JP4016167B2 - Playback method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for reproducing a recording medium on which audio data is recorded, particularly a digital audio data CD (compact disc) on which audio data and accompanying data are recorded in accordance with a CD text format.To the lawRelated.
[0002]
[Prior art]
Conventionally, in a microcomputer controlling a CD player system, when reading CD text data from a compact disc on which CD text is recorded, a RAM (Random Access Memory) capacity of 4096 bytes per language is required. And Furthermore, in order to read all text data (for example, 8 languages) recorded on the disc, a RAM capacity of 4096 × 8 = 32768 bytes is required.
[0003]
The capacity of the RAM provided in the microcomputer for controlling the system of the CD player is usually about 2000 to 4000 bytes, but most of it is used for controlling the system, and it is equivalent to one language. In many cases, sufficient RAM capacity does not remain to read CD text data.
[0004]
Therefore, in order to read the CD text data, it is necessary to connect the RAM having a large capacity to the microcomputer. In such a configuration, the cost is increased, and it has been impossible to realize a function of reading CD text data with a low-priced model.
[0005]
[Problems to be solved by the invention]
  Accordingly, an object of the present invention is to provide a reproduction method that enables reading of data having a large amount of information such as CD text data from a recording medium using low-cost hardware.The lawIt is to provide.
[0006]
[Means for Solving the Problems]
  The invention of claim 1In a reproduction method for reproducing content data recorded on a mounted recording medium,
  Read related information that is similarly recorded on the recording medium and manages information related to the content data in units of related data of a predetermined size,
  The related data identification information included in each related data to identify the type of the related data is determined,
  When it is determined by the determination that certain related data includes information regarding the size of the related information, the size regarding the related information is calculated based on the information regarding the size,
  After the calculation is performed, if it is determined by the same determination that other related data includes a part or all of the related information, the related information is stored based on the calculated size.
This is a reproduction method characterized by the above.
[0012]
According to the invention as described above, it is possible to efficiently use a RAM or the like in which information recorded on a recording medium such as a CD is read in accordance with a CD text format or the like.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described. An example of the overall configuration of a playback apparatus to which the present invention can be applied is shown in FIG. When the disk 1 is mounted on a loading mechanism having a detachable tray 501, a transport mechanism to which power generated by the transport motor 502 is applied transports the disk 1 to a chucking position. The disk 1 is driven to rotate at a CLV (Constant Linear Velocity) by a spindle motor 2. Then, the pit information on the disk 1 is read by the optical head 3. Here, the disk 1 mounted on the tray 501 is shown to be different in size from the disk 1 rotated by the spindle motor 2, but this is because the description space is taken into consideration and the conveyance is carried out. The size of the disk 1 is constant both at the time and at the time of rotational driving.
[0014]
Although not shown, the optical head 3 is provided with a laser diode and an optical system composed of a diffraction grating, a beam splitter, a quarter-wave plate, etc., and the laser emitted from the laser diode by the optical system. Light is irradiated in a predetermined state (for example, having a predetermined spot diameter) onto the recording surface of the disk 1. Then, the reflected light enters the above-described optical system, is separated from the irradiated light by the beam splitter, is taken out, and is guided to the detector via a cylindrical lens or the like. The detector converts incident light into an electrical signal.
[0015]
An electric signal generated by the detector is supplied to the RF calculation unit 4 as a read signal by the optical head 3. The RF operation unit 4 generates an RF signal, a focus error signal EF, and a tracking error signal ET as reproduction data based on the supplied signal. The focus error signal EF and the tracking error signal ET are supplied to the servo circuit 5. The servo circuit 5 generates a focus drive signal FD and a tracking drive signal TD based on the supplied focus error signal EF and tracking error signal ET, and generates the generated focus drive signal FD and tracking drive signal TD from the optical head 3. This is supplied to a biaxial mechanism (not shown) that controls the position of the objective lens.
[0016]
The biaxial mechanism displaces the position of the objective lens according to the supplied signal. As a result, the focus error and the tracking error are within a predetermined range for obtaining an appropriate read signal. The servo circuit 5 generates a thread drive signal SD based on the supplied tracking error signal ET, and supplies the generated thread drive signal SD to the thread mechanism 6 that drives the optical head 3 in the radial direction of the disk 1. To do. As a result, position control on a relatively large scale in the radial direction of the disk 1 is performed, for example, movement to a target track to be accessed. The servo circuit 5 is further supplied with a spindle servo signal SS, a track jump signal TJ, and the like, and performs operations based on these signals, which will be described later.
[0017]
On the other hand, the RF signal is supplied from the RF operation unit 4 to the decoder 7. The decoder 7 performs EFM modulation, CIRC (Cross Interleave Read-Solomon Code) error correction processing, and the like on the supplied RF signal, and supplies a signal generated by these processing to the D / A converter 8. The D / A converter 8 converts the supplied signal into, for example, 2-channel analog audio signals L and R. Then, the amplifier circuit 9 drives the speakers 10a and 10b based on the analog audio signals L and R, thereby generating an audio output. Although the case of two channels has been described here, the number of channels is not limited to two. In general, the number of speakers equal to the number of channels is provided.
[0018]
The decoder 6 extracts subcode data CSUB, CD text data CDTEXT, a clock error signal ESP for performing spindle servo, and the like from the supplied RF signal, and supplies the extracted data to the controller 100. The controller 100 includes a microcomputer and a RAM (Random Access Memory) 100a. The controller 100 controls each component in the apparatus according to an operation performed by a user, subcode data CSUB, CD text data CDTEXT, and the like. Further, the controller 100 stores TOC data, CD text data CDTEXT, and the like reproduced from the disk 1 in the RAM 100a. 1 shows the case where the RAM 100a is built in the controller 100, a RAM having the same function as the RAM 100a may be provided separately from the controller 100.
[0019]
For example, the spindle servo signal SS and the track jump signal TJ are supplied to the servo circuit 5. The servo circuit 5 generates a spindle drive signal SPD based on the supplied spindle servo signal SS, and supplies the spindle drive signal SPD to the spindle motor 2, thereby controlling the spindle servo, that is, the spindle motor 2. The servo circuit 5 controls the sled mechanism 6 and the like based on the track jump signal TJ, and causes the optical head 3 to access an appropriate track corresponding to an operation performed by the user.
[0020]
Operations performed by the user are input via the operation unit 200. The operation unit 200 is an operation unit having various operation keys provided on the outer casing panel of the apparatus. The operation unit 200 includes CD operations such as a play key, a stop key, a fast forward key, a fast rewind key, and an AMS (cue) key related to operations on the disc 1 that has been mounted at a chucking position or the like by an operation of a loading mechanism or the like. Keys and playback mode operation keys such as shuffle playback and program playback.
[0021]
The operation unit 200 is further provided with an operation switch related to a power operation (secondary power source) by the user, an open / close key for inputting a command for storing / removing the disk 1 (tray 501), and the like. By operating the open / close key, for example, the tray 501 is ejected from the chucking position, and the disc 1 can be loaded / removed from the tray 501. Further, the display unit 300 displays time information of the CD being played, various mode states, and the like based on the control of the controller 100.
[0022]
On the other hand, the power supply circuit 400 rectifies and smoothes the current supplied from the commercial AC power supply to generate a DC operating power supply voltage, and supplies the generated DC operating power supply voltage to each component. When the outlet is connected to the commercial AC power supply, the primary power supply is turned on and the standby power supply voltage V2 is output. The standby power supply voltage V2 is supplied to the controller 100 and the like. For example, when the user turns on a power operation switch installed in the operation unit 200, the operation power supply voltage V1 is supplied to each component.
[0023]
When the outlet is connected to the commercial AC power supply, the controller 100 is always supplied with the standby power supply voltage V2. For this reason, a certain amount of operation can be performed even in the standby state. For example, it is possible to control the power supply circuit 400 to automatically output the operating power supply voltage V1 when a predetermined condition is satisfied.
[0024]
The motor driver unit 500 drives a transport motor 502 that provides power to a loading mechanism that transports the tray 501. That is, the motor driver unit 500 applies an operating current to the transport motor 502 of the tray 501 in accordance with the motor control information SMD supplied from the controller 100. As a result, the rotation direction and the rotation operation period of the transport motor 502 are controlled by the controller 100.
[0025]
Further, signals from various sensors are supplied from the loading mechanism to the controller 100. That is, the signal SEN is supplied from the chucking detection switch 503 and the signal SSEN is supplied from the out switch 504 to the controller 100. With these signals, the controller 100 can detect various states in the loading mechanism.
[0026]
In the configuration as described above, for a disc that is not ready for playback at the present time, that is, a disc that has not yet read the TOC and CD text, the TOC and CD text are transferred after the disc is transported from the eject to the chucking position. Reading is executed.
[0027]
The CD text data will be described below. FIG. 2 shows an example of the format of CD text data. ID1, ID2, ID3, and ID4 are identification data composed of, for example, 8 bits (1 byte). Twelve text data text1 to text12 each having 8 bits (1 byte) are provided at positions following these identification data. These 16 bytes constitute one pack.
[0028]
ID1 to ID4 will be described. ID1 is set to “100” in which the upper 3 bits starting from the MSB among the upper 4 bits of the 8 bits represent mode 4. Since the remaining 1 bit in the upper 4 bits is set to 0, the upper 4 bits are set to “1000”. Mode 4 is an undefined mode before the CD-text format is proposed. As a result, when a disc recorded in accordance with the CD-text format is loaded into an existing playback device that does not support the CD-text format, an unrecognizable mode is detected and it is determined that playback is not possible, and malfunction is prevented. Is done.
[0029]
Further, the lower 4 bits represent the contents (16 types) of data handled by the pack starting with ID1 as described below. That is, ID1 is expressed as (8xh) (h means a hexadecimal number, and x means a value of lower 4 bits). Specifically, when ID1 is (80h), the texts from text1 to text12 indicate the album title / track title. When the ID1 is (81h), the texts from text1 to text12 are the album artist / track. Show the artist. Also, if ID1 is (82h), a composer, (83h) is a composer, (84h) is an arranger, (85h) is a message, (86h) is a discID, (87h) Is handled as a genre ID, (88h) as TOC information, and (89h) as 2nd TOC information.
[0030]
Further, (8ah), (8bh), and (8ch) mean reservation, that is, currently undefined. It is said. When ID1 is 8 dh, closed information is handled. When it is (8 eh), UPC / EAN (POS code) of the album and ISRC (International Standard Recording Code) of each track are handled. When ID1 is (8fh), block size information is handled by a pack starting with ID1. That is, a pack whose ID1 is (8 fh) is a size pack.
[0031]
ID2 includes a 1-bit extension flag and a 7-bit track number or pack element number. The track number indicates the track number to which the first character of the text data of the pack belongs. ID3 is a serial number (sequence number) given to the pack. This serial number is from 0 to 255 (00h to ffh). ID4 consists of a 1-bit (MSB) DBCC (Double Byte Character Code) identification bit, a 3-bit block number, and 4 bits indicating the character position of the pack.
[0032]
Next, the text data includes a character string or binary information depending on the pack information indicated by ID1. In packs other than (ID1 = 88h), (ID1 = 89h), and (ID1 = 8fh), text data is represented by a character string. The character string consists of a character sequence and a null code as a terminal. When (ID1 = 8 fh), the pack is a size pack. An example of a size pack is shown in FIG. text1 indicates the character (character) code of the block. text2 and text3 indicate the first track number and the last track number, respectively. text4 indicates a copy control flag. text5 to text12 represent the total number of packs having (ID1 = 80h) to (ID1 = 87h), respectively.
[0033]
The data format of the CD text is composed of blocks containing a maximum of 256 packs (4096 bytes) of one pack of 16 bytes as described above. In addition, it is possible to record 8 blocks corresponding to 8 languages (that is, 32768 bytes at the maximum) on one disc 1. In the CD text data format as described above, the RAM capacity required to read CD text data in one language is usually 4096 bytes.
[0034]
In one embodiment of the present invention, the following allocation is made to the RAM 100a in the controller 100 in order to read CD text under a limited RAM capacity. That is, as shown in FIG. 4A, text1 to text12 excluding the identification data ID1 to ID4 in the CD text data are allocated to the RAM 100a. In this case, as shown in FIG. 4B, a total of 12 bytes of text1 to text12 are treated as one packet on the RAM 100a, and the address on the RAM 100a is expressed as save_pack_no / save_text_no in the vertical / horizontal direction.
[0035]
Next, a process of reading one packet of CD text data and storing it in the RAM 100a will be described with reference to the flowchart of FIG. In step S1, [flag 8F00] = OFF is set. This process is initialization of a flag for storing whether or not the data of the size / pack whose ID1 = 8F has been read. Next, in step S2, it is determined whether one packet of CD text data has been read. If read, the process proceeds to step S3. If not read, the process proceeds to step S2 again. That is, step S2 is a step in which the process waits until one packet of CD text data is read, and then proceeds to step S3.
[0036]
In step S3, it is determined whether or not ID1 = 8F, that is, whether or not one read pack is a size pack. If ID1 = 8F, the process proceeds to step S4, and otherwise, the process proceeds to step S9. In step S4, it is determined whether or not ID2 = 00. If ID2 = 00, the process proceeds to step S5. Otherwise, the process proceeds to step S2, and one subsequent packet is read. Wait until In step S5, it is determined whether or not [flag 8F00] = OFF. If [Flag 8F00] = OFF, ID1 = 8F is first obtained, that is, if the first size pack is read, the process proceeds to Step S6. Otherwise, Step S2 is performed. The process waits until one subsequent packet is read.
[0037]
In step S6, the text size is calculated based on the read size pack data. Then, the process proceeds to step S7, and [flag 8F00] = ON is set. Thereby, it is memorized that Step S6 was performed once. Further, the process proceeds to step S11.
[0038]
On the other hand, in step S9, it is determined whether or not [flag 8F00] = ON. If it is determined that [Flag 8F00] = ON, the text size calculation has already been completed. In this case, the process proceeds to Step S10 to execute font data storage. On the other hand, if it is determined in step S9 that [flag 8F00] = OFF, the process proceeds to step S2 and waits until one subsequent packet is read.
[0039]
The text size calculation in step S6 will be described in detail with reference to the flowcharts of FIGS. Here, the description is divided into two drawings for the convenience of description space. In the following description, FIGS. 6 and 7 are referred to as one body. 6 and 7 are shown as (A) and (B). In step S101, the number of title songs (title_track) is calculated. For example, the number of title songs is calculated by subtracting the track number (start_track) where the first title song is recorded from the track number (last_track) where the last title song is recorded, and adding 1 to the difference. be able to. Next, the process proceeds to step S102, where text5 = total number of title packs (see FIG. 3) is set as the value of variable pack_80. Next, the process proceeds to step S103, where text6 = total number of artists pack (see FIG. 3) is set as the value of variable pack_81.
[0040]
Next, the process proceeds to step S104, where the last pack number = “title total pack number” + “artist total pack number” −1. Next, the process proceeds to step S105, and MAX_ARTIST_FONT, which is defined in advance as the number of characters for storing the artist, is converted into the number of packets to be artist_pack. Since one packet is 12 bytes, the conversion formula is MAX_ARTIST_FONT ÷ 12. When a remainder occurs in this division, the value obtained by adding 1 to the quotient is the value of artist_pack. Next, the process proceeds to step S106, and the RAM capacity for title allocation is obtained in units of packets. That is, title pack (title_pack) = MAX_TEXT_PACK−artist_pack. Here, MAX_TEXT_PACK defines a RAM capacity for storing text data.
[0041]
Next, the process proceeds to step 107, and it is determined whether or not the value of the variable pack_80 (text5 = total number of title packs set in step S102) is equal to or less than the title pack (title_pack). If the value of the variable pack_80 is equal to or less than the number of title packs (title_pack), the process proceeds to step S108 based on the determination that the total number of packs of titles can fit into the title pack. In other cases, the process proceeds to step S200 based on the determination that the total number of packs of the title does not fit in the title pack.
[0042]
The process proceeds to step S108, where the number of title characters (title_font) = the value of the variable pack_80 (text5 = total number of title packs set in step S102) × 12. Next, the process proceeds to step S109, where the number of artist characters (artist_font) = (MAX_TEXT_PACK−value of variable pack_80) × 12 is calculated. Next, the process proceeds to step S111, where the number of title packs (title_pack) = the total number of title packs (pack_80 value) is stored. Next, the process proceeds to step S112, and a flag (2 for recalculating the remaining RAM of the title).^ndSet _cal) to OFF so that it is not recalculated. Then, the process proceeds to step S301.
[0043]
On the other hand, if it is determined in step S107 that the value of the variable pack_80 is less than or equal to the number of title packs (title_pack), the process proceeds to step S200, and MAX_TITLE_TRACK <title song number (title_track). Check whether or not. Here, MAX_TITLE_TRACK defines the number of songs storing the title. When MAX_TITLE_TRACK = 0, only the album title is available. If MAX_TITLE_TRACK <title song number (title_track), the process proceeds to step S201, and otherwise, the process proceeds to step S203. In step S201, the number of title songs (title_track) = MAX_TITLE_TRACK is set. Next, the process proceeds to step S202, where the last track number (last_track) = the first track number (start_track) + MAX_TITLE_TRACK-1 is set. Then, the process proceeds to step S203.
[0044]
In step S203, the number of title characters (title_font) = the number of title packs (title_pack) × 12 ÷ (the number of title songs (title_track) +1 (for album)). Next, the process proceeds to step 204 where the number of artist characters (artist_font) = MAX_ARTIST_FONT is set. Next, the process proceeds to step 205, where a flag (2 for recalculating the remaining RAM of the title).^nd_Cal) is turned ON to recalculate. Then, the process proceeds to step S301.
[0045]
In step S301, the number of ID3 for reading the text data is designated. That is, read ID 3 (read_id 3) = 0. In step S302, a variable value indicating the RAM address to be stored is set. That is, the packet number (save_pack_no) = 0 and the text number (save_text_no) = 0. Next, the process proceeds to step S303, where the number of stored tracks (save_track) = 0. Next, the process proceeds to step S304, and the number of stored characters (save_font) = 0 is set.
[0046]
Next, the font data storage in step S10 in FIG. 5 will be described with reference to the flowcharts in FIGS. Here, the description is divided into two drawings for the convenience of description space, and in the following description, FIGS. 8 and 9 are referred to as one body. 8 and 9 are shown as (C), (D), (E), and (F). Since the font data is stored by reading according to the read ID 3 (read_id3) that designates the ID 3 number for reading the CD text data, whether or not ID3 = read ID3 (read_id3) is determined as step S401. To check. If it is determined that ID3 = read ID3 (read_id3), the process proceeds to step S402. Otherwise, the process waits for a subsequent packet.
[0047]
In step S402, it is checked whether or not CD text data ID1 = 80h (title). If it is determined that ID1 = 80h, the process proceeds to step S404; otherwise, the process proceeds to step S403. In step S403, it is checked whether or not CD1 text data ID1 = 81h (artist). If it is determined that ID1 = 81h, the process proceeds to step S406. Otherwise, the storage ends. Therefore, the storage ends when the ID 1 of the CD text data is neither 80h nor 81h.
[0048]
If it is determined in step S402 that ID1 = 80h, the maximum number of stored songs (track_max) = title / track (title_track) is set in step S404, and the maximum number of stored characters (font_max) = in step S405. Set the number of title characters (title_font). Then, the process proceeds to step S408. On the other hand, if it is determined in step S403 that ID1 = 81h, the maximum number of stored songs (track_max) = 0 is set in step S406 (may be set similarly to the title / track), and further, step In S407, the maximum number of characters stored (font_max) = the number of artist characters (artist_font) is set. Then, the process proceeds to step S408.
[0049]
In step S408, the text text 1 to text12 of the CD text data is checked one byte at a time, and if stored, the process proceeds to step S500, otherwise the process proceeds to step S409 and stored. In step S500, 1 is added to the read ID3 (read_id3) which is a variable for specifying the ID3 number for reading the CD text data, and the subsequent one packet is awaited. On the other hand, in step S410, the stored text is checked. That is, if the data is null data (00), the process proceeds to step S601. Otherwise, the process proceeds to S411.
[0050]
In step S411, the number of stored characters (save_font) is checked, and it is determined whether or not the number of stored characters (save_font) <the maximum number of stored characters (font_max). If the number of stored characters (save_font) <the maximum number of stored characters (font_max), the process proceeds to step S412. Otherwise, the process proceeds to step S413. In step S412, 1 is added to the number of stored characters (save_font), and the process proceeds to step S414, and 1 is added to the storage address (save_pack_no, save_text_no). Then, the process proceeds to step S408, and the remaining text is checked.
[0051]
On the other hand, in step S413, the number of stored characters (save_font) and the storage address (save_pack_no, save_text_no) are kept as they are. In addition, when the number of stored characters (save_font) <the maximum number of stored characters (font_max) is not satisfied, the maximum storage address is overflowed once, so a flag (2 for recalculating the remaining RAM capacity)^nd_Cal) is turned OFF not to recalculate. Then, the process proceeds to step S408, and the remaining text is checked.
[0052]
On the other hand, in step S601, the number of stored characters (save_font) = 0 is set, and the process proceeds to step S602, where 1 is added to the number of stored tracks (save_track). Next, the process proceeds to step S603, where it is determined whether or not the number of stored tracks (save_track) ≦ the maximum number of stored songs (track_max). If the number of stored tracks (save_track) ≦ the maximum number of stored songs (track_max), the process proceeds to step S604. Otherwise, the process proceeds to step S605.
[0053]
In step S604, 1 is added to the storage address (save_pack_no, save_text_no). Next, the process proceeds to step S606 and a flag (2 for recalculating the remaining RAM capacity).^ndCheck _cal). If not recalculated (OFF), the process proceeds to step S408, and the remaining text is checked. On the other hand, if recalculation is set (ON), the process proceeds to step S607. In step S607, it is checked whether or not CD text data ID1 = 80h (title). If ID1 = 80h (title) is not satisfied, the process proceeds to step S408, and the remaining text is checked. On the other hand, if ID1 = 80h (title), the process proceeds to step S608.
[0054]
In step S608, the remaining RAM capacity is recalculated. That is, the number of characters assigned to the title is calculated as “title assigned characters” = “title pack (title_pack)” × 12, and the number of stored characters is calculated as “number of stored characters” = “storage address (save_pack_no × 12 + save_text_no)”. To do. Based on these calculated values, the remaining title RAM capacity is calculated as “title remaining RAM capacity” = “number of characters assigned to title” − “number of stored characters”.
[0055]
Also, the number of remaining songs is calculated as “number of remaining songs” = “number of title songs (title_track)” − “number of stored tracks (save_track)” + 1, and the remaining number of characters per song is calculated as “remaining, The number of characters per song is calculated as “title remaining RAM capacity” ÷ “number of remaining songs”. In this calculation, the remaining RAM capacity is allocated to the number of characters, but may be allocated to the number of songs. After recalculating the remaining RAM capacity, the maximum number of stored characters (font_max) is set to [maximum stored number of characters (font_max)] = title character (title_font) = “number of remaining characters per song”. Then, the process proceeds to step S408, and the remaining text is checked.
[0056]
On the other hand, in step S605, “the number of stored tracks (save_track) = 0” is set, and the process proceeds to step S609. In step S609, null data (00) is stored up to text12 of the storage address, and the process proceeds to step S610. In step S610, a storage address is set. That is, 1 is added to save_pack_no, and the value of save_text_no is set to 0.
[0057]
Next, the process proceeds to step S611, and it is checked whether or not ID1 = 80h (title). If ID1 = 80h (title), the process proceeds to step S612. Otherwise, the process proceeds to step S613. Transition. In step S612, the number lead ID3 (read_id3) of ID3 for reading the next CD text data is set to “lead ID3 (read_id3) = total number of title packs (pack_80)” (first pack number of artist). The process proceeds to step S614. In step S614, “total number of title packs (pack_80) = storage address (save_pack_no)” (the number of stored packs) is set. Then, control goes to a step S615.
[0058]
In step S615, it is determined whether or not the total number of artists pack = 0. When the total number of packed artists = 0, that is, when there is no artist, the storage is terminated. In cases other than that described here, process flow proceeds to Step S616. In step S616, “number of artist characters = (MAX_TEXT_PACK−save_pack_no) × 12” (all remaining RAM capacity) is waited for one subsequent packet. On the other hand, in step S613, “artist total pack number (pack_81) = storage address (save_pack_no) (stored pack number) −total title pack number stored (pack_80) is set.
[0059]
  The algorithm as described above with reference to FIGS. 5, 6 and 7, and FIGS. 8 and 9, ie, CD text data is transmitted in one packet (12Bytes), and if the packet is a size pack, the text size is calculated. If the packet is not a size pack, the font data storage algorithm is used. By specifying _TEXT_PACK, MAX_TITLE_TRACK, and MAX_ARTIST_FONT, it becomes possible to read CD text data accurately. For example, 60 packets (1 packet is 12 bytes as described above) can be set as MAX_TEXT_PACK, 20 songs can be set as MAX_TITLE_TRACK, and 30 characters can be set as MAX_ARTIST_FONT.
[0060]
In addition to the algorithm described above, an algorithm using another definition method may be used. For example, when a size pack is read by defining MAX_TEXT_PACK (RAM capacity), MAX_TRACK (MAX_TITLE_TRACK, MAX_ARTIST_TRACK) (number of songs), and MAX_FONT (MAX_TITLE_FONT, MAX_ARTIST_FONT) (number of characters) It is also possible to use an algorithm that calculates how titles, artists, and the like are read into a user-specified RAM capacity. Specifically, the following processing can be performed.
[0061]
(1) The maximum number of characters can be defined by a calculation of RAM capacity / total number of songs on the disk, and can be made constant. It is also possible to increase the maximum number of characters from the remaining RAM capacity while storing data.
[0062]
(2) The maximum number of songs can be defined by a calculation of RAM capacity / total number of characters of the disk, and can be made constant. It is also possible to increase the maximum number of songs from the remaining RAM capacity while storing data.
[0063]
(3) The maximum number of characters can be defined by a calculation of RAM capacity / MAX_TRACK and can be made constant. It is also possible to increase the maximum number of characters from the remaining RAM capacity while storing data.
[0064]
(4) The maximum number of songs can be defined by a calculation of RAM capacity / MAX_FONT and can be made constant. It is also possible to increase the maximum number of songs from the remaining RAM capacity while storing data.
[0065]
In the above-described embodiment of the present invention, the present invention is applied to a CD. However, the present invention reproduces other information recording media as long as it uses a recording format similar to a CD text. It can be applied even in the case of.
[0066]
The present invention is not limited to the above-described embodiment, and various applications and modifications can be considered without departing from the gist of the present invention.
[0067]
【The invention's effect】
As described above, according to the present invention, at least one of the parameters specifying the total storage capacity allocated for reading the text data, the number of characters read from the text data, and the number of songs read from the text data is used. By using an algorithm including predetermined processing using such parameters, the storage capacity of a storage circuit such as a RAM for reading text data provided in a controller that controls the operation of each unit of the apparatus, for example, can be made more efficient. Can be used.
[0068]
For this reason, even when the storage capacity allocated for reading the text data is limited, the text data can be read appropriately. Therefore, it is possible to reduce the storage capacity allocated for reading the text data without impairing the function of the playback device.
[0069]
For this reason, the total storage capacity of the storage circuit in the device can be reduced without impairing the function of the device or while minimizing the degree thereof, which can contribute to the cost reduction of the device.
[Brief description of the drawings]
FIG. 1 is a block diagram for explaining a configuration of a playback apparatus to which the present invention can be applied.
FIG. 2 is a schematic diagram illustrating an example of a format (1 pack) of CD text data.
FIG. 3 is a schematic diagram illustrating an example of a size pack format;
FIG. 4 is a schematic diagram for explaining allocation of a RAM for storing CD text data in an embodiment of the present invention.
FIG. 5 is a flowchart for explaining a process of reading one packet of CD text data and storing it in a RAM according to an embodiment of the present invention;
6 is a part of a flowchart for explaining in detail a part of the processing (text size calculation) shown in FIG. 5;
7 is another part of the flowchart for explaining in detail a part of the processing (text size calculation) shown in FIG. 5;
FIG. 8 is a part of a flowchart for explaining in detail another part (font data storage) of the process shown in FIG. 5;
FIG. 9 is another part of a flowchart for explaining in detail another part (font data storage) of the process shown in FIG. 5;
[Explanation of symbols]
100: Controller, 100a: RAM

Claims (4)

In a reproduction method for reproducing content data recorded on a mounted recording medium,
Read related information that is similarly recorded on the recording medium and manages information related to the content data in units of related data of a predetermined size,
The related data identification information included in each related data to identify the type of the related data is determined,
When it is determined by the determination that certain related data includes information regarding the size of the related information, the size regarding the related information is calculated based on the information regarding the size,
After the calculation is performed, if it is determined by the same determination that other related data includes a part or all of the related information, the related information is stored based on the calculated size. A reproduction method characterized by the above. Calculated in storing the related information based on the size, method of reproducing the specifying the maximum value of the associated information <br/> that you characterized according to claim 1, in which the storage. The content data is audio data, and the related information is title information or artist information.
The reproducing method according to claim 1, wherein: When the processing corresponding to the related data identification information included in any related data cannot be executed, the recording medium is made unplayable.
Claims 1 The playback method described.

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