JPH103749A - Reproducing device and recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a burden of a controller in the case of data compression processing and data expansion processing. SOLUTION: Command signals for a memory controller 6, an ATRAC (adaptive transform acoustic coding) decoder 8, and a D/A converter 9 are simultaneously transferred to the memory controller 6 from a controller 11 with a prescribed timing. The memory controller 6 controls a memory 7 based on the command signal, while command signals for the ATRAC decoder 8 and the D/A converter 9 are transferred with processed data, the ATRAC decoder 8 performs expansion processing of processed data based on a transferred command from the memory controller 6, while transferring a command signal for the D/A converter 9 with expansion data, the A/D converter 9 converts a digital audio signal to an analog signal based on a transferred command from an expansion device and outputs it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus suitable for use in a mini-disc recording / reproducing apparatus for compressing a digital audio signal and recording it on a disk.

[0002]

2. Description of the Related Art For example, a mini disk recording / reproducing apparatus for recording a digital audio signal on an optical disk or a magneto-optical disk having a diameter of 64 mm stored in a cartridge is known. In such a mini-disc recording / reproducing apparatus, at the time of recording, an input audio signal has, for example, a sampling frequency of 44.1 kHz and a quantization bit number of 16 bits.
Digitized in bits. This audio data is divided into high, middle and low frequencies to avoid pre-echo.
Divided. And, this audio data is maximum 1
The data is cut out at a time window of 1.6 msec, converted into frequency domain data by a modified DCT transform, and processed by the minimum audible characteristic based on human hearing. As a result, the audio data is compressed to about 1/5. Such compression processing is performed by ATRAC (Adaptive Transform A).
coustic Coding).

At the time of reproduction, audio data is expanded. The decompression process is performed in units of a 424-byte sound group. One sound group expands the compressed data and returns it to the time axis information, and then 512 samples of the left and right channels (512 × 16 × 2/8 =
2048 bytes). When one sound group is reproduced, it takes 11.6 ms.

[0004] Reproduced data is temporarily stored in a memory,
It is read for each sound group. And high frequency,
Digital audio data that has been compressed into three bands, a middle band and a low band, is returned to the original time axis information by an inverse DCT operation for each of the left and right channels. Then, the reproduction data of the high band, the middle band, and the low band are combined, D / A converted, and output.

[0005] In a mini-disc, data is stored in CIRC (Cross Interleaved) according to the mode 2 of the CD-ROM.
Reed-Solomon Code), error correction coding, EF
M (8-14) modulation is performed and recorded on the disk. While the CIRC interleave length is 108 frames, the size of one sector is 98 frames,
The interleave length is longer than the size of the sector. For this reason, in the minidisk, 36 sectors are formed into one block (called one cluster), and a link sector is provided at the head of one cluster.

As described above, in the mini disc recording / reproducing apparatus, the compression / expansion processing of the digital audio signal by ATRAC is performed. However, in the conventional mini-disc recording / reproducing apparatus, since such compression / decompression processing needs to be performed according to timing, there is a problem that the load on the controller is increased.

FIG. 10 shows an example of a reproducing system of a conventional mini-disc recording / reproducing apparatus. In FIG.
The disk 101 is a so-called mini disk, and the disk 1
In 01, a digital audio signal compressed by ATRAC is recorded. The recording signal of the disk 101 is reproduced by the optical pickup 102. The output of the optical pickup 102 is supplied to the demodulation circuit 104 via the RF amplifier 103. The demodulation circuit 104 has an EFM (8-
14 demodulation). The output of the EFM demodulation circuit 104 is supplied to the error correction circuit 105. In the error correction circuit 105, a CIRC (Cross-Interleave R
Error correction processing by eed-Solomon) is performed. R
The F amplifier 103, the EFM demodulation circuit 104, and the error forming circuit 105 are controlled by the controller 111.

The output of the error correction circuit 105 is supplied to a RAM 107 under the control of a memory controller 106. The RAM 107 is called a shock proof memory. In the RAM 107, for each sound frame,
A compressed digital audio signal is stored. RAM1
07 is read out for each sound frame under the control of the memory controller 106. This compressed digital audio signal is
The data is supplied to the RAC decoder 108.

The ATRAC decoder 108 performs an inverse DCT on the left and right channels of the digital audio data which has been divided into three, ie, a high band, a middle band, and a low band.
Performs calculation and returns to the original time axis information. The output of the ATRAC decoder 108 is supplied to a D / A converter 109. The D / A converter 109 converts the digital audio signal into an analog audio signal. D /
The output of the A converter 109 is output from the output terminal 110.

Data expansion processing by the memory controller 106, ATRAC decoder 108, and D / A converter 109 is controlled by the controller 111. In order to perform such data decompression processing, the controller 1
11 include commands CM101, CM102, CM10
3 are prepared. Command CM101 is a command for controlling data transfer from the memory. Command CM102 is a command for performing ATRAC decode control. The command CM103 is a command for controlling data output.

[0011] As shown in FIG.
From the command CM101 to the memory controller 106.
Is sent. Command C in the memory controller 106
When M101 is received, the data of the designated sound frame is stored in the RAM1 based on the command CM101.
07.

The system controller 111 determines whether the data transfer has been completed. When the data transfer is completed, the command CM is sent from the system controller 111 to the ATRAC decoder 108 as shown in FIG.
102 is sent. When command CM 102 is received by ATRAC decoder 108, ATRAC decoder 108 performs ATRAC decoding processing.

The system controller 111 determines whether or not the data expansion has been completed. When the data transfer is completed, a command CM 103 is sent from the controller 111 to the D / A converter 109 as shown in FIG. In the D / A converter 109, the command CM103
Is received, the data from the ATRAC decoder 108 is D / A converted and output from the output terminal 110.

FIG. 14 is a flowchart showing the processing at this time. As shown in FIG. 14, when performing the decompression process, the process enters a decode data request interrupt process. Then, a command CM101 for data transfer processing is given from the controller 111 to the memory controller 101 (step ST101).

The controller 111 receives the command CM10
When 1 is sent, it is on standby whether or not the data transfer has been completed (step ST102). When the data transfer is completed, the command CM1 for ATRAC decoding is executed.
02 from the controller 111 to the ATRAC decoder 10
8 (step ST103).

The controller 111 receives the command CM10
When "2" is sent, it is on standby whether or not the decompression process has been completed (step ST104). When the decompression process is completed,
The output control command CM103 of the audio signal is given to the / A converter 109 (step ST10).
5).

[0017]

As described above, conventionally, when the system controller 111 sends the command CM101 for data transfer, the system controller 111 determines whether the data transfer has been completed and determines whether the command CM1 for data decompression has been sent.
02, and a command CM102 for data decompression is transmitted, and it is determined whether or not the data decompression process is completed.
When the data decompression process is completed, the output control command CM1
03 is sent. As described above, the system controller 111 has to wait until the processing in each stage is completed, and the load on the controller 111 is large.

Accordingly, it is an object of the present invention to provide a reproducing apparatus and a recording apparatus which can reduce the load on a controller during, for example, data compression processing or data expansion processing.

Another object of the present invention is to provide a reproducing apparatus and a recording apparatus in which the time axis of the control of the controller does not shift.

[0020]

SUMMARY OF THE INVENTION The present invention provides a memory for temporarily storing compressed data reproduced from a recording medium, a memory controller for controlling reading / writing of data from / to the memory, and a decompression of compressed data read from the memory. A decompressor, a D / A converter for converting decompressed digital data from the decompressor into analog data, and a control device for controlling the memory controller, the decompressor, and the D / A converter. Means for transmitting a command signal to each of the memory controller, the decompressor, and the D / A converter at a predetermined timing. The command signal to the A converter is transferred together with the processing data, and the decompressor Performs decompression processing of the processing data based on the transfer command from the controller,
A command signal for the D / A converter is transferred together with the decompressed data, and the A / D converter converts the digital audio signal into a D / A signal based on the command transferred from the decompressor.
A playback device characterized by performing A-conversion and outputting.

According to the present invention, there is provided an A / D converter for digitizing an input audio signal and inputting the digitized audio signal.
A compressor for compressing digital audio signals digitized by the D converter, a memory for temporarily storing data compressed by the compressor, a memory controller for controlling reading / writing of data from / to the memory, an A / D converter, In a recording apparatus provided with control means for controlling a compressor and a memory controller, the control means transfers a command signal to each of an A / D converter, a compressor and a memory controller at a predetermined timing, and
The converter digitizes the input analog audio signal based on the command signal transferred from the control means, and transfers the command signal to the compressor and the memory controller together with the processing data, and the compressor transfers the command signal to the A / D converter. A recording device that performs data compression processing based on a command and transfers a command signal to a memory controller together with compressed data, and the memory controller controls the memory based on the command transferred from the compressor. is there.

When the processing is completed, a command for the next processing circuit is sequentially transferred to the subsequent stage together with the processing data, so that the controller does not need to perform an operation of waiting for completion of the processing, and the burden on the controller is reduced. Is greatly reduced.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. The present invention relates to a mini disc recording / recording apparatus for compressing and recording digital audio signals.
Used for playback devices. In FIG. 1, a disk 1 is a so-called mini disk, and a digital audio signal compressed by ATRAC is recorded on the disk 1.

The recorded signal on the disk 1 is reproduced by the optical pickup 2. The output of the optical pickup 2 is supplied to the demodulation circuit 4 via the RF amplifier 3. Demodulation circuit 4
Performs demodulation of EFM (8-14 modulation). The output of the EFM demodulation circuit 4 is supplied to the error correction circuit 5. In the error correction circuit 5, the CIRC (Cross-Interl
eave Reed-Solomon) performs error correction processing. The RF amplifier 3, the demodulation circuit 4, and the error correction circuit 5
It is controlled by the controller 11.

The output of the error correction circuit 5 is supplied to a RAM 7 under the control of a memory controller 6. RAM
7 is called a shock-proof memory. RAM
7, a compressed digital audio signal is stored for each sound frame. The compressed digital audio signal in the RAM 7 is read out for each sound frame under the control of the memory controller 6. This compressed digital audio signal is supplied to the ATRAC decoder 8.

The ATRAC decoder 8 performs an inverse DCT operation for each of the left and right channels on the digital audio data that has been divided into high, middle, and low bands, and compresses the original time axis information. Return to The output of the ATRAC decoder 8 is supplied to the D / A converter 9. The digital audio signal is converted into an analog audio signal by the D / A converter 9. The output of the D / A converter 9 is output from the output terminal 10.

In this example, commands for controlling the memory controller 6, the ATARAC decoder 8, and the D / A converter 9 are output from the controller 11, and these commands are transmitted to the memory controller 6, the ATRAC decoder 8, and the D / A converter 9. 9 is transferred. For this reason, the controller 11 uses the memory controller 6, the AT
There is no need to wait for the end of the operation in the RAC decoder 8 and the D / A converter 9, and the burden on the controller 9 is reduced.

That is, when performing data decompression processing,
As shown in FIG. 2, commands CM1, CM2, CM3 are transmitted from the system controller 11 to the memory controller 6.
Are sent at the same time.

Command CM1 is a command for controlling the transfer of data from the memory. The command CM1 specifies sound frame data to be transferred. Command CM2 is a command for performing ATRAC decode control. With this command CM2, control parameters of the ATRAC decoder for the sound frame are set. Command CM3 is a command for data output control. The command CM3 sets the output timing of the data whose time axis has been returned.

The memory controller 6 has a command CM
When receiving CM1, CM2 and CM3, the RAM of the data of the designated sound frame is stored based on the command CM1.
7 and the other command CM2
And CM3.

The command C is issued by the memory controller 6.
Based on M1, the transfer processing of the sound frame data is performed. During that time, other commands CM2 and CM3 are held in the memory controller 6, and the memory controller 6 terminates the transfer control of the designated sound frame. As shown in FIG. 3, the commands CM2 and CM3 are transferred to the ATRAC decoder 8.

The ATRAC decoder 8 receives the data read via the memory controller 6 and
Commands CM2 and CM3 from the memory controller 6
To receive. The ATRAC decoder 8 outputs the command CM2
Received, the ATRA for the sound frame
The control parameters of the C decoder are set, ATRAC decoding processing is performed, and another command CM3 is held.

The ATRAC decoder 8 outputs a command C
Based on M2, transfer processing of sound frame data is performed, during which another command CM3 receives ATRAC
Held in the decoder 8 and the ATRAC decoder 8
As shown in FIG. 4, when the time axis extension processing is completed,
The command CM3 is transferred to the D / A converter 9.

Upon receiving the command CM 3, the D / A converter 9 fetches data from the ATRAC decoder 8, performs D / A conversion on the data, and outputs the data from the output terminal 10.

As described above, in the recording apparatus to which the present invention is applied, the controller 11 sends the memory controller 6
And the memory controller 6 sends the commands CM2 and CM3 to the ATRAC decoder 8 when the processing is completed,
Upon completion of the processing, the RAC decoder 8 issues a command CM
3 is sent to the D / A converter 9. When the processing is completed as described above, commands for the processing circuit of the next stage are sequentially transferred, so that the controller 11 does not need to perform an operation of waiting for whether the processing is completed, and the burden on the controller 11 is reduced. It is greatly reduced.

FIG. 5 is a flowchart showing the operation of the controller 11. As shown in FIG. 5, when the controller 11 expands the data, when a decode request interrupt occurs, a command CM1 for controlling the transfer of data from the memory, a command CM2 for controlling the ATRAC decode, Only the process of simultaneously transferring the command CM3 for data output control (step ST1) is sufficient.

The present invention can be similarly applied to a recording system of a mini disc recording / reproducing apparatus. FIG. 6 shows an example in which the present invention is applied to a recording system of a minidisk recording / reproducing apparatus.

In FIG. 6, an analog audio signal is supplied to an input terminal 21. This analog audio signal is supplied to the A / D converter 22. The analog audio signal is digitized by the A / D converter 22 at a sampling frequency of 44.1 KHz and a quantization bit number of 16 bits.

The output of the A / D converter 22 is ATRAC
It is supplied to the encoder 23. ATRAC encoder 2
3 divides the audio data into high, middle, and low bands, and divides the audio data into a maximum of 11.6.
The data is cut out at a time window of every m seconds, converted into frequency domain data by a modified DCT transform, and a process based on a minimum audible characteristic based on human hearing is performed. As a result, the audio data is compressed to about 1/5. The output of the ATRAC encoder 23 is stored in the RAM 25 under the control of the memory controller 24.

Data is transferred from the RAM 25 to the error correction coding circuit 26 under the control of the memory 24. The error correction coding circuit 26 performs error correction coding processing by CIRC. Error correction encoding circuit 26
Is supplied to the EFM modulation circuit 27. The recording data is EFM-modulated by the EFM modulation circuit 27. E
The output of the FM modulation circuit 27 is supplied to the magnetic head 30 via the drive amplifier 29. The compressed audio data is recorded on the disk 31 by the magnetic head 30 by the magnetic field modulation method.

When performing data compression processing, as shown in FIG.
2, the commands CM11, CM12, and CM13 are sent at the same time.

The command CM11 is a command for controlling data input. The command CM11 sets the data input timing. Command CM12
Is a command for performing ATRAC encoding control. Command CM13 is a command for controlling data transfer to the memory.

The A / D converter 22 receives the command CM1
When receiving 1, the audio signal converted into digital data is controlled to be transferred to the ATRAC encoder 23, and the commands CM12 and CM13 are held. Then, when the transfer of the digital audio data is completed, as shown in FIG.
13 to the ATRAC encoder 23.

The ATRAC encoder 23 outputs the command C
Upon receiving M12, ATRAC encode processing is performed, and the command CM13 is held. And A
When the TRAC encoding process is completed, the command CM 13 is transferred to the memory controller 24 as shown in FIG.

The memory controller 24 has a command CM
When receiving “13”, the digital audio data compressed by ATRAC is transferred to the RAM 25.

As described above, the A / D signal is output from the controller 32.
The command CM11, CM12, CM
13 at the same time, and the A / D converter 22
When the processing is completed, the commands CM12 and CM13 are
Send to AC encoder 23, ATRAC encoder 13
Sends the command CM13 to the memory controller 24 when the processing is completed. This way,
In the controller 32, there is no need to perform an operation of waiting for whether the processing is completed, and the burden on the controller 32 is greatly reduced.

[0047]

In the recording apparatus to which the present invention is applied, commands for the memory controller, the ATRAC decoder, and the D / A converter are sent from the controller to the memory controller at the same time. Is sent to the ATRAC decoder together with the data, and the ATRAC decoder sends the next command to the D / A converter together with the data when the processing is completed.

In the reproducing apparatus to which the present invention is applied, commands for the A / D converter, the ATRAC encoder, and the memory controller are simultaneously sent from the controller to the A / D converter. When the processing is completed, the A / D converter sends a command for the next processing to the ATRAC encoder, and when the processing is completed, the ATRAC encoder sends the next command to the memory controller 24.

When the processing is completed as described above, the commands for the next processing circuit are sequentially transferred, so that the controller does not need to perform an operation of waiting for whether the processing is completed, and the load on the controller is greatly increased. Is reduced to

Further, since all the processes are completely synchronized with the sound frame, it is possible to prevent an unintended sound from being output due to a shift in the time axis of the control of the controller.

[Brief description of the drawings]

FIG. 1 is a block diagram of an example in which the present invention is applied to a reproducing system of a minidisc recording / reproducing apparatus.

FIG. 2 is a block diagram used for explaining an example in which the present invention is applied to a reproducing system of a minidisc recording / reproducing apparatus.

FIG. 3 is a block diagram used for explaining an example in which the present invention is applied to a reproducing system of a minidisc recording / reproducing apparatus.

FIG. 4 is a block diagram used for explaining an example in which the present invention is applied to a reproducing system of a minidisc recording / reproducing apparatus.

FIG. 5 is a flowchart used for explaining an example in which the present invention is applied to a reproducing system of a minidisc recording / reproducing apparatus.

FIG. 6 is a block diagram of an example in which the present invention is applied to a recording system of a minidisc recording / reproducing apparatus.

FIG. 7 is a block diagram used for explaining an example in which the present invention is applied to a recording system of a minidisc recording / reproducing apparatus.

FIG. 8 is a block diagram used for explaining an example in which the present invention is applied to a recording system of a minidisc recording / reproducing apparatus.

FIG. 9 is a block diagram used for explaining an example in which the present invention is applied to a recording system of a minidisc recording / reproducing apparatus.

FIG. 10 is a block diagram of a reproducing system of a conventional minidisc recording / reproducing apparatus.

FIG. 11 is a block diagram used for explaining a reproducing system of a conventional minidisc recording / reproducing apparatus.

FIG. 12 is a block diagram used for describing a reproducing system of a conventional minidisc recording / reproducing apparatus.

FIG. 13 is a block diagram used for explaining a reproducing system of a conventional minidisc recording / reproducing apparatus.

FIG. 14 is a flowchart used to describe a reproducing system of a conventional minidisc recording / reproducing apparatus.

[Explanation of symbols]

6 ... memory controller, 7 ... memory, 8 ...
・ ATRAC decoder, 9 ... D / A converter, 1
1 ... controller

Claims (2)

[Claims] A memory for temporarily storing compressed data reproduced from a recording medium; a memory controller for controlling reading / writing of data from / to the memory; an expander for expanding compressed data read from the memory; A reproducing apparatus comprising: a D / A converter for converting digital data expanded from an expander into analog data; and control means for controlling the memory controller, the expander, and the D / A converter. At a predetermined timing, a command signal for each of the memory controller, the decompressor, and the D / A converter is transferred to the memory controller. The memory controller, based on the command signal transferred from the control means, Control device and the decompressor and the D / A converter To the decompressor together with the processing data, the decompressor performs decompression processing of the processing data based on the command signal transferred from the memory controller, and transmits the command signal to the D / A converter. Is transferred to the D / A converter together with the decompressed data. The D / A converter converts the digital audio signal to a D / A signal based on the command signal transferred from the decompressor.
A reproducing apparatus characterized by performing A-conversion and outputting. 2. An A / D converter for digitizing an input audio signal for input, a compressor for compressing a digital audio signal digitized by the A / D converter, and data compressed by the compressor. A memory for temporarily storing data, a memory controller for controlling reading / writing of data to / from the memory, and control means for controlling the A / D converter, the compressor, and the memory controller. A command signal for each of the A / D converter, the compressor, and the memory controller is transferred to the A / D converter at a predetermined timing by the control means, and the A / D converter transmits the command signal transferred from the control means. Digitizes the input analog audio signal based on the And transmitting the command signal to the compressor and the memory controller together with processing data. The compressor performs a compression process on the data based on the command signal transferred from the A / D converter. A recording device, wherein the command signal to the memory controller is transferred to the memory controller together with the compressed data, and the memory controller controls the memory based on the command signal transferred from the compressor.