JP2003029792A - Compressed audio data reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressed audio data reproducing device in which the processing load of a control means is reduced. SOLUTION: When storing enciphered compressed audio data from a recording medium 1 to a data storage medium 4, information to be used for processing in a deciphering processing part 6 and an extending processing part 7 is set to an additional information storage medium 5. Thus, the control of transfer to the deciphering processing part 6 and the extending processing part 7 in a control means 3 is reduced and the processing load of the control part can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio compressed data reproducing device.

[0002]

2. Description of the Related Art In recent years, a reproducing apparatus for encrypted and highly compressed audio data is becoming popular in order to support music distribution via the Internet or the like. Particularly, as highly compressed audio data, MPEG2_AAC (hereinafter referred to as AAC
There is an audio data compression method called
The usage of editing / playback devices corresponding to this is expanding. In AAC, the data length of a frame, which is a reproduction unit, is not constant even in the same file. Therefore, when it is necessary to limit the number of frames to be reproduced, the number of frames is counted by some method to determine the amount of data to be expanded. I had to decide.

An example of a conventional audio compressed data reproducing apparatus will be described with reference to FIG. On the recording medium 101, the encrypted AAC and the reproduction information and recording information of the encrypted AAC are recorded. The data reading unit 102 reads the encrypted AAC and the reproduction information and recording information of the encrypted AAC. The encrypted AAC is recorded on the recording medium 101 as shown in FIG. 2, and one file of the encrypted AAC is composed of a plurality of recording units (hereinafter referred to as clusters). The control unit 103 encrypts the data in units of reading (hereinafter referred to as a sector) from the recording medium 101 in order from the beginning of the file.
The data reading means 102 is controlled to read the AC. The encrypted AAC read by the data reading means 102 is the primary data storage medium A1 for each sector.
04, and after the storage in the storage medium A 104 is completed, the control means 103 transfers the data to the data storage medium B 105. When the transfer to the data storage medium B105 is completed, the control means 103 reads the next encrypted AAC from the recording medium 101 and continuously stores it in the data storage medium B105, for example, a cluster as a storage unit. Storage control is completed. The control means 103 stores in the data storage medium B105, for example, two clusters of encrypted AA.
When C is stored and the encrypted AAC for the previously stored clusters is transferred to the data storage medium C106, the acquisition of the next encrypted AAC from the recording medium 101 is started. Further, the control means 103 controls the data storage medium B10.
For the encrypted AAC stored in No. 5, the decryption processing and decompression processing target data to be used for reproduction is determined, and in accordance with the transfer request from the decryption processing unit 107, the data is transferred to the data storage medium C106 in sector units at any time. . Furthermore, the control means 1
03 stores, in the additional information storage medium 109, information used for decryption processing and decompression processing of the encrypted AAC transferred to the data storage medium C106, and the encrypted AAC
The data is transferred to the decoding processing unit 107 in synchronization with the AC transfer. The decryption processing unit 107 performs decryption processing on the encrypted AAC transferred from the data storage medium C106 for each reproduction minimum unit (hereinafter referred to as a frame), and in accordance with the transfer request from the decompression processing unit 108, the decompression processing unit 108 receives the decompression processing unit 108. The decrypted AAC is transferred.

The decompression processing unit 108 requests the decoding processing unit 107 to have a data amount M times as large as a sector (M is a natural number of 1 or more) as a transfer request unit, and at the same time, the decoding processing unit 1
The decompressed AAC sent from 07 is expanded.

The processing of the control means 103 will be described with reference to FIG. The control unit 103 controls the data reading unit 102, transfer control from the data storage medium A to the data storage medium B, transfer control from the data storage medium B to the data storage medium C, and addition to the additional information storage medium. The information storage control and the determination of the encrypted AAC for analyzing the data in the data storage medium B and transferring it to the storage medium C are performed in a time division manner. Since the transfer control from the data storage medium A104 to the data storage medium B105 and the transfer control from the data storage medium B105 to the data storage medium C106 are performed asynchronously, the transfer time overlaps as in time zone A in FIG. In this case, in order to continue the reproduction process in the decompression processing unit 108, the transfer control from the data storage medium B to the data storage medium C is prioritized for the transfer.

As described above, the control means manages the processing for the acquisition, decryption and decompression of the encrypted AAC from the recording medium.
Data can be reproduced.

[0007]

However, in the conventional audio compressed data reproducing apparatus, the control means performs the encrypted AAC read control from the recording medium and the transfer control for the decryption processing and the decompression processing. The load was increasing. Further, when reproducing only a predetermined number of frames at the time of fast-forward reproduction, it is necessary to count the number of encrypted AAC frames read from the recording medium and determine the data amount to the decryption processing unit and the decompression processing unit. However, the processing load was further increased. In order to absorb the processing time of the control means, the processing speed of the control means is increased, or the encrypted AAC read from the recording medium is read.
It is necessary to increase the capacity of the data storage medium for storing the data, and there is a problem in realizing power saving and miniaturization.

In view of the above points, the present invention has as its object the provision of an audio compressed data reproducing apparatus in which the processing load of the control means is reduced.

[0009]

According to a first aspect of the present invention, there is provided a reading means for reading the management information of the encrypted audio compressed data and the encrypted audio compressed data from a recording medium, and the reading means. A data storage medium for storing the read out encrypted voice compression data, a decryption processing unit for performing the decryption process by reading out the encrypted voice compressed data from the data storage medium, and data for the decryption processing unit. A decompression processing unit that performs a transfer request and decompresses the audio compression data output from the decoding processing unit;
From the recording medium, which controls the reading means based on the additional information storage medium in which the first additional information used in the processing of the decoding processing section and the decompression processing section is stored, and the management information of the audio compression data. Control means for storing the first additional information in the additional information storage medium for each read unit of the encrypted audio compressed data, and managing the data in the data storage medium and the additional information storage medium. Means for making a data storage request to the data storage medium to the means, and the encrypted voice compression to the data storage medium based on the data storage request from the data remaining volume management means. Storing the data and storing the first additional information in the additional information storage medium,
Is characterized by performing a decoding process and a decompression process of the encrypted voice compression data based on the additional information of, when storing the encrypted voice compression data from the recording medium in the data storage medium, Since the information used for the processing in the decoding processing unit and the decompression processing unit can be set, the transfer control to the decoding processing unit and the decompression processing unit in the control unit can be reduced, and the processing load of the control unit can be reduced.

According to a second aspect of the present invention, in the audio compressed data reproducing apparatus according to the first aspect, the encrypted audio compressed data read from the recording medium is the encrypted audio necessary for the reproduction. It is characterized in that it is only compressed data, and when the encrypted audio compressed data from the recording medium is stored in the data storage medium, only the encrypted audio compressed data necessary for the reproduction is stored. Therefore, the capacity of the data storage medium can be reduced.

According to a third aspect of the present invention, in the audio compressed data reproducing apparatus according to the first aspect, the control means is
In addition to the first additional information, additional information including second additional information that is not used in the processing of the decoding processing unit and the decompression processing unit is stored in the additional information storage medium, By obtaining the set second additional information by the control means at the time of outputting the reproduction data of the decompression processing unit,
It is possible to absorb the time delay between the time of acquiring the encrypted audio compressed data from the recording medium and the time of reproduction output.

According to a fourth aspect of the present invention, in the audio compressed data reproducing apparatus according to the first aspect, the control means is
When reproducing N (N is a natural number of 1 or more) frames of the encrypted audio compression data recorded on the recording medium, the N frames are set to the additional information storage medium. The decoding processing unit counts the number of frames when transferring to the decompression processing unit, and N + 1
It is characterized in that the transfer of data after the frame to the decompression processing unit is stopped and the transfer end is notified to the control unit, and the number of frames of the voice compression data encrypted by the control unit is counted. Since it is not necessary to determine the data amount to the decoding processing unit and the decompression processing unit, the processing load of the control means can be reduced.

According to a fifth aspect of the present invention, in the audio compressed data reproducing apparatus according to the first aspect, the control means is
When reproducing N (N is a natural number of 1 or more) frames of the encrypted audio compression data recorded on the recording medium, the N frames are set to the additional information storage medium. The decoding processing unit counts the number of frames when transferring to the decompression processing unit, and N + 1
With respect to the data after the frame, invalid data is added to the end of the transfer request unit from the decompression processing unit and transferred, and the amount of data to the decompression processing unit after counting N frames is decompressed. Since it can be set by the decryption processing unit in accordance with the transfer unit from, the processing load on the control means can be reduced.

According to a sixth aspect of the present invention, in the audio compressed data reproducing apparatus according to the first aspect, the control means is
By setting final notification information in the additional information storage medium at the end of a series of reproductions, a transfer request from the decompression processing unit for data after the encrypted audio compressed data read from the recording medium. It is characterized by adding invalid data to the end of the unit and transferring it, and at the end of a series of playback, the amount of data to the expansion processing unit is set in the decoding processing unit according to the transfer unit from the expansion processing unit. Therefore, the processing load of the control means can be reduced.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Embodiment 1 of the present invention will be described with reference to FIGS. In the recording medium 1, the encrypted AAC and its reproduction information and recording information are recorded. The data reading means 2 reads the encrypted AAC and its reproduction information and recording information. The control means 3 controls the data reading means 2 based on the reproduction information and the recording information so that the data is sequentially read from the data necessary for the reproduction (hatched portion in FIG. 2) in the file. The encrypted AAC read by the data reading means 2 is sequentially stored in the data storage medium 4 from the recording medium 1 for each sector. At that time, the control means 3 stores the information used in the decryption process and the decompression process of the encrypted AAC in the additional information storage medium 5. The data remaining amount management means 7 manages the difference between the stored data amount in the data storage medium 4 and the additional information storage medium 5 and the read data amount, respectively, and stores the data in the control means 3 when the difference becomes a predetermined amount or less. Make a request. According to the data storage request from the data remaining amount management means 7, the control means 3 stores the encrypted AAC data from the recording medium 1 and the additional information storage medium of the first additional information used in the decryption and decompression processing. 5 is stored. The decryption processing unit 6
According to the transfer request from the decompression processing unit 8, the encrypted AAC is read from the data storage medium 4 in sector units. that time,
The sector-by-sector additional information used for the decoding process and the decompression process is read from the additional information storage medium 5, the decoding process is performed based on the additional information, and the additional information used for the decompression process is transferred to the decompression processing unit 8. . The decryption processing unit 6 decrypts the encrypted AAC read from the data storage medium 4 in frame units, and the decompression processing unit 8 decrypts AAC.
Transfer AC.

The processing of the control means 3 will be described with reference to FIG. The control unit 3 can delete the transfer control described in the conventional example of FIG. 8 by performing only the control of the data reading unit 2 and the control of storing the additional information in the additional information storage medium 5.

Thus, when storing the encrypted audio compressed data from the recording medium in the data storage medium, the information used for the processing in the decryption processing unit and the decompression processing unit is set, so that the control means can control it. The transfer control to the decoding processing unit and the decompression processing unit can be reduced to reduce the processing load. Further, since the data required for reproduction is read from the recording medium 1 without reading the data from the beginning of the file, the capacity of the data storage medium can be reduced.

(Second Embodiment) The second embodiment of the present invention will be described with reference to FIG. It should be noted that the description of the same processing in FIG. 1 will be omitted. In the present embodiment, as additional information to be stored in the additional information storage medium 5 from the control means 3, in addition to the above-mentioned first additional information, the recording information of the sector, for example, the address information in the recording medium 1 or the like is decoded. Second not used for processing of processing unit and decompression processing unit
The additional information of is added. The added recording information is notified to the control unit 3 when the expansion processing unit 8 outputs a voice.

This makes it possible to determine the reproduction start data for skip reproduction or resume reproduction.

(Embodiment 3) Referring to FIGS. 1 and 3,
A third embodiment of the present invention will be described. It should be noted that the description of the same processing in FIG. 1 will be omitted. In the present embodiment, in the case of reproducing only a predetermined number of frames at the time of fast-forward reproduction, the control means 3 causes the additional information storage medium 5 to be reproduced.
The number of frames (n (a natural number greater than or equal to 1)) is added to the second additional information stored in. The decryption processing unit 6 counts the number of frames when decoding the AAC data encrypted on a frame-by-frame basis based on the additional information from the additional information storage medium 5 and sets the data after the set number of frames (N). For, the data transfer to the decompression processing unit 8 is stopped.
At this time, a frame transfer end notification signal is output to the control unit 3 and the expansion processing unit 8.

As a result, at the time of fast-forward reproduction, the control means does not need to count the number of frames of the encrypted audio compressed data to determine the data amount to the decoding processing unit and the decompression processing unit, and the processing load can be reduced. .

(Embodiment 4) Referring to FIG. 1 and FIG.
A fourth embodiment of the present invention will be described. It should be noted that the description of the same processing in FIG. 1 will be omitted. In the present embodiment, in the case of reproducing only a predetermined number of frames at the time of fast-forward reproduction, the control means 3 causes the additional information storage medium 5 to be reproduced.
The number of frames (N (a natural number greater than or equal to 1)) is added to the second additional information stored in. The decryption processing unit 6 counts the number of frames when decrypting the AAC data encrypted on a frame-by-frame basis based on the additional information from the additional information storage medium 5, and regards the data after the set number of frames (N). 4 performs "null" data transfer up to the end of the sector in the middle of the sector and "null" data transfer up to the end of the transfer request unit of the decompression processing unit 8, as shown in FIG. At this time, a frame transfer end notification signal is output to the control means 3.

As a result, even during fast-forward reproduction, the transfer between the decoding processing unit and the expansion processing unit can be processed in the same manner as the normal reproduction, so that the processing load of the control means can be reduced without increasing the processing load of the expansion processing unit. it can.

(Embodiment 5) Referring to FIG. 1 and FIG.
A fourth embodiment of the present invention will be described. It should be noted that the description of the same processing in FIG. 1 will be omitted. In the present embodiment, at the end of a series of reproductions, the music ending information is added from the control means 3 to the second additional information stored in the additional information storage medium 5. As for the data after the final decoding processing based on the music end information from the additional information storage medium 5, the decoding processing unit 6 transfers the "null" data up to the sector end in the middle of the sector and the expansion processing unit as shown in FIG. "Null" data transfer up to the end of transfer request unit 8 is performed.

As a result, the transfer between the decoding processing unit and the decompression processing unit can be processed in the same manner as in the normal reproduction even at the end of a series of reproductions, so that the "null" data transfer control by the control means can be reduced and the processing load can be reduced. it can.

[0026]

As described above, according to the first aspect of the present invention, it is possible to obtain an effect that the transfer control to the decoding processing unit and the decompression processing unit in the control unit can be reduced and the processing load of the control unit can be reduced. To be

According to the second aspect of the present invention, it is possible to obtain the effect of reducing the capacity of the data storage medium for storing the encrypted voice compression data.

According to the third aspect of the present invention, it is possible to easily determine the head encrypted voice compression data to be read from the recording medium during the skip reproduction and the resume reproduction.

According to the fourth aspect of the present invention, since the frame count processing and the data transfer control in the control means can be reduced during the fast-forward reproduction, the processing load of the control means can be reduced.

According to the fifth aspect of the present invention, during the fast-forward reproduction, the processing load of the control means can be reduced by the same processing as the normal reproduction in the expansion processing section.

According to the sixth aspect of the present invention, at the end of the song,
In the decompression processing unit, the same processing as that of the normal reproduction can reduce the processing load of the control unit.

[Brief description of drawings]

FIG. 1 is a block diagram showing an audio compressed data reproducing device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a data recording state according to the first embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a process of a control unit according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing data transfer according to the third embodiment of the present invention.

FIG. 5 is a schematic diagram showing data transfer according to the fourth embodiment of the present invention.

FIG. 6 is a schematic diagram showing data transfer according to the fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a conventional audio compressed data reproducing device.

FIG. 8 is a conceptual diagram showing the processing of a conventional control means.

[Explanation of symbols]

1, 101 recording medium 2, 102 data reading means 3, 103 Control means 4 Data storage medium 5, 109 Additional information storage medium 6, 107 Decoding processing unit 7 Remaining amount management means 8, 108 Decompression processing unit 104 data storage medium A 105 data storage medium B 106 data storage medium C

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shuji Morita             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Akira Nakajima             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Masahiko Hatanaka             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5D044 AB05 DE03 DE42 FG10 GK02                       GK12 GK17 HH05                 5D045 DB10

Claims (6)

[Claims] 1. A reading means for reading the encrypted audio compressed data management information and the encrypted audio compressed data from a recording medium, and the encrypted audio compressed data read by the reading means. A data storage medium to be stored, a decryption processing unit that performs the decryption process by reading the encrypted audio compressed data from the data storage medium, a data transfer request to the decryption processing unit, and an output from the decryption processing unit A decompression processing unit for decompressing audio compressed data, an additional information storage medium in which first additional information used in the processing of the decoding processing unit and the decompression processing unit is stored, and management information of the audio compressed data And controlling the reading means to read the encrypted audio compressed data from the recording medium in units of the first unit of the additional information storage medium. A control means for storing additional information; and a data remaining amount management means for managing data of the data storage medium and the additional information storage medium and requesting the control means to store data in the data storage medium, Storing the encrypted compressed audio data in the data storage medium and storing the first additional information in the additional information storage medium based on a data storage request from the data remaining amount management means; An audio compressed data reproducing apparatus, which performs a decoding process and a decompressing process of the encrypted audio compressed data based on additional information. 2. The audio compressed data according to claim 1, wherein the encrypted audio compressed data read from the recording medium is only the encrypted audio compressed data necessary for the reproduction. Playback device. 3. The additional information including the second additional information, which is not used in the processing of the decoding processing unit and the decompression processing unit, in addition to the first additional information, is stored in the additional information storage medium. The audio compressed data reproducing apparatus according to claim 1, wherein 4. The N-th of the encrypted audio compression data recorded in the recording medium is stored in the control means.
When reproducing the number of frames (natural number of 1 or more), the number of N frames is set in the additional information storage medium, and the decoding processing unit counts the number of frames when transferring to the decompression processing unit. 2. The audio compressed data reproducing apparatus according to claim 1, wherein the transfer of the data of N + 1 frames and subsequent frames to the decompression processing unit is stopped, and the control unit is notified of the end of the transfer. 5. The control means includes N (where N is, N) of the encrypted audio compression data recorded on the recording medium.
When reproducing the number of frames (natural number of 1 or more), the number of N frames is set in the additional information storage medium, and the decoding processing unit counts the number of frames when transferring to the decompression processing unit. 2. The audio compressed data reproducing apparatus according to claim 1, wherein invalid data is added to the end of the transfer request unit from the decompression processing unit for the data on and after N + 1 frames and transferred. 6. The control means sets final notification information in the additional information storage medium at the end of a series of reproductions, so that the encrypted audio compressed data after the encrypted audio data read from the recording medium is recorded. 2. The audio compressed data reproducing apparatus according to claim 1, wherein invalid data is added to the end of the transfer request unit from the decompression processing unit and transferred with respect to the data.