ZA200601482B - Method for recording information on a multi layer record carrier, and record carrier for use by such method - Google Patents

Description

PHNLO031042 PCT /iB2004/051518

Method for recording @nformation on a multi layer record carrier, and record carrier Sor use by such method

The invention relates to a method of recording information on a multm layer record carrier. The inwention relates especially to a method of recording informatiorm on a dual layer recordable WDVD disc, such that this disc can bee played in any DVD-ROM player.

The invention further relates to a record carrier for sue byy the method according to t. he invention, said record carrier comprising at least two infomation layers for storing she information.

After recording information on a recordabmle DVD record carrier special actions need to be tak—en to make the record carrier compatible with existing playback devices. When a recordable DVD record carrier has to bee made DVD-ROM compli ant, such that the recordable D™VD record carrier can be played baczk in any DVD-ROM playe=r, any unwritten areas need —to be filled with dummy data accoreding to the DVD-ROM spe=cification.

This because most D™VD players cannot cope with a record carrier on which the infomation layer opposite to the Enformation layer holding information has no information written on it. 1S This needs to be done= when closing a session and/or finalizing a disc.

The to tal available size for storing data orn a dual layer OTP-type (Opposite

Track Path) DVD rec=crd carrier (recordable, rewritable, as well as read-only discs) is dependent on the location of the middle zone. When the amount of information to toe written is known on forehancd, the location of the middle zone can be decided prior to writinng.

However, when infor-mation of a previously unknown si ze has to be written on a dial layer recordable DVD record carrier, the location of the midd 1e zone should preferably bee placed at the maximum allowe=d position, which results in a maximum storage space. A dowmmnside of placing the middle zone at the maximum allowed positieon is the amount of time thee filling with dummy data mamy take.

Figure 1A shows an example of a worst-case situation where a compplete data zone in a layer (Laye=r |) has to be filled with dummy deata. When the complete avamilable data zone space on a first layer, such as Layer 0 in figure | A , is written with informatio n, the complete available d ata zone on a second layer, suchas Layer 1 in figure 1A, need sto be

PHNL031042 PCT/\B2004/051518 filled with dummmy data in order to make the rec ordable disc DVD-ROM compsliant. This will take a substaratial amount of time.

It is an object of the present inve ntion to provide a method of amrranging the

S information cena dual layer record carrier such that the amount of time require=d for making the record camrrier compatible with existing play back devices, especially with [DVD-ROM players, will Wbe reduced to a minimum. This wi thout prior knowledge of the a_mount of information t hat should be stored.

This object is achieved by providing a method in which a specmfic filling pattern is use=d during the recordings for physically distributing the informaticon to be recorded ove=r the information layers of the mu 1ti layer record carrier. By usin_g this specific filling pattern the amount of time required to cRose/finalize the session or disc= is significantly reduced.

In the method according to the i nvention recording is switched from a first information layer of the disc to a second inforrmation layer of the disc each tire a predefined amount of st-orage space is filled. This is schennatically depicted in figure 2, v=vhere paths 1 and 3 indicaste write sequences, and paths 2 and 4 indicate layer jumps. A duaml layer disc, as is shown in #Figures (A, 1B and 2, comprises two information layers, generally referred to as the Layer O &L0) and Layer 1 (L1) layer. The L_0 layer is the information laye=r located closest to the side o—f a disc where a radiation beam, suach as a laser beam, used for re - ading and/or recording thee information enters the disc. The drive initially writes a predefirmed amount of information (block 1) to layer LO and then swi tches to layer L1 to write the nmext predefined amount of irformation (block 2). Next, the drive jump back to layer LO to reacord a subsequent gpredefined amount of information (block 3) behind the previously recorded block 1.

Data to be recorded on a record carrier normally consists of se=veral files. The logical location of each of these files is stored in file system tables. Since, foxx example, a

DVD recorc carrier acts like a random access memory, the location of the fil _es stored on the record carriezris not dependent on the order of these files in the file system. Ey balancing the amount of irformation to be written over all layers using the special filling p- attern according to the invention, each of the layers will be filled at approximately the same raate.

In an embodiment of the methavd according to the invention thme predefined amount of imnformation (that is, the block size) is not a fixed amount, but it is an amount that

PHITNLO031042 PCT /1B2004/051518 is v- ariably set by the method itself. In a preferred embodiment of the method accordi ng to the inveention, a value specifying this predefined amount of information (that is, the blocMk size) is reaed from the record carrier itself.

The size of the predefined amount of information influences the time - required for closing a session and/or finalizing a disc. The smaller the size of the storage spac -e for hol. ding the predefined amount of information, the faster the closing of a session and./or the finaalizing of a disc will be. This because the amount of dummy data that needs to be= recorded upeon closing and/or finalizing is reduced. However, such a small size of the storage space will increase the amount of layer jumps, which could negatively affect the recording pemcformance. Moreover, because of the small block sizes, the number of track jumpss (jumps fromm one block of information to another block of information) when reading the reacord carrier will increase. Therefore, the optimum size of the storage space for holding thme predefined amount of information is dependent on the type of use of the record carrmer (such as,. for example, recording of a continuous video stream or recording of data files).

According to the above-described embodiments of the invention, the size of thes predefined amount of information (that is, the block size) is flexibly set dependi ng on the type of use of the record carrier. The method may set the size automatically depending on the ar—ount of data to be stored, on the way the data to be stored is supplied to the meth_od (streaming or as fragmented blocks), or on the application. Alternatively, a user setss the size of the predefined amount of information manually.

Moreover, this size of the predefined amount of information needs neot be fixed during the entire use of the record carrier, but according to an embodiment may be changed be=tween recording sessions. For example, a first recording session may be recorded witha fir—st size of the predefined amount of information, while a subsequent second recorading se=ssion may be recorded with a second size of the predefined amount of informatio: n, the se=cond size being different from the first size. In this way, a single record carrier m. ay support di fferent types of uses.

According to a preferred embod iment, the method reads information regarding thaee size of the predefined amount of information from the record carrier itself. This . inmformation may be stored on the record carrier as a parameter in an area on the rec=ord carrier comprising parameters indicative of the recording process. When the type of use oft the re=cord carrier is fixed and/or a preferred size of the predefined amount of informati on is kmnown beforehand, this information may be prerecorded on the record carrier. Alte atively, those information regarding the size of the predefined amount of information may be recorded

PHNL031042 P= CT/IB2004/051518 on the record carrier by the method itself. For example, the last selected size of thme predefined amount of information is stored on the record carrier for re-use in a subsequent recording sessiorm.

Ermbodiments of the invention will now We explained in more detail with reference to the amccompanying drawings.

The DVD-ROM format specification describes that an area identified as middle zone doess not necessary have to be filled with lata. When the middle zore is located at a position priowr to its maximum position, less space nas to be filled with dumnmny data, as is shown in figure 1B. When the amount of information te be written is known on Sforehand, the location of the riddle zone can be decided prior to wri ting. However, when this is not the case, the special filling pattern according to this invention can be used to achieves an optimal balance between. available user space and required clossure time.

A_n embodiment of the method accordin gto the invention is now described with reference to figure 3 in which the various record Carrier states are shown dumring the various steps of the method, and in which the special f3lling pattem is represente=d by a sequence of pats:

Step one starting from an empty dual layer record carrser (figure 3A): - During recording the record carrier is treeated as an open session, =soa file system (FS) wil not be written until the session is closed; - The middle zone location is placed imaginary at the maximum lo- cation, thus providing the m axirnum amount of storage space.

Step two (figure= 3B). - The files (1, 2 and 3) are written on the record carrier. These filess are written sequentially (pa_th a). It is noted that although the files in figure 3 have identical sizes, the actually written files may vary in size.

Step three (figu=xre 3C): \SVhen a predefined amount of storage space is filled, writing of subsequent files will stop oan Layer 0 and will continue on Layer L (path b). It is noted that sthis storage space for holdirg the predefined amount of information is the maximum amourmt of space (i.e., a worst-ca_se situation) that should be padded (th=at is, written with dummy data) when closing a sessio n and/or finalizing a disc. For a record able DVD disc where asi ngle layer

PHINLO031042 PCT/IB2004/051518 m=ay hold up to 4.7 Gbyte of data, the size of storage space for holding the pr edefined amount of information should preferably be in th range of 1% (approximately SOMiDyte) to 10% (a_pproximately 500 Mbyte). The size of the pre-defined recording area should at least be si_gnificantly less than the total amount of storage space available on a single layer. 5 - The next files (4, 5, 6 and. 7 are written sequentially (path c) osnLayer 1; - Since the dual layer record carrier in this example is of an OTP (Opposite track Path) type, the direction of writing on Layer 0 (path a) is reverse to the= direction of writing on Layer 1 (path ¢).

S tep four (figure 3D): - When the storage space feor holding the predefined amount of~ information on

L_ayer 1 is filled, or the next file to be written (8) does not fit in the remainirmg space, writing ¢ ontinues on Layer 0 again (path d); - The next files (8, 9, 10 arad 11) are written sequentially on Lamyer 0 (path €) umntil a predefined location is reached.

Step five (figure 3E): - The writing process will continue on Layer 1 again (path ; - The next files (12, 13, 14- and 15) are sequentially located on. Layer 1 (path g).

Step six (figure 3F): — When the current writings operation is finished, future files tom be recorded (16) can be located at the next available user space (path h).

In an embodiment of the method according to the invention zn alternative _sspecial filling pattern is used for record ing information on a record carrier Lasing a Parallel “Track Path (PTP) addressing mode. In such a record carrier using a PTP ad dressing mode e=ach layer has the addresses ranging from the inner diameter of the disc to she outer diameter.

Moth layers have their own lead-in and lead-out areas. There is no middle z-one present like in @®OPT type record carriers. The steps of his embodiment are now described with reference to figure 4: —- Reserving the file system space (FS) when the writing starts ; -— Writing the information on Layer O until a predefined positieon is reached (that is, until the storage space for holding the predefined amount of informatiora is filled). The files (1, 2 and 3) are written sequential By (path a); - After a first layer jump Cpath b) writing the next files (4, 5, & and 7) on Layer 1 (pathc);

PHNL «031042 PCT/IB2004/051518 - When a predefined position on Layer I is reached, writing continues again at

Layer O (path e) after a second layer jump (pakhd).

The method according to the in vention is not only suitable for —use with dual layer mrecord carriers, but also for use with multi layer record carriers comprising more than

S two immformation layers. Such multi layer recor=d carriers may use any of the O®TP and PTP addressing modes. The special filling patterns for use with such multi layer discs correspond to the ones described above for dual layer discs. Figures S depicts embodimemnts of the method according to the invention for use wit h multi layer record carriers comnsisting of ‘n’ layerss, with either the OTP (figure SA) or the PTP (figure 5B) addressing made.

For a multi layer OTP type record carrier (figure 5A) it is assummed that the addre=ss ranges for each layer is opposite in direction with respect to the prev -jous layer. Now, filling takes place from the lowest layer (Layeer 0) up until the last layer (Lay ern).

Subsequent blocks (that is, storage spaces for holding the predefined amount= of information) are re=corded on the layers as depicted in figumre SA according to the following special filling pattemrn (that is, sequence of paths): a> bocoadoasotosuasvresxf—og2hoaowasxoy—oz

Each time the topmost layer (Layer n) is reached, the next block of information will be writteen on the lowest layer (Layer 0) after a j ump (path v, respectively, path 2).

For a multi layer PTP type record carrier (figure 5B) it is assummed that the addre=ss ranges for each layer is in the same Rirection as the previous layer. Again, filling takess place from the lowest layer (Layer 0) u_p until the last layer (Layer n) ina saw-pattern like sshape. Now the subsequent blocks (that Ts, storage spaces for holding thme predefined amount of information) are recorded on the 1 ayers by a special filling patterr as depicted in figur-e 5B: a— boacodoasoataru-dvoeaf agshawoax—2y—z

Again, when the topmost laye r (Layer n) is reached, the next file will be written on the lowest layer (Layer 0) after th e jump (path v, respectively, pasth z).

By applying the special filling patterns according to the inver—tion it is possible to exploit the maximum available user space= on a record carrier to the fullesst, while minimizing the amount of time required to c lose/finalize the disc or session—. When, for exarmnple, a recordable DVD disc is written umsing the filling patterns according to the inve ntion, such a DVD disc is fully compatilble with the existing DVD-RONa standard and can “be read by any standard DVD player, inecluding DVD-ROM players.

PHNL 031042 PCT/IB2004/051518

Figure 6 shows a table compar lng the best-case and the worst-camse situations of the= closing/finalizing time when using eitheer the filling pattern strategy accomrding to the inven. tion or a conventional sequential filling_ In the best-case situation no clos-ing/finalizing time is required in both situation: for sequent al filling the complete data area i sused and no

S extra filling time is required for padding (that is, writing the dummy data); whe=n using the speci-al filling patterns according to the invem tion the session/disc will be close=d/finalized after writing sequence g, and again no paddirg needs to be performed. Howeveer, in the worst-case situation a significant reduction of the time required for closing/fin=alizing is obtai med when the method according to the imnvention is applied. For conventional sequential fillin_g the closing/finalizing time equals the time required for recording a com plete layer.

Whemn half of the available disc capacity is ussed (that is, only one layer is recomrded), the other half eof the disc capacity (i.e., the other layer)» needs to be padded (that is, written with dummy datas. Now, when using the special filling patterns according to the invention, the closi ng/finalizing time equals only the time required for recording the storage space for holding the predefined amount of information with dummy data. On Layer 1 &an area with the size of the storage space for holding the preciefined amount of information, which is signmficantly less than the total recording are-aon Layer 1, should be padded ir order for the disc to be DVD-ROM compliant. For a recoxdable DVD disc where a single l=ayer may hold up to 4.7 Gbyte of data, the size of the pre-defined recording area should prefa=rably be in the rangze of 50Mbyte to S00 Mbyte (that is, at least significantly less than the tot=al amount of storage space available on a single layer).

Claims (11)

PHNL031042 PCT/IB2004/@051518 CLAIMS:

1. A me=thod of recording information on a multi layer record carrier, said record carrier comprising aut least two information layers for recordi ng the information, wherein the information to be re corded is distributed over the at least two layers according to a distribution pattern =such that the amount of information store=d on the at least two layers differs between the layers by a predefined amount of informzation or less.

2. Method as claimed in claim1 wherein the information is recorded in subsequent blocks, each block for holding the predefined amount of information, and where®in the distribution patt—emn is such that two subsequent biocks are not recorded on the same information layer.

3. Method according to claim 1 or 2, wherein areas holding recorded informatio n on the at least two Mayers are superjacent.

4 Methhod according to claim 1 or 2, wherein thme predefined amount of information is significantly less than the total amount of storage space available on one of the at least two informaation layers.

5. Method according to claim 2, wherein the method comprises an initialization step of setting the size of sai«d block for holding the predefine=d amount of information, and a subsequent recording step of recording information on said at least two information layers such that the information is recorded altezmately on said at least two information layers... the recording step comprising the steps of recording information on a layer until the block for holding the predefined amount of information is filled, and subsequently recor—ding information on a different layer of ssaid at least two information layers.

PHNEL031042 PCT/IB2004. /051518

6. Method according to cl aim 5, wherein in the initializ=ation step a value indic-ative of the size of the block for Tholding the predefined amourit of information is read from the record carrier, and wherein thhe size of the block for holdirg the predefined amount of in- formation is set in dependence ox the read value.

7. Method according to ¢ 1aim 6, wherein the method c omprises a further step off recomrding a value indicative of the set size of the block for holding. the predefined amount o—f infomrmation on the record carrier.

8. Method according to claim 5, wherein the size of thme block for holding the predefined amount of information is set in dependence on the amowunt of information to be store=d, or on the way the information. to be stored is supplied to thee method, or on the type aof the mapplication supplying the information.

9. A method of recording information on a multi layemr record carrier, said recomrd carrier comprising at least two inforrmation layers for storing the i=nformation, wherein the met hod comprises a first initialization step of setting the size of a first= block for holding the preciefined amount of information, amd a subsequent first recording step in a first recording sesssion for recording information on. said at least two information layers such that the information is recorded alternately on said at least two informatio-n layers, the first recordirag step> comprising the steps of recordirag information on a layer unt il the first block for holdi ng the predefined amount of informatio n is filled, and subsequently recording informationon a different layer of said at least two in formation layers, and a second initializatiorx step of setting the size of a ssecond block for holding nthe pre-defined amount of information, a.nd a subsequent second recording step in a second receording session, the second record. ing step comprising the steps= of recording informatiomn on a layer until the second block for holding the predefined amoumnt of information is fille3, anc subsequently recording informa tion on a different layer of sa. id at least two information lay ers

10. A recording device for recording information on a_ multi layer record carrie, saiad record carrier comprising at least two information layers for recording the informatiom,

WO) 2005/020232 PCT/IB2004/051518 PHNL031042 PCT/IB2004/051518 wherein the device is adapted for c-amying out a method as claimed in any of the preceding claims.

11. A multi layer recor carrier comprising at least two inforrmation layers for storing information, said record carrier comprising a region holding paraameter values indicative of a recording process for recording information on the recorc carrier, characterized in that said region comprises a value indicative of the size of a block for holding a predefined amount of in. formation, said value indicative of the= size of the block for holding the predefined amount of information used in a method accordimng to claim 6 or 7.