JP2003015691A - Audio compressed data reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio compressed data reproducing device, which is inexpensive, reduces power consumption and is convenient for displaying time information. SOLUTION: A ROM decode part 17A and an MP3 decode part 17B are formed in a DSP 17, time information on reproducing of a recording file on a CD 11 is formed in the DSP 17 as well, and the time information is transferred from the DSP 17 to the MCU 18 and displayed in response to a command from an MCU 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM in which audio compression data such as a music performance file compressed according to the MP3 data compression standard is recorded.
The present invention relates to an audio compressed data reproducing device using a digital data recording medium such as a CD-R and a CD-RW.

[0002]

2. Description of the Related Art In a normal audio CD called CD-DA, information necessary for reproducing audio data is recorded in a TOC located at the innermost circumference of a recording surface of a CD (compact disc) and a performance time of each music piece or recorded. It is recorded together with time information such as the total performance time of all the existing music, and the performance elapsed time from the beginning of each music is directly obtained from the bit stream output from the pickup. As a result, the user can confirm the total playing time, the playing time of each song, and the like from the display on the display unit before the performance of the first music specified by loading the audio CD into the CD player is started. It is also possible to confirm the elapsed time after the performance of the music is started.

However, CD-ROM, CD-R,
Digital data CDs such as CD-RW can be recorded on the TO
C does not include time information such as CD-DA in the part called volume descriptor and path table, and also in the bit stream of the performance file data of each music output from the pickup. It does not include time information indicating playing time or elapsed time. Therefore, conventional CD-ROM, CD-R, CD-
In a digital data CD player such as RW, a microcomputer having a built-in microcomputer performs all the complicated data processing for obtaining the time information from the reproduced bit stream.

FIG. 11 is a block diagram showing an example of the circuit configuration of a digital audio CD player compressed according to MP3 which is one of the conventional MPEG audio CD data compression standards. In FIG. 11, a CD6 in which digital audio data compressed according to MP3 is recorded
1 is rotated by a motor 63 driven by a driver 62. The driver 62 is controlled by the CD servo 64, and rotates the CD 61 at a constant angular velocity, for example.

An analog bit stream obtained corresponding to the pit train on the recording track as the CD 61 rotates is supplied from the pickup 65 to the RFAMP 66, amplified, and converted into a digital bit stream by the CD servo 64. It is supplied to the ROM decoder 67.

CD servo 64 and ROM decoder 67
Is controlled by a microcomputer (MCU) 68, and MP3 data, which is audio digital compressed data, is read from an input bit stream by a ROM decoder 67.
This MP3 data is generated by
And is transferred to the MP3 decoder 69.

The MP3 decoder 69 expands and decodes this MP3 data to generate PCM audio data, an analog audio signal is reproduced by the digital-analog converter 70, amplified by the AMP 71, and then reproduced by the speaker 72. Is obtained.

The information indicating the file structure obtained from the volume descriptor and the path table recording area of the CD 61 in the bit stream obtained from the CD 61 is
Information is sent from the ROM decoder 67 to the file memory 73 via the MCU 68 to indicate the file / folder structure of the CD 61, and the total number of files on the CD 61, the number of bytes for each file, the start and end addresses for each file, etc. Is stored.

Further, M obtained from the ROM decoder 67
When decompressing P3 data with the MP3 decoder 69,
Information indicating the fixed bit rate or the variable bit rate of the three files can be obtained.

The MCU 68, based on these information,
The playing time per song of the MP3 file and the playing time are calculated and displayed on the display device 74. The key device 75 is used by the user for play, stop, FF,
Includes operating keys such as FR.

[0011]

The MCU 68 is a C
Control of all D player systems, eg CD61
In addition to performing the above file analysis, management, control of the CD servo 64 for controlling the rotation of the CD 61, control of the ROM decoder 67, the MP3 decoder 69, and the like, complicated data processing for obtaining the above time information is performed. What needs high-speed and large-capacity data processing is required.

Since a high-performance microcomputer such as the MCU 68 is expensive and consumes a large amount of power, a C
This causes an increase in cost of the D player and an increase in power consumption.

In particular, when this microcomputer is commonly used for controlling other digital data processing devices other than a CD player, such as a cassette tape recorder or a mini disk recorder for recording reproduced audio data. In addition, the required data processing capacity is further increased, which leads to an increase in price and power consumption.

Regarding the time information during the performance, for example, the MCU 68 of FIG. 11 sequentially grasps the transfer amount of the compressed data of the audio compressed data, for example, from the ROM decoder 67 to the MP3 decoder 69, the bit rate, etc. during the performance. It is necessary to calculate and display. In particular, in the case of a variable bit rate in which the bit rate changes during the performance of one song, or when performing FF, FR, etc., M
A great burden is placed on the CU 68.

Therefore, an object of the present invention is to provide an audio compressed data reproducing apparatus which has the same usability as a CD-DA with respect to the display of time information from the user's perspective, is inexpensive and consumes less power.

[0016]

An audio compressed data reproducing apparatus of the present invention includes a first decoder for generating audio compressed data from an input bit stream and a second decoder for generating audio decompressed data from the audio compressed data. Decoder, and time information generating means for generating time information regarding reproduction of audio compressed data based on at least the input bit stream, and the first,
A first processor for controlling the operations of the second decoder and the time information generating means, a means for outputting an audio signal based on the audio decompression data, and the time information received from the first processor on a display device. It is composed of a second processor such as a microcomputer for displaying.

With this configuration, it is possible to provide an audio compressed data reproducing apparatus which can reduce the burden on the microcomputer and can be inexpensive and consume less power.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, a CD 11 in which audio data compressed according to the MP3 standard is recorded is rotated by a motor 13 driven by a driver 12. The driver 12 is controlled by the CD servo 14, and C
D11 is rotated at a constant angular velocity, for example. The reproduction signal obtained corresponding to the pit train on the track accompanying the rotation of the CD 11 is supplied from the pickup 15 to the RF AMP 16 and amplified, and is digitized in the CD servo 14 controlled by the microcomputer (MCU) 18. Corresponding bit stream data is formed, and this data (DATA) is supplied from the CD servo 14 to the ROM decoding unit 17B via the input buffer 17A formed in the DSP 17, and converted into audio digital data compressed by MP3. Be decrypted. Input buffer 1
The bit stream supplied to 7A is the file memory 2
3 is stored.

Bitstream to ROM decoding unit 1
MP3 data generated by 7B is the same DSP17
It is transferred to the MP3 decoding unit 17C formed inside.
The MP3 decoding unit 17C decompresses and decodes this MP3 data to generate PCM audio data. The decompressed and formed PCM audio data is sent to the digital-analog converter (DA) via the output buffer 17E.
C) Played back to analog audio signal at 20, AM
After amplification at P21, a reproduction sound of the music is obtained from the speaker 22.

From the MP3 decoding section 17C, as will be described later, various data as a basis for calculating time information relating to the performance of the loaded music file of the CD 11 are obtained,
This data is sent to the time calculation processing unit 17F and a predetermined calculation is performed, and the calculated time information is stored in the time information storage unit 17F.
Stored in G. The stored time information is transferred to the MCU 18 via the microcomputer command interface 17H upon receiving a command from the MCU 18, as described later. The DSP 17 has a function as a processor for controlling the operation of various circuits 17A-17H inside the DSP 17.

An example of the structure of the data recording surface of the CD 11 is shown in FIG. In FIG. 2, the data recording surface sequentially includes the lead-in area 31 including the TOC from the innermost circumference,
It is a volume descriptor (VD) and path table (PT) 32, a data area 33, and an outermost lead-out area 34. In the TOC of the lead-in area 31, this CD 11 is a CD-DA on which normal PCM data is recorded, or digital data including audio compression data is recorded, for example, C of MP3.
Information such as D is recorded.

In the volume descriptor and path table 32, details of the folder / file structure such as the total number of folders / files recorded on the CD 11, the number of bytes of each file, the start address StartMSF and the end address EndMSF of each file are recorded. Has been done.

The data structure recorded in the data area 33 is shown in FIG. In FIG. 3, the data recorded on the recording track of the data area 33 is grouped by sector unit, and a plurality of sectors S1, S2, ... Are sequentially arranged in series from the inner circumference side to the outer circumference side. Have.

For example, the sector S1 has synchronization data SC1.
, The header SC2, the data section SC3,
It is composed of error detection code (EDC) data SC4, padding data SC5, and error correction code (ECC) data SC6. The subsequent sectors S2 ... Have the same configuration.

The header SC2 in the sector S1 is divided into an address section SA and a mode section M, and the address section SA is further divided into M (minute) address section SA1 and S (second) address section S.
It is divided into A2 and F (frame) address section SA3. Data indicating the sector format is arranged in the mode section M.

The data section SC3 of the sector S1 has a serial configuration of frames F1, F2, ... Recorded corresponding to a plurality of music pieces. For example, the first frame F1 is a portion in which the audio data of the first song is compressed and recorded by MP3,
It is composed of a header FH and data FD.

The header FH has, at its head, a synchronous data portion FH1 consisting of a plurality of consecutive "1" bits,
Subsequently, an ID data part FH2 of 1 bit of "1" follows, and a 2-bit layer data part FH3 is further provided. The layer indicates the content of the data compression standard, and for example, 2 bits distinguish layer I, layer II, and layer III. MP3 corresponds to this layer III. C
The RC section FH4 is a section indicating a protection bit, and then
Bit rate section FH5, sampling frequency section FH6 ...
And so on.

The bit rate part FH5 is used for this frame F1.
The data indicating the bit rate of the audio digital data recorded in is recorded in the sampling frequency part FH.
Reference numeral 6 is a sampling frequency when the original sound data is recorded on the CD 11.

Returning to FIG. 1, in the bit stream obtained from the CD 11, information indicating the file structure from the volume descriptor of the CD 11 and the path table 32 is stored in the file memory 23 provided by the MP3 decoding unit 17C. The file / folder structure data of the CD11 is stored and the total number of folders / files on the CD11, the number of bytes for each file, the start address StartMSF for each file, and the end address EndMS.
Information indicating F and the like is stored.

The time calculation processing unit 17F in the DSP 17 is
Based on these information, the playing time per MP3 file song, the playing time, etc. are calculated and stored in the time information storage unit 17G which is a part of the internal memory.
Upon receiving the command from the MCU 18, the time information is transferred to the MCU 18 via the microcomputer command interface 17H. This time information has, for example, a 2-byte structure. The first byte is performance time data per file, and the second byte is data indicating the elapsed performance time of the file being played. The MCU 18 receives this time information and displays it on the display device 24. The key device 25 is used by the user to play, stop, FF, and F.
Includes operating keys such as R.

The file memory 23 shown in FIG. 1 has an input buffer 23A, as shown in FIG.
It includes a file table (FAT) 23B and a directory table (SPT) 23C. For example, the input buffer 23A has a capacity of 24 * 2340 = 56160 bytes, and the file table 23B has a capacity of 256 * 144 =.
It has a capacity of 36864 bytes, and the directory table 23C has a capacity of 256 * 144 = 36864 bytes.

FIG. 4B shows these file memories 23.
Shows the hierarchical structure of the files configured in the file memory 23 based on the data stored in the file memory 23. The file name data <root> 1 is stored in the uppermost folder and the file name data <POPS> is stored in the middle hierarchical folder. 2, <ROCK> 3,
And aaa.mp31, file name data <AYU> 4, ... ccc.mp33 in the lowest level folder, file name data ddd.mp34, ... iii.mp3 in the lower level files.
9 is placed. For example, the file names ddd.mp34 and eee.mp35 belong to the folder <AYA> 4. Here, the superscripts 1, 2, ... 9 indicate song numbers (Song No) in the file table 23B of FIG. 4C.

The operation for acquiring time information in the embodiment shown in FIGS. 1 to 4 will be described in detail below with reference to FIGS. 5 to 10.

FIG. 5 is a flowchart showing the entire operation. First, in step S1, the disc CD11 is loaded on the disc table driven by the motor 13.

Then, the pickup 15 first reads the CD 1
The disk is moved to the reading position of the lead-in area 31 at the innermost circumference of No. 1, and the contents of the lead-in area 31 are read to first perform the disk analysis. That is, the pickup 15 reads the TOC in the lead-in area 31, and the read TOC data is RFAMP 16 and CD servo 1
It is sent to the MCU 18 via 4 and analyzes what kind of disc the CD 11 is.

In this TOC 31, what kind of CD the loaded CD 11 is is recorded.
Based on the contents of the TOC 13, the U 18 checks in step S3 whether the disc is a CD for MP3 data, that is, CDMP3 or CD-DA.
If it is found to be a CD-DA, the reproduction process is performed.

When it is found that the loaded disc is CDMP3, the process proceeds to step S4 and the TOC3 of CD11 is set.
The data analysis of the volume descriptor and the path table 32 recorded after the outer peripheral side of 1 is performed by the DSP 17
Done by By this data analysis, step S
5 in the file memory 23 as shown in FIG.
Information indicating the total number of folders / files on D11, the number of bytes for each file, the start address StartMSF for each file, the end address EndMSF, and the like is stored, and a file / folder structure is formed.

Then, in step S6, it is checked whether or not the performance is started, that is, whether or not the play key on the key device 25 is operated.

If YES, the process proceeds to step S7, and it is checked whether the file (musical piece) to be reproduced is designated by the key on the key device 25. If it is designated, the frame of the designated file, for example, the frame F2 is designated for the second music, and if not designated, the first frame F1 is designated.

Next, in step S8, the start address StartMSF and end address EndMSF of the reproduction file are extracted from the file table in the file memory 23.

When the processing of step S8 is completed, the CD 11
The state in which the data of can be reproduced is set, and step S9 is performed.
Then, the pickup 15 is moved to the head position of the data area 33, and the reproduction of the recorded data is started. As a result, the CD servo 14 to the input buffer 17 of the DSP 17
The bit stream is input to A.

Then, the process proceeds to step S10, and the reproduction data in this bit stream state is stored in the ROM decoding unit 1.
7B and is decoded into MP3 data. For example, the sector header SC of the sector S1 of the MP3 data in this state
From 2, the address data MSF as shown in FIG. 3 is extracted.

Then, the process proceeds to step S11, where MP3
The MP3 decoding unit 17C starts the decompression operation of the compressed audio data.

Here, in step S12, the bit rate is extracted from the bit rate part FH5 in the MP3 frame header FH of the file of FIG.

That is, the bit stream from the data area 33 read from the pickup 15 is the DSP 17
The ROM decoding unit 17B converts the audio compressed data into a format that can be processed by the MP3 decoding unit 17C, and then the MP3 decoding unit 17C decompresses the compressed data.

Therefore, in step S13 of FIG.
For example, the bit rate index FH5 included in the header FH of the first frame F1 in the first sector S1
For example, the content of the bit rate of the data of the frame F1 can be known from the content of 4 bits. This bit rate data is stored in the internal register or the file memory 23 as a part of the time information of the file being played.

Hereinafter, the time information storage unit 17G or the file memory 23 will be referred to with reference to the steps after step S13.
A method of acquiring time information based on the information stored in will be described.

First, in step S13, it is checked whether the acquired bit rate is fixed (1) or variable (2). In the case of a fixed bit rate, it moves to the step of "1" to calculate the playing time by the fixed bit rate, and in the case of a variable bit rate, it moves to the step of "2" to calculate the playing time of the variable bit rate. To do.

(1) The method of calculating the playing time at a fixed bit rate will be described with reference to FIG.

(1) A method of acquiring playing time per file.

In step S21 of FIG. 6, the DSP1
Among the file table information stored in the file memory 23 attached to 7, the start address of the playback file Star
tMSF and end address EndMSF (however, M: minutes,
S: second, F: frame) are extracted.

In the next step S22, decoding, that is, decompression of MP3 data is started from the first frame of the file. In this state, MP3 in step S23
Extract the bitrate from the frame header.

From these extracted data, the playing time is calculated in the next step S24.

First, the total number of bytes of one file (song) is the total number of bytes of one file = (EndMSF-StartMSF)
* 2048byte As described above, MP3 decoding unit 17C uses MP3
Since the bit rate is known when the decoding operation is started, the playing time T (s) per file is T (s) = 1 total number of bytes (byte) / bit rate (bit / s) = ( EndMSF-StartMSF) * 2048byt
It can be obtained by calculating e ÷ bitrate by the time calculation processing unit 17F in the DSP 17. The calculated playing time is step S2.
5 is stored in the time information storage unit 17G.

The calculation of the elapsed time during the performance in the case of the fixed bit rate, which is usually required when operating the FF and FR, is performed by the operation shown in the flowchart of FIG.

First, as in step S21 of FIG. 6, in step S31, the start address StartMSF of the reproduction file is read from the file table in the file memory 23.
Extract end address EndMSF.

When the processing of step S31 ends, CD1
The state in which the data of No. 1 can be reproduced is set, and step S
At 32, the pickup 15 is moved to the head position of the data area 33, and the reproduction of the recorded data is started. As a result, the bit stream is input from the CD servo 14 to the input buffer 17A of the DSP 17.

Then, the process proceeds to step S33, and the reproduction data in this bit stream state is stored in the ROM decoding unit 1.
7B and is decoded into MP3 data. For example, the sector header SC of the sector S1 of the MP3 data in this state
From 2, the address data MSF as shown in FIG. 3 is extracted.

Then, the process proceeds to step S34 and MP3
The MP3 decoding unit 17C starts the decompression operation of the compressed audio data. Here, in step S35, for example, the current address (CurrentMSF) of the sector S1 at which the MP3 data decompression operation is started is extracted.

Then, in step S36, the bit rate (bit rat) is calculated from the MP3 frame header FH of the file.
e) is extracted.

From each data thus obtained, the elapsed time t is calculated based on the following formula in step S37.
(S) is calculated by the time calculation processing unit 17F.

T (s) = ((CurrentMSF-StartMSF) × 20
48 bytes) ÷ bitrate The elapsed time t (s) thus calculated is sent from the time calculation processing section 17F to the time information storage section 17G and stored therein in step S38.

On the other hand, when the bit rate is a variable bit rate in step S13 of FIG. 5, the playing time is calculated according to the flowchart of FIG.

First, in step S41, the start address StartMSF and end address EndMSF of the reproduced file are extracted from the file table in the file memory 23.

Next, in step S42, the bit rate (bitrate 1) of the first frame is extracted from the MP3 frame header of the file.

Then, in step S43, the bit rate (bit rate 2) of the second frame is extracted from the MP3 frame header of the file.

Similarly, in step S44, the bit rate (bit rate n) of the nth frame is extracted from the MP3 frame header of the file.

In this way, the bit rate (bitrate 1, bitrate 2, ... Bitrate n) of each frame is acquired from the bit rate index contained in the header information for n frames from the first frame of the file, and step S45 Then, the bit rate of this file can be approximated to a fixed bit rate by calculating the average value, that is, the average bit rate (average bit rate) by the time calculation processing unit 17F by the following method.

(Average bitrate) = (bitrate 1 + bitra
te 2 + ... + bitrate n Therefore, the playing time Tvb (s) at this time is Tvb (s) = ((CurrentMSF-StartMSF) × 2048 bytes) ÷ average b
You can get it at itrate. The obtained performance time information is similarly stored in the time information storage unit 17G in the DSP 17 in step S46.

Here, the routine proceeds to step S47, where it is checked whether the current operating state is FF / FR. If YES, FF for variable bit rate /
The process proceeds to the step of calculating the elapsed time of FR, and if NO, proceeds to the step of calculating the normal elapsed time in the case of a variable bit rate.

In the case of the variable bit rate, the bit rate for each frame is different, and in the case of the elapsed time, it cannot be processed by averaging several frames. Therefore, with the method described below with reference to FIG. Calculate.

First, similarly to step S31 in FIG. 7, in step S51, the start address StartMSF of the reproduction file is read from the file table in the file memory 23.
Extract end address EndMSF.

When the process of step S51 ends, CD1
The state in which the data of No. 1 can be reproduced is set, and step S
In step 52, the pickup 15 is moved to the head position of the data area 33, and reproduction of recorded data is started. As a result, the bit stream is input from the CD servo 14 to the input buffer 17A of the DSP 17.

Then, the process proceeds to step S53, and the reproduction data in this bit stream state is stored in the ROM decoding unit 1.
7B and is decoded into MP3 data. For example, the sector header SC of the sector S1 of the MP3 data in this state
From 2, the address data MSF as shown in FIG. 3 is extracted.

Then, the process proceeds to step S54, where MP3
The MP3 decoding unit 17C starts the decompression operation of the compressed audio data.

Subsequently, in step S55, the 44.1 KHz LR clock (LRCK) supplied from the CD servo 14 of FIG. 1 is counted by the counter by the CPU 17I in the DSP 17. Therefore, when this counter reaches 441000 count, one second has elapsed. For example, if a carry is output at 441000 counts, one carry output is obtained every second.

When this carry signal is calculated in step S56 by the time calculation processor 17F using a counter, elapsed time information updated every second can be obtained. The elapsed time information thus obtained is stored in the time information storage unit 17
Stored in G.

In the case of a variable bit rate, the elapsed time in FF / FR is not continuous unlike in normal performance, so that
The same calculation as for the fixed bit rate of is performed. However, it is necessary to hold the bit rate value at the time of entering FF / FR. Hereinafter, a method of calculating the elapsed time during FF / FR will be described with reference to FIG.

First, as in step S31 of FIG. 7, in step S61, the start address StartMSF of the reproduction file is read from the file table in the file memory 23.
Extract end address EndMSF.

When the processing of step S61 ends, CD1
The state in which the data of No. 1 can be reproduced is set, and step S
In step 62, the pickup 15 is moved to the head position of the data area 33, and the reproduction of recorded data is started. As a result, the bit stream is input from the CD servo 14 to the input buffer 17A of the DSP 17.

Then, the process proceeds to step S63, and the reproduction data in this bit stream state is stored in the ROM decoding unit 1.
7B and is decoded into MP3 data. For example, the sector header SC of the sector S1 of the MP3 data in this state
From 2, the address data MSF as shown in FIG. 3 is extracted.

Then, the process proceeds to step S64, where MP3
The MP3 decoding unit 17C starts the decompression operation of the compressed audio data. Here, in step S65, for example, the current address (CurrentMSF) of the sector S1 at which the MP3 data decompression operation is started is extracted.

Subsequently, in step S66, FF /
The bit rate is extracted from the MP3 frame header FH of the file immediately after entering the FR.

From each data thus obtained, in step S67, the elapsed time t is calculated based on the following calculation formula.
(S) is calculated by the time calculation processing unit 17F.

T (s) = ((CurrentMSF-StartMSF) × 20
However, the bit rate at this time is the bit rate immediately after entering the FF / FR.

The elapsed time t calculated in this way
(S) is the time calculation processing unit 17 in step S68.
It is sent from F to the time information storage unit 17G and stored therein.

As described above, various time information is acquired in step S7 in FIG. 5, and these are acquired as the time information storage unit 1 built in the file memory 23 or the DSP 17.
It is stored in 7G.

Returning to FIG. 5, in this state, the DSP 17 sends, for example, SongTime from the MCU 18 in step S14.
It is checked whether or not there is a command, and if there is, the predetermined time information is sent in step S15 according to this command SongTime.
At, it is transferred to the MCU 18 via the microcomputer command interface 17H.

This command SongTime is generated, for example, every one second, and if the configuration is a two-byte configuration as described above, the first byte indicates the playing time per file and the second byte indicates the elapsed time. It will indicate the time.

Upon receiving this time information, the MCU 18 displays predetermined time information on the display device 24, for example, total playing time, 1
Display performance time etc. for each file.

[0092]

As described above in detail, according to the present invention,
It is possible to provide an inexpensive and low power consumption audio compressed data reproducing device capable of displaying a playing time and the like by an operation similar to that of a conventional CD-DA player without burdening the MCU with complicated processing and unnecessary load. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a plan view schematically showing the structure of the data recording surface of the CD shown in FIG.

FIG. 3 is a diagram showing an internal configuration of sectors and frames of data recorded on the CD of FIG.

FIG. 4 is a diagram showing a memory map of the file memory shown in FIG.

5 is a flowchart showing a main flow for explaining the operation of the embodiment shown in FIGS. 1 to 4. FIG.

FIG. 6 is a flowchart showing a playing time calculation method at a fixed bit rate.

FIG. 7 is a flowchart showing a method of calculating elapsed time at a fixed bit rate.

FIG. 8 is a flowchart showing a playing time calculation method at a variable bit rate.

FIG. 9 is a flowchart showing a method for calculating elapsed time at a variable bit rate.

FIG. 10 is a flowchart showing a method of calculating elapsed time in FF / FR at a variable bit rate.

FIG. 11 is a block diagram showing an example of a conventional audio compressed data reproducing device.

[Explanation of symbols]

11 ... CD, 12 ... driver, 13 ... motor, 14 ... CD servo, 15 ... Pickup, 16 ... RFAMP, 17 ... DSP, 18 ... MCU, 20 ... DAC, 21 ... AMP 22 ... speaker, 23 ... File memory, 24 ... Display device, 31 ... TOC, 32 ... Volume descriptor and path table, 33 ... Data area.

Continued front page    (72) Inventor Jun Wakasugi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Ceremony Company Toshiba Microelectronics Sen             Inside F-term (reference) 5D044 AB05 BC03 BC05 BC06 CC06                       DE38 GK02 GK08                 5D045 DA20                 5D077 AA29 AA30 HA01 HB01 HC08                       HC15

Claims (9)

[Claims] 1. A first decoder for generating audio compression data from an input bit stream, a second decoder for generating audio decompression data from the audio compression data, and audio compression data based on the input bit stream. Time information generating means for generating time information relating to reproduction of data, a first processor for controlling operations of the first and second decoders and the time information generating means, and means for outputting an audio signal based on the audio decompression data. And a second processor which receives the time information from the first processor and displays the time information on a display device. 2. The first and second decoders, the time information generating means, and the first processor are DSPs (Digital Signals).
The audio compressed data reproducing apparatus according to claim 1, wherein the audio compressed data reproducing apparatus is incorporated in a processor. 3. The audio compressed data includes performance file data of a plurality of songs, and the time information generating means generates a performance time of each music and an elapsed time during performance from the performance file data of each music. The audio compressed data reproducing apparatus according to claim 1 or 2, further comprising: 4. The time information generating means generates start time and end address of each performance file data from the input bit stream, and audio decompression data in order to generate performance time and elapsed time during performance. The audio compressed data reproducing apparatus according to claim 3, wherein the audio compressed data reproducing apparatus is provided in association with a memory that stores data representing a fixed bit rate and a variable bit rate. 5. A system control microprocessor for controlling the overall operation of a plurality of data processing devices including at least an audio compressed data reproducing device, wherein the audio compressed data reproducing device receives audio from an input bit stream. A first decoder for generating compressed data, a second decoder for generating audio decompressed data from the audio compressed data, and a time information generation for generating time information regarding reproduction of the audio compressed data based on at least the input bit stream Means, a processor for controlling the operations of the first and second decoders and the time information generation means, and means for outputting an audio signal based on the audio decompression data, wherein the microprocessor outputs the time information. Display from the processor A data processing system characterized by being displayed above. 6. The data processing system according to claim 5, wherein the first and second decoders, the time information generating means, and the processor are incorporated in a DSP. 7. The audio compressed data includes performance file data of a plurality of songs, and the time information generating means generates a performance time of each music and an elapsed time during performance from the performance file data of each music. The data processing system according to claim 5, further comprising: 8. The time information generating means generates start time and end address of each performance file data from the input bit stream, and audio decompression data in order to generate performance time and elapsed time during performance. The data processing system according to claim 3, wherein the data processing system is provided in association with a memory that stores data representing a fixed bit rate and a variable bit rate. 9. A DSP that generates audio compression data from an input bit stream, generates audio decompression data from the audio compression data, and generates time information regarding reproduction of the audio compression data based on at least the input bit stream. An audio compressed data reproducing apparatus comprising: a means for outputting an audio signal based on the audio decompression data; and a processor for receiving the time information from the DSP and displaying the time information on a display device.