JPH09282805A - Data recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output only effective data by converting data sent in a specified unit and a dummy added to it into each sector to record it with an added flag indicating which data is effective. SOLUTION: A sector converter 111 adds a header to a packet of data to convert it to a sector. A number, for example, indicating a sector order is assigned to each sector by this header. A dummy generator 112 generates a dummy to send to the sector convertor 111. And, the sector converter 111 also converts the dummy into a sector to insert it between data sectors if necessary. Each sector converted by the sector converter 111 is further processed for recording on a tape in a frame unit of N numbers of sectors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording device for recording digital data such as a multimedia system.

[0002]

2. Description of the Related Art Recently, as the performance of computer equipment has improved, the amount of data to be handled has increased, and accordingly, the capacity of recording media has been required to be increased. Therefore, various devices have been commercialized or developed. Examples of devices currently used as recording devices include hard disk devices and CDs.
-Using a disk medium such as a ROM device, 8m
Some tape media such as m tape and DAT (Digital Audio Tape) are used. The capacity of these conventional devices is increasing year by year due to technological development.

In each of these recording devices, computer data is recorded on a recording medium in sector units of a fixed length. The computer accesses the recording device in units of this sector.

For example, a recording device using a tape is shown in FIG.
It is recorded in block units as shown in. The block divides the data into fixed bytes, and the synchronization data and ID
It is generated by adding data, an error correction code (ECC) and the like. This is modulated and arranged in the data recording area of the track on the tape as shown in FIG. At this time, a large number of tracks are set as one edit unit (frame), and an error correction code is further added if necessary.

When recording data in units of packets of a predetermined length on a tape, each packet is sequentially stored in a block and recorded. At this time, if you try to specify specific data, information about the position where the packet is recorded,
For example, a track number, a block number, and a byte number may be designated as the position information. For example, a tape (H that can record current television signals for 4 hours and 30 minutes)
Specifications of Consumer-U by D-VCR Council
In the case of se Digital VCRs), about 5 million tracks can be recorded, so the track number is 23 bits, and if the number of blocks of data that can be recorded per track is 135, the number of data bytes per block is 77 bits. If it is a byte, it becomes 7 bits. A total of 38 bits are required as the amount of position information.
At the time of track reproduction, the packet position is detected based on these three position information.

[0006]

In order to facilitate the access to the packets on the tape at the time of reproduction in the recording apparatus using the above-mentioned tape, as shown in FIG. The input data is stored and recorded in L blocks. At this time, add a header to the packet and convert it to the sector format on the tape,
Store the sector in a fixed number of blocks. At this time, a number indicating the order of sectors is added to the header. If a sector group consisting of N sectors is formed and processed as a frame as shown in FIG. 9, access to the packet becomes easier. At this time, if the last sector of the data ends at the Mth sector (M <N) in the middle of the frame, the remaining (N−M) sector areas become empty, so a dummy sector is recorded here. . However, since the tape uses frames as a unit, it is necessary to temporarily create and record a dummy sector, but the operation of reproducing this frame and overwriting the dummy sector at the time of the next recording is a heavy burden on the tape device. , It is desirable to connect and record new frames while leaving dummy sectors. Therefore, even if the sector is read during playback,
There is a problem that it is not possible to judge whether it is sent data or a dummy.

In addition, MPEG (Motion Picture Expert)
When recording data encoded by Group) or the like, it is necessary to adjust the rate by inserting a dummy sector when the bit rate of the transmitted data is lower than the recording rate on the recording medium. However, even in this case, there is no means for determining whether the sector of the transmitted data or the dummy sector. Further, when the data rate changes in the middle of the data, there is a problem that the transfer rate cannot be changed corresponding to this during reproduction.

In consideration of the problems of the conventional recording apparatus, the present invention can judge whether the data is valid data or dummy data and can output only the valid data at the time of reproducing, and the change of the data rate. It is an object of the present invention to provide a data recording device capable of changing the transfer rate according to the above.

[0009]

According to the present invention, dummy data generating means for generating dummy data and each data input in a predetermined data size unit are converted into a sector, and the sector of the converted input data is converted into a sector. Store in a storage area in units of N sectors in a predetermined data size unit,
In the case of storing, when the converted sectors of the input data of a predetermined data size are M (M <N), the dummy data generating means dummies the difference (N−M) sectors. A data recording device comprising: a recording unit that generates data and stores it in an empty area of a storage area.

Further, according to the present invention, the dummy data generating means for generating dummy data and the input when the input rate of the data inputted in a predetermined data size unit are slower than the recording rate at the time of recording the data on the recording medium. The data recording device includes a recording unit that inserts the dummy data generated by the dummy data generating unit between the input data so that the rate matches the recording rate.

In each of the above constructions, the recording means further indicates that the input data is valid data,
When a flag indicating that the dummy data is invalid data is added to each sector, it is possible to determine whether the data is valid or invalid during reproduction.

Further, the present invention is a data comprising an input rate detecting means for detecting an input rate of input data, and a recording means for adding the detected input rate information to the input data and recording it on a recording medium. It is a recording device. As a result, the transfer rate during reproduction can be associated with the input rate using the input rate information.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. (Embodiment 1) FIG. 1 is a block diagram showing a data recording device according to a first embodiment of the present invention. The first embodiment will be described by taking as an example a data recording device that records input data on a tape. The data recording device of the present embodiment includes a recording circuit 101, a head 102, a tape 103, a sector converter 111, and a dummy generator 112. Here, the recording circuit 101 and the head 1
02 and the sector converter 111 constitute a recording means.

Next, the operation of the data recording device of the first embodiment will be described with reference to the drawings.

First, the frame data sent in packet units of a predetermined length are input to the sector converter 111. The sector converter 111 adds a header to the packet data and converts the data into sectors. In this header, for example, a number indicating the order of sectors is assigned to each sector. Further, the dummy generator 112 generates a dummy, and the sector converter 1
11 is sent. Then, the sector converter 111 also converts a dummy into a sector and inserts it between data sectors as necessary. The method of inserting the dummy sector will be described later. Next, the input data converted into sectors by the sector converter 111 and the dummy are the recording circuit 1
Is output to 01. In the recording circuit 101, each sector is converted into a block which is a recording unit on the tape. At this time 1
The data is stored in a predetermined number of blocks for each sector. Synchronous data, ID data, error correction code, etc. are added to each block. Then, the data in this block is modulated into a signal suitable for recording. The modulated signal output from the recording circuit 101 is recorded in the recording area of the tape 103 by the head 102.

Next, a method of adding a flag for distinguishing between data and dummy sectors will be described. The sector converter 111 converts the input data and the dummy sent from the dummy generator 112 into sectors. At that time, a flag indicating that the input data is valid and indicating that the dummy is invalid is added to the header of each sector. This need only add at least 1 bit. This makes it possible to select a sector in which valid data is recorded during reproduction and output only the input data.

Next, a method of inserting a dummy sector will be described. Each sector converted by the sector converter 111 is further subjected to processing for recording on the tape in a frame in which a group of N sectors is one unit. The data input at this time is sequentially stored in the sectors in the frame. For example, as shown in FIG. 2, the data converted into the sectors is stored up to the Mth (M <N) in the middle of the frame. And Then, the dummy sectors generated by the dummy generator 112 are stored in the remaining (N−M) sectors to fill the frame with N sectors. This allows data to be recorded on the tape in frame units.

Also, when recording data encoded by MPEG or the like, it is necessary to insert this dummy sector. In MPEG and the like, the data rate to be transferred is generally determined by the transmitting side, and since there are a plurality of these rates, this may be lower than the recording rate when recording on tape. Therefore, in order to make the transmitted data rate close to the recording rate, the sector converter 1
At 11, dummy sectors are inserted between the sectors of each data as shown in FIG. As a result, even when data such as MPEG which is lower than the recording rate is input, it is possible to record according to the recording rate.

In the data recording apparatus of the first embodiment described above, a tape is used as an example of the recording medium, but the recording medium is not limited to this, and other recording medium such as a disk may be used. Arrangement of blocks may be arbitrary.

In the first embodiment, the MPE
Although it has been stated that a dummy sector is inserted when recording data encoded by G or the like, a dummy sector may be inserted and recorded even when inputting data encoded by another method.

Further, the header added to the packet to be recorded may be arbitrary data, and the position to be added is the head, but it may be another position.

The number of tracks per frame may be arbitrary. (Embodiment 2) The second embodiment will also be described by taking as an example a data recording apparatus for inputting data and recording it on a tape as in the first embodiment. FIG. 4 shows a block diagram of a data recording apparatus according to the second embodiment of the present invention. In the data recording apparatus of the second embodiment, the recording circuit 101, the head 102, the tape 103, the sector converter 111, and the dummy generator 112 have the same configuration as in the first embodiment, and further, sector management information generation A vessel 121 is added.

Next, the operation of the data recording device of the second embodiment will be described with reference to the drawings.

First, the data delimited by a predetermined length is input to the sector converter 111. The sector converter 111 adds a header to data of a predetermined length and converts the data into sectors. The dummy generator 112 also generates a dummy and sends the generated dummy to the sector converter 111. Then, the sector converter 111 also converts a dummy into a sector and inserts it between data sectors as necessary. At this time, the sectors are stored in a frame in which a group of N sectors is one unit.

In the present embodiment, the position of each sector is fixed in each frame. Then, it is not necessary to add a sector number to each sector in the frame, and if the sector number is assigned only to the leading sector, the positions of all sectors can be determined.
Information for discriminating whether each sector in the frame is a valid data sector or a dummy sector is also managed in frame units. Sector management information generator 121
Then, the number of the head sector of this frame and information for determining whether the sector in the frame is a valid data sector or a dummy sector are generated. As for the sector management information, for example, when storing data sectors in the frame either left-justified or right-justified, only the number of valid data sectors needs to be known, which can further reduce the amount of necessary information. You can Alternatively, a bit map for discriminating a sector of valid data or invalid data is provided for each sector.

Next, the data converted into sectors by the sector converter 111, the dummy, and the sector management information are recorded in the recording circuit 1.
Is output to 01. In the recording circuit 101, each sector is converted into a block which is a recording unit on the tape. At this time 1
The data is stored in a predetermined number of blocks for each sector. Synchronous data, ID data, error correction code, etc. are added to each block. Then, the data in this block is modulated into a signal suitable for recording. The signal output from the recording circuit 101 is recorded in the recording area of the tape 103 by the head 102.

At this time, if the sector management information is recorded in, for example, the header of the first sector in the frame, the sector management becomes easier.

With the above configuration, it is not necessary to add a sector number and a flag for discriminating between valid data and dummy sector for each sector, and more data can be recorded. Further, each sector can be managed in frame units. In addition, the amount of information required to access the sector can be reduced.

In the second embodiment, the same effect can be obtained by using other methods such as the last sector number of valid data in the frame as the sector management information.

In the second embodiment, the sector management information is recorded in the header of the first sector in the frame. However, the sector management information is recorded in a data recording area other than the header of any sector or the sector recording area. You can record it. (Third Embodiment) A third embodiment will also be described by taking as an example a data recording apparatus for inputting data and recording it on a tape as in the first embodiment. FIG. 5 shows a block diagram of a data recording apparatus according to the third embodiment of the present invention. The data recording apparatus according to the present embodiment includes a recording circuit 101 and a head 1.
02, the tape 103, and the sector converter 111 have the same configuration as in the first embodiment, and further, there is no dummy generator,
A data rate detector 131, which is an input rate detector, is added.

Next, the operation of the data recording device of the third embodiment will be described with reference to the drawings.

First, the data delimited by a predetermined length is input to the sector converter 111 and the data rate detector 131. The sector converter 111 adds a header to data of a predetermined length and converts the data into sectors. The data rate detector 131 counts the input data, detects the rate thereof, and outputs the information to the sector converter 111 for each data of a predetermined length. As the data rate information, for example, the maximum rate that the data recording device can record,
The information is 1/2 or 1/4. Or the number of heads of the data recording device will be added in the future,
In preparation for increasing the recording rate, an integer multiple of the maximum rate is also prepared and added as data rate information.

Next, the sector converter 111 adds the data rate information obtained from the data rate detector 131 to the input data and converts it into a sector. The data converted into sectors by the sector converter 111 and the data rate information are recorded in the recording circuit 1.
Is output to 01. In the recording circuit 101, each sector is converted into a block which is a recording unit on the tape. At this time 1
The data is stored in a predetermined number of blocks for each sector. Synchronous data, ID data, error correction code, etc. are added to each block. Then, the data in this block is modulated into a signal suitable for recording. The signal output from the recording circuit 101 is recorded in the recording area of the tape 103 by the head 102.

With the above-described structure, it is possible to cope with the change even when recording and reproducing data whose rate changes from the middle of the data.
Even in the case of data encoded by G or the like, the data can be transferred to the decoder at an appropriate rate.

In the third embodiment, as the data rate information, the maximum rate that the data recording device can record, 1/2 or 1/4 of the maximum rate, or the number of heads of the future data recording device is added. In order to increase the recording rate, the maximum rate is set to an integral multiple, but this information may be any other value.

In addition, in the above-mentioned embodiments, the reproducing side is not particularly explained, but in the reproducing side,
Flag of valid data or invalid data, sector management information,
Alternatively, it goes without saying that the data rate information may be detected and identified, and when the flag indicates invalid data, the data may be ignored. In the case of data rate information, it goes without saying that the data transfer rate may be controlled according to the information.

In each of the above embodiments, the predetermined data size unit is the frame unit.
The data size unit for storing N sectors is not limited to this.

[0038]

As is apparent from the above description, according to the present invention, the data sent in a predetermined unit and the dummy added thereto are converted into sectors, respectively, and whether the data in each sector is valid or not When the recording is performed by adding a flag indicating whether the data is invalid, it has an advantage that only valid data can be output during reproduction. .

Further, according to the present invention, for example, each sector is handled as a frame in which a group of N sectors is one unit, and the number of the sector at the head of the frame and the sector in the frame are used as the management information of each sector. When the information for discriminating whether each is a valid data sector or a dummy sector is provided in frame units, the amount of information is reduced by having one sector management information per frame, and recording is accordingly performed. There is an advantage that the amount of data that can be obtained can be increased.

Further, according to the present invention, when the input data is converted into the sector, the data rate information is also added and recorded for each sector at the same time, so that the data whose data rate changes in the middle of the data is recorded. Even in the case of reproduction, there is an advantage that the transfer rate can be changed correspondingly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a data recording device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of an arrangement of data sectors and dummy sectors in a frame in the data recording device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an example of a dummy sector insertion method during MPEG data recording in the data recording device according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a data recording device according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a data recording device according to a third embodiment of the present invention.

FIG. 6 is a block diagram of a block on a conventional tape.

FIG. 7 is a layout diagram of tracks and blocks on a conventional tape.

FIG. 8 is an explanatory diagram of a conventional packet-to-block conversion method.

FIG. 9 is a layout diagram of sectors in a conventional frame.

[Explanation of symbols]

 101 recording circuit 102 head 103 tape 111 sector converter 112 dummy generator 121 sector management information generator 131 data rate detector

Claims (7)

[Claims] 1. A dummy data generation means for generating dummy data, and each data input in a predetermined data size unit is converted into a sector, and the sector of the converted input data is converted in the predetermined data size unit. The data is stored in a storage area in units of N sectors, and at the time of storage, when the converted sectors of the input data of the predetermined data size are M (M <N), the difference A data recording device, comprising: a recording unit that generates dummy data by the dummy data generating unit for (N−M) sectors and stores the dummy data in an empty area of the storage area. 2. The recording means, when the input data is the M sectors, stores the M sectors in the storage unit M.
2. The data recording device according to claim 1, wherein the data recording device stores up to the first sector and then stores the (N−M) sectors of dummy data. 3. Sector management information generation means for generating sector management information having identification information for identifying whether each sector in the storage area is the input data or dummy data, and the recording means stores the sector management information. The data recording apparatus according to claim 1, wherein the data is recorded in a predetermined place on the recording medium. 4. The sector management information is stored on the recording medium.
The data recording apparatus according to claim 3, wherein the data is recorded in a predetermined area different from the recording area of the sector. 5. A dummy data generating means for generating dummy data, and when the input rate of the data input in a predetermined data size unit is slower than the recording rate when recording the data on the recording medium, the input rate is set. A data recording apparatus comprising: a recording unit that inserts dummy data generated by the dummy data generating unit between the input data so as to match the recording rate. 6. The recording means adds a flag indicating that the input data is valid data and the dummy data is invalid data for each sector. Alternatively, the data recording device according to item 5. 7. An input rate detecting means for detecting an input rate of input data, and a recording means for adding the detected input rate information to the input data and recording it on a recording medium. And a data recording device.