JPH05143244A - Information reproducing device - Google Patents

Abstract

PURPOSE:To easily drive the time information of a reproducing time, etc. CONSTITUTION:At the time of reproduction, an information signal is applied to an audio decoder 40 through a CD decoder 32 and a CD-ROM decoder 34, and its timewise length is expanded to inverse number (1/P) folds of compressibility P, and thereafter, outputted through a D/A converter 42. The CD-ROM decoder 34 extracts address information and stores it in a RAM 38, and a microcomputer 36 multiplies the stored address information by the inverse number 1/P of the compressibility P and derives time information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reproducing device,
In particular, the present invention relates to an information reproducing apparatus for reproducing information from a recording medium in which a recording signal of audio or video is compressed and recorded.

[0002]

2. Description of the Related Art CD-ROM (CD-Read Only Memory)
), CD-WO (CD-Write Once) or CD-M
Address information unique to each recording medium such as O (CD-Magneto Optic) is recorded. For example, CD-RO
In M, a block structure with 2352 bytes as one block is adopted, and the address area provided in each block has address information representing a physical position in minutes, seconds, and blocks (75 blocks = 1 second). To be recorded. Then, conventionally, the time information is obtained by directly reading the address information.

[0003]

In a recording medium such as a CD-ROM, a recording signal may be compressed and recorded in order to record information (music etc.) for a long time on one disc. .. In such a case, since the reproduction signal is expanded during reproduction, there is a problem in that accurate time information cannot be obtained by the conventional technique of directly reading the address information.

Therefore, a main object of the present invention is to provide an information reproducing apparatus which can easily obtain accurate time information even with a recording medium which is compressed and recorded.

[0005]

SUMMARY OF THE INVENTION The present invention is a reproducing apparatus for a recording medium in which a recording signal is compressed and recorded, and a first means for expanding and reproducing a recording signal read from the recording medium, and recording. The information reproducing apparatus comprises second means for obtaining time information by multiplying time-related information obtained from the medium by the reciprocal of the compression ratio of the recording signal.

[0006]

When reproducing, the reproduced signal is expanded at the reciprocal of the compression rate. Therefore, accurate time information can be obtained by multiplying the time-related information obtained from the address information or the time-related information obtained by counting the number of reproduction blocks by the reciprocal of the compression rate.

[0007]

According to the present invention, it is possible to easily obtain accurate time information, such as the reproduction time, even when reproducing a compressed recording medium. The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0008]

EXAMPLE An information reproducing apparatus 10 of this example shown in FIG.
Is, for example, CD-ROM, CD-WO or CD-
The information recorded on the disk 12 such as an MO is reproduced. For example, as shown in FIG. 2, the disk 12 includes a lead-in area 14 at the inner peripheral portion and a lead-out area 1 at the outer peripheral portion
It includes a recording area 18 provided up to 6. The recording area 18 is composed of a plurality of blocks 20 each having 2352 bytes (1/75 seconds) as one block. Each of the constituent blocks 20 includes a synchronization signal area 22 in which a synchronization signal is recorded and a physical position of the disk 12. Address area 24 in which address information indicating minutes, seconds, and the number of blocks is recorded, and an information area 26 in which various information signals are recorded.
And so on.

In the recording area 18, 1 minute 0 seconds 0
A predetermined compression rate P is set in the second area 18b after the block.
Four files (tunes in case of music) compressed by are interleaved and recorded in block units as shown in FIG. 3, for example. On the other hand, in the first area 18a of the recording area 18 up to 1 minute 0 second 0 block, for example, as shown in FIG.
Signals for various controls including the conversion table 28 as shown in FIG. The conversion table 28 shows the start physical time T _A and the end physical time T _B indicating the address information of the start position and the end position of each file recorded in the second area 18b, when each file is continuously reproduced in the order of the file number. Continuous start time T _C and continuous end time T _D indicating the actual start time and end time of each file in
It also has information such as the compression rate P of each file.

The files 1 to 4 may be arranged in a block-by-block interleaved arrangement (FIG. 3), or may be arranged continuously for each file as shown in FIG. However, as shown in FIG. 6, an empty area may be provided between two collected files to arrange them. Returning to FIG. 1, the information reproducing apparatus 10 includes a pickup 30 and the disc 30 is picked up by the pickup 30.
The reproduction signal read from the No. 2 is given to the CD decoder 32. The CD decoder 32 demodulates the reproduction signal,
The CD-ROM decoder 34 detects and corrects the error and corrects it.
Give to. The CD-ROM decoder 34 returns the array (FIG. 3) of each file interleaved in block units to the original array (deinterleave processing), and extracts address information from the reproduced signal returned to the original array. This is stored in the RAM 38 through the microcomputer 36. However, when the array of each file is the array shown in FIG. 5 or 6, the deinterleaving process is unnecessary. CD
The reproduction signal processed by the ROM decoder 32 is given to the audio decoder 40. Audio decoder 40
In, the compressed reproduction signal is restored to the original signal. Therefore, the time length of the reproduction file is expanded to the reciprocal (1 / P) times of the compression rate P, as can be seen from FIG. Then, the expanded signal is converted into an analog signal by the D / A converter 42 and output.

The CD decoder 32, the CD-ROM decoder 34 and the audio decoder 40 are controlled by the microcomputer 36. The microcomputer 36 is connected to a ROM 44 that stores various calculation formulas, a RAM 38 that stores the conversion table 28 and address information (FIG. 2), and a display unit 46 that displays time information and the like. During reproduction, the pickup 30 sequentially reads the signals recorded in the recording area 18 (FIG. 2) from the inner peripheral portion of the disc 12 toward the outer peripheral portion thereof. First, the first area 18a
The signal including the conversion table 28 recorded in (1) is read out and stored in the RAM 38 through the CD decoder 32, the CD-ROM decoder 34 and the microcomputer 36. Then, the reading of the originally necessary information signal is started from the point where the information address is 1 minute 0 second 0 block, and the address information corresponding to the information signal is sequentially stored in the RAM 38 from the CD-ROM decoder 34 through the microcomputer 36. The microcomputer 36 uses the conversion table 2 stored in the RAM 38.
Various calculation formulas stored in the ROM 44 are executed based on the information in 8 and the address information, and the result is displayed on the display unit 46.

For example, when files 1 to 4 are reproduced in the order of file numbers 1, 2, 4, and 3, and the middle of file number 3 is reproduced, the address information of the pickup position is T _X. Then, the reproduction time T _E3 , the continuous elapsed time (the elapsed time from the beginning of the file 1) T _F3 and the remaining time T _G3 in the file number 3 are included in the address information T _X and the information in the conversion table 28 (FIG. 4). It can be obtained by the calculation formula shown in Formula 1 which is called from the ROM 44.

[0013]

## EQU1 ## T _E3 = (T _X −T _A3 ) × 1 / P ₃ T _F3 = (T _D2 −T _C1 ) + T _E3 T _G3 = (T _D4 −T _C1 ) −T _{F3 The} above-mentioned embodiment Then, the conversion table (FIG. 4) recorded on the disk 12 is provided with the compression rate P. However, when the compression rates of the respective files are the same, this compression rate P of the information reproducing apparatus 10 is used. For example, it may be stored in the ROM 44.

In the above embodiment, the pickup 3
Address information read by 0 and conversion table 2
Although various time information is calculated based on the information in 8 and displayed, for example, reproduced block 2
It is also possible to obtain the time-related information by counting the number of 0s and calculate and display various time information based on this time-related information and the information in the conversion table 28. That is, the reproduction time of 1 block is 1/75 second, and 1 block after expansion of 1 / (75 · P) seconds obtained by multiplying 1/75 second by the reciprocal 1 / P of the compression rate P (see FIG. 7). ), The elapsed time can be obtained by multiplying 1 / (75 · P) seconds by the count number. Then, the obtained elapsed time and the conversion table 2
It is possible to calculate various kinds of time information based on the information in 8 and.

For example, files 1 to 4 are
When playing back in the order of number 1, 2, 4, 3
When the middle of file number 3 is being played back,
The number of counts from the start of playback of file number 3 is N
_XThen, the playback time T of file 3_E3′, Continuous
Overtime T_F3′ And remaining time T_G3′ Is the count number N _X
And the ROM based on the information in the conversion table 28.
It can be calculated by the formula shown in Equation 2 called from 44
it can.

[0016]

## EQU2 ## T _E3 ′ = 1 / (75 · P ₃ ) × N _X T _F3 ′ = (T _D2 −T _C1 ) + T _E3 ′ T _G3 ′ = (T _D4 −T _C1 ) −T _F3 ′ In this case, a count area 48 for counting the number of blocks is provided inside the RAM 38, for example.

[Brief description of drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention.

FIG. 2 is an illustrative view showing a recording format of a disc used in the embodiment of FIG.

FIG. 3 is an illustrative view showing a state in which each file is interleaved and arranged.

FIG. 4 is an illustrative view showing a conversion table used in the embodiment of FIG.

FIG. 5 is an illustrative view showing a state in which files, each of which is collected into one, are continuously arranged.

FIG. 6 is an illustrative view showing a state in which files each grouped into one are arranged with an empty area.

FIG. 7 is an illustrative view showing a state where each file is expanded.

[Explanation of symbols]

 10 ... Information reproducing device 12 ... Disk 20 ... Block 24 ... Address area 28 ... Conversion table 30 ... Pickup 32 ... CD decoder 34 ... CD-ROM decoder 36 ... Microcomputer 38 ... RAM 40 ... Audio decoder 44 ... ROM 46 ... Display unit

Claims (3)

[Claims] 1. A reproducing apparatus for a recording medium in which a recording signal is compressed and recorded, wherein first means for expanding and reproducing a recording signal read from the recording medium, and time-related information obtained from the recording medium. An information reproducing apparatus, comprising second means for obtaining time information by multiplying information by the reciprocal of the compression ratio of the recording signal. 2. The address information indicating the physical position of the recording medium is recorded in the recording medium as the time-related information, and the second means reads the address information from the recording medium. 2. The information reproducing apparatus according to claim 1, further comprising: a storage unit that stores, and a unit that multiplies the address information stored in the storage unit by the reciprocal. 3. The second means includes counting means for counting the number of reproduction blocks of the recording medium, and means for multiplying the count number of the counting means by the reciprocal.
The information reproducing apparatus according to claim 1.