JPS6363170A - Filing system - Google Patents

Abstract

PURPOSE:To quickly synchronize audio data and image data by selecting necessary audio data, image data and controlling data and registering in a block. CONSTITUTION:User data of one block, the smallest unit handled by a filing system consisting of header and user data, which are positional information are combination of data selected from respective group of audio data, image data and controlling data. For instance, the content of data is, 0-11th are synchronizing signals, 12-15th are headers, 8 bytes of 16-23rd are controlling data of audio and image signals. For 24-2,351st, they are classified to A0j-A11j making every 12 bytes a set, and regarded as assemblage of 194 sets. 194 bytes of A0j are made to audio data, and 2,134 bytes of A1j-A11j are made to image data. Synchronizing signals can be detected from such data.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a file system, and particularly to a file system for audio (in this invention, this is used in a broad sense including music signals, etc.) and images.

(Prior art) Conventional systems that apply audio and images include the CD system, which is based on audio-only standards, and the compact disc (
Blocks the area of audio data (which is not substantially different from the audio data mentioned above, but since this is generally said about CDs, the audio data related to CDs will be referred to as audio data hereinafter) handled by CDs. There is a CD-ROM system that is used as a data memory.

FIG. 1 is a block diagram of the signal processing circuit of the above-mentioned CD system and CD-ROM system. A CD signal recorded on the CDI is taken out by an optical pickup 2 and input to a CD signal processing circuit 3. As shown in the second diagram, the input CD signal is composed of a frame consisting of a sub code, audio data, C2 parity, audio data, and C1 parity. The CD signal processing circuit 3 extracts the sub-code (1 byte) in the frame and checks whether an error has occurred in the other frame using C, parity (4 bytes) 01 shown in Figure 6. Check the series and correct any errors.

Next, using another 02 series, C2 parity (4 bytes)
It is checked whether an error has occurred in the audio data (24 bytes), and if there is an error, it is corrected.

Further, correction processing such as prefix holding and intermediate value correction is performed as necessary.

A changeover switch 4 is connected to the output of the CD signal processing circuit 3, and this changeover switch 4 switches the output of the CD signal processing circuit 3 between a D/A converter 5 and a CD-ROM signal processing circuit 6. In this case, the CD signal is Audio data (Audio 12 + 24 of Audio 12 in Figure 6).
If it is only CD-ROM data, it is connected to the D/A converter 5 to output an analog audio signal, and if it is CD-ROM data, it is connected to the CD-ROM signal processing circuit 6 to output audio and image signals as data signals. Output. In this case, the switching operation of the changeover switch 4 is performed based on the TOC data in the lead-in area recorded on the innermost circumference of the CD.

゛Next, the structure of the above-mentioned sub-code will be explained. FIG. 3 is an enlarged configuration diagram of the sub-code portion. The sub-code block consists of 8 bits on the left side of the figure and consists of 98 frames.

Sub-code sync (synchronization signal) So + 31 is used twice to increase reliability, and the other bits are used as follows: 1) P and Q are control bits and are recorded. Indicates the starting point, ending point, etc. of a song.

2) In R-W, arbitrary data such as graphics is recorded as user bits. The data transfer rate in this state is 9, excluding sub code sinks S and SS.
There are 6 frames, 6 R-W bits, and 1 block frequency of 7 GHz, so 96 (frame) x 6 (bi
t) x75Hz = 43.2k (bit/5ee), but [Note: Near 5Hz is the CD sampling frequency of 44.1
kHz, number of CD channels 2.1 word number of bytes 2
, the number of bytes of audio data is 24, and the frequency of one frame is 44.1 kHz x 2 x 2 xi/24=7.
35k) In the Iz98 frame, 7.35kHzXl/98=75Hz) As it is, the probability of data error is 10--10-', which is not very good quality data. Therefore, a mode in which parity for error correction is added to the data is being considered, and according to this mode, the data transfer rate is the above-mentioned 43.2k (bit/5ee) with error correction added, which is a mode that can be used by users. Toshi”i2
It becomes 8.8k (bit/5ec).

As mentioned above, images such as graphics and control data for other devices can be registered separately from the CD audio data using the R-W user bit of the sub code, but data transfer The rate is low and it is difficult to use for images etc.

Therefore, the format of the CD-ROM has been standardized in consideration of the application of the CD not only as an audio disc but also as a data memory.

FIG. 4 is a block diagram of the CD-ROM system, and a block is defined as a block corresponding to 2352 bytes of audio data corresponding to 98 frames managed by the sub-code shown in FIG. This data can be taken out as the output of the D/A converter 5, and is shown as ^u in Figure 3.
This data is of a different series from the 2352 bytes of dio data.

In mode 1, this block consists of 12 bytes as a synchronization signal, 4 bytes as a header, and 20 bytes as user data.
48 bytes, 4 bytes as parity for error detection, “O
It consists of 8 bytes as O'' data and 276 bytes as error correction parity. In mode 2, it consists of 12 bytes as a synchronization signal, 4 bytes as a header, and 2336 bytes as user data.

Control data such as minute and second, number of blocks, mode distinction, etc. are registered in a part of the header, so it is possible to access each block.

Mode 1 includes standardized error detection and error correction codes, and is designed to have a data error rate of 1g-12 or less.

Mode 2 has a large area for user data,
It can be used with a high degree of freedom. Furthermore, recently standardized methods for using this area have been created.

Next, an example using the above CD system and CD-ROM system will be described.

1) Since the CD system uses sub-codes, mode 1 and mode 2
Regardless, still images, graphics, etc. are synchronized with the audio data and a screen related to the audio is displayed.

2') In the case of a CD-ROM system In both mode 1 and mode 2, audio data and image data are registered in separate blocks.

The CD-RO old language processing circuit 6 recognizes the block number based on header information to determine whether the block is necessary for an image or for audio, and allocates the data.

In other words, the usage of data is determined on a block-by-block basis.

(Problem to be solved by the invention) The above-mentioned method of using CDs has the following problems.

1) In the case of the CD system, the data transfer rate of sub-codes is low, making it difficult to obtain moving images such as animations. Also, Au
It is also difficult to synchronize with dio data.

2) In the case of a CD-ROM system, if you try to output image data and audio data in synchronization, the image data and audio data will be output in block units.

Since the data is registered, for example, in order to switch images while continuing audio, the audio data must be stored in the buffer memory for the time required to switch the image data. Therefore, although it depends on the quality of the audio, the memory capacity needs to be extremely large.

Furthermore, recognition of each block and access to necessary blocks are essential.

The present invention solves the above problems and arbitrarily selects Aud.
It is an object of the present invention to provide an audio and image file system that allows io data and image data to be quickly and easily synchronized.

(Means for Solving the Problem) The present invention provides that one block of user data, which is the smallest unit handled by a file system consisting of a synchronization signal, a header that is position information, and user data,
It consists of a combination of data selected from the respective groups of udlo data, image data, and control data.

(Operation) As mentioned above, necessary related audio data, image data, and control data are selected and registered in one block, so just by accessing that block, one
All the necessary data can be retrieved simultaneously and synchronously with just one file.

(Example) First example (story picture book) In this case, mode 2 in FIG. 4 is used.

FIG. 5 shows numbers 0 to 2351 rearranged by 12 bytes starting from O.

The content of this data is 1) The 0th to 11th signals are synchronization signals.

2) The 12th to 15th are headers.

3) The 8 bytes 16th to 23rd are control data for audio and 9 image signals.

4) For numbers 24 to 2351, each set of 12 bytes is classified as AOJ""AIIJ, and this set is 19
It is assumed that 4 have been collected. Here, j is any one from 1 to 194.

5) 194 bytes of AOJ are audio data.

6) 2134 bytes of AxJ=AnJ are image data.

? ) Audio data is 8 to compensate for the decrease in sound quality.
bit quantized ADPCM (Adaptive
Differential Pulse Code
Modulation, dynamic range equivalent to 16 bits), adaptive quantization is performed.

If the synchronization signal can be detected from the data with the above structure and the data can be extracted, then if the data is handled as a set of 12 bytes from the 25th byte from the beginning of the synchronization signal, the first byte goes to the audio processing circuit, and the second byte goes to the audio processing circuit. The subsequent 11 bytes are sent to the image processing circuit.

As a result, the audio data transfer rate is 194 (bytes) x 75 + Iz = 14.5
The data transfer rate for a 5k (byte/5ec) image is 11 (byte) x 194 x 75Hz = 160.0
5k (byte/5ec) can be obtained.

Second Example (Talking-Book) In FIG. 5, all AOJ"" A 11 J are audio data.

1) Take out only AOJ first, and then extract other data (AI
J-A u J) is ignored.

Repeat this operation from the beginning to the end of the CD.

2) Next, extract only AIJ, ignore other data, and repeat this operation in the same way as in 1) from the beginning to the end of CO.

3) Following the operation in 2), such operations are performed in order up to Al1-.

In this way, it is possible to construct a Talking-Book that lasts for about 14 hours, although the sound quality is somewhat degraded.

(Effects of the invention) As mentioned above, as long as the synchronization signal for the block can be detected, all that is left is to allocate the number of data to where, and the rest of the data to which. Alternatively, it is possible to obtain data that is always synchronized with other controls.

Also, there is no need to know what data is in that block, and there is no need to perform time-consuming accesses such as which block's data must be accessed; in other words, accessing other blocks or locks is not necessary. There is no need for buffer 1 memory, especially for CD-ROMs.
This is extremely effective when blocks arranged on a CD are consecutive for one file, such as in a system.

Furthermore, if there is an area in which information having the structure shown in Figure 5 is registered in a specific location on the CD, the data can be automatically distributed by a program that manages and operates the file.

[Brief explanation of drawings]

Figure 1 is a block diagram of the signal processing circuit of the CD system and CD-ROM system, Figure 2 is a frame configuration diagram within the CD, Figure 3 is an enlarged frame configuration diagram of the sub-code part of Figure 2, FIG. 4 is a block diagram of the CD-ROM system, FIG. 5 is a data arrangement diagram of an example of rearranged mode 2 data arrangement, and FIG. 6 is an explanatory diagram of error correction. 1jCD, 3: CD signal processing circuit, 4: Selector switch, 5: D/A converter, 6: CD-ROM (
No. processing circuit. ) Mooku (sword mode) so-called (13n Mo\in

Claims (1)

[Claims] In a file system that consists of a synchronization signal, a header that is position information, and user data, a block of user data, which is the smallest unit handled by this file system, is included in each group of audio data, image data, and control data. A file system comprising a combination of data selected from.