WO2006134511A2

WO2006134511A2 - Recording and session closing methods

Info

Publication number: WO2006134511A2
Application number: PCT/IB2006/051794
Authority: WO
Inventors: Robert Albertus Brondijk; Wiebe De Haan
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2005-06-15
Filing date: 2006-06-06
Publication date: 2006-12-21
Also published as: WO2006134511A3; TW200703289A

Abstract

A method for writing information in a DVD+R disc (32) comprises the steps of: defining a first start address (A) for a first storage portion (12); defining a second start address (B) for a second storage portion (13); writing information into the first storage portion up to a first end address (C); defining a first dummy data end address (X) higher than the first end address (C); defining a second dummy data end address (Y) lower than the second start address (B) yet higher than the first dummy data end address (X); writing dummy data in the first storage portion (12) from the first end address (C) up to the first dummy data end address (X) and from the second dummy data end address (Y) up to the second start address (B).

Description

METHOD FOR WRITING INFORMATION IN A RECORD MEDIUM

FIELD OF THE INVENTION

The present invention relates in general to the field of storing data on a record medium. The present invention relates particularly to the field of optical storage, such as CD, DVD, BluRay. Especially, the present invention relates to the field of storing information on an optical disk of type +R.

BACKGROUND OF THE INVENTION

Since the technology of optical data storage is general, including the way in which information can be stored in an optical disc, is commonly known, it is not necessary here to explain this technology in great detail. It is briefly summarized that an optical storage disc comprises at least one track, either in the form of a continuous spiral or in the form of multiple concentric circles, of storage space where information may be stored in the form of a data pattern. The storage space is divided into blocks. The data to be written is organized into data sectors, each sector comprising a user data portion and a header portion. A data sector is written into a storage block.

For writing information into the storage space of the optical storage disc, or for reading information from the storage space of the optical storage disc, the storage track is scanned by an optical beam, typically a laser beam. The actual handling of the storage disc is performed by an apparatus that will be indicated as disc drive apparatus. This handling includes the functions of receiving, holding, and rotating the disc. This handling also includes the functions of generating the laser beam(s); directing, focussing and displacing the laser beam(s); suitably modulating the laser beam(s) for writing; sensing the reflected beam(s) for reading. This handling also includes the functions of error correction, deciding which information to write at which physical addresses, etc. The above-mentioned general functions of the disc drive apparatus are known per se.

The present invention is not aiming at improving these general functions; in fact, the present invention may be implemented while using the general functions according to the state of the art. Therefore, a more detailed description and explanation of these general functions is omitted here. It suffices to say that the disc drive apparatus has a data input for receiving data- to-be-stored, and a data output for outputting data-read-from-disc.

Optical discs are very successful, and several different types have been developed. One such type is DVD (Digital Versatile Disc), and the present invention relates particularly to DVD discs, for which reason the present invention will be explained in the following for DVD discs. However, the gist of the present invention is also applicable to other types of recordable discs; therefore, the following description is not to be understood as limiting the scope of the present invention to DVD discs only. Optical discs may be read-only type, indicated as ROM discs, where information is recorded during manufacturing, which information can only be read by a user. The optical storage disc may also be a writeable or recordable type, where information may be stored by a user. Such discs may be a write-once type, indicated as writable (R), but there are also storage discs where information can be written many times, indicated as rewritable (RW). In the case of DVD, a distinction is made between two formats, i.e. DVD-RW and DVD+RW.

Likewise, several different types of disc drive apparatus have been developed. A disc drive apparatus may be designed for reading only, or a disc drive apparatus may be capable of writing as well. Further, disc drives may be designed for reading all types of discs, but a disc drive apparatus may also be designed for reading one type or a limited number of types only. Finally, a distinction can be made between different types of information. For instance, information can be audio, video, data.

In general, it can safely be said that a certain type of information written by a certain type of apparatus on a certain type of disc can be read by a same type of apparatus. However, problems occur if such disc is offered to a different type of apparatus: it may be that such different apparatus is not capable of correctly reading the disc.

A particular problem of this kind involves the combination of video and data. When a blanc +R disc is prepared for writing video information as well as data, data space is allocated at the end of the storage space of the disc while video space is allocated at the beginning of the storage space of the disc. When video information is written, the disc drive starts writing at the beginning of the video space, and writing is continued in a sequential manner, i.e. when a block is full, writing continues at the beginning of the next following block. When data is written, the disc drive starts writing at the beginning of the data space, and writing is continued in a sequential manner. Thus, when the amount of video written is smaller than the size of the video space, the portion of the video space between the actual video information and the actual data information is still empty. This situation would not constitute a problem for +R-type readers, but ROM-readers (i.e. a disc drive designed for reading ROM discs only) can not handle such discs. For the user, however, it would be much more convenient if the disc could also be read by a ROM-reader. Therefore, in order to allow the disc to be capable of being read by a ROM-reader, the standard rules that the entire space between the video and the data must be written with dummy information. A disadvantage of this solution is, however, that this operation of writing dummy data may take quite a long time, while the user, being ready with recording, wishes to eject the disc as soon as possible. Accordingly, an important objective of the present invention is to overcome the above problems, disadvantages and inconveniences.

Particularly, it is an objective of the present invention to provide a modified method and apparatus for writing a +R-disc such as to provide fast eject when a writing operation is completed while assuring that the disc can be read by a ROM-reader.

SUMMARY OF THE INVENTION

According to an important aspect of the present invention, dummy information is only written at the margins of the empty storage spaces, and then the session is closed. According to the state of the art, a session can only be closed after the entire empty storage space has been filled with dummy information, and the fact that a session is declared "closed" indicates that the entire storage space associated with the session has been written. A ROM-reader will only accept a +R-disc with a closed session, because this indicates that the ROM-reader can handle the entire storage space associated with the session. In contrast, the present invention declares a session closed even if the corresponding storage space contains empty space (thus declaring corresponding storage space as being "fully written" while this is actually not true), but this can safely be done since it is assured that jumps can never terminate in the empty space.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of the present invention will be further explained by the following description with reference to the drawings, in which same reference numerals indicate same or similar parts, and in which: figure IA is a diagram schematically illustrating a storage space with a reserved administrative storage portion and two user storage portions; figure IB is a diagram schematically illustrating part of the user storage portions being written; figure 1C is a diagram schematically illustrating empty remainder portions of the user storage portions being written with dummy information according to the state of the art; figure 2 is a diagram schematically illustrating small dummy data portions of the empty remainder portions of the user storage portions being written with dummy information, leaving a large portion of the empty remainder portions of the user storage portions blanc in accordance with the present invention; figure 3 is a block diagram schematically illustrating a recording system; figure 4 is a table illustrating a CLOSE TRACK/SESSION command descriptor block suitable for use in a write method in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION

Figure IA schematically shows the storage space 10 of an optical disc as a longitudinal ribbon, which at its beginning (lowermost addresses, innermost disc portion, lefthand side of the drawing) comprises a reserved portion 11 for administrative purposes, inter alia for storing a file system; this portion is also indicated as lead-in portion. When the disc is initialized for a combination of video and data, a video start address A is defined for a video storage portion 12, and a data start address B is defined for a data storage portion 13. The video storage portion 12 follows the administrative portion 11, which is not accessible to a user, and the data storage portion 13 follows the video storage portion 12. The data start address B marks an end address for the video; beyond this address, no video information can be written.

A session 18 is defined as the combination of the video storage portion 12 and the data storage portion 13. A session has a session end address E. In the illustration of figure IA, a session 18 may span the entire storage space 10, but this is not necessary. In case a session is smaller than the storage space 10, the session end address E is lower than the end address of the storage space 10.

During a write operation, video information is written sequentially, starting from the video start address A. When a storage block is full, writing continues at the next neighbouring block. Thus, a video recording occupies a contiguous storage portion 14 between the video start address A and a certain video end address C. Likewise, data is written sequentially, starting from the data start address B. When a storage block is full, writing continues at the next neighbouring block. Thus, a data recording occupies a contiguous storage portion 16 between the data start address B and a certain data end address D. These written portions 14 and 16 are indicated as hatched portions in figure IB. The user may add video recordings; in such case, writing continues from address C.

Likewise, the user may continue storing data. However, he can only do so as long as the disc remains inside the disc drive. If the user wants to eject the disc, the session 18 has to be closed. According to the state of the art, closing the session involves writing dummy information into the remaining portion of the video storage portion 12, indicated as empty video storage remainder portion 15 in figure IB; this dummy information is indicated by the crosses in figure 1C. The same applies to empty data storage remainder portion 17. A problem is that the operation of writing dummy data into said remainder portions 15 and 17 takes a lot of time.

The reason for writing the dummy data into said remainder portions 15 and 17 is to avoid the possibility of a ROM-player entering terra incognito: a ROM-player expects to receive a disc which is completely written, and can not handle unwritten track portions.

It is true that a ROM-player can not handle unwritten track portions, and, for stability of performance, it is to be avoided that a ROM-player tries an access to an unwritten track portion. According to the state of the art, this objective is achieved by totally avoiding the existence of unwritten track portions. The present invention is based on the inventive understanding that it is not necessary to employ such extreme measures, but that it is possible to allow the existence of unwritten track portions while still effectively avoiding the possibility of a ROM-player trying to access such unwritten track portion. This will be explained with reference to figure 2.

According to a preferred embodiment of the invention, when a session is closed, a first dummy data portion 21 is defined from the video end address C up to a first dummy data end address X higher than the video end address C but lower than the data start address B. A second dummy data portion 22 is defined from the data start address B down to a second dummy data end address Y lower than the data start address B and higher than the first dummy data end address X. A third dummy data portion 23 is defined from the data end address D up to a third dummy data end address Z higher than the data end address D but lower than the session end address E (highest possible address of the session). Only these dummy data portions 21, 22, 23 are written with dummy data, as indicated by crosses in figure 2, leaving a large portion 25 of the video remainder portion 15 and a large portion 27 of the data remainder portion 17 actually blanc. Thus, the operation of writing these dummy data portions 21, 22, 23 takes very little time. The length of these dummy data portions 21, 22, 23 is not critical: a few ECC blocks may be sufficient in practice, but, to be on the safe side, it might be preferable to have a length in the order of about 10 to 20 ECC blocks. A longer length will do also, of course, but will take more writing time.

Further, the video end address C is noted in the file system, so that a video space A-C is defined in the file system. Likewise, a data space B-D is defined in the file system.

Finally, the disc is closed. Information is written into the administrative portion 11 indicating that the disc is completely written, while this is actually not true, but the disc will be accepted and played by a ROM-player.

Although the information in the file system indicates a session with a start address A and an end address E, such ROM-player can not in practice access any unwritten area 25, 27. The information in the file system indicates a video space A-C, so when trying an access on the basis of the file system, the ROM-player always accesses written area. Inside the video space A-C, pointers will always be directed to addresses within the video space A-C, as well. Only when a jump is made to an address close to the end address C, it might be possible that the ROM-player overshoots and reaches an address beyond the video end address C. Although this will be an address in the remainder portion 15, it will be an address within the first dummy data portion 21, thus containing dummy data written therein. The ROM-player, reading the address information in the track where it is reading, will realize that it is at a wrong location and will jump back. From the above, it should be clear to a person skilled in the art that the length of the first dummy data portion 21 should be chosen in relation the length of overshoot to be anticipated in ROM-readers. As mentioned, a few ECC blocks should be sufficient in general.

A similar explanation applies to the data space B-D: based on the information in the file system, a ROM-player will only try an access to an address within the data space B-D. Only when jumping back to an address close to the data start address B, it may overshoot and land in the second dummy data portion 22, or when jumping forward to an address close to the data end address D it may overshoot and land in the third dummy data portion 23.

It is noted that, after an overshoot but before realizing that an overshoot has taken place, the ROM-reader plays forward away from the landing location. In the case of the first and third dummy data portions 21, 23, such forward play is directed away from the video end address C or the data end address D, respectively, while in the case of the second dummy data portion 22 such forward play is directed towards the data start address B. Therefore, the length of the second dummy data portion 22 may be smaller than the length of the first and third dummy data portions 21, 23.

It is further noted that, if the length of the remainder portion 15 is smaller than a predetermined threshold length, the remainder portion 15 may be written entirely with dummy data, as in the state of the art.

Figure 3 schematically illustrates a recording system 30, comprising a host apparatus

34, a writing apparatus 33, and a record medium 32. In an exemplary embodiment, the record medium is a DVD+R disc, the writing apparatus is a disc drive capable of writing DVD+R discs, and the host apparatus is a PC. In an information writing operation, the host apparatus 34 sends information to the disc drive 33, either video or data or a combination of both, and the disc drive 33 writes this information onto the disc 32. When the host apparatus 34 is ready and the user wishes to eject the disc 32 from the disc drive 33, the host apparatus 34 sends a CLOSE command to the disc drive 33.

A host apparatus which is designed in accordance with the prior art will generate the CLOSE command in accordance with the prior art. However, a host apparatus which is designed in accordance with the present invention will generate an improved CLOSE command in accordance with the present invention, which improved CLOSE command will be indicated as a CLOSE QUICKLY command CQ. In a specific embodiment, the CLOSE QUICKLY command may be identical to a CLOSE command, provided with a QUICKLY parameter; this QUICKLY parameter indicates a CLOSE QUICKLY command only if this QUICKLY parameter has a predetermined value.

A disc drive which is designed in accordance with the present invention, when receiving the CLOSE QUICKLY command, will write dummy data only into the first, second and third dummy data portions 21, 22, 23 and declare the disc 32 closed, as described above. A disc drive which is designed in accordance with the prior art will receive the CLOSE QUICKLY command but will act as if receiving the prior art CLOSE command. Likewise, in the case of a disc drive which is designed in accordance with the present invention yet cooperating with a host apparatus which is designed in accordance with the prior art, the prior art CLOSE command will be executed.

Figure 4 is a table illustrating a CLOSE TRACK/SESSION command descriptor block, adapted in accordance with the present invention to implement a CLOSE QUICKLY command. As illustrated by the table in figure 4, the CLOSE command comprises 12 bytes of 8 bits each. Byte 0 contains an operation code, bytes 4-5 are used to indicate a track number, byte 9 is a control byte.

Bytes 1-3 and 6-8 and 10-11 are reserved for later definition, i.e. they do not have a defined meaning yet. So, it is possible to use any bit of these bytes as QUICKLY parameter. In the embodiment as illustrated in figure 4, the first three bits 0-2 of the third byte 2 are used as QUICKLY parameter, a value 7 (i.e. al three bits being 1) indicating the CLOSE

QUICKLY command.

Thus, the present invention succeeds in providing a method for writing information in a DVD+R disc 32, comprising the steps of: defining a first start address A for a first storage portion 12; defining a second start address B for a second storage portion 13; writing information into the first storage portion up to a first end address C; defining a first dummy data end address X higher than the first end address C; defining a second dummy data end address Y lower than the second start address B yet higher than the first dummy data end address X; writing dummy data in the first storage portion 12 from the first end address C up to the first dummy data end address X and from the second dummy data end address Y up to the second start address B.

It should be clear to a person skilled in the art that the present invention is not limited to the exemplary embodiments discussed above, but that several variations and modifications are possible within the protective scope of the invention as defined in the appending claims.

For instance, in the above preferred example, dummy information is written into three dummy data portions. However, having only one of these dummy data portions is already an improvement over prior art.

Further, it may be that the possibility of a potential overshoot into a remainder portion

15 or 17 is only a real problem at the end of the video recording (after address C), or at the beginning of the data recording (before address B), or at the end of the data recording (after address D). Also, it may be that the amount of data written into the second storage portion 13 is equal to zero; in that case D=B applies, and a jump to the second storage portion 13 with the associated chances on overshoot is not to be expected. Also, it may be that the amount of video written into the first storage portion 12 is equal to zero; in that case C=A applies, and a jump to the first storage portion 12 with the associated chances on overshoot is not to be expected.

Further, it may be that the amount of video written into the first storage portion 12 is so large and the remainder portion 15 is so small that it is decided to fill the entire remainder portion 15 with dummy data, while only a "reduced size" dummy data portion 23 according to the present invention is written after the data recording 16. Or, it may be that the amount of data written into the second storage portion 13 is so large and the remainder portion 17 is so small that it is decided to fill the entire remainder portion 17 with dummy data, while only "reduced size" dummy data portions 21 and 22 according to the present invention are written after the video recording 14 and/or before the data recording 16. In the above, the present invention has been explained with reference to block diagrams, which illustrate functional blocks of the device according to the present invention. It is to be understood that one or more of these functional blocks may be implemented in hardware, where the function of such functional block is performed by individual hardware components, but it is also possible that one or more of these functional blocks are implemented in software, so that the function of such functional block is performed by one or more program lines of a computer program or a programmable device such as a microprocessor, microcontroller, digital signal processor, etc.

Claims

Method for writing information in a record medium (32), the method comprising the steps of:

(a) defining a first start address (A) for a first storage portion (12);

(b) defining a second start address (B) for a second storage portion (13), the second start address (B) being higher than the first start address (A); (c) defining an end address (E) for the second storage portion (13), the end address

(E) being higher than the second start address (B);

(d) sequentially writing a first amount of information into the first storage portion (12), starting at the first start address (A), up to a first information end address (C), the first amount being larger than or equal to zero; (e) sequentially writing a second amount of information into the second storage portion (13), starting at the second start address (B), up to a second information end address (D), the second amount being larger than or equal to zero;

(f) performing at least one of the following steps (fl), (f2), (f3):

(fl) defining a first dummy data end address (X) higher than the first information end address (C) but lower than the second start address (B), and writing dummy data into the first storage portion (12) from the first information end address (C) up to the first dummy data end address

(X);

(f2) defining a second dummy data end address (Y) lower than the second start address (B) but higher than the first information end address (C), and writing dummy data into the first storage portion (12) from the second dummy data end address (Y) up to the second start address (B); (β) defining a third dummy data end address (Z) higher than the second information end address (D) but lower than the end address (E), and writing dummy data into the second storage portion (13) from the second information end address (D) up to the third dummy data end address (Z); wherein, in case the above steps (fl) and (f2) are performed in combination, the second dummy data end address (Y) is higher than the first dummy data end address (X);

(g) defining a file system with a first storage space (A-C) having the first start address (A) and the first information end address (C) and a second storage space (B-D) having the second start address (B) and the second information end address (D); and (h) closing the record medium.

2. Method according to claim 1, wherein the record medium (32) is an optical disc.

3. Method according to claim 1, wherein the record medium (32) is a DVD+R disc.

4. Recording system (30), comprising a record medium (32), a writing apparatus (33) for writing information to the record medium (32), and a host apparatus (34) for sending information and commands to the writing apparatus (33); the system (30) being designed for performing the method of any of claims 1 -3.

5. Method for quickly closing a write session of a record medium (32), the record medium (32) having a first storage portion (12) and a second storage portion (13), the first storage portion (12) having a first start address (A), the second storage portion (13) having a second start address (B) higher than the first start address (A) and an end address (E) higher than the second start address (B), the method comprising the steps of:

(a) determining a first information end address (C) of information written into the first storage portion (12);

(b) determining a second information end address (D) of information written into the second storage portion (13);

(c) performing at least one of the following steps (cl), (c2), (c3):

(cl) defining a first dummy data end address (X) higher than the first information end address (C) but lower than the second start address (B), and writing dummy data into the first storage portion (12) from the first information end address (C) up to the first dummy data end address (X);

(c2) defining a second dummy data end address (Y) lower than the second start address (B) but higher than the first information end address (C), and writing dummy data into the first storage portion (12) from the second dummy data end address (Y) up to the second start address (B); (c3) defining a third dummy data end address (Z) higher than the second information end address (D) but lower than the end address (E), and writing dummy data into the second storage portion (13) from the second information end address (D) up to the third dummy data end address (Z); wherein, in case the above steps (cl) and (c2) are performed in combination, the second dummy data end address (Y) is higher than the first dummy data end address

(X);

(d) defining a file system with a first storage space (A-C) having the first start address (A) and the first information end address (C) and a second storage space (B-D) having the second start address (B) and the second information end address (D); and (e) closing the record medium.

6. Writing apparatus (33) for writing information to a record medium (32), the writing apparatus (33) being designed for executing the method of any of the claims 1-3 or 5.

7. Writing apparatus (33) according to claim 6, wherein the record medium (32) is an optical disc.

8. Writing apparatus (33) according to claim 6, wherein the record medium (32) is a DVD+R disc.

9. CLOSE command (CQ) for a writing apparatus (33) according to claim 6, the CLOSE command comprising a QUICKLY parameter.

10. Writing apparatus (33) according to claim 6, adapted to receive the CLOSE command

(CQ) according to claim 9; the writing apparatus (33) being designed to evaluate the QUICKLY parameter and, in response to finding that the QUICKLY parameter has a certain predetermined value, to execute the method of claim 5.

11. Host apparatus (34) suitable for cooperating with the writing apparatus (33) according to claim 10; the host apparatus (34) being designed to send the CLOSE command (CQ) according to claim

9 with the QUICKLY parameter set at said predetermined value.