JPH0547108A - Multiplexing data separating device - Google Patents

Abstract

PURPOSE:To provide a multiplexing data separating device with simple structure capable of separating plural original data from plural data recorded in time division multiplexing in a recording medium. CONSTITUTION:This device is provided with a control means (NOR gate) 11 to stop the read of plural data recorded in time division multiplexing in the recording medium DSM when no free area is present on either of plural buffers S1, S2 to Sn for recording the plural original data. Consequently, read from the recording medium is controlled and the plural original data are separated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplexed data demultiplexing device for reading out a plurality of data recorded in a storage medium by time division multiplexing and demultiplexing the original data into a plurality of data.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional time division multiplexing and demultiplexing device. Variable rate time series data D1 and D consisting of compressed digital moving image (or audio) data
2, ... Dn are code buffers M1 and M, respectively.
2, ... Stored in Mn. The variable rate time-series data includes a synchronization signal in itself, that is, information regarding a data read interval after passing through a separating device described later. The output terminals of the code buffers M1, M2, ... Mn are input terminals E1 and E of the switching circuit 2, respectively.
2, ... En are connected. Switching circuit 2
The output terminal F of is connected to the input terminal of the header addition circuit 3. The output of the header addition circuit 3 is adapted to be supplied to a variable rate data storage medium DSM composed of, for example, an optical disc. Variable rate data storage medium DSM
Is a storage medium that can be constantly read at an arbitrary rate less than or equal to the maximum transfer rate according to the request from the reading side.

The controller 4 receives the output of the multiplexer system clock 5 and receives the output of the switching circuit 2 at a predetermined cycle.
, En to sequentially connect the input terminals E1, E2, ... En of the output terminals F to the code buffers M1, M2 ,.
n to variable rate time series data D1, D2, ... Dn
Are sequentially extracted, and are grouped by time series (the grouped data is referred to as a packet hereinafter), and the packets for all the groups are grouped together (the grouped data is referred to as a pack hereinafter). .. Then, the control device 4
The header adding circuit 3 is controlled to add a packet header to the beginning of each packet and add a pack header to the beginning of each pack (see FIG. 4). The pack header includes time information for reading. The time division multiplexed data to which the packet header and the pack header are added by the header adding circuit 3 is the variable rate data storage medium DSM.
Is supplied to.

The header separation circuit 6 of the separation device separates the pack header from the data read from the storage medium DSM and supplies it to the pack time information holding circuit 7, as well as the variable rate time series data D1, D2 ,. Dn is supplied to the input terminal G of the switching circuit 8. The output terminals H1, H2, ... Hn of the switching circuit 8 are connected to the input terminals of the code buffers S1, S2 ,. The input terminal G and the output terminals H1, H2, ... Hn of the switching circuit 8 are controlled by a control device (not shown).
Are sequentially connected in a predetermined cycle, and the variable rate time series data D1, D2, ... Dn are supplied to the code buffers S1, S2 ,.

The pack time information holding circuit 7 holds the time information contained in the pack header and supplies it to one input of the comparator 10. The comparator 10 receives the output of the separator system clock 9 at the other input. Comparator 10
Outputs a read request to the storage medium DSM when the time indicated by the output of the pack time information holding circuit 7 and the time indicated by the system clock 9 match.

Next, the operation of the conventional apparatus of FIG. 3 will be described with reference to FIG. First, the first time of the system clock 9 is set to the time indicated by the header of the first pack.
Therefore, the comparator 10 outputs a read request for the storage medium DSM. Accordingly, the variable rate time series data D1 included in the first pack from the storage medium DSM,
After D2, ... Dn have passed through the header separation circuit 6, the switching circuit 8 causes the code buffers S respectively.
1, S2, ... Sn. On the other hand, the header separation circuit 6 outputs the pack header of the pack next to the first pack to the pack time information holding circuit 7. Holding circuit 7
Is the time information included in the pack header (in the example of FIG. 2,
"11") is retained. When the time indicated by the system clock 9 matches the time held by the holding circuit 7, the comparator 10 outputs a read request for the storage medium DSM. In response to this, the variable rate time series data D1, D2, ... Dn contained in the pack next to the first pack from the storage medium DSM passes through the header separation circuit 6 and then is switched by the switching circuit 8 to the code buffer S1. , S2, ... Sn. In this way, the variable rate time series data D1, D2, ... Dn divided into a plurality of packs are stored in the code buffers S1, S2 ,. , D2, ... Dn.

[0007]

The above-mentioned conventional multiplexed data demultiplexing device of FIG. 3 needs to write time information in the pack header, requires the time information holding circuit 7 and the comparator 10, and has a structure. There was a problem that it became complicated.

The present invention has been made in view of the above circumstances, and provides a multiplexed data demultiplexing device having a simple structure capable of demultiplexing a plurality of original data from a plurality of data time-division-multiplexed and recorded on a storage medium. The purpose is to provide.

[0009]

A multiplexed data demultiplexing device of the present invention is a multiplex data demultiplexing device for reading a plurality of data recorded in a storage medium in a time division multiplex manner and demultiplexing them into a plurality of original data. , A plurality of buffers provided respectively corresponding to a plurality of original data, a reading means for reading the data recorded in the storage medium at a predetermined speed, and a read operation when there is no free area in any of the plurality of buffers. And a control unit for stopping the reading operation of the unit.

[0010]

In the multiplexed data demultiplexing apparatus of the present invention having the above-mentioned structure, the control means suspends the read operation from the storage medium when there is no space in the plurality of buffers, so that the read control from the storage medium is simple. It can be performed. Further, since the reading is continued as long as the buffer has a free space, the maximum data prefetch can be performed from the storage medium.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the configuration of an embodiment of a multiplexed data demultiplexing device of the present invention. In FIG. 1, the same components as those in FIG. 3 are designated by the same reference numerals. That is, the code buffers M1, M2, ... Mn, the switching circuit 2, the header addition circuit 3, the variable rate data storage medium DSM, the control device 4, the multiplexer system clock 5, the header separation circuit 6, the switching circuit 8 and the code. Buffer S
The configuration and operation of 1, S2, ... Sn are the same as those in FIG.

In the embodiment of FIG. 1, the NOR gate 11 whose n input terminals are connected to the code buffers S1, S2, ... Sn respectively constitutes the read control means of the storage medium DSM. That is, when the NOR gate 11 receives a no space signal “1” indicating that there is no space in the storage area from any of the code buffers S1, S2, ... Sn, it outputs a read stop signal “0” to the storage medium DSM. Output to. Further, when the NOR gate 11 receives a free space signal “0” indicating that there is free space in the storage area from any of the code buffers S1, S2, ... Sn, it outputs a read request signal “1” to the storage medium DSM. Output to.

Next, the operation of the embodiment of FIG. 1 configured as described above will be described with reference to FIG. Storage medium DSM
Is read at the maximum rate from the storage medium DSM and the maximum read-ahead is performed from the storage medium DSM. As a result, for example, the code buffer S1 becomes full, and the NOR gate 11 receives the no-empty signal "1" from the code buffer S1. , NO
The R gate 11 outputs a read stop signal “0” for the storage medium DSM. As a result, reading from the storage medium DSM is stopped. After that, when the reading of the code buffer S1 progresses and the NOR gate 11 receives the vacancy signal “0” from the code buffer S1, the NOR gate 11 outputs the read request signal “1” for the storage medium DSM. As a result, reading from the storage medium DSM is restarted. In this way, the read control for the storage medium DSM is performed.

With the above configuration, the time information need not be recorded in the header for separating the multiplexed data, but it may be recorded for random access.

Further, in the above embodiment, the NOR gate is used as the read control means, but other logic circuits having similar functions can be used.

In the above embodiment, an optical disk is used as the storage medium, but a magneto-optical disk, a magnetic hard disk, a digital audio tape, etc. can also be used.

[0017]

As is apparent from the above description, according to the multiplexed data demultiplexing device of the present invention, the read operation from the storage medium is stopped when there is no space in the plurality of buffers, so that the pack header is different from the conventional one. Since it is not necessary to write the time information in and the time information holding circuit and the comparator are not necessary, the read control from the storage medium can be performed with a simple configuration, and the original plurality of data can be separated. Further, since the reading is continued as long as the buffer has a free space, the maximum data prefetch can be performed from the storage medium.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a multiplexed data demultiplexing device of the present invention.

FIG. 2 is an explanatory diagram showing the operation of the embodiment of FIG. 1 and the conventional example of FIG.

FIG. 3 is a block diagram showing a configuration of an example of a conventional multiplexed data demultiplexing device.

FIG. 4 is an explanatory diagram showing a pack created by a multiplexer.

[Explanation of symbols]

 11 NOR gate DSM variable rate data storage medium S1, S2, ... Sn code buffer

Claims (1)

[Claims] 1. A multiplexed data demultiplexing device for reading out a plurality of data recorded in a storage medium in a time-division multiplex manner and demultiplexing into a plurality of original data, each of which is provided corresponding to each of the plurality of original data. A plurality of buffers, a reading unit that reads data recorded in the storage medium at a predetermined speed, and a control unit that stops the reading operation of the reading unit when there is no free area in any of the plurality of buffers. And a multiplexed data demultiplexing device.