JPH06225258A - Digital data recording/reproducing device - Google Patents

Abstract

PURPOSE:To provide a digital data recording/reproducing device which can stably and surely record digital data in a digital video recorder by encoding digital data except a video on the format of a digital video signal so that it becomes optimum, adding horizontal/vertical synchronizing signals and setting them to be pseudo digital video signals. CONSTITUTION:A multiplexer 10 which time base multiplexes digital audio data of plural channels on data of one channel, an ECC adder 11 adding an error correction code to data, an encoder 12 encoding digital data so that it does not coincide with the inhibition code of the digital video signal and the synchronizing signal, a data rate converter 13 converting the rate of encoded data into the data rate of the digital video signal and a horizontal/vertical synchronizing signal adder 14 adding the horizontal/vertical synchronizing signals to video signal data whose data rate is converted are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital data recording / reproducing apparatus for recording / reproducing digital data other than video on a digital video recorder.

[0002]

2. Description of the Related Art A typical video recorder is a video tape recorder. Video tape recorders are also shifting from analog recording to digital recording due to numerous technological innovations.

As a video recorder, a product having a large storage capacity and recording data other than video has been proposed. As a device capable of recording audio data, which is data other than video, in the video recording area of a video recorder, there is an 8 mm PCM using an 8 mm VTR. This is to construct a multi-channel PCM recorder by expanding a normal PCM audio recording area for two channels to a video recording area.

However, in this case, since the format on the tape is different, the circuit is different between the 8 mm VTR and the 8 mm PCM.

A standard for converting digital audio data into an NTSC-TV signal and recording it on an analog VTR without changing the recording format of a video signal is a technical file (STC-00) of the Electronic Industries Association of Japan (EIAJ).
7) There is a "commercial PCM encoder / decoder". This is to convert digital data into a video signal by converting audio digital data into a serial signal and associating digital 1 and 0 with the white level and the black level of the video signal.

By the way, with the recent trend of digitalization, video equipment is also being digitized. Currently, it is mainly for business use, but digital VTRs for business use, digital video discs for business use, etc. are on sale.

Digital video recorders such as digital VTRs and digital video discs also have a large recording capacity, and it is conceivable to record digital data other than video.

The digital data may be pure digital data or digital audio data used in a computer. The former digital data is usually treated as a basic unit of 8 bits (1 byte), and the digital audio data has 16 bits or 20 bits depending on the number of quantization bits at the time of sampling. Further, although compressed audio data and video data, which are the recent trends, compressed video data can be cited as digital data.

Unlike a conventional recorder, a digital video recorder can directly record a digital signal, and thus has a great merit that there is no signal deterioration.

[0010] However, rather than changing the format or changing the circuit for that reason, it is a great merit that digital data can be converted into a pseudo digital video signal like a "commercial PCM encoder / decoder". Become.

Here, the digital video signal will be described. For digital video signals, standardization of sampling frequency, quantized bits, digital interface, etc. is the Society of Picture
And Television Engineers (SMPTE)
And the American National Standard Institute (ANSI).
Some of them are shown below. SMPTE Standard 170M Studio Standard for Composite Video Signal System M / NTSC (Studio St
andard for Composite Video Signal, System M / NTSC) 2. ANSI / SMPTE standard T14.22 / 08
2A Composite NTSC Digital Encoding and Bit Parallel Interface (Co
mposite NTSC Digital Encoding and Bit Parallel Int
erface) SMPTE standard T14.22 / 080 bit parallel digital interface for system M / NTSC composite video
Signals (Bit Parallel Digital Interface for S
ystem M / NTSC Composite Video Signals) 3. ANSI / SMPTE Standard RP125 Bit Parallel Digital Interface for Component Video Signals (Bit-para
llel Digital Interface for Component VideoSignal
s) 4. SMPTE standard T14.224 serial digital interface for 10
Bit 4: 2: 2 component and 4fsc
NTSC Composite Digital Signals
(Serial Digital Interface for 10-bit 4: 2: 2 Compon
ent and 4fsc NTSC Composite Digital Signals) 1 and 2 show the digital composite video signal format and the parallel digital interface standard of the signal, 3 is the parallel digital interface standard of the digital component video signal, 4 is the digital component and the digital composite video signal. Indicates the standard of serial digital interface.

The standard of the digital composite video signal will be described with reference to FIG. The sampling frequency is 4 fsc, which is four times the color subcarrier fsc, and the quantization bit number is determined to be 8 bits or 10 bits. NTS
In C, the number of samples per line is 910 samples, but in the horizontal 1-line period, there are a blanking period including a horizontal synchronizing signal and the like, and a valid data period, which are 142 samples and 768 samples, respectively. Figure 7
768 samples of the effective data period of are actually recorded and reproduced as a video signal.

Next, FIG. 8 shows analog video signal levels and 8
The relationship between the bit and 10-bit digital sample values is shown. As can be seen from FIG. 8, the white level, blanking level, and sync tip level of the video signal are C8h, 3Ch, 0 in hexadecimal in 8-bit quantization.
4h, 320h · 0F for 10-bit quantization
It has been decided that it must be 0h and 010h.
In addition, the area that can be used for the quantized data itself is determined, and from 8-h quantization to 01h to FEh, 10
Bit quantization is from 004h to 3FBh. In other words, since the data itself has meaning and there is data that should not be used, it is not possible to simply replace digital data with video data.

By the way, in the "commercial PCM encoder / decoder", two-channel audio data is recorded as pseudo video data, and the data for the two channels is converted into one signal as a video signal. Therefore, there is no concept of a channel in the state of a video signal, and it is impossible to separate data for one channel. Separation is performed in the decoding process. For example, when it is desired to replace only one of the two channels encoded in the video signal, the decoding is performed once and then the channel is replaced and the encoding is performed again. More complex with more channels.

[0015]

A first problem to be solved by the present invention is to enable digital data other than video to be recorded / reproduced in a digital video recorder without changing the circuit configuration of the digital video recorder. It is a thing.

A second problem is to realize data exchange in units of channels with a simple structure, for example, when digital data is composed of a plurality of blocks like audio multi-channel data.

The present invention solves the above problems, and provides a digital data recording / reproducing apparatus capable of stably and reliably recording digital data in a digital video recorder without changing the circuit configuration of the digital video recorder. With the goal.

It is another object of the present invention to provide a digital data recording / reproducing apparatus capable of handling data such as recording / reproducing in units of channels or blocks.

[0019]

In order to solve the first problem, a digital data recording / reproducing apparatus of the present invention is a coding for coding digital data so as not to match a prohibition code or a synchronizing signal of a digital video signal. , A data rate converter, a horizontal and vertical sync signal adder, a horizontal and vertical sync signal separator, a data rate inverse converter, and a decoder for decoding encoded data.

In order to solve the second problem, in the digital data recording / reproducing apparatus of the present invention, the encoded digital data amount is divided into blocks so as to be an integral multiple of the data amount for one line of the digital video signal. Blocker, an encoder that encodes digital data so that it does not match the inhibit code or sync signal of the digital video signal, a data rate converter, a data mixer that mixes data in blocks, and a horizontal And vertical sync signal adder, horizontal and vertical sync signal separator, data rate inverse converter, block separator that separates blocks from block data into blocks, and decodes encoded data It is composed of a decoder.

[0021]

According to the present invention, with the above configuration, digital data other than video is encoded so as to match the format of the digital video signal, and then horizontal / vertical synchronization signals are added to form a pseudo digital video signal. it can.

Further, by dividing one block of data into data blocks using the horizontal synchronizing signal as a delimiter signal, it is possible to handle the data in channel units or block units.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a digital data recording / reproducing apparatus of the present invention will be described below with reference to the drawings.
FIG. 1 shows a digital data recording / reproducing apparatus according to a first embodiment of the present invention. In this embodiment, the digital data is digital audio data, and the digital audio data for a plurality of channels is recorded and reproduced as a pseudo digital video signal.

In FIG. 1, 10 is a multiplexer for time-multiplexing digital audio data of a plurality of channels into 1-channel data, 11 is an ECC adder for adding an error correction code to the multiplexed data, and 12 is digital data. An encoder that encodes so as not to match the prohibition code or the sync signal of the video signal, 13 is a data rate converter that converts the rate of the encoded data into the data rate of the digital video signal, and 14 is the data rate that is converted. A horizontal / vertical sync signal adder that generates a pseudo digital video signal by adding a horizontal / vertical sync signal to the video signal data, and 15 is a horizontal / vertical sync that separates the horizontal / vertical sync signal from the input pseudo digital video signal. Signal separator, 16 data rate inverse converter, 17 encodes encoded data Decoder for decoding the data, 18
Is an ECC corrector for error correction, and 19 is a demultiplexer for expanding the data into digital audio data of a plurality of channels on the time axis.

FIG. 2 is a connection diagram when the digital data recording / reproducing apparatus of the present invention is connected to a digital video recorder via a digital video interface. The pseudo digital video output of the digital data recording / playback apparatus is connected to the digital video input of the digital video recorder, and conversely, the digital video output of the digital video recorder is connected to the digital input of the digital data recording / playback apparatus. In this case, it is assumed that the digital video recorder has a configuration in which video data having 8 bits of quantized bits is input from the interface and recorded by the NTSC.

First, let us consider the number of digital samples (equal to the number of bytes since it is quantized 8 bits) that composes a digital video signal. In the case of NTSC, as described above, valid data is composed of 768 samples per line, which is 255 lines per field. Therefore, the number of samples per field is 768 × 255 = 195840 samples / field. In addition to these, data obtained by sampling horizontal or vertical blanking is added to these, but the valid data is the number of samples described above.

By the way, the rate of digital audio data is 48 KHz × 16 bits = 768 Kbit / sec = 96 Kbyte / sec per channel in the case of a system having a sampling frequency of 48 KHz and quantization bits of 16 bits, which corresponds to one field time. The number of bytes of audio data is 96K / 59.94Hz = 1601.6 bytes / field If the ECC code of about 30% is added to the audio data, simply calculating the number of recording channels is 195840 / (1601.6 ÷ 0.7) = 85 channels (1), which shows that digital audio data for 85 channels can be recorded.

However, in reality, 85 channels cannot be recorded. This is because, as already mentioned, the digital video signal has a code whose use is prohibited.
Therefore, it is necessary to perform some encoding without directly assigning 8 bits of audio data to 8 bits of a digital video signal. Since 00h and FFh cannot be used in 8-bit quantized data of video, it is of course necessary to code so that they do not match the code, but the data between blanking level 3Ch and sync chip level 04h is also the original synchronization. Since it may be mistaken as a signal, it is not preferable to appear in the valid data area.

Therefore, an example of encoding 8-bit data will be described. This will be described below with reference to FIG. In FIG. 3, * is a portion where data is entered. In order to avoid coincidence with the prohibition code or the sync signal level, consider a method in which a fixed pattern is inserted at the expense of the upper 2 bits of 8 bits and the remaining 6 bits are used as a data portion. As the fixed pattern, 10h and 01h can be considered. As a result, 8-bit data is 80h or more and less than C0h (BFh or less) or 40h or more and less than 80h (7Fh or less).
Will definitely be. 10h and 01h can be selectively used for identification depending on the case. In this system, 3 bytes of input data are added with 10h and 01h and encoded into 4 bytes.

The number of recording channels in the above encoding is
Since the valid data is 6 bits out of 8 bits, (1)
If the same calculation as the formula is performed, 195840 × 6/8 ÷ (1601.6 ÷ 0.7) = 6
It has 4 channels.

Another encoding example will be given. First, when the MSB of 8 bits is sacrificed and the data of the lower 7 bits is other than all 1, the MSB is set to 1, and is set to 0 only when the value is all 1. As a result, the data is 7F
It can be limited to the range from h to FEh. In this method, the created MSB is added to 7 bytes of input data and encoded into 8 bytes.

In this case, the number of recording channels is 7 bits out of 8 bits of effective data. Therefore, if the same calculation as in formula (1) is performed, 195840 × 7/8 ÷ (1601.6 ÷ 0.7) ) = 7
It has 4 channels.

Here, the case where the digital video signal is quantized by 8 bits has been described, but similar encoding is performed by 10 bit quantization.

The operation of the digital data recording / reproducing apparatus of the first embodiment of the present invention constructed as above will be described with reference to FIG.

First, digital audio data for a plurality of channels is input to the multiplexer 10. The number of channels is determined by the addition amount of the ECC code and the encoding method as in the above example. For example, in the encoding method using 6 bits out of 8 bits at ECC 30%, data for 64 channels can be recorded. The number of input channels to the multiplexer 10 may be 64 or less.

The multiplexer 10 compresses these data on the time axis to form one data stream.

The data stream is input to the ECC adder 11 and an error correction code is added. Generally, the video signal is added with an error correction code in the digital video recorder when it is recorded, but it is a less powerful error correction code. This is because if the video signal cannot be error-corrected, interpolation processing may be performed. In order to record digital data other than the digital video signal as in the present invention, an externally strong error correction code is used. Therefore, an ECC adder is required because it has to be added.

The data stream to which the error correction code has been added by the ECC adder 11 is subjected to the above-mentioned encoding by the encoder 12, and the encoding processing is performed so that it does not match the prohibition code or the synchronization signal. After that, the data rate converter 1
Converted to the data rate of digital video signal in 3,
At that time, for the data shortage amount, a prohibition code and fixed pattern dummy data that does not become a sync signal component are added as in the case of encoding. The horizontal and vertical sync signal adder 14 adds vertical and horizontal sync signals to form a pseudo digital video signal, which is then output. If the signal is connected as shown in FIG. 2, it will be recorded in the digital video recorder.

On the contrary, when the pseudo digital video signal is inputted from the outside, the data rate is converted by the data rate reverse converter 16 after entering the horizontal / vertical sync signal separator 15 to separate the horizontal / vertical sync signals. To be done. The output data from the data rate inverse converter 16 is decoded by the decoder 17 after being subjected to the reverse processing of the encoder 12. afterwards,
The ECC corrector 18 performs error correction, and the demultiplexer 19 separates and expands into a plurality of digital audio data.

As described above, according to this embodiment, the digital data is encoded so as not to match the prohibition code and the synchronizing signal to generate the pseudo digital video signal, so that stable recording and reproduction can be performed.

Next, a second embodiment of the digital data recording / reproducing apparatus of the present invention will be described with reference to the drawings. FIG. 4 shows a digital data recording / reproducing apparatus according to the second embodiment of the present invention. Also in this embodiment, digital data is digital audio data as in FIG. 1, and recording / reproduction is performed by using digital audio data for a plurality of channels as pseudo digital video signals.

In FIG. 4, 40 is a multiplexer for time-multiplexing digital audio data of a plurality of channels into 1-channel data, and 41 is an integer of data of one line of digital video for the number of channels of digital audio data to be blocked. A blocker that divides the data into doubles, 42 is an ECC adder that adds an error correction code to the data in block units, and 43 is a code that encodes the digital data so as not to match the prohibition code or the synchronization signal of the digital video signal. A data rate converter for converting the coded data rate into a digital video signal data rate, a data mixer for mixing the input pseudo digital video signal in block units, and a data rate conversion for 46. By adding horizontal and vertical sync signals to the data A horizontal / vertical sync signal adder for generating a similar digital video signal, 47 is a horizontal / vertical sync signal separator for separating a horizontal / vertical sync signal from an input pseudo digital video signal, 48 is a data rate inverse converter, and 49 is a block. A block separator that can separate data in units,
Reference numeral 410 is a decoder for decoding the encoded data into data before encoding, 411 is an ECC corrector for error correction, and 412 is a demultiplexer for expanding the data into digital audio data of a plurality of channels on the time axis.

In the digital data recording / reproducing apparatus of the first embodiment described above, since the data channels to be recorded are integrated in the pseudo digital video signal, they are separated until the data rate inverse conversion / decoding / ECC correction processing is performed. I can't do it.

Therefore, in the digital data recording / reproducing apparatus of FIG. 4, the blocker 41 and the block separator 49 are provided. The blocker 41 divides the horizontal synchronization signal into blocks so as to serve as block delimiters. The blocks here are divided into blocks so that the amount of data becomes an integral multiple of the amount of data that can be recorded in one horizontal line at the time when encoding is completed after ECC is added. If there is not enough data, dummy data will be added to each block.

As in the case of FIG. 1, consider the block formation of digital audio data as an example. As already mentioned, 48KH equivalent to the time of NTSC1 field
The amount of digital audio data for one channel of z 16 bits is 1601.6 bytes. The effective data of one line of the digital video signal is 768 samples, but when converting 8 bits to 6 bits by encoding as described above, the actual data amount in 768 samples is 768 × 6 ÷ 8 = 576 samples. Becomes If 30% ECC is added to the audio data, the number of horizontal lines required to record one channel of digital audio data is (1601.6 ÷ 0.7) ÷ 576 = 3.97 lines, which is You can see that it can record on 4 lines. In this case, if you want to block each channel,
Dummy data is added so that it has 4 lines. Also,
If it is desired to form blocks for every two channels, dummy data may be added so that eight lines are not divided into four lines and become one unit. How many channels will be blocked will be determined by the system specifications.

The operation of the digital data recording / reproducing apparatus of this embodiment constructed as above will be described. In this embodiment, the digital audio to be divided into blocks has 8 channels. In order to clarify the handling of data in block units, the first record and the second and subsequent records will be described separately.

First, the first recording will be described. The system is assumed to be connected as shown in FIG. In FIG. 4, eight channels of digital audio data are input to the multiplexer 40. In the multiplexer 40, those data are time-axis compressed and become one data stream. The blocker 41 adds dummy data so that the data becomes 32 lines after encoding and is divided into blocks.

After that, it is input to the ECC adder 42 and an error correction code is added. The data stream to which the error correction code has been added by the ECC adder 42 is the encoder 4
Encoding is performed in step 3, and encoding processing is performed so that it does not match the prohibition code or the synchronization signal component.

After that, the data rate converter 44 converts the data into a data rate of a digital video signal. At that time, the unused portion of the data (in this case, only 32 lines are used in the 255 lines of the field). , 223 lines per field), dummy data having a pattern that does not match the prohibition code or the sync signal component is added as in the case of encoding. The vertical and horizontal synchronizing signals are added by the horizontal and vertical synchronizing signal adder 46, converted into a pseudo digital video signal, and then output. If the signal is connected as shown in FIG. 2, it will be recorded in the digital video recorder.

During reproduction, a pseudo digital video signal is input from the outside. Enter the horizontal / vertical sync signal separator 47
After the vertical synchronizing signal is separated, the data rate inverse converter 4
8, the data rate is converted. The output data from the data rate inverse converter 48 is input to the block separator 49 and the blocks are separated. After being decoded by the decoder 410, error correction is performed by the ECC corrector 411, and demultiplexer 412 separates into 8-channel digital audio data and expands it on the time axis.

Next, the operation of re-recording some channels while recording and reproducing for the second time and thereafter will be described. FIG. 5 is a connection diagram for the second and subsequent recordings. In FIG. 5, it is assumed that the digital video recorder 1 reproduces a medium in which digital data is recorded in block units one or more times and outputs it as a pseudo digital video signal. The digital data recording / reproducing apparatus is the same as the digital data recording / reproducing apparatus of FIG. 4, and the + symbol indicates the data mixer 45. The digital video recorder 2 records the output.

The second and subsequent recording will be described with reference to FIGS. 4 and 5. The pseudo digital video output containing the blocked data from the digital video recorder 1 of FIG. 5 is input to the vertical / horizontal signal separator 47 of FIG. The output of the vertical / horizontal signal separator 47 is input to the data mixer 45. At that time, new data that has been divided into blocks as in the first recording is output from the data rate converter 44.
In the data mixer 45, the data is inserted into the set block according to the setting of which block the data is recorded (block number setting means is omitted in the figure). In this setting, since the data is recorded in the first block by the first recording, the second block is set. Since the horizontal sync signal is used as a block delimiter, the block management only needs to count the horizontal sync signal and the contents of the block become irrelevant. Therefore, the first block is not affected and the second block is not affected. You will be able to write. By repeating this operation, recording can be performed in block units. According to this method, it is also possible to rewrite data in block units by setting a recording block number on an already recorded block.

Although the connection of FIG. 5 is shown after the second recording, when the digital video recorder has a function of rerecording the data previously reproduced from the medium at the same position, the connection diagram of FIG. You can do the same thing.

FIG. 6 shows a schematic diagram of a format of a block-shaped pseudo digital video signal. The digital video signal 255 lines are divided into blocks by adding dummy data so that 8 lines of data are 32 lines and 1 block.

As described above, according to the present embodiment, the digital data is encoded so as not to match the prohibition code and the synchronizing signal to generate the pseudo digital video signal, so that stable recording and reproduction can be performed. Further, since the data is divided into blocks by using the horizontal synchronizing signal as a delimiter signal, the data can be recorded and reproduced in the block unit such as the exchange of the data in the channel unit, and the data can be handled very easily.

[0056]

According to the present invention, with the above configuration, digital data other than the digital video signal can be stably and surely recorded / reproduced on / from the digital video recorder without changing the circuit configuration of the digital video recorder.

Further, since the data can be divided into blocks, the recording / reproducing of the data in block units can be facilitated and its effect is great.

[Brief description of drawings]

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

FIG. 2 is a connection diagram (1) of a digital data recording / reproducing apparatus of the present invention and a digital video recorder.

FIG. 3 is a schematic diagram of an encoding example.

FIG. 4 is a block diagram of a digital data recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 5 is a connection diagram (2) of the digital data recording / reproducing apparatus of the present invention and a digital video recorder.

FIG. 6 is a schematic diagram of a pseudo digital video signal blocked in units of 8 channels.

FIG. 7 is a waveform diagram of a digital sample of a digital video signal (NTSC).

FIG. 8 is a diagram showing a relationship between 8-bit and 10-bit quantized data and an analog video signal.

[Explanation of symbols]

 10 multiplexer 11 ECC adder 12 encoder 13 data rate converter 14 horizontal / vertical sync signal adder 15 horizontal / vertical sync signal separator 16 data rate inverse converter 17 decoder 18 ECC corrector 19 demultiplexer 40 multiplexer 41 block 42 42 ECC adder 43 Encoder 44 Data rate converter 45 Data mixer 46 Horizontal / vertical sync signal adder 47 Horizontal / vertical sync signal separator 48 Data rate inverse converter 49 Block separator 410 Decoder 411 ECC correction Vessel 412 demultiplexer

Claims (6)

[Claims] 1. An encoder for encoding digital data so as not to coincide with a prohibition code or a sync signal of a digital video signal, and a data rate conversion for converting an output signal of the encoder into a data rate of the digital video signal. And a horizontal / vertical sync signal adder for adding horizontal and vertical sync signals to the output signal of the data rate converter to generate a pseudo digital video signal, and a horizontal and vertical sync signal adder for separating the horizontal and vertical sync signals from the pseudo digital video signal. A vertical sync signal separator, a data rate inverse converter that converts the data rate of the output signal of the horizontal vertical sync signal adder in the opposite direction to the conversion, and a decoding that decodes the output signal of the data rate inverse converter. A digital data recording / reproducing apparatus comprising: 2. An ECC adder for adding error correction data to digital data, and an ECC corrector for performing error correction on an output signal of a decoder, wherein the output signal of the ECC adder is an encoder. The digital recording / reproducing apparatus according to claim 1, wherein the digital recording / reproducing apparatus is encoded. 3. The output of the horizontal / vertical synchronization signal adder, the input of the horizontal / vertical synchronization signal separator, or both of them are connected to a digital video recording / reproducing apparatus. The described digital recording / reproducing apparatus. 4. A blocker for blocking digital data into blocks in which a data amount of a signal encoded by the following encoder is an integral multiple of a data amount of one line of a digital video signal, and the blocker. An encoder that encodes the output signal of the encoder so as not to match the prohibition code or the synchronization signal of the digital video signal; a data rate converter that converts the output signal of the encoder to the data rate of the digital video signal; A data mixer that mixes the output signal of the data rate converter and the output signal of the horizontal / vertical sync signal adder described below in units of the blocks, and a horizontal and vertical sync signal is added to the output signal of the data mixer to generate a pseudo digital image. A horizontal and vertical sync signal adder for generating a signal, and a horizontal and vertical sync signal separator for separating the horizontal and vertical sync signals from the pseudo digital video signal A data rate inverse converter for converting the data rate of the output signal of the horizontal / vertical synchronization signal separator in the opposite direction to the conversion, and a decoder for decoding the output signal of the data rate inverse converter. A digital data recording / reproducing apparatus characterized by: 5. An ECC adder for adding error correction data to digital data, and an ECC corrector for performing error correction on an output signal of a decoder, wherein an output signal of the ECC adder is an encoder. The digital recording / reproducing apparatus according to claim 4, which is encoded. 6. The output of the horizontal / vertical sync signal adder or the input of the horizontal / vertical sync signal separator or both of them are connected to a digital video recording / reproducing apparatus. The described digital recording / reproducing apparatus.