JP4145853B2 - Method, program, and computer-readable recording medium for determining whether recording medium is original medium or duplicate medium - Google Patents

Description

  In the present invention, recording media such as CD-R discs, CD-RW discs, DVD-R discs, DVD-RW discs, DVD + R discs, DVD + RW discs, DVD-RAM discs and the like on which various data are recorded are legitimately created. A method for determining whether the recording medium for determining whether the original medium or the illegally created duplicate medium is an original medium or a duplicate medium, a program that is a procedure for causing a computer to execute the process of the method, and The present invention relates to a computer-readable recording medium on which a program is recorded.

Due to the recent increase in data amount, in the infrastructure of personal computers, it is a recording medium such as CD-R disc, CD-RW disc, DVD-R disc, DVD-RW disc, DVD + R disc, DVD + RW disc, DVD-RAM disc, etc. An optical drive capable of recording and reproducing a large amount of data (information) at high density and high speed on an optical disc has become a standard equipment and has become widespread.
Accordingly, it has become common to distribute or sell large-capacity data such as application software, music data, and image data (still image data, moving image data) on the optical disc as described above.

The optical disk as described above is manufactured by first producing a stamper through the steps of applying a photoresist material to a glass master, laser exposure, development, and electroforming, and using the stamper to form a molded substrate such as polycarbonate by a general method. Transcript.
Furthermore, a data structure is recorded in which digital data is recorded along with time information (physical address: header address) as pits by laminating a reflective layer and a protective layer on the molded substrate. A desired optical disk for reproducing data based on the time information thus obtained is obtained.
For example, a CD-ROM disc, which is a read-only optical information recording medium, records a logical address called a logical block number (LBN) in addition to a physical address, and reproduces data mainly based on the LBN. .

In contrast, CD-R (CD-Recordable) discs and CD-RW (CD-Rewriteable) disc recording optical recording media, which are writable optical information recording media, are also widely used.
The recording optical recording medium has a groove (guide groove) in which time information is recorded on the entire surface, and a recording layer (an organic dye or the like is used for a CD-R disc) on a molded substrate on which the groove is formed. In a CD-RW disc, it is an inorganic phase change film), and a reflection layer and a protective layer are laminated to write pits with a CD-R / RW recording device so as to match the recorded time information. An optical recording medium having a structure for recording information and data can be obtained.
In the CD-R disc and CD-RW disc after data recording, data is reproduced based on time information recorded in the pits in a reproducing apparatus such as a CD player or a CD-ROM drive.

In the recording optical recording medium as described above, data is recorded in different formats depending on the application. For example, in the case of a music CD, data is recorded in the CD format and in the ISO 9660 format for data storage.
Normally, when data is additionally written in the ISO9660 format, it is added in units of sessions, and an optical disc having a plurality of sessions is called a multi-session disc.
FIG. 7 is an explanatory diagram showing the multi-session disc format of the optical disc.
As shown in FIG. 7, since the session is composed of a program area (PA) sandwiched between a lead-in area (LIA) and a lead-out area (LOA), even when a file with a small data capacity is additionally written, the session is read. In area and lead out area must be recorded. Therefore, overhead has occurred.
As a format for eliminating the overhead, there is a format format called Universal Disk Format (Universal Disc Format: UDF) that allows random access.

FIG. 8 is an explanatory diagram showing the universal disk format of the optical disk.
As shown in FIG. 8, in UDF, data is additionally recorded in packet units of about 64 Kbytes (32 blocks), and an optical disk such as a CD-RW disk recorded in this format is a CD as well as an ISO9660 format medium. -It can be played back by a playback device such as a ROM drive.
In the data recording in the above packet unit, the positional deviation in the track direction at the writing start position at the time of additional writing, that is, the time information (physical address) engraved in the groove and the time information (logical address) recorded in the pit In order to prevent data destruction caused by overlap or separation caused by deviation, a link portion as shown in FIG. For example, in a CD-R disc and a CD-RW disc, data is additionally written across a link portion of 7 blocks, and the data is read with the link portion omitted during reproduction.

There are two types of data recording methods in packet units: fixed-length packets that are recorded for each fixed-length packet and variable packets that are recorded with different packet lengths depending on the data size. Then, a link part is added for every packet.
Since no logical address is assigned to the link part, the logical address and the physical address are shifted at a constant rate.
For example, in the case of a CD-RW disc, since a link portion of 7 blocks is formed for every 32 blocks (64 Kbytes) of one packet, all data to be recorded is divided and recorded for every 32 blocks.
In addition, some of the optical disks as described above have a data structure in which prepits are formed for reproduction only. CD-R disks, CD-RW disks, and the like having such a data structure are hybrid disks (for example, , Refer to Patent Document 1).
JP 2000-99338 A

In the above-described recording medium, a backup method is widely used to store contents such as applications and data, or to use them as an individual. Even if the recorded part is damaged, it is possible to easily reproduce the same content as the source contained in the source by playing back the recording medium that backed up the content, or to select all the content in the source recording medium. It is possible to extract and edit / save only the contents that the individual needs, and to efficiently use and manage the information.
However, the conventional recording medium has the above-mentioned advantages, but there is a problem that data with copyright set by unauthorized copying is illegally used.
The present invention has been made in view of the above points, and an object thereof is to easily determine whether a recording medium is a legitimately created original medium or an illegally created duplicate medium.

In order to achieve the above object, the present invention provides a method for determining whether the following recording media (1) to (7) are original media or duplicate media.
(1) A physical address acquisition step for acquiring the end physical address of the end fixed length packet of the recording medium on which a plurality of fixed length packets are recorded, and the end fixed length based on the physical address acquired by the physical address acquisition step A logical address calculating step for calculating a logical address of the packet, a logical address acquiring step for acquiring the logical address of the fixed-length packet from the recording medium, a logical address calculated by the logical address calculating step, and the logical address acquiring step A determination step for determining whether or not the logical address acquired by the above-mentioned recording address matches, and when it is determined by the determination step that the logical address does not match, the recording medium is determined to be an original medium and is determined to match In addition, the recording medium is an original medium that is determined to be a duplicate medium. Recording medium comprising a manufacturing medium determining step process determines whether the original medium or replication medium.

(2) A physical address acquisition step for acquiring a physical address at the end of the last session of a recording medium on which a plurality of sessions are recorded, and all sessions on the recording medium based on the physical address acquired by the physical address acquisition step A logical address calculating step for calculating a logical address at the end of the last session when it is assumed that the packet is composed of fixed-length packets; and a logical address acquiring step for acquiring a logical address at the end of the last session from the recording medium. A determination step for determining whether the logical address calculated by the logical address calculation step and the logical address acquired by the logical address acquisition step match, and the determination step determines that the logical addresses do not match It is determined that the recording medium is an original medium, and Then the recording medium is how recording medium determines whether the original medium or replication medium consisting of the original medium-replication medium determining step of determining that the replication medium when it is determined.

(3) A physical address acquisition step for acquiring a physical address at the end of the last session of a recording medium on which a plurality of sessions are recorded, and all sessions on the recording medium based on the physical address acquired by the physical address acquisition step A logical address calculating step for calculating a logical address at the end of the last session when it is assumed that the packet is composed of fixed-length packets; and a logical address acquiring step for acquiring a logical address at the end of the last session from the recording medium. And an address difference calculation step for calculating an address difference between the logical address calculated by the logical address calculation step and the logical address acquired by the logical address acquisition step, and an address difference calculated by the address difference calculation step is preset. When the recording medium is less than the predetermined value, A method for determining whether a recording medium is an original medium or a duplicate medium, comprising: an original medium / duplicate medium judgment step for judging that the recording medium is a duplicate medium when the predetermined value is reached .

(4) In the method for determining whether the recording medium of any one of (1) to (3) is an original medium or a duplicate medium, the original medium / duplicate medium determination step determines that the recording medium is a duplicate medium. In this case, a method of determining whether the recording medium provided with a reproduction prohibiting step for prohibiting reproduction of data recorded on the recording medium is an original medium or a duplicate medium.
(5) In the method for determining whether the recording medium of (3) or (4) is an original medium or a duplicate medium, the other sessions excluding the first session among the plurality of sessions of the recording medium are configured by fixed-length packets. A method for determining whether a recording medium is an original medium or a duplicate medium.
(6) In the method for determining whether the recording medium of (3) or (4) is an original medium or a duplicate medium, the other sessions excluding the first session among the plurality of sessions of the recording medium are configured with fixed-length packets. A method for determining whether a recording medium in which a session exists is an original medium or a duplicate medium.
(7) In the method of determining whether the recording medium of (3) or (4) is an original medium or a duplicate medium, a recording medium in which a first session is composed of fixed-length packets among a plurality of sessions of the recording medium. A method for determining whether an original medium or a duplicate medium.

Also provided is a method for determining whether the following recording media (8) to (14) are original media or duplicate media.
(8) A physical address acquisition procedure for acquiring a physical address at the end of a tail fixed-length packet of a recording medium on which a plurality of fixed-length packets are recorded in a computer, and the above-described physical address acquisition procedure based on the physical address acquired by the physical address acquisition procedure Logical address calculation procedure for calculating the logical address of the fixed end packet, logical address acquisition procedure for acquiring the logical address of the fixed fixed packet from the recording medium, logical address calculated by the logical address calculation procedure and the logical address A determination procedure for determining whether or not the logical address acquired by the address acquisition procedure matches, and a determination that the logical address does not match by the determination procedure determines that the recording medium is an original medium and When the determination is made, it is determined that the recording medium is a duplicate medium Original casing medium-replication medium determining procedure program for executing.

(9) A physical address acquisition procedure for acquiring a physical address at the end of the last session of a recording medium on which a plurality of sessions are recorded in a computer, and the recording medium on the recording medium based on the physical address acquired by the physical address acquisition procedure Logical address calculation procedure for calculating the logical address at the end of the end session when it is assumed that all sessions are composed of fixed-length packets, and the logic for acquiring the logical address at the end of the end session from the recording medium An address acquisition procedure, a determination procedure for determining whether or not the logical address calculated by the logical address calculation procedure matches the logical address acquired by the logical address acquisition procedure, and the logical address does not match by the determination procedure When judged, the recording medium is the original medium. That the determination, the program for the recording medium to execute the original medium-replication medium determining step determines that a copy medium when it is determined that the matching.

(10) A physical address acquisition procedure for acquiring a physical address at the end of the last session of a recording medium on which a plurality of sessions are recorded in a computer, and the recording medium on the recording medium based on the physical address acquired by the physical address acquisition procedure Logical address calculation procedure for calculating the logical address at the end of the end session when it is assumed that all sessions are composed of fixed-length packets, and the logic for acquiring the logical address at the end of the end session from the recording medium An address acquisition procedure, an address difference calculation procedure for calculating an address difference between a logical address calculated by the logical address calculation procedure and a logical address acquired by the logical address acquisition procedure, and an address difference calculated by the address difference calculation procedure When the value is less than the preset value Recording medium is determined to be the original medium, the program for the recording medium to execute the original medium-replication medium determining step determines that a copy medium upon reaching the predetermined value.

(11) In the program of any one of (9) to (10), when the recording medium is determined to be a replication medium by the original medium / replication medium determination procedure, the data recorded on the recording medium is reproduced. A program with a playback prohibition procedure that prohibits playback.
(12) The program according to (9) or (10), wherein a session other than the first session among the plurality of sessions of the recording medium is configured with a fixed-length packet.
(13) The program according to (9) or (10), wherein a session composed of fixed-length packets exists in other sessions excluding the top session among the plurality of sessions on the recording medium.
(14) The program according to (9) or (10), wherein the first session among the plurality of sessions of the recording medium is composed of fixed-length packets.

Furthermore, the following computer-readable recording media (15) to (22) are also provided.
(15) A computer-readable recording medium on which the program according to any one of (9) to (14) is recorded.
(16) A computer-readable recording medium comprising only a reproduction-only area and recording the program according to any one of (9) to (14) in the reproduction-only area.
(17) A computer-readable recording medium comprising a recordable area and a reproduction-only area, and recording the program according to any one of (9) to (14) in the reproduction-only area.
(18) A computer-readable recording medium comprising only a recordable area and having recorded the program according to any one of (9) to (14) in the recordable area.
(19) A program that includes a recordable area and a reproduction-only area, and causes the computer to execute a procedure for recording information in the recordable area, and any one of (9) to (14) A computer-readable recording medium that records such a program.

(20) A program that includes a recordable area and a reproduction-only area, and that causes the computer to execute a procedure for recording a session composed of fixed-length packets in the recordable area; A computer-readable recording medium recording the program according to any one of (1) to (14).
(21) A session composed of a recordable area and a reproduction-only area, and if the reproduction-only area is not composed of fixed-length packets in the computer, a session composed of fixed-length packets in the recordable area And a computer-readable recording medium recording the program according to any one of (9) to (14).
(22) A recordable area and a reproduction-only area, and in the reproduction-only area, if the reproduction-only area is composed of fixed-length packets in the computer, a session not composed of fixed-length packets is added to the recordable area. A computer-readable recording medium on which a program for executing a recording procedure and any one of the programs (9) to (14) are recorded.

  The method for determining whether a recording medium according to the present invention is an original medium or a duplication medium can easily determine whether the recording medium is a legitimately created original medium or an illegally created duplication medium. Further, the program according to the present invention can cause a computer to execute the procedure for making the above-described determination. Furthermore, the computer-readable recording medium according to the present invention can install a program for performing the above-described determination in a computer and introduce a function for performing the above-described determination into the computer.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an information recording / reproducing apparatus that executes a method for determining whether a recording medium is an original medium or a duplicate medium according to an embodiment of the present invention.
This information recording / reproducing apparatus is a CD-R that reads and writes information from and on an optical disc 1 that is a writable recording medium such as a CD-R disc, a CD-RW disc, a DVD + RW disc, a DVD-RW disc, and a DVD-RAM disc. It is an optical disk device such as a drive, a CD-RW drive, a DVD + RW drive, a DVD-RW drive, or a DVD-RAM drive.
The optical disc 1 is a writable recording medium such as a CD-R disc, a CD-RW disc, a DVD + RW disc, a DVD-RW disc, or a DVD-RAM disc.

The spindle motor (motor) 2 is a motor that rotates the optical disc 1 at a predetermined rotational speed during data recording and data reproduction.
The rotation control unit 3 performs rotation control of the motor 2.
The optical pickup 4 is a device that emits and emits a laser beam L with a predetermined recording power when data is recorded on the optical disc 1 and data recorded on the optical disc 1 is reproduced.
The actuator control unit 5 performs control to move the optical pickup 4 when focusing and tracking the optical disk 1.
The signal control unit 6 controls the reproduction signal output from the optical pickup 4 and the recording signal output to the optical pickup 4.

The drive controller 7 is realized by a microcomputer including a CPU, a ROM, a RAM, and the like, and controls the entire information recording / reproducing apparatus, and also controls a method for determining whether the recording medium according to the present invention is an original medium or a duplicate medium. Processing is also executed.
The buffer 8 is a memory used by the drive controller 7 as a temporary storage area for storing data.
The laser drive circuit 9 drives the emission of the laser light L from the optical pickup 4.
The external interface 10 is used for transmitting / receiving commands, data, and the like to / from the host device 11.
The host apparatus 11 is a host computer such as a personal computer that controls the information recording / reproducing apparatus.

[Example 1]
A first embodiment of processing for determining whether the optical disc 1 in the information recording / reproducing apparatus shown in FIG. 1 is an original medium or a duplicate medium will be described.
In the first embodiment, the program according to claims 8 and 11 of the present invention is stored in the ROM of the drive controller 7, and the recording medium according to claims 1 and 4 of the present invention is executed by the CPU executing the program. A process of a method for determining whether the medium is an original medium or a duplicate medium is executed.

Next, processing for determining whether the optical disk 1 of the first embodiment is an original medium or a duplicate medium by the drive controller 7 will be described.
The drive controller 7 acquires a physical address at the end of a fixed-length packet (tail fixed-length packet) recorded at the end from the optical disc 1 on which a plurality of fixed-length packets are recorded, and based on the acquired physical address To calculate the logical address of the last fixed-length packet. Also, the logical address of the tail fixed length packet is obtained from the optical disc 1.
Further, it is determined whether or not the calculated logical address matches the acquired logical address. When it is determined that the two logical addresses do not match, it is determined that the optical disc 1 is an original medium. When it is determined that they match, it is determined that the optical disc 1 is a duplicate medium.

  If it is determined in the above determination that the optical disc 1 is a duplicate medium, reproduction of application software, music data, and image data (still image data and moving image data) recorded on the optical disc 1 is prohibited. In addition, it is important that the information such as software and data recorded on the optical disc includes a program for continuously operating when the optical disc is determined as the original medium.

Next, a process for determining whether the optical disc 1 is an original medium or a duplicate medium will be described.
FIG. 2 is an explanatory diagram showing the relationship between the logical address and the physical address of each packet of an optical disc on which a plurality of fixed-length packets are recorded.
In the original medium, tracks in the UDF format are recorded as fixed-length packets. A link portion is added as a joint between each fixed-length packet.
For example, in the case of a fixed-length packet unit of 64 Kbytes (32 blocks), a link portion of 7 frames is continuously generated every 39 frames (= 32 packets + 7 links) of the physical address. Since the logical address of the link portion cannot be read, in the case of the original medium, the relationship between the physical address and the logical address of the fixed-length packet changes as shown by a line L1 in FIG. That is, assuming that all sessions are recorded in the FP format, a logical address can be obtained based on the line L1.

  Therefore, in a session where data is recorded in fixed-length packets, a certain amount of deviation occurs between the physical address and the logical address (d1, d2, d3 in FIG. 2), and the logical address acquired from the optical disk and the acquired from the optical disk. Unlike the logical address calculated based on the physical address, it does not match.

On the other hand, for example, when data of an original medium is duplicated on an optical disk using a recording device such as a CD-R / RW drive using the original medium as a source, for example, the entire surface is recorded once (disc at once: DAO). Since the link portion is not inserted into the optical disc as the replication medium, the relationship between the physical address and the logical address of the fixed-length packet changes linearly as indicated by a line L2 in FIG.
Therefore, the logical address acquired from the optical disc matches the logical address calculated based on the physical address acquired from the optical disc.
Thus, when the calculated logical address does not match the acquired logical address, it can be determined that the optical disc 1 is an original medium, and when it matches, it can be determined that the optical disc 1 is a duplicate medium.

In this way, since it is possible to easily determine whether the optical disc is a legitimately created original medium or an illegally created duplicate medium, it is possible to prevent the illegally copied optical disc from being used.
Also, when it is determined that the optical disc is a copy medium, the execution of software programs recorded on the optical disc and the reproduction of data are prohibited, thus preventing unauthorized use of copyrighted programs and data. It is possible.

[Example 2]
A second embodiment of the process of determining whether the recording medium in the information recording / reproducing apparatus shown in FIG. 1 is an original medium or a duplicate medium will be described.
In the second embodiment, the program according to claims 9 and 11 of the present invention is stored in the ROM of the drive controller 7, and the recording medium according to claims 2 and 4 of the present invention is executed by the CPU executing the program. A process of a method for determining whether the medium is an original medium or a duplicate medium is executed.

Next, processing for determining whether the optical disk 1 of the second embodiment is an original medium or a duplicate medium by the drive controller 7 will be described.
FIG. 3 is a flowchart of processing for determining whether the optical disk 1 is an original medium or a duplicate medium by the drive controller 7.
When the optical disk 1 is inserted into the information recording / reproducing apparatus, the drive controller 7 acquires the physical address of the end of the first session in step (indicated by “S” in the figure) 1, and the acquired physical address in step 2. Thus, the logical address when it is assumed that the first session is recorded in the fixed-length packet (FP) format is calculated, and the calculated logical address and the logic of the actual first session end point obtained from the optical disc are calculated. Compare the address.
In step 3, it is determined whether or not the calculated logical address matches the acquired logical address. If they match, it is determined in step 4 that the first session is recorded in the FP format, and the process proceeds to step 5. If they do not match, it is determined in step 12 that the first session is not recorded in the FP format, and the process proceeds to step 13.

  In step 5, the physical address of the last session end point (end of the last fixed length packet of the last session) is obtained from the optical disc, and all sessions on the optical disc are recorded in FP format from the obtained physical address in step 6. The logical address of the end of the last session is calculated, and the logical address of the end of the last session is obtained from the optical disc. The calculated logical address and the actual end of the last session obtained from the optical disc are calculated. Compare with logical address.

In step 7, it is determined whether or not the calculated logical address matches the acquired logical address. If they match, the logical address shift amount is the maximum. If it is determined that the data is recorded in the FP format, it is determined in step 9 that the optical disk is a duplicate medium, and this process is terminated.
If it is determined in step 7 that the calculated logical address does not match the acquired logical address, a part of all sessions is recorded in FP format in step 10 (for example, recorded in FP format). In other words, it is determined that the optical disk is an original medium in step 11 and the process is terminated.

  On the other hand, in step 13, the final session end physical address is acquired from the optical disc, and in step 14, it is assumed that all sessions on the optical disc are not recorded in the FP format from the acquired physical address. The logical address of the end location is calculated, the logical address of the final session end location is acquired from the optical disc, and the calculated logical address is compared with the logical address of the actual final session end location acquired from the optical disc.

In step 15, it is determined whether or not the calculated logical address matches the acquired logical address. If they match, there is no logical address shift. In step 16, all sessions on the optical disc are recorded in the FP format. It is determined that it is not recorded (for example, the case where it is recorded in the DAO format), and it is determined in step 17 that the optical disk is a duplicate medium, and this process is terminated.
If it is determined in step 15 that the calculated logical address does not match the acquired logical address, a part of all sessions is recorded in FP format in step 10 (for example, recorded in FP format). In other words, it is determined that the optical disk is an original medium in step 11 and the process is terminated.

Example 3
A third embodiment of the process for determining whether the recording medium in the information recording / reproducing apparatus shown in FIG. 1 is an original medium or a duplicate medium will be described.
In the third embodiment, the program according to the tenth and eleventh aspects of the present invention is stored in the ROM of the drive controller 7, and the CPU executes the program, whereby the recording medium according to the third and fourth aspects of the present invention is stored. A process of a method for determining whether the medium is an original medium or a duplicate medium is executed.

Next, processing for determining whether the optical disk 1 of the third embodiment is an original medium or a duplicate medium by the drive controller 7 will be described.
The drive controller 7 obtains the physical address of the last session end point (end of the tail fixed-length packet of the tail session) of the optical disc 1 on which a plurality of sessions are recorded, and on the optical disc 1 based on the obtained physical address. When it is assumed that all sessions are composed of fixed-length packets, the logical address at the end of the last session is calculated. Also, the logical address of the last session end point is obtained from the optical disc 1. Further, an address difference between the calculated logical address and the acquired logical address is calculated, and when the calculated address difference is less than a predetermined value set in advance, the optical disc 1 is determined to be an original medium, and the predetermined value is determined. Is reached, it is determined that the optical disc 1 is a duplicate medium.

For example, the amount of deviation between a physical address and a logical address generated by a link portion inserted between fixed-length packets configured after the second session is less than the amount of deviation (the above predetermined value) in a normal UDF format optical disc. Sometimes it can be determined that the optical disc is the original medium.
Also, when the deviation amount is “0” (when all sessions do not include FP format data recording) and when the deviation amount is the maximum value (when all sessions are FP format data recording). ) Can be determined that the optical disc is a duplicate medium.
If it is determined in the above determination that the optical disc 1 is a duplicate medium, reproduction of application software, music data, and image data (still image data and moving image data) recorded on the optical disc 1 is prohibited. In addition, it is important that the information such as software and data recorded on the optical disc includes a program for continuously operating when the optical disc is determined as the original medium.

Next, a process for determining whether the optical disc 1 is an original medium or a duplicate medium will be described.
FIG. 4 is another explanatory diagram showing the relationship between the logical address and the physical address of each packet of an optical disc on which a plurality of fixed-length packets are recorded.
For example, when data of an original medium is duplicated on an optical disc using a recording device such as a CD-R / RW drive using the original medium as a source, for example, if the whole surface is recorded once (disc at once: DAO), the duplication is performed. Since no link portion is inserted in the medium optical disk, the relationship between the physical address and the logical address of the fixed-length packet changes linearly as shown by a line L3 in FIG.

Therefore, the logical address acquired from the optical disc matches the logical address calculated based on the physical address acquired from the optical disc.
Thus, when the calculated logical address does not match the acquired logical address, it can be determined that the optical disc 1 is an original medium, and when it matches, it can be determined that the optical disc 1 is a duplicate medium.

On the other hand, as shown by the line L4 in FIG. 4, when data is copied in the normal UDF format, data is recorded in units of fixed-length packets, there are tracks recorded in fixed-length packets, physical addresses and logical addresses. Therefore, the above-described determination process alone is not sufficient because it may be determined as an original medium. Here, if it is assumed that all sessions are recorded in the FP format, a logical address can be obtained based on the line L4.
However, since the copy source optical disk used as the source includes an ISO9660 format that does not include a link part, or a session recorded by a variable packet in which a logical address is also assigned to the link part. There is no discrepancy between the physical address and the logical address in the session. That is, for each session, since a logical address changes linearly with respect to a physical address in a session (for example, TAO format) that is not configured in the FP format, the address does not shift. On the other hand, if the entire recording area of the optical disc includes a session recorded in the FP format, the address is always shifted after that session. Therefore, the FP format session need not be the final session.

On the other hand, in the UDF format type optical disk replicated in a fixed-length packet, information on a session part that does not include a link part in the original medium is also recorded in a fixed-length packet, resulting in a link part.
That is, an optical disk copied in the normal UDF format has a larger amount of deviation between the physical address and the logical address than the original medium indicated by the line L5 in FIG.

Further, in a recording device such as a CD-R / RW drive and a recording means existing on a personal computer, an ISO9660 format format in which a link portion is not included in one optical disk as in an original medium, or a logical address is also provided in the link portion. It is too complicated to mix recording with variable packets allocated and recording with fixed-length packets.
Therefore, the deviation amount between the physical address and the logical address of the optical disk generated by the link portion inserted between the fixed-length packets configured after the second session is the deviation amount in the normal UDF format optical disc (the above-mentioned predetermined amount). ), It can be determined that the optical disc is the original medium, and illegal copying of the optical disc can be better prevented.

Next, the configuration of the session formed on the optical disc 1 will be described.
FIG. 5 is an explanatory diagram showing an example of the configuration of a session formed on the optical disc 1.
As an example, the following four types are shown in the optical recording medium in which data is recorded up to the second session by the multi-session method.
First session end physical address = 04: 21: 39
Second session end physical address = 06: 52: 34
(A) of the figure shows a format in which both the first session and the second session are recorded in the TAO (track at once) format, and the first session end logical address = 19464 (04:19:39 equivalent) ), Second session end logical address = 30784 (equivalent to 06:50:34).

(B) of the figure shows a format in which the first session is recorded in the TAO format and the second session is recorded in the FP format. The first session end logical address = 19464 (equivalent to 04:19:39), The second session end logical address = 28754 (equivalent to 06:23:29).
(C) of the figure shows a format in which the first session is recorded in the FP format and the second session is recorded in the TAO format. The first session end logical address = 15971 (corresponding to 03:32:71), The second session end logical address = 27291 (equivalent to 06:03:66).
(D) of the figure shows a format in which both the first session and the second session are recorded in the FP format, and the first session end logical address = 15971 (equivalent to 03:32:71), the second session. End logical address = 25261 (equivalent to 05:36:61).
The logical address in the figure is “0” when the physical address is 00:02:00.

In the case of the format shown in FIG. 5A, since both the first session and the second session are recorded in the TAO format, no link portion is generated during both sessions.
Therefore, the logical address increases linearly with the physical address, and no deviation occurs from the start of the logical address to the end of the second session.
Further, in the case of the format shown in FIG. 5B, since the first session is TAO format recording and there is no link portion, there is no deviation from the start of the logical address until the end of the first session. However, since the second session is an FP format record, a link portion is generated after the fixed-length packet. A logical address is not given to the link part, and the logical address is shifted by 7 blocks per link part. Accordingly, the logical address at the end of the second session is equal to the number of link parts of the second session ((30784-28754) / 7 = 290 as compared with the case of the format shown in FIG. Min)) shift to the smaller one.

In the case of the format shown in FIG. 5C, since the first session is FP format recording, a link portion exists after the fixed-length packet. A logical address is not given to the link part, and the logical address is shifted by 7 blocks per link part. Therefore, the logical address at the end of the first session is equal to the number of link parts of the first session ((19464-15971) / 7 = 499) as compared with the case of the format shown in FIG. Just shift to the smaller one. Since the second session is a TAO format record, the logical address after the start of the second session increases linearly with the physical address. Accordingly, even in the overall configuration, the logical address is shifted to a smaller one by the number of link portions of the first session.
In the case of the format shown in FIG. 6D, since both the first session and the second session are recorded in the FP format, a link portion exists in both sessions. The amount of deviation of the logical address of the first session is equal to the case of the format shown in (c) of the figure, and the amount of deviation of the logical address of the second session is equal to the case of the format shown in (b) of the figure. Therefore, the logical addresses are shifted as many as the number of link portions of both sessions ((30784-25261) / 7 = 789) as the entire configuration. Therefore, since both sessions are FP format recording, the amount of logical address shift is maximized.

When data of an original medium is duplicated on an optical disk using a normal recording drive and recording software, if the entire surface is recorded by the DAO method, the link portion is not inserted into the duplication destination optical disk. That is, since the logical address continues to increase linearly with the physical address, the logical address does not shift, and the configuration of both logical addresses is the same as that of the format shown in FIG.
Further, when the FP method is used for duplication, since the entire surface is recorded in units of fixed-length packets, the logical address shift by the link portion continues to occur from the start to the end of the logical address.
That is, the amount of address shift is the maximum, and the configuration of the physical address and the logical address is the same as that in the format shown in FIG.

  Therefore, in the optical disc recorded in the multi-session format, when the first session is not configured in the FP format, that is, configured in the TAO format, the data recording after the second session is configured in the FP format. If at least one session exists, the amount of deviation of the logical address of the optical disc is not less than the value in the format shown in FIG. 5A and not more than the value in the format shown in FIG. Therefore, it can be distinguished from the original medium.

Similarly, when the first session is configured in the FP format, if there is at least one session configured in the TAO format as the information recording after the second session, the deviation amount of the logical address of the optical disc is Since it is not less than the value in the format shown in FIG. 5A and not more than the value in the format shown in FIG. 5D, it can be determined as the original medium.
In addition, in an optical disc recorded in a multi-session format, a session configured in the TAO format may be configured in a variable-length packet (VP) format. This is because, unlike the FP format, a logical address is given to the link portion generated in the VP format.

Next, the above optical disk may be a multi-session disk in which all other sessions (all sessions after the second session) except for the first session (first session) among a plurality of sessions are composed of fixed-length packets.
For example, the first session is recorded in ISO 9660 format not including a link part, or is recorded as a variable packet in which a logical address is also assigned to the link part, and the program according to the present invention is recorded in the first session, Software programs and data are recorded in fixed-length packets after the second session.
In this way, it is possible to record more important data on the optical disc in terms of the configuration of the original medium, and it is possible to manage data more efficiently. Further, since the optical disk is a hybrid disk, important data can be added later, so that the usability is improved.

Next, a multi-session in which at least one session composed of fixed-length packets exists in other sessions (all sessions after the second session) except for the first session (first session) among the plurality of sessions on the optical disc. It may be a disc.
In this way, not only when the optical disc is configured up to the second session, but also when there are a plurality of sessions after the second session, if at least one session is configured with fixed-length packets, There are places where there is a difference between the logical address calculated from the physical address and the actual logical address of the optical disc.
In other words, it is possible to detect that there is a difference between the logical address calculated from the physical address in the session and the actual logical address, and when the difference between the two logical addresses is detected, it can be determined that the original medium is used. It becomes.

Next, the optical disk may be a multi-session disk in which the first session (first session) of a plurality of sessions is composed of fixed-length packets.
In this case, even if the information recording after the second session is composed of an ISO9660 format without a link part or a variable packet to which a logical address is also assigned to the link part, the first session is a fixed-length packet in the entire optical disc. Due to the configuration, there is a difference between the logical address calculated from the physical address and the actual logical address. Therefore, it is possible to detect that there is a difference between the logical address calculated from the physical address in the session and the actual logical address, and to determine that it is the original medium when a difference between the two logical addresses is detected. Become.

  Next, if the program according to the eighth, eleventh, ninth, eleventh, tenth and eleventh aspects of the present invention is recorded on the optical disc 1 so as to be executed by the drive controller 7 when the disc is inserted, the optical disc 1 is recorded. It is possible to provide originality, and it is possible to guarantee the safety of the operation of the program recorded in the optical recording medium.

Further, the optical disk 1 may be limited to a read-only area (ROM area), and the programs according to claims 8 and 11, 9, 11, 10, and 11 of the present invention may be recorded in the ROM area. In this case, the program is formed as a pit row in the stamper manufacturing process, transferred to the stamper (mastering), and transferred to the molded substrate using the stamper as a mold.
In this way, since the reflective layer and the protective layer can be easily laminated on the molded substrate of the optical disc 1, it can be easily made into a disc, so that an original medium equipped with the program according to the present invention can be produced in large quantities and at low cost. It becomes possible, and it can contribute to the reduction of production cost.

Further, the optical disc 1 is composed of a read-only area (ROM area) and a recordable area, and the programs according to claims 8, 11, 9, 11, 10, and 11 of the present invention are recorded in the ROM area. It may be.
In this way, even if the software program or data to be recorded in the recordable area of the optical disc varies from user to user, the program according to the present invention is originally recorded in the ROM area. There is an advantage that versatility is improved over a wide range.

Further, the optical disk 1 may be limited to a recordable area, and the programs according to claims 8 and 11, 9 and 11, 10 and 11 of the present invention may be recorded in the recordable area.
In this way, for example, when recording a software program and data necessary for an optical disc composed of a recordable area such as a normal CD-R disc and a CD-RW disc, the optical disc having the normal recordable area is illegally copied. It can be converted into an original medium that is effective for prevention, and the originality and security can be maintained in the recorded data.

Further, the optical disk 1 is composed of a read-only area (ROM area) and a recordable area, and the ROM area includes a program according to claims 8 and 11, 9, 11, 10, and 11, and a drive controller. 7 may be recorded with a program for executing a procedure for recording data in the recordable area of the optical disc 1.
In this way, the drive controller 7 executes the program for executing the procedure for recording data in the recordable area of the optical disc 1 recorded in the ROM area, thereby recording the data in the recordable area of the optical disc 1, The recorded data can also have originality.

Further, the optical disk 1 is composed of a read-only area (ROM area) and a recordable area, and the ROM area includes a program according to claims 8 and 11, 9, 11, 10, and 11, and a drive controller. 7 may record a program for executing a procedure for recording a session composed of fixed-length packets in the recordable area of the optical disc 1.
In this way, a session in which a difference between the logical address calculated from the physical address and the actual logical address can be included in the recordable area.
That is, since it is possible to create a location in a single hybrid disk where a deviation occurs between the logical address calculated from the physical address and the actual logical address, it is discriminated from the original medium by executing the program according to the present invention recorded in the ROM area. It becomes possible to do.

Further, the optical disk 1 is composed of a recordable area and a reproduction-only area (ROM area), and the ROM area includes a program according to claims 8 and 11, 9, 11, 10, and 11, and a drive. When the ROM area is not composed of fixed-length packets, the controller 7 may record a program for executing a procedure for recording a session composed of fixed-length packets in the recordable area.
For example, if the data recording of the first session, which is the ROM area, is not configured with fixed-length packets, the data recording after the second session is recorded so that there is at least one session configured with fixed-length packets. .

In this way, the recordable area includes a session in which the logical address calculated from the physical address differs from the actual logical address, so that the entire optical disk has the logical address calculated from the physical address and the actual logical address. It can be mixed with sessions where there is no discrepancy in address.
That is, even if an optical disc is copied as a source, the amount of deviation between the logical address calculated from the physical address and the actual logical address is greater than or equal to the one-time recording (DAO) medium and less than or equal to the entire fixed-length packet recording. It becomes possible to prevent.

Furthermore, the optical disk 1 is composed of a recordable area and a reproduction-only area (ROM area), and the ROM area includes a program according to claims 8 and 11, 9 and 11, 10 and 11 of the present invention, When the ROM area is composed of fixed-length packets, the drive controller 7 may record a program for executing a procedure for recording a session not composed of fixed-length packets in the recordable area.
In this way, a session in which a difference between the logical address calculated from the physical address and the actual logical address is included in the recordable area by the track at once (TAO) method or the variable packet method.
Therefore, it is possible to mix the logical address calculated from the physical address with the session in which the actual logical address is shifted as the entire optical disk.
That is, as described above, even if the optical disk is copied as a source, the amount of deviation between the logical address calculated from the physical address and the actual logical address is not less than one-time recording (DAO) medium and not more than whole fixed-length packet recording. Unauthorized copying can be prevented.

FIG. 6 is a flowchart showing processing at the time of multi-session recording by the drive controller 7.
In this processing, the optical disc 1 is a hybrid disc in which a plurality of sessions are recorded and has both a ROM area and a recordable area, and at least a program according to the present invention is recorded in the ROM area. Further, recording information such as applications, contents, and data may be set in advance in the ROM area as necessary.
When the optical disk 1 is inserted into the information recording / reproducing apparatus and data is recorded in the recordable area of the optical disk 1, the drive controller 7 has already recorded from the optical disk to the ROM area in step 21 (indicated by “S” in the figure). Information on the number of existing sessions being acquired is acquired, and it is determined in step 22 whether or not the number of existing sessions in the ROM area is one.

If it is determined in step 22 that the number of existing sessions is one, the physical address of the end of the first session is acquired in step 23, and the first session is recorded in the fixed length packet (FP) format from the acquired physical address in step 24. Then, the logical address when it is assumed to be calculated is calculated, and the calculated logical address is compared with the logical address of the actual end of the first session acquired from the optical disc.
In step 25, it is determined whether or not the calculated logical address matches the acquired logical address. If they match, a logical address shift occurs in the first session in step 26, and the first session is in the FP format. The track-at-once (TAO) format is selected as the recording format when data is recorded in the recordable area after the second session. In step 27, the TAO format is selected after the second session. The data is recorded at, and this processing is terminated.

  On the other hand, if it is determined in step 25 that the calculated logical address does not match the acquired logical address, there is no logical address shift in the first session in step 28, and data in the first session is in TAO format. Is recorded, and the fixed-length packet (FP) format is selected as the recording format when data is recorded in the recordable area after the second session. In step 27, the FP format is selected after the second session. Data is recorded and this process is terminated.

If it is determined in step 22 that the number of existing sessions is not one, the number of existing sessions is two or more (plural) in step 29, and the physical address of the end of the last session is obtained from the optical disc. From the acquired physical address, calculate the logical address of the last session end when assuming that all sessions of the optical disc are recorded in the TAO format, obtain the logical address of the final session end from the optical disc, and The calculated logical address is compared with the logical address of the actual end of the last session acquired from the optical disc.
In step 31, it is determined whether the calculated logical address does not match the acquired logical address. If they match, there is no logical address shift. In step 28, all sessions existing in the ROM area of the optical disc Since it is determined that the data is not recorded in the FP format, the fixed length packet (FP) format is selected as the recording format when data is recorded in the recordable area, and in step 27, the data is recorded in the FP format in the recordable area. This process is terminated.

On the other hand, if it is determined in step 31 that the calculated logical address does not match the acquired logical address, there is a difference in the logical address, and all the optical discs on the optical disc are determined from the physical address of the end of the last session acquired from the optical disc in step 32. Calculates the logical address of the last session end when it is assumed that the session is recorded in the FP format, acquires the logical address of the final session end from the optical disc, and obtains the calculated logical address and the optical disc from the optical disc Compare the actual logical address of the last session end.
In step 33, it is determined whether or not the calculated logical address and the acquired logical address do not match. If they match, the logical address shift is the maximum value, and in step 26 all sessions existing in the ROM area of the optical disk are found. It is determined that the data is recorded in the FP format, the TAO format is selected as the recording format when data is recorded in the recordable area, the data is recorded in the TAO format in the recordable area in step 27, and the process is terminated. To do.

  If the calculated logical address does not match the acquired logical address in the determination in step 33, the logical address shift amount is less than the maximum value, and is recorded in the ROM area of the optical disc in the TAO format in step 34. And the session recorded in the FP format are mixed, and either the TAO format or the FP format is arbitrarily selected as the recording format when recording data in the recordable area (from the user) The recording format designated by the selection operation or a preset recording format is selected), and in step 27, data is recorded in the recordable area in the selected recording format, and this processing is terminated.

In the above-described processing, the case where the FP format and the TAO format are used as an example of the recording format has been described. However, a recording format for recording a session configured in the TAO format in the variable length packet (VP) format is used. Also good.
This is because, unlike the FP format, a logical address is given to the link portion generated by the recording in the VP format, so that no deviation occurs in the logical address.

  The method, program, and computer-readable recording medium for determining whether the recording medium according to the present invention is an original medium or a duplicate medium can be applied to a personal computer such as a desktop personal computer or a notebook personal computer.

It is a block diagram which shows the structure of the information recording / reproducing apparatus which performs the method of determining whether the recording medium which is one Embodiment of this invention is an original medium or a replication medium. It is explanatory drawing which shows the relationship between the logical address and physical address of each packet of the optical disk in which the several fixed length packet was recorded. FIG. 2 is a flowchart of processing for determining whether an optical disk 1 is an original medium or a duplicate medium by the drive controller 7 shown in FIG. It is another explanatory drawing which shows the relationship between the logical address and physical address of each packet of the optical disk in which the several fixed length packet was recorded.

FIG. 2 is an explanatory diagram illustrating an example of a configuration of a session formed on the optical disc 1 illustrated in FIG. 1. It is a flowchart figure which shows the process at the time of the multisession recording by the drive controller 7 shown in FIG. It is explanatory drawing which shows the multi session disc format of an optical disk. It is explanatory drawing which shows the universal disk format of an optical disk.

Explanation of symbols

1: Optical disk 2: Spindle motor 3: Rotation control unit 4: Optical pickup 5: Actuator control unit 6: Signal control unit 7: Drive controller 8: Buffer 9: Laser drive circuit 10: External interface 11: Host device

Claims (22)

  A physical address acquisition step of acquiring a physical address at the end of a tail fixed-length packet of a recording medium on which a plurality of fixed-length packets are recorded; and a logic of the tail fixed-length packet based on the physical address acquired by the physical address acquisition step A logical address calculation step for calculating an address; a logical address acquisition step for acquiring a logical address of the fixed-length packet from the recording medium; a logical address calculated by the logical address calculation step; and a logical address acquisition step acquired A determination step of determining whether or not the logical address matches; and when the determination step determines that the logical address does not match, the recording medium is determined to be an original medium; The original media / duplicate media format is judged to be duplicate media. How the recording medium determines whether the original medium or replication medium characterized by comprising a step.   A physical address acquisition step of acquiring the end physical address of the end session of the recording medium on which a plurality of sessions are recorded, and all sessions on the recording medium are fixed-length packets based on the physical address acquired by the physical address acquisition step A logical address calculating step for calculating a logical address at the end of the end session when it is assumed that the end address is configured, a logical address acquiring step for acquiring a logical address at the end of the end session from the recording medium, A determination step for determining whether or not the logical address calculated by the logical address calculation step matches the logical address acquired by the logical address acquisition step; and the recording when the logical address does not match by the determination step It is determined that the medium is the original medium and is matched. The recording medium is how recording medium determines whether the original medium or replication medium characterized by comprising the original medium-replication medium determining step of determining that the replication medium when.   A physical address acquisition step of acquiring the end physical address of the end session of the recording medium on which a plurality of sessions are recorded, and all sessions on the recording medium are fixed-length packets based on the physical address acquired by the physical address acquisition step A logical address calculating step for calculating a logical address at the end of the end session when it is assumed that the end address is configured, a logical address acquiring step for acquiring a logical address at the end of the end session from the recording medium, An address difference calculating step for calculating an address difference between the logical address calculated by the logical address calculating step and the logical address acquired by the logical address acquiring step; and the address difference calculated by the address difference calculating step is less than a predetermined value set in advance. When the recording medium is an original medium And determining whether the recording medium is an original medium or a duplicating medium, comprising: an original medium / duplicating medium judging step for judging that the recording medium is a duplicating medium when the predetermined value is reached. how to.   In the method for determining whether the recording medium according to any one of claims 1 to 3 is an original medium or a duplicate medium, and when the recording medium is determined to be a duplicate medium in the original medium / duplicate medium determination step. A method for determining whether a recording medium is an original medium or a duplication medium, comprising a reproduction prohibiting step for prohibiting reproduction of data recorded on the recording medium.   5. The method for determining whether the recording medium according to claim 3 or 4 is an original medium or a duplicate medium, wherein other sessions excluding the first session among the plurality of sessions of the recording medium are configured by fixed-length packets. To determine whether the recording medium is an original medium or a duplicate medium.   5. The method for determining whether a recording medium according to claim 3 or 4 is an original medium or a duplication medium, wherein a session composed of fixed-length packets exists in other sessions excluding the first session among a plurality of sessions of the recording medium. A method for determining whether a recording medium is an original medium or a duplicate medium.   5. The method of determining whether the recording medium according to claim 3 or 4 is an original medium or a duplication medium, wherein a head session is composed of fixed-length packets among a plurality of sessions of the recording medium. A method for determining whether an original medium or a duplicate medium.   A physical address acquisition procedure for acquiring a physical address at the end of the end fixed length packet of a recording medium on which a plurality of fixed length packets are recorded in a computer, and the end fixed length based on the physical address acquired by the physical address acquisition procedure A logical address calculation procedure for calculating a logical address of the packet; a logical address acquisition procedure for acquiring the logical address of the fixed-length packet from the recording medium; a logical address calculated by the logical address calculation procedure; and the logical address acquisition procedure A determination procedure for determining whether or not the logical address acquired by the above-mentioned logical address matches, and when it is determined by the determination procedure that the logical address does not match, the recording medium is determined to be an original medium, and is determined to match In addition, the original that determines that the recording medium is a duplication medium Program for executing a body-replicating medium determining step.   In the computer, a physical address acquisition procedure for acquiring a physical address at the end of the last session of a recording medium on which a plurality of sessions are recorded, and all sessions on the recording medium based on the physical address acquired by the physical address acquisition procedure Logical address calculation procedure for calculating a logical address at the end of the end session when it is assumed that the packet is composed of fixed-length packets, and a logical address acquisition procedure for acquiring a logical address at the end of the end session from the recording medium A determination procedure for determining whether or not the logical address calculated by the logical address calculation procedure matches the logical address acquired by the logical address acquisition procedure, and when the logical address is determined not to match by the determination procedure Determined that the recording medium is an original medium. The program for the recording medium to execute the original medium-replication medium determining step determines that a copy medium when it is determined that the matching.   In the computer, a physical address acquisition procedure for acquiring a physical address at the end of the last session of a recording medium on which a plurality of sessions are recorded, and all sessions on the recording medium based on the physical address acquired by the physical address acquisition procedure Logical address calculation procedure for calculating a logical address at the end of the end session when it is assumed that the packet is composed of fixed-length packets, and a logical address acquisition procedure for acquiring a logical address at the end of the end session from the recording medium The address difference calculation procedure for calculating the address difference between the logical address calculated by the logical address calculation procedure and the logical address acquired by the logical address acquisition procedure, and the address difference calculated by the address difference calculation procedure is preset. When the recording medium is less than a predetermined value, It determines that the original casing medium, a program for the recording medium to execute the original medium-replication medium determining step determines that a copy medium when it reaches a predetermined value.   11. The program according to claim 9, wherein reproduction of data recorded on the recording medium is prohibited when the original medium / replicating medium determination procedure determines that the recording medium is a replicating medium. A program with a playback prohibition procedure.   11. The program according to claim 9, wherein the other sessions excluding the first session among the plurality of sessions of the recording medium are configured with fixed-length packets.   The program according to claim 9 or 10, wherein a session composed of fixed-length packets exists in other sessions excluding the top session among the plurality of sessions of the recording medium.   11. The program according to claim 9 or 10, wherein the first session among a plurality of sessions on the recording medium is composed of fixed-length packets.   The computer-readable recording medium which recorded the program as described in any one of Claims 9 thru | or 14.   The computer-readable recording medium which consists only of reproduction | regeneration exclusive areas and recorded the program as described in any one of Claims 9 thru | or 14 in this reproduction | regeneration exclusive area | region.   15. A computer-readable recording medium comprising a recordable area and a reproduction-only area, wherein the program according to any one of claims 9 to 14 is recorded in the reproduction-only area.   The computer-readable recording medium which consists only of recordable area | regions, and recorded the program as described in any one of Claims 9 thru | or 14 in this recordable area | region.   The program according to any one of claims 9 to 14, comprising a recordable area and a reproduction-only area, and causing the computer to execute a procedure for causing the computer to record information in the recordable area. A computer-readable recording medium on which a program is recorded.   15. A program comprising: a recordable area and a reproduction-only area, and causing the computer to execute a procedure for recording a session composed of fixed-length packets in the recordable area in the reproduction-only area; A computer-readable recording medium on which the program according to any one of the above items is recorded.   A recordable area and a reproduction-only area, and if the reproduction-only area is not composed of fixed-length packets in the computer, a session composed of fixed-length packets is recorded in the recordable area. A computer-readable recording medium recording the program for executing the procedure and the program according to any one of claims 9 to 14.   A procedure comprising a recordable area and a reproduction-only area, and when the reproduction-only area is composed of fixed-length packets in the computer, a session not composed of fixed-length packets is recorded in the recordable area. A computer-readable recording medium storing the program for executing the program and the program according to any one of claims 9 to 14.

Images