KR0171838B1 - Method for data interfacing of mini disc decoding system - Google Patents

Abstract

[Technical field to which the invention described in the claims belong]

The present invention relates to a data interface method between a Shock Resistant Memory Controller (SRMC) and an Adapted Transform Acoustic Coding (ATRAC) decoder in a mini disc decoding system.

[Technical Problem to Solve]

By buffering the data already buffered through the buffer memory and then processing it in the ATRAC decoder, not only is the buffer wasted but also the processing time required for decoding is improved.

[Summary of the solution of the invention]

When the data of the sound group stored in the buffer memory is transmitted to the ATRAC by the SRMC, decoding information of the audio data and its copy information are alternately transmitted in byte units.

[Important Uses of the Invention]

Used for decoding in the mini disc decoding system.

Description

Data interface method of mini disc decoding system

1 is a data interface format diagram of a typical mini disc decoding system.

2 is a block diagram of a general mini disc decoding system.

3 is a data interface format diagram between an SRMC and an ATRAC decoder according to the format of FIG.

4 is a data interface format diagram between an SRMC and an ATRAC decoder according to the present invention.

5 is a block diagram of a mini disc decoding system according to the present invention.

6 is a data interface processing flow chart according to the present invention.

* Explanation of symbols for main parts of the drawings

200: ACIRC decoder 202: SRMC

204: buffer memory 206: ATRAC decoder

208: bit allocation decoder 210: WL buffer

212: SF buffer 214: sample buffer

216: kidney processing unit

The present invention relates to a mini-disc (MD) decoding system, and more particularly, to a data interface method between a Shock Resistant Memory Controller (SRMC) and an Adapted Transform Acoustic Coding (ATRAC) decoder.

In general, in a MD system, a decoding system reads data recorded on a disk, corrects an error, and then decompresses the data that was compressed at the time of encoding to restore original audio data. At this time, in order to prevent an error due to vibration generated by the movement of the system or the user's portable during the operation of the system, the read data is buffered and expanded using the buffer memory.

The MD system processes read data in data units called sound groups according to a specially defined data interface format. If the above data interface format is shown, it is as shown in FIG. In FIG. 1, reference numeral 100 denotes a sound group consisting of 212 bytes, and reference numeral 102 denotes an error flag added by 1 bit for each byte of the sound group 100 according to an error correction result. Set when the error for that data byte has not been completely eliminated. One sound group includes one byte of first block mode information F_BLK, one byte of first mount information F_AMT, and one byte of first word length (Word Length: WL) information FWL, j bytes First scale factor (hereinafter referred to as SF) information FSF, audio data of 212- (i + j + k + l + 4) bytes, second SF information SSF of k bytes, second WL information SWL of l bytes 1 byte of second mount information S_AMT and 1 byte of second block mode information S_BLK. Audio data has a form of a bit stream in which words having a variable length are continuous. The first block mode information F_BLK, the first mount information F_AMT, the first WL information FWL, and the first SF information FSF are decoding information for decoding audio data. The first WL information FWL is information specifying the length of words included in the bit stream of the audio data, the first SF information FSF, the SF information is information indicating SF for words, and the first mount information F_AMT is a corresponding sound group. Information indicating the data amounts of the first and second WL information FWL and SWL and the first and second SF information FSF and SSF included in the information. The second SF information is SSF is copy information of the first SF information FSF, the second WL information SWL is copy information of the first WL information FWL, the second mount information S_AMT is copy information of the first mount information F_AMT, The second block mode information S_BLK is copy information of the first block mode information F_BLK. The reason for including the copy information as described above is as follows. When the MD decoding system corrects an error on read data, an error may not be completely eliminated. If the data byte is WL information or SF information, serious errors may occur in the decompression processing. In preparation for such a case, the MD system includes copy information for each of the WL information and the SF information in the sound group. Accordingly, even if an error occurs in the WL information or the SF information, normal decompression processing can be performed by using the copy information. Also, the second SF information SSF and the second WL information SWL are copied in whole or in part in the first SF information, the FSF, and the first WL information FWL, respectively, according to the size of the data area.

An MD decoding system employing the data interface format as described above typically has an ACIRC decoder 104, SRMC 106, buffer memory 108 and ATRAC as shown in FIG. The ATRAC decoder 110 includes an input buffer 112, a bit allocation decoder 114, a WL buffer 116, an SF buffer 118, and a sample buffer 120. ) And an extension processing unit 122.

Referring to FIG. 2, the operation of the MD decoding system useful for understanding the present invention will be described as follows. First, the ACIRC decoder 104 is applied with a waveform-shaped read data after being picked up from the disc by a pick-up device. The ACIRC decoder 104 detects and corrects an error regarding the input read data and outputs the correction to the SRMC 106. At this time, the ACIREC decoder 104 adds an error flag according to the error correction result for each byte of data as shown in FIG. 1 and transmits it to the SRMC 106. Data applied to SRMC 106 from ACIRC decoder 104 is buffered through buffer memory 108 and then transmitted to ATRAC 110. As described above, the reason for buffering the data input from the ACIRC decoder 104 to the SRMC 106 using the buffer memory 108 is to prevent an error due to vibration that may occur during system operation as described above. The buffered data is applied to the ACIREC decoder 110 and stored in the input buffer 112. Then, when all the data of one sound group are stored in the input buffer 112, the bit allocation decoder 114 extracts the WL information and the SF information from the data stored in the input buffer 112, respectively, the WL buffer 116 and SF Stored in the buffer 118, the bit stream of the audio data is divided into a plurality of words having a variable length of 0 to 15 bits in accordance with the WL information to generate 16-bit normalized sample data. In this case, when an error flag for any data byte of the first block mode information F_BLK, the first mount information F_AMT, the first WL information FWL, and the first SF information FSF is set, the second SF information SSF, the second WL information SWL, and the first 2 Copy information of the corresponding data byte among the mount information S_AMT and the second block mode information S_BLK is used. The bit allocation decoder 114 applies the sample data generated in this way to the sample buffer 120 and stores the sample data. The decompression processing unit 122 then decompresses the data stored in the sample buffer 120 by the ATRAC algorithm using the SF information stored in the SF buffer 118 to restore the original audio data.

At this time, the data transmitted from the ACIRC decoder 104 to the ATRAC decoder 110 via the SRMC 106 and the buffer memory 108 is transferred from the first block mode information F_BLK as shown in FIG. 3 according to the interface format of FIG. The second block mode information S_BLK is sequentially transmitted in byte units. That is, 1 byte of first block mode information F_BLK → 1 byte of first mount information F_AMT → i byte of 1st WL information FWL (FWL ₀ , FWL ₁ , FWL ₂ ,... Information FSF (FSF ₀ , FSF ₁ , FSF ₂ , ..., FSF _j-1 ) → 212- (i + j + k + l + 4) bytes of audio data → k bytes of second SF information SSF (SSF _k-1 , SSF _k-2 , SSF _k-3 , ..., SSF ₀ ) → l bytes of second WL information SWL (SWL _l-1 , SWL _l-2 , SWL _l-3 ,…, SWL ₀ ) → 1 byte of first byte 2 Mount information S_AMT? 1 byte of second block mode information S_BLK.

As described above, in the MD decoding system, the format of the sound group stored in the buffer memory 108 and the sound group stored in the input buffer 112 of the ATRAC decoder 110 are the same. In addition, the ATRAC decoder 110 may operate in the following process only when all the sound group data is stored in the input buffer 112. When an error occurs in the first block mode information F_BLK, the first mount information F_AMT, the first WL information FWL, and the first SF information FSF, the copy information thereof should be used, and the copy information is used in the first block mode information F_BLK and the first. This is because the mount information F_AMT, the first WL information FWL, the first SF information FSF, and audio data are transmitted from the SRMC 106 to the ATRAC decoder 110.

Therefore, as the data already buffered through the buffer memory 108 is buffered by the ATRAC decoder 110 and then processed, there is a problem that not only the buffer is wasted but also the processing time required for decoding is increased.

Accordingly, an object of the present invention is to provide a data interface method of an MD decoding system which can shorten processing time.

Another object of the present invention is to provide a data interface method of an MD decoding system which can reduce the use of a buffer.

The present invention for achieving the above object is characterized in that when transmitting the data of the sound group stored in the buffer memory to the ATRAC by the SRMC alternately transmits the decoding information and the copy information of the audio data by byte unit .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Many specific details are set forth in the following description, such as specific processing flows, to provide a more general understanding of the invention. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

First, the present invention transmits data of a sound group stored in a buffer memory in accordance with the format as shown in FIG. 4 when transmitting data to the ATRAC decoder by SRMC. Referring to FIG. 4, first, the first block mode information F_BLK and the second block mode information S_BLK are sequentially transmitted, and then the first mount information F_AMT and the second mount information S_AMT are sequentially transmitted. Next, the WL information and its copy information are alternately transmitted in byte units. That is, FWL ₀ , SWL ₀ , FWL ₁ , SWL ₁ ,. , FWL _l-1 and SWL _l-1 . If there is no remaining 1WL information FWL not copied, i.e., if the data amount of the first WL information FWL and the data amount of the second WL information SWL, which is its copy information, are the same (i = l), then FWL _l-1 and SWL _l. Send it to _-1 . On the other hand, when there is a remaining 1WL information FWL which is not copied, that is, when the data amount of the first WL information FWL is larger than the data amount of the second WL information SWL, which is its copy information (il), FWL _l-1 and SWL _{l- 1} followed by FWL _l , FWL _{l + 1} ,. , The remaining first WL information FWL is transmitted in the order of FWL _i-1 . Next, the SF information and its copy information are alternately transmitted in byte units. That is, FSF ₀ , SSF ₀ , FSF ₁ , SSF ₁ ,. , FSF _k-1 , SSF _k-1 . In this case, when there is no remaining 1SF information FSF not copied, that is, when the data amount of the first SF information FSF and the data amount of the second SF information SSF, which is its copy information, are the same (when k = k), the FSF _k-1 , SSF If the transmission is up to _k-1. On the other hand, if there is a remaining first SF information FSF not copied, that is, if the data amount of the first SF information FSF is larger than the data amount of the second SF information SSF, which is its copy information (when jk), FWL _k-1 and SWL _{k- 1} followed by FSF _k , FSF _{k + 1} ,. , The _first FSF information is transmitted in the order of FWL _j-1 . Finally, the audio data is transmitted.

As described above, in the ATRAC decoder, original decoding information and its copy information are input in succession in pairs of bytes. Accordingly, the ATARC decoder does not need to use a separate input buffer for the ATRAC decoder by checking the error flag of the original decoding information byte inputted earlier and taking the copy information byte immediately following the error flag set when the error state is set. In addition, the processing time required for decoding can be shortened as compared with the related art by not buffering the input buffer.

Therefore, as shown in the block diagram of the MD decoding system according to the present invention as shown in FIG. 5, the ACIRC decoder 200, the SRMC 202, the buffer memory 204, and the ATRAC decoder 206 are shown. The ATRAC decoder 206 includes a bit allocation decoder 208, a WL buffer 210, an SF buffer 212, a sample buffer 214, and a decompression processor 216. Compared to the MD decoding system of FIG. 2 described above, the ATRAC decoder 206 is configured to transmit data directly from the SRMC 202 to the bit allocation decoder 208 without using a separate input buffer.

6 is a flowchart of a data interface processing according to the present invention as described above, in which SRMC (transmission of data of one sound group stored in the buffer memory 204) to the ATRAC decoder 206 according to the format shown in FIG. The processing flow chart 202 is shown.

An operation example of the present invention will now be described in detail with reference to FIG.

First, in a state in which data of one sound group error corrected by the ACIRC 200 is stored in the buffer memory 204, the SRMC 202 performs the first block mode information F_BLK and the second block mode in step 300 of FIG. The information S_BLK, the first mount information F-AMT, and the second mount information S-AMT are sequentially transmitted to the ATRAC decoder 206.

In step 302, the SRMC 202 decodes the first mount information F_AMT or the second mount information S_AMT to check the data amount of the WL information and the SF information included in the sound group. This will be described in more detail as follows. First, one byte, that is, the lower three bits b0, b1 and b2 of the eight-bit mount information b0 to b7, the next two bits b3 and b4 and the upper three bits b5, b6 and b7 respectively indicate different numbers of blocks. . The lower 3 bits b0, b1, b2 indicate the number of blocks as shown in Table 1 below, the next two bits b3, b4 indicate the number of blocks shown in Table 2 below, and the upper 3 bits b5, b6, b7 indicate Represent the same number of blocks.

According to the lower 3 bits b0, b1, b2 as shown in Table 1, the byte number i representing the data amount of the first WL information FWL and the byte number j representing the data amount of the first SF information FSF are respectively represented by (1). Obtained by the formula and (2).

The number of bytes l representing the data amount of the second WL information SWL is obtained by the following equation (3) according to the mounting information of the two bits b3 and b4 shown in Table 2 above.

The number of bytes k representing the data amount of the second SF information SSF is obtained by the following equation (4) according to the mounting information of the three bits b5, b6, and b7 shown in Table 3 above.

As described above, it is common to check the data amount of the WL information and the SF information included in the sound group by decoding the first mount information F_AMT or the second mount information S_AMT.

Next, the SRMC 202 alternately transmits the WL information and its copy information in units of bytes in steps 304 to 316. That is, FWL ₀ , SWL ₀ , FWL ₁ , SWL ₁ ,. , FWL _l-1 , SWL _l-1 , FWL _l , FWL _{l + 1} ,. , FWL _i-1 in order. At this time, if there is no remaining 1WL information FWL not copied as described above, that is, i = l, only up to FWL _l-1 and SWL _{l-1 are} transmitted.

Thereafter, the SRMC 202 alternately transmits SF information and its copy information in units of bytes in steps 318 to 330. That is, FSF ₀ , SSF ₀ , FSF ₁ , SSF ₁ ,. , FSF _k-1 , SSF _k-1 , FSF _k , FSF _{k + 1} ,. Transmit in the order of FWL _j-1 . In this case, when there is no remaining first SF information FSF that is not copied as described above, that is, when j = k, only up to FSF _k-1 and SSF _{k-1 are} transmitted.

Finally, the SRMC 202 transmits audio data in step 332 to complete transmission of data of one sound group stored in the buffer memory 204.

Accordingly, the bit allocation decoder 208 of the ATRAC decoder 206 extracts the WL information and the SF information from the data of the sound group input from the SRMC 202 as shown in FIG. 4, respectively, and the WL buffer 116 and the SF buffer 118, respectively. The bit stream of the audio data is divided into words having a variable length of 0 to 15 bits according to the WL information to generate 16-bit normalized sample data. At this time, the error flag for the original decoding information byte inputted earlier is checked, and if the error state is set, the copy information byte immediately following is taken.

Thereafter, the operation of the ATRAC decoder 206 is performed in the same manner as in FIG. 1 to restore the original audio data.

As described above, according to the present invention, the original decoding information and its copy information included in the sound group stored in the buffer memory are transmitted in pairs by byte to the ATRAC decoder, thereby eliminating the need for a separate input buffer for the ATRAC decoder. There is an advantage to reduce the use of. In addition, the ATRAC decoder can reduce the processing time required for decoding by not buffering the input buffer.

Meanwhile, in the above description of the present invention, specific embodiments have been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the invention should not be defined by the described embodiments, but should be defined by the equivalents of the claims and the claims.

Claims (4)

A data interface method of a mini-disc decoding system having an SRMC which buffers data of every sound group read from a disk and error-corrected through a buffer memory and then transmits the data to an ATRAC decoder, wherein the sound stored in the buffer memory Sequentially transmitting block mode information and copy information included in group data to the ATRAC decoder, and mounting information and copy information included in one sound group data stored in the buffer memory to the ATRAC decoder. Transmitting the data to the data; determining the amount of data of the word length information and scale factor information included in the sound group by decoding the mount information; and the word length information corresponding to the data amount of the checked word length information. And its copy information alternately in bytes Reading from the buffer memory and transmitting the same to the ATRAC decoder, and scaling factor information corresponding to the data amount of the checked scale factor information and its copy information are alternately read in bytes from the buffer memory to the ATRAC decoder. And alternately transmitting the data, and transmitting the audio data of the corresponding sound group stored in the buffer memory to the ATRAC. The data interface method of claim 1, further comprising transmitting an error flag added every byte when transmitting the stored data of the buffer memory to the ATRAC decoder. A data interface method of a mini-disc decoding system having an SRMC which buffers data of every sound group read from a disk and error-corrected through a buffer memory, and then transmits the data to an ATRAC decoder, wherein the sound stored in the buffer memory is provided. Sequentially transmitting block mode information and copy information included in group data to the ATRAC decoder, and mounting information and copy information included in one sound group data stored in the buffer memory to the ATRAC decoder. Transmitting the data to the data; determining the amount of data of the word length information and scale factor information included in the sound group by decoding the mount information; and the word length information corresponding to the data amount of the checked word length information. And its copy information alternately in bytes Reading out from the buffer memory and transmitting to the ATRAC decoder followed by remaining word length information which has not been copied from the buffer memory in bytes and transmitting to the ATRAC decoder in the data amount of the checked scale factor information; Corresponding scale factor information and its copy information are read out alternately from the buffer memory in byte units and transmitted to the ATRAC decoder alternately, and then the remaining scale factor information which has not been copied is read out from the buffer memory in byte units. And transmitting the audio data of the sound group stored in the buffer memory to the ATRAC. 4. The data interface method of claim 3, further comprising transmitting an error flag added every byte when transmitting the stored data of the buffer memory to the ATRAC decoder.