JP2005044455A - Final session discrimination circuit and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time till the start of a reproduction processing by quickly completing the read of all TOCs in all the sessions. <P>SOLUTION: The final session determination circuit is provided with a TOC read means for the respective sessions in a CD of a multisession system, a data read means which reads the present session and reads the data of a place beyond the TOC of the next session with respect to the present session, and a final session determination means which determines whether the present session is the final session or not under the prescribed discrimination standards on the basis of information of the TOC read by the TOC read means and the contents of the data read by the data read means. Whether the final session or not can be discriminated under the prescribed discrimination standards and therefore the time before the discrimination of the final session can be made considerably shorter as compared with the case whether the final session or not is discriminated by a number of times of trials or time out like heretofore and in addition, the time from a reproduction instruction till the start of the reproduction processing can be considerably shortened. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a final session determination circuit and a playback device, and more particularly to a CD-R / RW playback device that plays back a recordable CD-R (Compact Disc-Recordable) or a CD-RW (Compact Disc-ReWritable). And suitable.

Conventionally, a CD has a single session composed of one session and a multi-session composed of a plurality of sessions of the write once recording type (hereinafter referred to as a multi-session CD). In the multi-session CD, the first session, The second session, the third session,... Can be sequentially increased within the range of the storage capacity (see, for example, Patent Document 1).
JP-A-7-326158

  Here, the session is a series of data (lead-in, actual data, lead-out) including a lead-in indicating the recording position of the actual data that is the content itself, a real data, and a lead-out indicating the recording end position.

  For example, CD-R and CD-RW exist as CDs recorded by the multi-session method, and according to a CD-R / RW playback apparatus that plays back these CD-Rs or CD-RWs, the CD-R / RW playback device starts from the first session. Can be played.

  By the way, in the CD-R / RW playback apparatus having such a configuration, when playing a multi-session CD, TOC (Table Of Contents) existing in the lead-in area of each session is sequentially read and stored in the multi-session CD. The contents relating to all the sessions are grasped, and then the reproduction process is started sequentially from the first session.

  However, in the multi-session CD, for example, when there is a first session to a third session, there is a possibility that the next fourth session may be additionally recorded if there is enough storage capacity after the third session.

  Therefore, if the CD has been finalized and information that “data is not recorded after the third session” is written, it can be determined that it is the final session, but additional recording is possible. If it is possible, since the information “data can be written to the next session” is written in the TOC of the third session, whether or not the data ends in the third session is actually It cannot be determined until the existence of the session is confirmed.

  That is, when the multi-session CD is in a recordable state, the CD-R / RW playback device searches for whether or not the fourth TOC corresponding to the next fourth session exists in the area immediately after the third session. Retry several times until the fourth TOC is found, or keep searching until time-out. If still not found, determine that the third session is the last session, and start the playback process from the first session to the third session It is made like that.

  Therefore, the CD-R / RW playback device keeps searching until the fourth TOC is found or timed out in order to determine whether or not the fourth TOC in the next fourth session exists after the third session. There is a problem that it takes a long time (for example, about 20 seconds) to start the reproduction process.

  The present invention has been made in consideration of the above points. A final session determination circuit capable of determining a final session for a multi-session CD in an additionally recordable state in a short time and shortening the time until the reproduction process is started, and The present invention intends to propose a playback device that is easy to use.

  In order to solve such a problem, in the present invention, the TOC reading means for reading the TOC of each session in a multi-session CD, the current session is read, and the location beyond the TOC of the next session with respect to the current session Whether or not the current session is the final session based on predetermined judgment criteria based on the data reading means for reading data, the TOC information read by the TOC reading means, and the contents of the data read by the data reading means And a final session determination means for determining

  As a result, it is possible to determine whether or not it is the last session based on a predetermined criterion. Thus, the time until the final session is determined can be significantly shortened.

  According to the present invention, in a playback apparatus for playing a multi-session CD, a TOC reading means for reading the TOC of each session in the multi-session CD, the current session is read, and the next session is read from the current session. Data reading means for reading out data at a location exceeding the TOC, the TOC information read by the TOC reading means, and the contents of the data read by the data reading means, based on the predetermined judgment criteria A final session determining means for determining whether the current session is a final session and a reproducing means for starting a reproduction process after the final session determining means has determined the final session are provided.

  As a result, it is possible to determine whether or not it is the last session based on a predetermined criterion. Thus, the time until the final session is determined can be remarkably shortened, and the time from the replay command to the start of replay processing can be remarkably shortened.

  Furthermore, in the present invention, a TOC reading step for reading the TOC of each session in a multi-session CD, and a data reading for reading the current session and reading data at a location beyond the TOC of the next session for the current session. A final session for determining whether or not the current session is the final session on the basis of a predetermined criterion based on the step, the TOC information read in the TOC read step, and the content of the data read in the data read step A determination step.

  As a result, it is possible to determine whether or not it is the last session based on a predetermined criterion. Thus, the time until the final session is determined can be significantly shortened.

  Furthermore, in the present invention, the TOC reading step for reading out the TOC of each session in the multi-session CD to the playback apparatus, and the location where the current session is read and the TOC of the next session is exceeded with respect to the current session. Whether or not the current session is the final session based on predetermined criteria based on the data read step for reading the data, the TOC information read in the TOC read step, and the contents of the data read in the data read step And a final session determination step for determining whether or not.

  As a result, it is possible to determine whether or not it is the last session based on a predetermined criterion. Thus, the time until the final session is determined can be significantly shortened.

  As described above, according to the present invention, it is possible to determine whether or not the session is the final session based on a predetermined determination criterion. It is possible to realize a final session determination circuit, a final session determination method, and a final session determination program that can significantly reduce the time until the final session is determined compared to the case of determining Thus, it is possible to realize a playback device with excellent usability that can shorten the time until the start of the playback.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(1) Circuit Configuration of CD-R / RW Playback Device In FIG. 1, 1 indicates a CD-R / RW playback device as a playback device of the present invention as a whole, and a CPU (Central Processing Unit) 2 performs overall control. At the same time, by starting a basic program or application program stored in a ROM (Read Only Memory) 2A on a RAM (Random Access Memory) 2B, a normal reproduction process and a final session determination process to be described later are executed. Has been made.

  In the normal playback mode, the CD-R / RW playback apparatus 1 rotates the multi-session CD 3 made of, for example, CD-RW at a predetermined rotational speed by the disk rotation motor 4 and controls it via the drive unit 6. Thus, the reproduction signal S1 read from the signal recording surface of the multi-session CD3 is sent to an RF (Radio Frequency) unit 7.

  The RF unit 7 binarizes the reproduction signal S1 to obtain reproduction data D2, and transmits this to a subsequent DSP (Digital Signal Processor) 8.

  The DSP 8 sends the attribute information D3 written in the TOC of the lead-in area of the reproduction data D2 to the CPU 2 and sends the audio data D4 of the reproduction data D2 to the digital / analog converter 9 in the subsequent stage.

  The digital-analog converter 9 converts the audio data D4 into an analog audio signal S5, and then outputs it through a speaker (not shown).

  The CPU 2 displays the song title, playback time, and the like on the display unit 10 based on the attribute information D3 supplied from the DSP 8. The CPU 2 gives various instructions for causing the DSP 8 to execute digital signal processing in accordance with an input operation from the user such as a reproduction instruction, a stop instruction, and a fast-forward instruction.

(2) Final Session Determination Processing Procedure Next, the final session determination processing procedure in the present invention will be described. By the way, in the final session determination processing procedure, when determining the final session of the multi-session CD3, it is determined whether each session from the first session to the final session is the final session.

  When determining whether or not it is the last session, the next session to be determined is recorded correctly (that is, the current session is not the last session but the next session is the last session). A first case (which may become a session), a second case in which no data is recorded and an unwritten state, and previous data remaining by overwriting are recorded (so-called logical erasure). There are a third case and a fourth case in which erasure data is written (so-called physical erasure). In the final session determination processing procedure, the first to fourth cases are determined, and the determination result is Accordingly, it is possible to determine whether or not it is the last session.

  As shown in FIG. 2, the CPU 2 of the CD-R / RW playback apparatus 1 is configured to execute a final session determination processing procedure according to a final session determination program that is one of application programs, and from the start step of the routine RT1. Enter and go to step SP1.

  In step SP1, when the CPU 2 recognizes the pressing operation of the playback button by the user, first, the CPU reads the first TOC (FIG. 3) of the first session in the multi-session CD3, and proceeds to the next step SP2.

  In step SP2, the CPU 2 determines whether or not there is a flag indicating that the next second session may exist in the attribute information of the first TOC.

  This flag can be set so that when a user records content in the multi-session CD3, the user still intends to record the content in the next session. On the other hand, when there is no intention to record content, that is, when finalizing, it is possible to prevent a flag from being set.

  If a negative result is obtained in step SP2, this indicates that the multi-session CD3 has been finalized by the user and there is no next session, and this first session is the last session. At this time, the CPU 2 Moves to step SP14.

  In step SP14, the CPU 2 determines that the first session is the final session, moves to the next step SP15, and ends the final session determination process. Thereafter, the CPU 2 immediately starts the reproduction process for the first session.

  On the other hand, if a positive result is obtained in step SP2, this indicates that there is a possibility that the next second session is recorded. At this time, the CPU 2 moves to the next step SP3.

  In step SP3, the CPU 2 causes the optical pickup 5 to access a location (actual data area) beyond the second TOC (FIG. 3) of the next second session, and proceeds to the next step SP4.

  In step SP4, the CPU 2 determines whether or not the data in the actual data area of the second session exceeding the second TOC can be read. If a negative result is obtained here, it can be determined that this is an unwritten state (second case) in which no data is recorded in the actual data area of the second session. Moves to the next step SP14.

  In step SP14, the CPU 2 can determine that the second session does not exist in this case, and the first session is the last session. After moving to the next step SP15 and ending the final session determination process, the CPU 2 immediately Playback processing is started for one session.

  On the other hand, if a positive result is obtained in step SP4, this indicates that some data is recorded in the actual data area of the second session, and at this time, the CPU 2 moves to the next step SP5.

  In step SP5, the CPU 2 reads information included in the Q channel of the subcode in the actual data area of the second session, and proceeds to the next step SP6. Here, information included in the Q channel of the subcode includes a track number, an index, a time code, address information, and the like.

  In step SP6, the CPU 2 determines whether or not the information included in the Q channel of the subcode is not actually meaningful data but meaningless erasure data is written. If an affirmative result is obtained here, this is a state in which meaningless erasure data such as “0” continues indefinitely is written in the Q channel of the subcode (the fourth case). At this time, the CPU 2 moves to step SP14.

  In step SP14, the CPU 2 can determine that the second session does not exist in this case as well, and the first session is the last session, and after moving to the next step SP15 and ending the last session determination process, Playback processing is started for one session.

  On the other hand, if a negative result is obtained in step SP6, this means that some meaningful data is actually written in the Q channel of the subcode. At this time, the CPU 2 proceeds to the next step SP7. Move.

  In step SP7, the CPU 2 recognizes the track number in the information included in the Q channel of the subcode, and determines whether or not the track number is consistent with the track number of the first session.

  If a negative result is obtained here, for example, when the last track number of the first session is “3”, the track number included in the Q channel of the subcode is “1”, for example. This indicates that a contradiction has occurred, such as being “2” or not being larger than “3”. At this time, the CPU 2 proceeds to step SP14.

  In step SP14, the CPU 2 is in a state (third case) in which the previous data remaining by overwriting by so-called logical erasure is recorded because the track number included in the Q channel of the subcode is inconsistent. Actually, it can be determined that the first session is the last session, and after proceeding to the next step SP15 and ending the final session determination process, the reproduction process is immediately started for the first session.

  On the other hand, if a positive result is obtained in step SP7, this means that, for example, when the last track number of the first session is “3”, the track number included in the Q channel of the subcode is, for example, This indicates that the track number is larger than “3”, that is, there is no contradiction in the track number included in the Q channel of the subcode. At this time, the CPU 2 proceeds to the next step SP8. Move.

  In step SP8, the CPU 2 recognizes the elapsed time of the track at that time based on the time code included in the Q channel of the subcode, and drives the optical pickup 5 to the head position of the track according to the elapsed time. It moves by the part 6, and moves to the following step SP9.

  In step SP9, the CPU 2 determines whether or not the optical pickup 5 has been accurately moved to the head position of the track. If a negative result is obtained here, this means that the optical pickup 5 cannot be accurately moved to the head position of the track even though it has been returned by the elapsed time, that is, there is no coincidence about the track number. However, the data recorded in the second session is in a state (third case) in which the previous data remaining by overwriting by logical erasure is recorded. At this time, the CPU 2 The process proceeds to step SP14.

  In step SP14, the CPU 2 can determine that the first session is the final session since the data recorded in the second session is actually the previous data remaining after overwriting by logical erasure, and the process proceeds to the next step SP15. Immediately after finishing the final session determination process, the reproduction process is started for the first session.

  On the other hand, if an affirmative result is obtained in step SP9, this means that the optical pickup 5 can be accurately moved to the head position of the track, that is, the track number is inconsistent as a result of returning by the elapsed time. In this case, the CPU 2 moves to the next step SP10.

  In step SP10, since the track recorded in the next session is consistent with the track number and the head position of the track exists, the track number of the second session is the same as the last track number of the first session. It is determined whether or not the serial number is larger by “1”.

  If a negative result is obtained here, this means that the optical pickup 5 can be accurately moved to the head position of the track, but the track number is larger by “1” than the last track number of the first session. In this case, the CPU 2 moves to the next step SP11.

  In step SP11, since the track numbers are not continuous, the CPU 2 moves the optical pickup 5 to the last part of the previous track, reads data, returns to step SP8, and repeats the subsequent processing. As a result, an affirmative result is obtained for the first time when track numbers are consecutive as the determination result of step SP10, and the process proceeds to the next step SP12.

  In step SP12, the CPU 2 determines whether or not the second TOC of the second session exists immediately before the first track of the second session. If a negative result is obtained here, the second TOC does not exist immediately before the first track of the second session, and the second session still records the previous data remaining after overwriting by logical erasure. (The third case). At this time, the CPU 2 moves to the next step SP14.

  In step SP14, the CPU 2 can determine that the first session is the final session since the data recorded in the second session is actually the previous data remaining after overwriting by logical erasure, and the process proceeds to the next step SP15. Immediately after finishing the final session determination process, the reproduction process is started for the first session.

  On the other hand, if a positive result is obtained in step SP12, this indicates that the second TOC of the second session exists, that is, the first session was not the final session. Control goes to step SP13.

  In step SP13, the CPU 2 moves the optical pickup 5 to the second TOC of the second session, returns to step SP1, and repeats the above processing.

  As a result, the CPU 2 moves to a process for determining whether or not the second session is the last session, and sequentially executes the third session, the fourth session,. Whether the current session is the last session is determined. When the final session is determined, the reproduction process is started from the first session.

(3) Operation and Effect In the above configuration, every time the CPU 2 of the CD-R / RW playback apparatus 1 reads the TOC of each session, the TOC of the next session is correctly recorded (that is, the current session is the last one). The first case (which may be the next session instead of the session) is recorded, the second case is an unwritten state in which no data is recorded, and the previous data remaining due to overwriting is recorded Whether the third case is the so-called (so-called logical erasure) third case or the fourth case where the erasing data is written (the so-called physical erasure) is determined with a clear judgment criterion.

  As a result, the CPU 2 can more accurately determine whether it is the last session after properly grasping which of the first case to the fourth case the next session of the current session corresponds to. it can.

  In addition, since the CPU 2 can determine the final session according to a clear determination criterion, the final session is determined in a shorter time than when retrying several times as in the past or continuing to search for the TOC until a timeout occurs. Thus, the reproduction process can be started.

  Thus, since the CPU 2 can further reduce the waiting time until the user starts the reproduction process, the reproduction result can be output without applying stress to the user.

  According to the above configuration, the CPU 2 of the CD-R / RW playback apparatus 1 can accurately determine the final session of the multi-session CD 3 in a short time. The time can be further shortened, and thus the playback result can be output in a short time after recognizing the pressing operation of the playback button, and the user is not stressed.

(4) Other Embodiments In the above-described embodiment, the case where the above-described final session determination process is started after recognizing the user's operation of pressing the play button has been described. The present invention is not limited to this, and the above-described final session determination process is executed when the multi-session CD recognizes that the multi-session CD has been loaded from the CD loading slot (not shown) of the CD-R / RW playback device 1. Anyway.

  In this case, since the CPU 2 of the CD-R / RW playback apparatus 1 executes the final session determination process from the time when the multi-session CD is loaded, the playback process is performed immediately when the user next presses the playback button. Can start.

  In the above-described embodiment, the case where the CD-RW is targeted as the multi-session CD3 has been described. However, the present invention is not limited to this, and the CD-R may be targeted. In this case, since the CD-R is write-once once and not rewritable, it is not necessary to determine the third case and the fourth case, and the final session is determined only by determining the first case and the second case. can do.

  Furthermore, in the above-described embodiment, the case where the CPU 2 expands the final session determination program stored in the ROM 2A on the RAM 2B and executes the above-described final session determination processing procedure according to the final session determination program will be described. However, the present invention is not limited to this, and the final session determination processing procedure may be executed by installing a program storage medium storing the final session determination program in the CD-R / RW playback apparatus 1.

  As a program storage medium for installing the final session determination program for executing the above-described final session determination processing procedure in the CD-R / RW playback device 1 and making it executable, for example, a flexible disk ( Not only package media such as registered trademark), CD-ROM (Compact Disc-Read Only Memory), DVD (Digital Versatile Disc), but also semiconductor memory, magnetic disk, etc. in which the final session determination program is temporarily or permanently stored It may be realized with. In addition, as a means for storing the final session determination program in these program storage media, wired and wireless communication media such as a local area network, the Internet, and digital satellite broadcasting may be used, and via various communication interfaces such as routers and modems. You may make it store.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to the CD-R / RW playback apparatus 1 has been described. However, the present invention is not limited to this, and a personal computer having a CD-R / RW playback function. You may make it apply this invention to other various electronic devices, such as a computer.

  Further, in the above-described embodiment, the final session determination circuit of the present invention is the optical pickup 5 as the TOC reading means, the RF unit 7, DSP 8, CPU 2, ROM 2A and RAM 2B, the optical pickup 5 as the data reading means, and the RF unit 7. , DSP8, CPU2, ROM2A and RAM2B, CPU2, ROM2A and RAM2B as final session determination means have been described, but the present invention is not limited to this, and TOC reading with other various circuit configurations The final session determination circuit may be configured by the means, the data reading unit, and the final session determination unit.

  The final session determination circuit and the playback apparatus of the present invention can be applied to the use of playing a multi-session CD recorded in a plurality of sessions, for example.

It is a basic block diagram which shows the circuit structure of the CD-R / RW reproducing | regenerating apparatus of this invention. It is a flowchart which shows the last session determination processing procedure. It is a basic diagram with which it uses for description of the structure of multisession CD.

Explanation of symbols

  1 ... CD-R / RW playback device, 2 ... CPU, 2A ... ROM, 2B ... RAM, 3 ... multi-session CD, 5 ... optical pickup, 6 ... drive unit, 7 ... RF unit , 8... DSP, 10.

Claims (7)

TOC (Table of each session in multi-session CD (Compact Disc)
of contents) and TOC reading means,
Data reading means for reading out the current session and reading out data at a location exceeding the TOC of the next session for the current session;
A final decision is made based on the TOC information read by the TOC reading means and the content of the data read by the data reading means, based on a predetermined criterion and whether or not the current session is the final session. A final session determination circuit comprising: a session determination unit. The final session determining means determines whether or not the current session is the final session by determining whether or not data at a location exceeding the TOC of the next session can be read by the data reading means. The final session determination circuit according to claim 1. The final session determination means determines whether or not the current session is the final session by determining whether or not the data in the location beyond the TOC of the next session is erased data that has no meaning due to physical erasure. The final session determination circuit according to claim 1, wherein: The final session determination means verifies the consistency between the data of the location beyond the TOC of the next session and the data related to the current session, and based on the verification result, whether or not the current session is the final session The final session determination circuit according to claim 1, wherein: In a playback device for playing a multi-session CD,
TOC reading means for reading the TOC of each session in the multi-session CD;
Data reading means for reading out the current session and reading out data at a location exceeding the TOC of the next session for the current session;
A final decision is made based on the TOC information read by the TOC reading means and the content of the data read by the data reading means, based on a predetermined criterion and whether or not the current session is the final session. Session determination means;
A playback device comprising: playback means for starting playback processing after the final session determination means finishes determining the final session. A TOC reading step for reading the TOC of each session in a multi-session CD;
A data reading step of reading out the current session and reading out data at a location exceeding the TOC of the next session for the current session;
A final decision is made based on the TOC information read in the TOC read step and the content of the data read in the data read step, based on a predetermined criterion and whether or not the current session is the final session. A method for determining a final session, comprising: a step for determining a session. For playback devices,
A TOC reading step for reading the TOC of each session in a multi-session CD;
A data reading step of reading out the current session and reading out data at a location exceeding the TOC of the next session for the current session;
A final decision is made based on the TOC information read in the TOC read step and the content of the data read in the data read step, based on a predetermined criterion and whether or not the current session is the final session. A final session determination program for executing a session determination step.

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