JPH07192408A - Recorder - Google Patents

Abstract

PURPOSE:To record a transmission signal making a block incorporating an inspection symbol of an error correction code as unit by a simple recorder with a smaller circuit scale. CONSTITUTION:First error correction encoding is performed to a signal inputted to an input part 21 by a first error correction encoder 22 so that no symbol constituting one block is allocated to the same code word of the first error correction code. Second error correction encoding is performed by a second error correction encoder 23 so that no symbol constituting one block is allocated to the same code word of the second error correction code, and no symbol constituting one code word of the first error correction code is allocated to the same code word of the second error correction code. A recording signal generator 24 performs addition, modulation, etc., of a sync/address to generate a recording signal, and a recording head 25 records the recording signal on a tape 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device suitable for use in a digital video tape recorder or the like.

[0002]

2. Description of the Related Art Recently, digital TV broadcasting and CAT
A business for supplying a highly efficient coded video signal by digital transmission, such as a video service using V or a telephone line, is under consideration. Along with this, a recording device for recording the digitally transmitted video signal is also required.

A block diagram of a conventional recording apparatus is shown in FIG. 4 and the operation of this recording apparatus will be described. An example of the transmission format of the video signal is shown in FIG. 5 and an example of the recording format is shown in FIG. In FIG. 4, 11 is an input unit, 12 is a transmission block detector, 13 is a transmission error correction decoder, 14 is a recording format converter, 15 is a recording signal generator, 16 is a recording head, and 17 is a tape. is there.

In the recording apparatus constructed as described above, the signal inputted to the input section 11 is first transmitted to the transmission block detector 12
Is divided into blocks. The transmission block is (Fig. 5)
As shown in FIG. 3, the channel control data, the asynchronous data, the audio signal, the system control data, and the video signal are added with the sync and the transmission parity obtained by the error correction coding. The transmission block and 524 second transmission blocks are repeatedly transmitted. The transmission error correction decoder 13 corrects an error generated during transmission. After taking out the video signal thus transmitted together with other data, the video signal and the other data are converted into the recording format while the recording format converter 14 generates information necessary for reproduction.

As shown in FIG. 6, the transmitted video signal is composed of variable-length macroblocks, and in the recording format, which macroblock (given by a macroblock address) is located at which position in each recording block. It requires information indicating whether it starts from (given by macroblock pointer). Then, the recording signal generator 15 performs error correction coding for recording, addition of a sync address,
Modulation is performed and recording is performed on the tape 17 using the recording head 16.

[0006]

However, the recording apparatus configured as described above has a transmission signal processing circuit, and obviously, in a reproducing apparatus which reproduces the signal thus recorded. However, a circuit for converting the reproduced recording block into a transmission signal is required. Then, after performing error correction decoding on the reproduced signal, the remaining error must be processed by the transmission signal decoding device.

In addition, in order to record video signals transmitted by various methods, there is a problem that a processing circuit for the transmission signal needs to be compatible with each method.

An object of the present invention is to solve the problems of the conventional recording apparatus.

[0009]

According to the present invention, there is provided input means for inputting data in units of a block including a check symbol of an error correction code, and first error correction coding for the input data. 1 error correction coding means, and the first
Second error correction coding means for performing second error correction coding on the output of the error correction coding means, and recording means for recording the output of the second error correction coding means on a recording medium. It is a recording device.

[0010]

According to the present invention, by recording the data in units of blocks including the check symbol of the error correction code as it is, a recording device having a circuit scale smaller than that of the conventional one can be constructed.

[0011]

Embodiments of the recording apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a recording apparatus according to the first embodiment of the present invention, in which 21 is an input unit, 22 is a first error correction encoder, and 23 is a second error correction encoder. , 24 is a recording signal generator, 25 is a recording head, and 26 is a tape.
The operation of this recording apparatus will be described below with reference to FIG.

First, when a transmission signal is input to the input unit 21, first error correction coding is performed on the data input by the first error correction encoder 22. Here, the transmission signal has a block as a unit, and each of the symbols constituting one block is assigned to a different code word of the first error correction code. The second error correction encoder 23 performs the second error correction encoding. Similar to the first error correction coding, each of the symbols forming one block is assigned to a different code word of the second error correction code. Further, each of the symbols forming one codeword of the first error correction code is
The error correction code of is assigned to a different code word. The recording signal generator 24 adds a sync address,
A recording signal is generated by performing a predetermined recording signal processing such as modulation, and the recording head 25 records the recording signal on the tape 26.

With the above arrangement, the transmission signal can be recorded without the transmission signal processing circuit. Further, when the reproduction state is very poor, the error remaining after the correction of the second and first error correction codes becomes an error of the transmission signal, so that detection or correction using the correction code used for the transmission signal is performed. Is possible.

FIG. 2 shows the configuration of the first error correction encoder 22. In FIG. 2, 31 is a memory and 32 is a first memory.
Is a parity generation circuit, and 33 is a control circuit. First, the input transmission signal is written in the memory 31. Then, the information symbol of the code word of the first error correction code is read for each code word in a direction different from the writing direction, the check symbol of each code word is generated by the first parity generation circuit 32, and the check symbol is also stored in the memory.
Write to 31. Finally, the information symbol of the code word of the first error correction code is read and output for each code word in a different direction. The control circuit 33 generates a write / read address of the memory 31 and a control signal, and generates a control signal of the first parity generation circuit. In error correction decoding, erroneous symbols are concentrated in a codeword that cannot be corrected if it cannot be corrected, and a codeword of the first error correction, a codeword of the second error correction code, and a code of the transmission signal. By preventing the words from overlapping, it is possible to strengthen the error correction capability as a whole.

An example of rearrangement that can be realized by the memory 31 will be described. First, the upper limit of blocks input at a predetermined time is 504, the block length is 190 symbols or less, and the number of tracks formed by the recording device at a predetermined time is 10,
It is assumed that there are 133 or more recording blocks to which transmission signals can be assigned among recording blocks that can be recorded on one track, and symbols of 72 symbols or more can be assigned to transmission signals in each recording block. Then, the transmission signal input at a predetermined time is T [p, q] (p =
0,1, ..., 503; q = 0,1, ..., 189), and data that can be recorded at a predetermined time is D [x, y, z] (x = 0,1, ..., 9; y = 0,1, ..., 1
32; z = 0,1, ..., 71), and the symbol that is the check symbol of the first error correction code is K [x, y, z] (x = 0,1, ..., 9; y = 0,1 , ..., C;
z = 0,1, ..., 71). C is a value determined by the recording device. Therefore, the symbols forming the (h + 1) th input block are T [h, q]. Also, (i +
The symbols constituting the recording block recorded on the 1) th track are D [i, y, z], and are the (j + 1) th recording block allocated to the transmission signal on the (i + 1) th track. The symbols that make up the recording block are D
[i, j, z]. Further, of the symbols D [i, j, z] assigned to the transmission signal, the (k + 1) th symbol is
It is D [i, j, k].

In such a case, x = q / 19 y = {(q / 19) .multidot.5 + (p / 72)} mod 7+ (q mod 19) .multidot.7 z = {(q mod 19) + If rearranged so that p} mod 72, the code words of the error correction codes do not overlap. Also, x is r and z is t
Collect symbols D [r, y, t] (y = 0,1, ..., 132)
These are information symbols of one code word of the first error correction code. When two or more types of first error correction codes are used properly, they can be combined. x
Is r and y is s Symbol D [r, s, z] (z = 0,1,
, 71) are collected and used as information symbols of one code word of the second error correction code. Similarly, the symbol K [r,
s, z] (z = 0, 1, ..., 71) is also an information symbol of one codeword of the second error correction code.

Here, it is assumed that the number of recording blocks assigned to the transmission signal is 132 or more. However, when the number of recording blocks is 133 or more, auxiliary data is assigned to the remaining recording blocks, and the first and second recording blocks are assigned. It can be included in the information symbol of the error correction code. Similarly, it is assumed that the number of symbols assigned to the transmission signal in one recording block is 72 or more. However, when the number of symbols is 73 or more, auxiliary data is assigned to the remaining symbols, and the first and second errors occur. It can be included in the information symbol of the correction code. On the other hand, when there are a plurality of transmission signal systems, by recording their identification information, it is possible to perform processing in which the systems are distinguished when reproducing. Also, T
If it is a V signal, it is required to record the information about the transmission signal such as the channel and the recording date and time of those signals, or the information about the copyright of the transmitted signal but not included in the transmission signal itself. There is. By doing so, it becomes possible to record such information as auxiliary data. These auxiliary data can also be processed by generating a pattern of a predetermined format in the control circuit 33 and writing the pattern in the memory 31.

Although the block of the transmission signal has been described as a unit, in order to prevent the code words of the error correction codes from overlapping each other, the transmission signal is obtained by dividing the transmission signal from an arbitrary position for each block length. Similar effects can be obtained by using a pseudo block as a unit.

FIG. 3 is a block diagram of a recording apparatus according to the second embodiment of the present invention, 41 is a video signal input section, and 42 is a video signal input section.
Is an audio signal input unit, 43 is a video / audio signal processor, 44 is a switch, 45 is a recording signal generator, 46 is a recording head, 47 is a tape, 48 is an adapter input unit, 49 is a transmission signal input unit, and 50 is a transmission signal input unit. An adapter, 51 is a memory, and 52 is a control circuit. The operation of this recording apparatus will be described below with reference to FIG.

This recording device is a device for recording a transmission signal by using a recording device for audio signals and video signals which has been used up to now, and a video signal input from a video signal input section 41 and an audio signal input section 42 respectively. The video / audio signal processor 43 performs signal processing on the audio signal, such as filtering, rearrangement, generation of auxiliary data, and high-efficiency encoding if necessary. Then, the output of the video / audio signal processor 43 is input to the recording signal generator 45 through the switch 44, and the recording signal generator 45 causes the first and second error correction coding, the addition of the sync address, and the modulation. The recording head 46 records the recording signal on the tape 47 by performing a predetermined recording signal processing to generate the recording signal. Note that (FIG. 3B) is an internal block diagram of the adapter 50.

When recording the transmission signal, the switch 44
Is connected to the adapter input unit 48, the transmission signal input from the transmission signal input unit 49 is converted by the adapter 50 into a format required by the recording signal generator 45, and the converted signal is input to the recording signal generator 45. In the adapter 50, the transmission signal input to the memory 51 is written. Since the first error correction coding and the second error correction coding use the same codes as those for the video signal or the audio signal, the reading is performed in such an order that the subsequent circuits can be shared at all. That is, 1 of the transmission signal
Each of the symbols forming the blocks is assigned to a different codeword of the first error correction code,
Each of the symbols that make up one block is
The second error correction code is rearranged so as to be assigned to different code words. The control circuit 52 generates a write / read address of the memory 51 and a control signal. Further, similar to the first embodiment, these auxiliary data are also generated by the control circuit 52 in the form of a pattern of a predetermined format, written in the memory 51, and rearranged at the same time as the transmission signal. The actual method of rearranging the signals may be exactly the same as that of the first embodiment, and the signal input to the adapter input unit 48 is not yet subjected to the first error correction coding.

With the above-mentioned structure, the transmission signal can be recorded with a very simple structure, and the existing recording apparatus for audio or video signals can be used. Further, as in the first embodiment, when the reproduction state is very poor, the error remaining after the correction of the second and first error correction codes becomes the error of the transmission signal, so it is used for the transmission signal. It is possible to detect or correct using a correction code that is present.

Although the constitutions of the first and second embodiments are recording devices, they may be recording portions of a recording / reproducing device, and 25 and 46 are recording heads. It may be a head.

In the embodiment, the auxiliary data is recorded on the tape at the same time as the transmission signal. However, if there is an auxiliary storage medium (memory or magnetic tape) attached to the cassette containing the tape, the auxiliary data is recorded. It is also possible to store these pieces of information or a part thereof in the storage medium. By doing so, it is possible to correctly obtain the identification information of the system of the recorded transmission signal before starting the reproducing operation.

An example of the rearrangement method has been described.
Number of blocks input at a given time, block length,
Number of tracks formed on the recording device at a given time, 1
The number of recording blocks to which a transmission signal can be assigned among the recording blocks that can be recorded on one track, and the number of symbols that can be assigned to a transmission signal in each recording block are different values, and different sorting methods are used. The same effect can be obtained by using.

As described above, the configuration of this embodiment is an example, and the same effect can be obtained by other configurations.

[0028]

As described above, according to the recording apparatus of the present invention, a recording apparatus that is simple and has a small circuit scale can be realized by directly recording data in units of blocks including check symbols of error correction codes. It can be configured and its practical effect is great.

[Brief description of drawings]

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

FIG. 2 is a block diagram of a first error correction encoder 22 according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a recording apparatus according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a conventional recording device.

FIG. 5 is an explanatory diagram of a transmission signal recorded by a conventional recording device.

FIG. 6 is an explanatory diagram of a recording format of a conventional recording device.

[Explanation of symbols]

 21 Input Unit 22 First Error Correction Encoder 23 Second Error Correction Encoder 24 Recording Signal Generator 25 Recording Head 26 Tape

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Nishino 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. Input means for inputting data in units of blocks including check symbols of error correction codes, and first error correction coding means for performing first error correction coding on the input data. A second error correction coding means for performing a second error correction coding on the output of the first error correction coding means, and a recording for recording the output of the second error correction coding means on a recording medium. And a recording device. 2. The first error correction coding is characterized in that the error correction coding is performed such that the symbols forming one block are included in different code words of the first error correction code. The recording device according to claim 1. 3. The second error correction coding is characterized in that the error correction coding is performed such that the symbols forming one block are included in different code words of the second error correction code. The recording apparatus according to claim 1 or 2. 4. The second error correction coding is an error correction code so that symbols forming one code word of the first error correction code are included in different code words of the second error correction code. The recording device according to claim 3, wherein the recording device is configured to perform the conversion.