (defective) area because meanwhile fingefprintsor dust might be renfoved from the medium or the anojb^r recorder has better recording capabilities foi^the medium. In an embodimem of the recording apparatus, the cop#6l unit 20 is adapted to determine whether the r#rccording can be done immediately while continuing recording of more data or aftej>tfie recording has been completed. In ti^fatter case, the control unit 20 can be modifiedtokeep data to be re-recorded in a memetfy. It is noted that the apparatus as skown in Figure 2 has recording and reproducing functions. Alternatively a reading apparatus for only retrieving information from a recording medium contains the scapmng elements and the read processing circuitry, but does not have the input unit 27^the formatter 28 and the modulator 29. Its control unit 20 does not perform functions^fated to recording. After ][g^ecording,the data comprised in the defective area may give errors during reading. In case of a stream of digital audio/video signals, this will result in "hicks" or strong artifacts in the content-stream noticeable to a user, unless a reading device is knowledgeable enough to take the right optimal decision to read the data from the replacement area instead of the defective area. This can be achieved by devices, which are capable of reading the MRW defect table and interpreting its content. Another way is to assure that the reading device can handle file system based features that allow for pointing to the replacement location instead of the original location in the CE device readable file system, for example using a remapper driver fiom GAA. In an embodiment, these functionalities are implemented in the control unit 20. The outputting of the stream of digital audio/video signalsby the output unit of the read processing unit 30 is carried out under control of the control unit 20. In particular, the control unit 20 can be adapted to monitor a speed (a data rate) of the outputting in order to maintain continuous supply of data according to requirements defined by a specific application. For example, in DVD recording with the DVD+RW media the following data rates are commonly used: Recording Mode s A Recording time Resolution PAL Resolution NT^C" Average bitrate (minutes) Pw^ (Mbits/sec) HQ 60 720 x 576 (Full Dl)^720 x 480 (Full Dl) 9.72 SP 120 720 x 576 (FjtfrfH) 720 x 480 (Full Dl) 5.07 SP+ 150 720 x SHftFullDl) 720x480 (FullDl) 4.06 LP 18( 3^576 (Half Dl) 360 x 480 (Half Dl) 3.38 EP 24( 360x 576 (HalfDl) 360x 480 (HalfDl) 2.54 EV+ 36( 360 x 576 (HalfDl) 360 x 480 (HalfDl) 1.70 8h 4$ 352 x 288 (SIF) 352 x 240 (SIF) 1.27 In an embodiment, the control unit 20 is adapted to monitor the speed of outputting the read digital audio/video signals, to read the defect table from the medium, to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area and to read the user data either fiom the replacement area or fiom the defect area corresponding to the replacement area in dependence on monitoring and speed requirements for the speed of outputting the read digital audio/video signals. Matching of a streaming capability with requirements of a specific application is done by optimizing scheduling of reading and outputting operations and/or employing a cache memory for temporary storage of data read from the medium. Accordingly, the control unit 20 decides to read the user data either from the defect location or its corresponding replacement location. It should be pointed out that reading data from the replacement location usually requires additional movements of the head 22, thus it introduces delays in supplying the data to the read processing unit 30. In an embodiment, the control unit 20 accounts for these delays while matching the streaming capability. Advantageously, the control unit 20 is adapted to use the information related to re-recording - comprised in the defect table - for taking decision on using replacement areas versus original areas. For example, the control unit 20 can employ different status bits as explained above. In particular, the control unit 20 can decide to read data from the replacement area, if the information related to re-recording indicates that no guaranties can be given with respect to quality of data in the original area. In an embodiment, the recording apparatus is arranged as a drive unit to be connected to a separate host system, for example a drive unit to be build in a PC. The control Oh unit 20 is arranged to communicate with a processing unit in the host system via a . Q standardized interface. // w In an embodiment of a computer data system comprising the ho^t^ystem and the recording apparatus, the processing unit in the host system is adaptecjxfctfcontrol the control unit 20 to perform methods and functions as described inpe^rence to embodiments of the recording apparatus presented above. s' A computer program product accordijigto the invention is operative to cause the control unit 20 or the processing unit to pppftirm methods and functions as described in reference to embodiments of the recorcjkfg apparatus presented above. Whilst the inveijtiefinas been described with reference to preferred embodiments thereof, it is to be understood that these are not limitative examples. Thus, various modifications may become apparent to those skilled in the art, without departing from the scope of the invention, as defined by the claims. Further, the invention lies in each and every novel feature or combination of features described above. Also, for the storage medium an optical disc has been described, but other media, such as a magneto-optical disc or magnetic tape, can be used. It is noted, that the invention may be implemented by means of a general purpose processor executing a computer program or by dedicated hardware or by a combination of both, and that in this document the word "comprising" does not exclude the presence of other elements or steps than those listed and the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements, that any reference signs do not limit the scope of the claims, that "means" may be represented by a single item or a plurality and that several "means" may be represented by the same item of hardware. CLAIMS: 1 ■ A recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the recording apparatus comprising input means for receiving the digital audio/video signals; recording means for recording the digital audio/video signals on the medium; reading means for reading digital audio/video signals recorded on the medium; output means for outputtingthe digital audio/video signals read; control means for controlling recording the digital audio/vided signals^ characterized in that . f Lr^ the control means are adapted to search the ^ectjtjjmle fpfa replacement area address of a replacement area comprising the user data, to search^Jbt detect table for a defect area address of a defect area corresponding to the replacemgtrf area, to localize the replacement area according to the replacement area a^efress, to localize the corresponding defect area according to the defect area address^to read the user data from the replacement area and to re-record the user data read iij^Ke defect area regardless of the defect management rules. A 2. A recording apparatus as claimed in claim 1, characterized in that the control means are adapted to collect re-recording information related to re-recording of the user data read in the defect area, to include the re-recording information in the defect table and to record the defect table in the table area. 3. A recording apparatus as claimed in claim 2, characterized in that the control means are adapted to read user data re-recorded in the defect area, to compare the user data read from the defect area with the user data read from the replacement area and to include results of comparing in the re-recording information. 4. A recording apparatus as claimed in claim 2, characterized in that the control means are adapted to use status bits in the defect table to include the re-recording information in the defect table. 5. A reading apparatus for reading digital audio/video signals from a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the reading apparatus comprising reading means for reading digital audio/video signals recorded on the medium; output means for outputting the digital audio/video signals read; control means for controlling reading the digital audio/video signals, characterized in that the control means are adapted to monitor a speed of outputting the digital audio/video signals read, to read the defect table from the medium, to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement arpa and to read the user data either fi-om the replacement area or from the defect arep^ corresponding to the replacement area in dependence on monitcjting an 6. A reading apparatus as claimed in oiaifn 5, the defect table comprising re-recording information related to the user da&Tin the defect area and the replacement area, the reading apparatus characterized in tjiecf the control means are adapted to read the user data either from the replacement tp€a or from the defect area in dependence on the re-recording information. 7. A method of arranging digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the method characterized by searching the defect table for a replacement area address of a replacement area comprising the user data; searching the defect table for a defect area address of a defect area corresponding to the replacement area; localizing the replacement area according to the replacement area address; localizing the corresponding defect area according to the defect area address; reading the user data from the replacement area; re-recording the user data read in the defect area regardless of the defect management rules. 8. A method as claimed in claim 7, characterized by collecting re-recording information related to re-recording of the user data read in the defect area; including the re-recording information in the defect table; recording the defect table in the table area. 9. A method as claimed in claim 8, characterized by reading user data re-recorded in the defect area; comparing the user data read from the de^efarea with the user data read from the replacement area; including results of compajitff* in the re-recording information. 10. A method acclaimed in claim 8, characterized by using status bits in the defect table for includingjh^re-recording information in the defect table. 11. A method of reading digital audio/video signals from a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the method comprising steps of reading the digital audio/video signals from the recording medium and outputting the digital audio/video signals read for processing, characterized by monitoring a speed of outputting the digital audio/video signals read; reading the defect table from the medium; searching the defect table for a replacement area address of a replacement area comprising the user data; searching the defect table for a defect area address of a defect area corresponding to the replacement area; reading the user data either from the replacement area or from the defect area corresponding to the replacement area in dependence on the monitoring and speed requirements for the speed of outputtingthe digital audio/video signals read, 12. A method as claimed in claim 1 l,the defect table comprising re-recording information related to the user data in the defect area and the replacement area, the method characterized by reading the user data either from the replacement area or from the defect area in dependence on the re-recording information. 13. A computer data system comprising a computer connected to a recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represeqladlSy the digital audio/video signals, a table area for recording a defect table compjising a list of addresses of defect areas in the user area and addresses of replacemejiHireas on the medium, the defect areas identified as defective according to predefine^Wefect managementiules, the recording apparatus comprising •* \r*^ input means connected to the cojattSuter for receiving t$a argitaljpKHo/video signals; recording means for recording the digital audio/videcvgignals on the medium; reading means for reading digital audio/video signals recorded on the medium; output means for outputting the digital audio/video signals read to the computer; control means for controlling recording the digital audio/video signals, characterized in that the computer is adapted to control the control means of the recording apparatus to perform the method according to any of claims 7-10. 14. A computer program product for arranging digital audio/video signals on a removable rewritable disc like recording medium, which progi processor to perform the method according to any of claims 7 •

Full Text

Apparatus for and method of recording digital audio/video signals
The invention relates to a recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and corresponding replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the recording apparatus comprising
input means for receiving the digital audio/video signals;
recording means for recording the digital audio/video signals on the medium;
reading means for reading digital audio/video signals recorded on the medium;
output means for outputting the digital audio/video signals read; and
control means for controlling recording the digital audio/video signals.
The invention further relates to a reading apparatus-for reading digital
audio/video signals from a removable rewritable disc like fording medium, the medium
comprising a user area comprising user data represents by the digital audio/video signals, a
table comprising a defect table, the defect table^6mprising a list of addresses of defeef areas
in the user area and correspondingreplacgatfent areas on the medium, the re^diri^apparatus
comprising .
reading means forfeading digital^ullio/video siggafs recorded on the medium;
output meaj^ror outouttiijg^e digital audi contro>6eans for controlling reading t}>e aigitai audio/video signals.
TJ*e invention also relates to a mejhod of arranging digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprjgfnguser data represented by th^Qigital audio/video signals, a table area comprising a d§iect table, the defect table comprising a list of addresses of defect areas in the user area and ^corresponding replacement^as on the medium, the defect areas identified as defective according to predefined delect management rules.
In addition, the invention relates to a method of reading digital audio/video signals from a removable rewritable disc like recording medium, the medium comprising a

user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and corresponding replacement areas on the medium, the method comprising steps of reading the digital audio/video signals from the recording medium and outputtingthe digital audio/video signals read for processing.
Further, the invention relates to a computer data system comprising a computer connected to a recording apparatus for recording digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area for recording a defect table comprising a list of addresses of defect areas in the user area and corresponding replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the recording apparatus comprising
input means connected to the computer for receiving the digital audio/video signals;
recording means for recording the digital audio/video signals on the medium;
reading means for reading digital audio/video signals recorded on the medium;
output means for outputtingthe digital audio/video signals read to the computer; and
control means for controlling recording th^dlgital audio/video signals.
The invention also relates to a compjrt€r program product for arranging digital audio/video signals on a removable rewritabl^disc like recording medium.
Recording modfa like optical
referenced to with use of logical addresses defining addressing space. Partitioning of a recording medium allocates a space on the medium for storing data under control (according to rules) of a file system.
At present, for example, DVD+RW discs are in use by Consumer Electronics (CE) devices and in the Personal Computer (PC) environment. In the CE environment DVD+RW discs are used mainly for recording digital video information according to a format of DVD Video Recording, commonly reffered to as DVD+VR. This means that there are defined specific allocation rules and set of files containing the video information itself and information about that video information such as title information, menu structures, etc. For example, in the DVD+VR format some files start at fixed addresses. Next to that, the (predefined) list of files has to be physically on a medium in a certain order.
The PC environment is based on a different philosophy. There are, in principle, no allocation requirements. Specific applications may require some files to be present in a certain directory and applications will typically have their own data format to store information in files or to retrieve information from a file. This means that as long as there is free space available on a medium it is possible to add data files to that medium from all kinds of different applications. As an example, on a single disc th^could be multi-media files, text files and executable files all mixed with each other.
Recently, more and more CE devices, li^^ideo players/recorders, have capability to seek through the file system infornmti^nonthe disc for files of a certain type that they can handle as well. Example of Airfare (mainly) JPEG files and also, already more and more, MP3 files. In the future ppsgibly more types of multi-media files will be supported in the CE world. Next to that^o new standards oiupeta-data are crepira (such as e.g. MPV or HighMAT) designedj#make it easier to mDYg/ngital conten£jb€tween PCs and home electronics device^g. by providing a*»flftmon "look an^^el" in different environments.
/The published international patent application WO 01 /22416 A1 discloses the recording'apparatus capable of performing initialization, formatting and defect management of Rewritable medium such as a CD-R^3isc. This is done to facilitate the use of CD-RW as a high-capacity floppy disc, so immediate writing or reading of files is possible. Such media are commonly referred to as Mount Rainier Rewritable (MRW) media, e.g. CD-MRW,DVD+MRW.
Further, said recording apparatus makes it possible to store file system data of different file systems on one recording medium, so-called "bridge medium". This facilitates sharing of the bridge medium between different environments, e.g. the CE environment and

the PC environment. A special part of a recording medium, called a general application area (GAA), is allocated for storing file system data of a file system used by other devices not capable of performing the defect management in line with WO 01/22416 Al.
In the PC environment the most likely way of adding data to the bridge medium is by means of "drag-and-drop" technique. A user can then make the medium compatible with legacy players through the use of a compliance (bridge) application running on the PC. Basically, the application writes a second ("limited") file system data, called "CE-bridge", to the medium, using the suitable file system(s) and content pointers, such that a legacy "non-MRW" system can interpret these as content under its main file system. As a result, the CE-player will play the content that is referenced by this file system data, for which it has suitable content decoders.
Examples of data stored on DVD+MRW discs in the PC environment are video, photo or audio data. If any defects are detected on a disc, the defect management^ applied. This could create a situation where some blocks of the playable multirpsdlacontent data are physically replaced to so-called Spare Area used by the defecps^nagement. In such a case, the data is still contiguous from a logical address point^view, however the data is not physically contiguous on the disc. Present DVD pl£iy€rs and recorders in the CE environment do not have any MRW capabiliti^&r^fhis means that they are not capable of reading MRW remapping tables to fincj^tit which blocks have been remapped to^he spare area. A further problem is cause$H5y the fact that navigation through DVQ>vl3eo data in video players is not base^moffsets within a file^isted in the filegyStem, but on so-called navigation packs^^fcW-PACKs, with/relSfrve offsets to aperfainpoint zero and other NAV-PACKs/piefefore, these present players and recojjlefs will not follow the remapping, but will by to read the data fi-om the defective^ It is an object of the invention to improve playback of multimedia content recorded on a medium with use of a defect management.
This object is achieved, according to a first aspect of the invention, by a recording apparatus of the type described in the opening paragraph, characterized in that the

control means are adapted to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area, to localize the replacement area according to the replacement area address, to localize the corresponding defect area according to the defect area address, to read the user data fiom the replacement area and to re-record the user data read in the defect area regardless of the defect management rules. This increases reliability of the content stored on the medium, as the defect area may contain good or partially good data after re-recording.
In an embodiment of the recording apparatus, the control means are adapted to collect re-recording information related to re-recording of the user data read in the defect area, to include the re-recording information in the defect table and to record the defect table in the table area. This embodiment is advantageous in that provides information, which can be used to optimize access to and management of the content stored on the medium.
In a further embodiment of the recording apparatus, the control meansjijre adapted to read user data re-recorded in the defect area, to compare the userjjataread fiom the defect area with the user data read fiom the corresponding replagertfent area and to include results of comparing in the re-recording informatioij^^Tiis provides a way of verifying how successful was the re-recording operatkrffand makes it possible to use this information while accessing data on the medparfiT
In another embodimenpefthe recording apparatus, the cojjj*ol means are adapted to use status bits in th^d€rect table to includoj^ie re-recojdifig information in the defect table. This is effiptent way of ^Mng ttoAnfonnatipHr
Apetfrdingto a secoi^sttect of thejntfention a reading apparatus of the type describedjurfhe opening paragraph is provijtedcharacterized in that the control means are adapted to monitor a speed of outputting the digital audio/video signals read, to read the defect table from the medium, to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area and to read the user data either from the replacement area or from the defect area corresponding to the replacement area in dependence on monitoring and speed requirements for the speed of outputting the digital audio/video signals read. This allows for optimizing the read-out of data from the medium.
It is advantageous, if the control means of the reading apparatus are adapted to read the user data either from the replacement area or from the defect area in dependence on a re-recording information related to the user data in the defect area and the replacement area,

the re-recording information comprised in the defect table. This further improves the read-out of the data.
According to a third aspect of the invention a method of arranging digital audio/video signals on a removable rewritable disc like recording medium of the type described in the opening paragraph is provided characterized by searching the defect table for a replacement area address of a replacement area comprising the user data;
searching the defect table for a defect area address of a defect area corresponding to the replacement area;
localizing the replacement area according to the replacement area address; localizing the corresponding defect area according to the defect area address; reading the user data from the replacement area;
re-recording the user data read in the defect area regardless of the defejef^ management rules.
According to a forth aspect of the invention a methodp£feading digital
audio/video signals from a removable rewritable disc like recording medium of the type
described in the opening paragraph is provided characterised by monitoring aspeed of
outputtingofthe digital audio/video signals reac^^ /l r i^\v
reading the defect table froprtne medium; v>
searching the defect t^bfe for a replacement area addrejs^f a replacement area
comprising the user data; yS
searchingtfie defect table for a defect area^ddress of a defect area correspondingto^le replacement area;
reading the user data either froi*uhe replacement area or from the defect area corrps^ondingto the replacement areajtf'aependence on the monitoring and speed -requirements for the speed of outputtingofthe digital audio/video signalsread.
According to a fifth aspect of the invention a computer data system of the type described in the opening paragraph is provided, characterized in that the computer is adapted to control the>e6htrol means of the recording apparatus to perform the method as described in relation to the third aspect of the invention.
According to a sixth aspect of the invention a computer program product for recording digital information signals is provided, which program is operative to cause a processor to perform the method as described in relation to the third aspect of the invention.

These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which: Figure la shows a recording medium (top view), Figure lb shows a recording medium (cross section), Figure 2 shows a recording apparatus, in accordance with the invention, Figure 3 a shows a simplified layout of a non-MRW type of medium, Figure 3b shows a simplified layout of a MRW type of medium, Figure 4 shows a simple example of a re-recordingprocess, in accordance with the invention.
Corresponding elements in different Figures have identical reference-
numerals. A
Figure 1 a shows an example of a receding medium 11 having aibrm of disc with a track 9 and a central hole 10. The track^oeing the position of the series of (to be) recorded marks representing digital infoafiation signals (data), is afranged in accordance with a spiral pattern of turns constitutm^substantiallyparallel trades on an information layer. The recording medium may be optfcally readable, called airoptical disc, and has an information layer of a recordable typz. Examples of a recorcjatfle disc are the CD-RW, and writable versions of DVD^uch as DVD+RW, andfllehigh density writable optical disc using blue lasers, calkd"Blu-ray Disc (BD). Digkm information signals (data) are represented on the infonp^uon layer by recording^nically detectable marks along the track, e.g. crystalline or ^morphous marks in phasp^hange material. The track 9 on the recordable type of recording medium is indicatedjay a pre-embossed track structure provided during manufacture of the blank recording^fiedium. The track structure is constituted, for example, by a pregroove 14, which enaj^s a read/write head to follow the track during scanning. The track structure comprises position information, e.g. addresses, for indication the location of units of information, usually called information blocks or packets.
Figure 1 b is a cross-section taken along the line b-b of the recording medium 11 of the recordable type, in which a transparent substrate 15 is provided with a recording layer 16 and a protective layer 17. The protective layer 17 may comprise a further substrate layer, for example as in DVD where the recording layer is at a 0.6 mm substrate and a further substrate of 0.6 mm is bonded to the back side thereof. The pregroove 14maybe

implemented as an indentation or an elevation of the substrate 15 material, or as a material property deviating from its surroundings.
Figure 2 shows a recording apparatus for recording digital information signals
a recording medium 11 such as CD-RW, DVD+RW or BD, in accordance with the invention.
The apparatus is provided with writing means for scanning the track on the recording
medium, which means include a drive unit 21 for rotating the recording medium 11, a head
22, and a positioning unit 25 for coarsely positioning the head 22 in the radial direction on
the track. The head 22 comprises an optical system of a known type for generating a radiation
beam 24 guided through optical elements focused to a radiation spot 23 on a track of the
information layer of the recording medium. The radiation beam 24 is generated by a radiation
source, e.g. a laser diode. The head further comprises (not shown) a focusing actuator for
moving the focus of the radiation beam 24 along the optical axis of said beam and a tracking
actuator for fine positioning of the spot 23 in a radial direction on the center of the track. The
tracking actuator may comprise coils for radially moving an optical element or ma^^ ft w
alternatively be arranged for changing the angle of a reflecting element. For^fmng digital I 1/
information signals (data) the radiation is controlled to create optically4€tectable marks in v, the recording layer. The marks may be in any optically readable fomi, e.g. in the form of areas with a reflection coefficient different from their surroprfaings, obtained when recording in materials such as dye, alloy or phase change materi^or in the form of areas witb^a direction of magnetization different from their sj^roundings, obtained wheirpe6ording in magneto-optical material. For reading, the^amation reflected by the inparcnation layer is detected by a detector of a usual type^g. a four-quadrant diod^ki'the head 22 for generating a read signal and further detector signals includipga tracking error and a focusing error signal for controllingafid tracking and focusing^dmators. The read signal is processed by read processing unitoO of a usual type including a demodulator, deformatter and output unit to retrieve Aefaigital information sign^(data). Hence retrieving means for reading informatiop^mclude the drive unit 2 L#fe head 22, the positioning unit 25 and the read processing unit 30. The apparatptfcomprises write processing means for processing the input digital information signals (data) to generate a write signal to drive the head 22, which means comprise an input unit 27, and modulator means comprising a formatter 28 and a modulator 29. The input digital information signals (data) may comprise for example real-time video and/or audio data or still images data. The input unit 27 processes the input data to units of information, which are passed to the formatter 28 for adding control data and formatting the data, e.g. by adding error correction codes (ECC) and/or interleaving. For computer

applications units of information may be interfaced to the formatter 28 directly - in such case, as an option, the input unit 27 does not have to be present in the apparatus. The formatted data from the output of the formatter 28 is passed to the modulation unit 29, which comprises for example a channel coder, for generating a modulated signal, which drives the head 22. Further the modulation unit 29 comprises synchronizing means for including synchronizingpatterns in the modulated signal. The formatted units presented to the input of the modulation unit 29 comprise address information and are written to corresponding addressable locations on the recording medium under the control of control unit 20. Further, the apparatus comprises a control unit 20, which controls the recording and retrieving of information and may be arranged for receiving commands from a user or from a host computer. The control unit 20 is connected via control lines 26, e.g. a system bus, to said input unit 27, formatter 28 and modulator 29, to the read processing unit 30, and to the drive unit 21, and the positioning unit 25. The control unit 20 comprises control circuitry, for example a microprocessor, a program memory and control gates, for performing the procedures and functions according to the invention as described below. The control unit 20 may also be implemented as a state machine in logic circuits.
The control unit 20 is capable of performing initialisation, formatting and defect management of a rewritable medium such as a DVp^KW disc. An example of simplified layout of such disc is shown in figure 3b^Ifcomprises lead-in area LI, lead-out area LO, a general application area GAA, a spare area SA (in this example cpmprising two sub-areas SA1 and SA2), a user area XJAfmd table atdftsMTA and SJ^C LI and LO contain mainly media read/write definitioja^uid adminia^rttondata. Thp^tfser area UA is used mainly for recording of data used forreal use$n@\aata related topdntent stored on a recording medium, such as user^Mm and first me'system data^tfmprising directory and file entries pointing to thejj«€r data according to rules of^irst file system. The general application area GAA can be used for storage of data th$tffoes not allow replacements by the defect management, such as application programs or device drivers that can handle defects, or file system data of additional file systems. The defect management is based on a main defect table MDT stored in a fnain table area MTA, a secondary defect table SDT stored in a secondary tabl^fea STA and replacement areas (packets) comprised in the spare area SA1, SA2. The secondary defect table is a copy of the main defect table; SDT contains the same information as MDT. STA is used as redundancy in case of issues with MTA, and for assuring that non-MRW PC-systems can use these tables for address remapper in order to logically construct the address space, compensating for the defect management reallocation

(not interpretableby non-MRW drives). The main table area MTA is located within the lead-in area LI. Recording media with a layout of the type shown in figure 3b are commonly referred to as Mount Rainier Rewritable (MRW) media, e.g. CD-MRW or DVD+MRW, in contrast to "non-MRW" media with a layout as in example shown in figure 3a. In case of DVD+MRW recording media, GAA, S Al and SA2 have a size of 2,8 and 120 (or 504) MBytes, respectively.
Based on the MRW definitions, it is possible to ensure that MRW media can
be read by non-MRW capable drives, by installing a remapping driver on the PC. This
remapping driver can be obtained easily, amongst other, by using GAA, such that the file
system in GAA launches an application, which installs this driver or downloads it from the
Internet. For convergence with non-MRW aware CE devices, the same or a different file
system, (typically IS09660 or UDF) can be used for allowing addressing of the content
typically recognized by CE devices. This is done by pointing to the multimedia content
stored in UA of the MRW medium, using file system data stored in GAA, hereinafter alsc A
referred to as second file system data, known by CE devices. There can be an extrafile \h^
system in GAA, dedicated to performing tasks related to the remapping drivepr / C*
The defect management employs predefined rules for ctejl&fmining defective areas in UA, for organizing spare areas on a medium, for defining^5ircumstances under which data can be recorded/modified on the medium, generally, for'controlling storing informp#6n on the medium. A defect table contains information^yviiich can be used to perfajra-fne defect management. In particular, the defect table contains a list of defective area^packets), which have been determined to be defective duprfg verification or during usp/6f the medium, according to rules of the defect majMf^ment. For example, a paptfoilar area may be classified as a defective area, if readinj^dma recorded in it gives etro^Further, the defect table contains a list of repla^prfient areas (packets), reseryedto be used as replacements of defective areas. Defective and replacement area^are referred to by their addresses on the medium. Different flags or status bits v^ytkfn the defect table indicate characteristicsof those areas, e.g. usability for data recordpag/The defect table also contains information related to areas on the medium, where the defect management shall not be active, such as a size and position of GAA.
After recording of DVD compliant video in the PC environment, there are few actions required before the MRW disc can be played in the (legacy) CE environment, as described in the introductorypart. These actions can be initiated automatically or via something like a "make convergent button" in a software application, or via a feature built

inside the operating system functionality or via a user activated device function. The latter can be performed with help of a physical push button, a remote control, the user's voice or any other way the user may interact with the device.
The control unit 20 is adapted to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area, to localize the replacement area according to the replacement area address, to localize the corresponding defect area according to the defect area address, to read the user data from the replacement area and to re-record the user data read in the defect area regardless of the defect management rules. Hereinafter, re-recording means attempting to record data stored in the replacement area at the original, defective location. The control unit 20 can perform these steps automatically as a default background operation of the apparatus or in response to the user's request as described above.
Figure 4 shows a simple example of a re-recording process according to the
invention. In figure 4a DVD compliant audio/video data 101 is recorded on a MRW disc^fitf
a single defect area 102. During recording this defective location is replaced by ^y^ %
replacement area 103 in the spare area 104. After re-recording is activated,^recorder reads j Ky
remapped data from position 103 and then attempts to record this data^t its originaMc^tj^b1^
102, as shown in figure 4b. \^/
This functionality of the control unit 20 kMsed on the following observ&tton. The MRW standard was defined with computer (kkfapplications in mind, where^m integrity is of the utmost importance. Acconiilig to the defect managementjalfes, user data is stored at a replacement location in th^g^are area instead of a particul^rtdefective) location, if a device can't be sure that awrtfe process at this location wiU^be successful. The same happens if write/read quality at the particular location is kg^than optimal to assure correct reading/writing at later stage in the device itself or in any other PC or CE device, which may be used for reading/writing this disc in the future. However, data recorded at the defective location may still be of a quality good enough for less sensitive applications, like in case of audio/video data. Moreover, rewriting information at the particular location might still be successful after the replacement is executed, for example as a result of using alternative recording parameters (\^rife strategy, laser power, servo tracking settings or simple retry strategies). Also, th^defective location might be readable giving no or less errors when read by a different device (e.g. by the CE device).

In an embodiment, the control unit 20 is adapted to collect information related to re-recording of the user data, read from the replacement location, at the corresponding original (defective) location. This information is than included in the defect table and recorded on the medium. It should comprise at least a flag indicating that the defective location was recorded with the user data from the corresponding replacement location.
In another embodiment, the control unit 20 is capable to verify results of re-recording the user data in the defect area (location). After the user data is re-recorded in the defect area, it is read from the defect area and compared with the user data read from the replacement area. The result of this comparison is included in the information related to re-recording.
In the process of rewriting the replaced user data at the defective location, the MRW defect table is involved. For example, the various status bits in the defect tablei^n indicate one of the following situations: Status 1 ~ valid replacement of the user data;
■ a defective area that has not been recorded at it^*6placement area; " a "free" entry, i.e. a replacement area usesjWe for future replacement; , j V/-"
" a replacement area unusable for fut)j*€replacement. 0 OAl^
Status 2 yS
" the original (defective)^rfea has been recorded with the sapiejiarta as the replacement area or the origyaafarea contains the most recently wrkj^tfunformation (represented by binary*5c00 according to the DVD+MRW specification); " thtfOTiginal area may contain different daja^s the replacement area corresponding to it (represented by binary xxOl according to the DVD+MRW specification).
After re-recording the^er data from the replacement location at the original location, following cases, gjv^jv^s examples, can be indicated in the defect table (e.g. by using binary xxOl for ^tetfis 2 of the related entry in the defect table):
" a case when such re-recording operation has been done, but no guaranties can be given with respect to quality of read-out performed by the receiving CE (other) device; " a read-out check by the MRW device after re-recording has given sufficient good results. In this case the MRW device may assume that next time the defective location is still readable and the replacement is a "preventive step" taken in order to recover the user data when the defective location gives problems, e.g. due to wear:

" it is expected that a read-out by CE devices will provide good data and the
replacement is a "preventive step" taken in order to recover the user data when the defective location gives problems, e.g. due to wear; " any other definition of strategy optimal for specific classes of devices or content types as described by the user, host or device, optimizing capability to stream the content in a specific environment.
In an embodiment, the control unit 20 is capable of setting in the defect table status bits related to the defect area and the replacement area corresponding to it, representing one or more of the cases defined above.
The entire process of re-recording the remapped data in the original area can
be employed as one of actions started with the "make convergent button". As an example,
this "button" can be a part of a special application in the PC environment executed after
recording of DVD compliant video on the disc; the application that makes the DVD+MR^^
disc with its content playable in the (legacy) CE environment. . y^
The re-recording process can be performed also in a CE DVp^MRW ^ * \^ recorder, i.e. the CE recorder with the MRW capability. Also, it can>tfperformed ^ immediately after recording of new audio/video data on a mejikim or at a later point in time, possibly by another recorder/device. The advantage ofpmorming the re-recording at the later point in time is that it can lead to good data^kuhe original (defective) area because meanwhile fingefprintsor dust might be renfoved from the medium or the anojb^r recorder has better recording capabilities foi^the medium.
In an embodimem of the recording apparatus, the cop#6l unit 20 is adapted to determine whether the r#rccording can be done immediately while continuing recording of more data or aftej>tfie recording has been completed. In ti^fatter case, the control unit 20 can be modifiedtokeep data to be re-recorded in a memetfy.
It is noted that the apparatus as skown in Figure 2 has recording and reproducing functions. Alternatively a reading apparatus for only retrieving information from a recording medium contains the scapmng elements and the read processing circuitry, but does not have the input unit 27^the formatter 28 and the modulator 29. Its control unit 20 does not perform functions^fated to recording.
After ][g^ecording,the data comprised in the defective area may give errors during reading. In case of a stream of digital audio/video signals, this will result in "hicks" or strong artifacts in the content-stream noticeable to a user, unless a reading device is knowledgeable enough to take the right optimal decision to read the data from the

replacement area instead of the defective area. This can be achieved by devices, which are capable of reading the MRW defect table and interpreting its content. Another way is to assure that the reading device can handle file system based features that allow for pointing to the replacement location instead of the original location in the CE device readable file system, for example using a remapper driver fiom GAA. In an embodiment, these functionalities are implemented in the control unit 20.
The outputting of the stream of digital audio/video signalsby the output unit of the read processing unit 30 is carried out under control of the control unit 20. In particular, the control unit 20 can be adapted to monitor a speed (a data rate) of the outputting in order to maintain continuous supply of data according to requirements defined by a specific application. For example, in DVD recording with the DVD+RW media the following data rates are commonly used:
Recording Mode s A
Recording time Resolution PAL Resolution NT^C" Average bitrate
(minutes) Pw^ (Mbits/sec)
HQ 60 720 x 576 (Full Dl)^720 x 480 (Full Dl) 9.72
SP 120 720 x 576 (FjtfrfH) 720 x 480 (Full Dl) 5.07
SP+ 150 720 x SHftFullDl) 720x480 (FullDl) 4.06
LP 18( 3^576 (Half Dl) 360 x 480 (Half Dl) 3.38
EP 24( 360x 576 (HalfDl) 360x 480 (HalfDl) 2.54
EV+ 36( 360 x 576 (HalfDl) 360 x 480 (HalfDl) 1.70
8h 4$ 352 x 288 (SIF) 352 x 240 (SIF) 1.27
In an embodiment, the control unit 20 is adapted to monitor the speed of outputting the read digital audio/video signals, to read the defect table from the medium, to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement area and to read the user data either fiom the replacement area or fiom the defect area corresponding to the replacement area in dependence on monitoring and speed requirements for the speed of outputting the read digital audio/video signals. Matching of a streaming capability with requirements of a specific application is done by optimizing

scheduling of reading and outputting operations and/or employing a cache memory for temporary storage of data read from the medium. Accordingly, the control unit 20 decides to read the user data either from the defect location or its corresponding replacement location.
It should be pointed out that reading data from the replacement location usually requires additional movements of the head 22, thus it introduces delays in supplying the data to the read processing unit 30. In an embodiment, the control unit 20 accounts for these delays while matching the streaming capability.
Advantageously, the control unit 20 is adapted to use the information related to re-recording - comprised in the defect table - for taking decision on using replacement areas versus original areas. For example, the control unit 20 can employ different status bits as explained above. In particular, the control unit 20 can decide to read data from the replacement area, if the information related to re-recording indicates that no guaranties can be given with respect to quality of data in the original area.
In an embodiment, the recording apparatus is arranged as a drive unit to be
connected to a separate host system, for example a drive unit to be build in a PC. The control Oh
unit 20 is arranged to communicate with a processing unit in the host system via a . Q
standardized interface. // w
In an embodiment of a computer data system comprising the ho^t^ystem and
the recording apparatus, the processing unit in the host system is adaptecjxfctfcontrol the
control unit 20 to perform methods and functions as described inpe^rence to embodiments
of the recording apparatus presented above. s'
A computer program product accordijigto the invention is operative to cause the control unit 20 or the processing unit to pppftirm methods and functions as described in reference to embodiments of the recorcjkfg apparatus presented above.
Whilst the inveijtiefinas been described with reference to preferred embodiments thereof, it is to be understood that these are not limitative examples. Thus, various modifications may become apparent to those skilled in the art, without departing from the scope of the invention, as defined by the claims. Further, the invention lies in each and every novel feature or combination of features described above. Also, for the storage medium an optical disc has been described, but other media, such as a magneto-optical disc or magnetic tape, can be used. It is noted, that the invention may be implemented by means of a general purpose processor executing a computer program or by dedicated hardware or by a combination of both, and that in this document the word "comprising" does not exclude the presence of other elements or steps than those listed and the word "a" or "an" preceding an

element does not exclude the presence of a plurality of such elements, that any reference signs do not limit the scope of the claims, that "means" may be represented by a single item or a plurality and that several "means" may be represented by the same item of hardware.

CLAIMS:
1 ■ A recording apparatus for recording digital audio/video signals on a removable
rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of
replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the recording apparatus comprising
input means for receiving the digital audio/video signals;
recording means for recording the digital audio/video signals on the medium;
reading means for reading digital audio/video signals recorded on the medium;
output means for outputtingthe digital audio/video signals read;
control means for controlling recording the digital audio/vided signals^
characterized in that . f Lr^
the control means are adapted to search the ^ectjtjjmle fpfa replacement area
address of a replacement area comprising the user data, to search^Jbt detect table for a defect
area address of a defect area corresponding to the replacemgtrf area, to localize the
replacement area according to the replacement area a^efress, to localize the corresponding
defect area according to the defect area address^to read the user data from the replacement
area and to re-record the user data read iij^Ke defect area regardless of the defect
management rules. A
2. A recording apparatus as claimed in claim 1, characterized in that the control means are adapted to collect re-recording information related to re-recording of the user data read in the defect area, to include the re-recording information in the defect table and to record the defect table in the table area.
3. A recording apparatus as claimed in claim 2, characterized in that the control means are adapted to read user data re-recorded in the defect area, to compare the user data read from the defect area with the user data read from the replacement area and to include results of comparing in the re-recording information.

4. A recording apparatus as claimed in claim 2, characterized in that the control means are adapted to use status bits in the defect table to include the re-recording information in the defect table.
5. A reading apparatus for reading digital audio/video signals from a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the reading apparatus comprising
reading means for reading digital audio/video signals recorded on the medium;
output means for outputting the digital audio/video signals read;
control means for controlling reading the digital audio/video signals, characterized in that
the control means are adapted to monitor a speed of outputting the digital audio/video signals read, to read the defect table from the medium, to search the defect table for a replacement area address of a replacement area comprising the user data, to search the defect table for a defect area address of a defect area corresponding to the replacement arpa and to read the user data either fi-om the replacement area or from the defect arep^ corresponding to the replacement area in dependence on monitcjting an 6. A reading apparatus as claimed in oiaifn 5, the defect table comprising re-recording information related to the user da&Tin the defect area and the replacement area, the reading apparatus characterized in tjiecf the control means are adapted to read the user data either from the replacement tp€a or from the defect area in dependence on the re-recording information.
7. A method of arranging digital audio/video signals on a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the defect areas identified as defective according to predefined defect management rules, the method characterized by

searching the defect table for a replacement area address of a replacement area comprising the user data;
searching the defect table for a defect area address of a defect area corresponding to the replacement area;
localizing the replacement area according to the replacement area address;
localizing the corresponding defect area according to the defect area address;
reading the user data from the replacement area;
re-recording the user data read in the defect area regardless of the defect management rules.
8. A method as claimed in claim 7, characterized by
collecting re-recording information related to re-recording of the user data read in the defect area;
including the re-recording information in the defect table; recording the defect table in the table area.
9. A method as claimed in claim 8, characterized by
reading user data re-recorded in the defect area;
comparing the user data read from the de^efarea with the user data read from the replacement area;
including results of compajitff* in the re-recording information.
10. A method acclaimed in claim 8, characterized by using status bits in the defect table for includingjh^re-recording information in the defect table.
11. A method of reading digital audio/video signals from a removable rewritable disc like recording medium, the medium comprising a user area comprising user data represented by the digital audio/video signals, a table area comprising a defect table, the defect table comprising a list of addresses of defect areas in the user area and addresses of replacement areas on the medium, the method comprising steps of reading the digital audio/video signals from the recording medium and outputting the digital audio/video signals
read for processing, characterized by
monitoring a speed of outputting the digital audio/video signals read; reading the defect table from the medium;

searching the defect table for a replacement area address of a replacement area comprising the user data;
searching the defect table for a defect area address of a defect area corresponding to the replacement area;
reading the user data either from the replacement area or from the defect area corresponding to the replacement area in dependence on the monitoring and speed requirements for the speed of outputtingthe digital audio/video signals read,
12. A method as claimed in claim 1 l,the defect table comprising re-recording
information related to the user data in the defect area and the replacement area, the method
characterized by reading the user data either from the replacement area or from the defect
area in dependence on the re-recording information.
13. A computer data system comprising a computer connected to a recording
apparatus for recording digital audio/video signals on a removable rewritable disc like
recording medium, the medium comprising a user area comprising user data represeqladlSy
the digital audio/video signals, a table area for recording a defect table compjising a list of
addresses of defect areas in the user area and addresses of replacemejiHireas on the medium,
the defect areas identified as defective according to predefine^Wefect managementiules, the
recording apparatus comprising •* \r*^
input means connected to the cojattSuter for receiving t$a argitaljpKHo/video signals;
recording means for recording the digital audio/videcvgignals on the medium;
reading means for reading digital audio/video signals recorded on the medium;
output means for outputting the digital audio/video signals read to the computer;
control means for controlling recording the digital audio/video signals, characterized in that
the computer is adapted to control the control means of the recording apparatus to perform the method according to any of claims 7-10.
14. A computer program product for arranging digital audio/video signals on a
removable rewritable disc like recording medium, which progi
processor to perform the method according to any of claims 7 •

Documents:

0310-chenp-2006 abstract duplicate.pdf

0310-chenp-2006 claims duplicate.pdf

0310-chenp-2006 description (complete) duplicate.pdf

0310-chenp-2006 drawings duplicate.pdf

0310-chenp-2006-abstract.pdf

0310-chenp-2006-claims.pdf

0310-chenp-2006-correspondnece-others.pdf

0310-chenp-2006-correspondnece-po.pdf

0310-chenp-2006-description(complete).pdf

0310-chenp-2006-drawings.pdf

0310-chenp-2006-form 1.pdf

0310-chenp-2006-form 26.pdf

0310-chenp-2006-form 3.pdf

0310-chenp-2006-form 5.pdf

0310-chenp-2006-form18.pdf

0310-chenp-2006-pct.pdf

310-CHENP-2006 ABSTRACT.pdf

310-CHENP-2006 CLAIMS.pdf

310-CHENP-2006 CORRESPONDENCE OTHERS.pdf

310-CHENP-2006 CORRESPONDENCE PO.pdf

310-CHENP-2006 DESCRIPTION (COMPLETE).pdf

310-CHENP-2006 DRAWINGS.pdf

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Patent Number

222689

Indian Patent Application Number

310/CHENP/2006

PG Journal Number

47/2008

Publication Date

21-Nov-2008

Grant Date

20-Aug-2008

Date of Filing

25-Jan-2006

Name of Patentee

KONINKLIJKE PHILIPS ELECTRONICS N.V

Applicant Address

GROENEWOUDSEWEG 1, NL-5621 BA EINDHOVEN,

Inventors:

#	Inventor's Name	Inventor's Address
1	BLACQUIERE, JOHANNIS, F. R	C/O PROF HOLSTLAAN 6, NL-5656 AA EINDHOVEN,
2	IJTSMA, POPE	C/O PROF HOLSTLAAN 6, NL-5656 AA EINDHOVEN,
3	HAMELINCK, DIRK	C/O PROF HOLSTLAAN 6, NL-5656 AA EINDHOVEN,

PCT International Classification Number

G11B20/18

PCT International Application Number

PCT/IB2004/051169

PCT International Filing date

2004-07-08

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	03102207.2	2003-07-17	EUROPEAN UNION