JPH06203485A - Method and device for transmission - Google Patents

Abstract

PURPOSE:To effectively use recording capacity by attaining transmitting even when a prohibition code exists in input data and taking a redundant component in bit by converting the prohibition code to the code having the redundancy containing no prohibition code. CONSTITUTION:From a changeover switch 35, the data as it is are outputted when the data supplied to a terminal 31 are not the conversion code of the prohibition code and a specific code, and the prohibition code is outputted when the data supplied to the terminal 31 are the conversion code of the prohibition code, and the specific code is outputted when the data are the conversion code of the specific code. The output of the switch 35 is sent to an FIFO memory 36, and the data supplied based on a clock from a timing clock generator 37 is written in the FIFO memory 36, and the data are read out in order of input. In such a case, a digital VTR is dealed with just as if no prohibition code exists.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission method and apparatus for transmitting data containing unusable prohibition codes.

[0002]

2. Description of the Related Art Conventionally, as one mode of transmitting certain digital data, for example, there is a case of recording / reproducing input digital data for transmission. In such a transmission, since a code (prohibited code described later) that is inconvenient to record at the time of recording / reproduction cannot be transmitted, the prohibited code is replaced with a code that is not a prohibited code before recording / recording. It is played back and transmitted.

That is, conventionally, when recording / reproducing digital data, it may happen that, for example, the data in the portion in which an error has occurred during recording / reproduction cannot be reproduced. Thus, the portion corresponding to the error data at the time of reproduction is replaced with a specific code indicating the error. Therefore, for example, when the same code as the specific code is supplied as the input data, if the same code as the specific code is recorded / reproduced, the reproduced code indicates an error. Therefore, it cannot be determined whether the input data has the same code or the input data having the same code as the specific code. Therefore, when the same code as the specific code is supplied as the input data, it is necessary to prevent this code from being recorded as the prohibited code.

For this reason, conventionally, the above-mentioned prohibition code which is inconvenient to record at the time of recording / reproducing input digital data when recording / reproducing the input digital data is not a prohibition code. The data is replaced with a code and then recorded / reproduced for transmission.

[0005]

By the way, when transmitting digital data, there are cases where all the codes including the above-mentioned prohibition code must be transmitted. But,
As described above, conventionally, when a prohibition code is supplied as input data, the prohibition code is simply converted into a code that is not a prohibition code and transmitted. Therefore, all codes including the prohibition code are transmitted. Even if it is necessary, if the prohibition code is supplied as the input data, the prohibition code cannot be transmitted.

Therefore, for example, in a system for recording / reproducing and transmitting the above digital data, when it is desired to use it for recording / reproducing all codes including forbidden codes (for example, for use as a data recorder). Cannot use the above-mentioned method of simply converting the prohibition code.

Therefore, in view of the above-mentioned problems, it is an object of the present invention to provide a transmission method and device capable of transmitting input data even if there is a prohibition code.

[0008]

DISCLOSURE OF THE INVENTION A transmission method and device according to the present invention have been proposed to achieve the above-mentioned object, and are transmission methods for transmitting data containing unusable prohibition codes, at least It is characterized in that it is composed of a conversion rule for converting a prohibited code into a code having redundancy without including a prohibited code, and an inverse conversion rule for performing an inverse conversion corresponding to the conversion rule.

Specifically, the above conversion rule converts the prohibited code into a code consisting of a special code which is not a prohibited code and an ID code which is not a prohibited code and a special code, and the special code is a special code. It is converted into a code composed of special codes, and the above-mentioned prohibited codes and codes that are not special codes are passed through as they are. The inverse conversion rule corresponding to this conversion rule converts (inverse conversion) a code consisting of a special code and an ID code into a prohibited code,
It is assumed that the special code and the code consisting of the special code are converted into the special code (inverse conversion), and the other codes are passed through as they are.

Further, the redundancy is set to 2 of the code byte.
It can be less than double. At this time, the redundant part does not match a part of the prohibition code, and the redundant part becomes a part of the next data.

Further, the transmission device of the present invention is a transmission device for transmitting data containing an unusable prohibition code, and at least the prohibition code comprises a special code which is not the prohibition code and an ID code which is not the prohibition code and the special code. A conversion means for converting into a code (converting a prohibited code into a code having redundancy not including a prohibited code); and an inverse conversion means for performing an inverse conversion corresponding to the conversion in the conversion means. It is a feature.

Here, the special code and the ID code are at least in byte units corresponding to the prohibition code. That is, the code converted by the conversion means is a code having redundancy with respect to the code to be converted (2 of the original data amount).
Code with redundancy such as double or triple).

More specifically, also in the transmission apparatus of the present invention, the converting means converts the prohibited code into a code including a special code which is not a prohibited code and an ID code which is not a prohibited code and a special code, and the special code. Converts into a code consisting of a special code and a special code, and the above-mentioned prohibition code and a code other than the special code are processed so as to pass through as they are. Further, in the inverse conversion means, a code composed of the special code and the ID code is converted into a prohibited code (inverse conversion), a code composed of the special code and the special code is converted into a special code (inverse conversion), and other codes are formed. Is processed as it is.

Further, when the code occurrence frequency distribution of the input data is not flat, it is desirable to select a code having a low occurrence frequency distribution as the special code and the ID code.

Further, in the converting means, the ID code can be less than twice the byte of the special code.
At this time, the ID code does not match a part of the prohibition code, and the conversion means makes the ID code a part of the next data.

In other words, according to the present invention, for example, for a digital recording device (such as a digital VTR) in which an unrecordable prohibition code exists, conversion to a code string that does not include a prohibition code in preprocessing and its reverse conversion in postprocessing are performed. By performing the above, it is possible to record and reproduce all the codes including the prohibited code. The code string here is a code having redundancy (one to several times the data amount of the original code string) with respect to the code string to be converted.

In the conversion into the code string, the redundancy is less than twice (for example, when the minimum recording unit of the recording device is 1 byte = 8 bits, this 1 byte is converted into 1 byte (8 bits)). It is possible to suppress the increase of data in the conversion by converting to the one with bits added).

Further, the redundant portion becomes a part of the next data, but by selecting the redundant portion so as not to coincide with a part of the prohibition code, the prohibition code does not appear continuously. At the same time, redundancy is suppressed.

[0019]

According to the transmission method and apparatus of the present invention, since the forbidden code is converted into the code having the redundancy which does not include the forbidden code, all the codes including the forbidden code can be transmitted.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the transmission method and apparatus of the present invention will be described below with reference to the drawings.

The transmission method of the embodiment of the present invention is a transmission method for transmitting data including an unusable prohibition code, and at least a conversion rule for converting the prohibition code into a code having redundancy not including the prohibition code, and the above-mentioned conversion rule. It is characterized by comprising an inverse conversion rule for performing an inverse conversion corresponding to the conversion rule. Specifically, the above conversion rule converts the prohibited code into a code including a special code that is not a prohibited code and an ID code that is not a prohibited code and a special code, and changes the special code to a code that includes a special code and a special code. The converted code and the code other than the special code are passed through as they are. The inverse conversion rule corresponding to this conversion rule converts (reverse conversion) a code composed of a special code and an ID code into a prohibited code and converts a special code and a code composed of a special code into a special code (reverse conversion). )
However, the other codes shall be passed as they are.

That is, the conversion rule in the transmission method of this embodiment is realized by the steps shown in the flowchart of FIG.

In FIG. 1, when data is input in step S1, it is determined in step S2 whether the input data is a prohibited code. If the input data is determined to be a prohibited code (Yes) in step S2, the process proceeds to step S6, which will be described later, and if it is determined that the input code is not the prohibited code (No), the process proceeds to step S3.

In step S3, it is determined whether the input data is a special code. If it is determined in step S3 that the input data is the special code (Yes), the process proceeds to step S9 described below, and if it is determined that the input data is not the special code (No), the process proceeds to step S4.

In step S4, the input data is output as it is, and the process proceeds to step S5.

When it is determined in step S2 that the input data is the prohibited code and the process proceeds to step S6, the input data is converted into the ID code in step S6, and the special code is output in the next step S7. Then, step S8
Then, the special code and the ID code are output together. That is, the prohibition code is converted in steps S6 to S8. After step S8, the process proceeds to step S5.

Further, when it is judged in step S3 that the input data is the special code and the process proceeds to step S9, the special code is output in step S9, and the special code is output in the next step S10. Output the combined one. In these steps S9 and S10, special code conversion is performed. After the step S10, the process proceeds to step S5.

In step S5 after the above-mentioned steps S4, S10 and S8, it is judged whether or not the input of all data is completed, and if it is judged that the input is not completed (No). Returns to step S1, and if it is determined that the input is completed (Yes), the conversion process is ended.

Here, more specifically, for example, the data is
If bit data (00h to FFh), the prohibition code is 00h, the special code that is not the prohibition code is FFh, and the ID code that is neither the prohibition code nor the special code is 01h, the transmission of the present embodiment is performed. The above conversion rule of the method becomes the following rule.

For example, if the input code is the prohibition code (00
h), the special code (FFh) and the ID code (0
Convert to 2 bytes (FFh · 01h) which is a set of 1h). That is, input (00h) → output (FFh · 01
h).

When the input code is the special code (FFh), it is converted into 2 bytes (FFh · FFh) which is a set of the special code (FFh) and the special code (FFh). That is, input (FFh) → output (FFh · FFh).
To send.

When the input code is a code other than these, the input code is passed as it is.

The inverse conversion rule corresponding to the above conversion rule in the transmission method of this embodiment is as follows.

For example, if the input code is a special code (FFh) and the next code following the special code (FFh) is a special code (FFh) (that is, (FFh · FFh)), a 1-byte special code is used. Only the code (FFh) is converted. After this conversion is completed, the inverse conversion process is restarted from the code next to the two consecutive special codes (FFh · FFh).

When the input code is the special code (FFh) and the next code connected to the special code (FFh) is the ID code (01h) which is not the special code (that is, (FFh.
(01h)) is converted into a 1-byte prohibited code.
After the conversion is completed, the inverse conversion process is restarted from the code next to the two codes (FFh · 01h) connected in series.

When the input code is not the special code (FFh), the input code is passed as it is.

In the conversion rule and the inverse conversion rule of the present embodiment described above, there is only one kind of forbidden code. However, even when there are a plurality of forbidden codes, the ID code is only the kind of the plural forbidden codes. By allocating, it becomes possible to perform the same conversion / inverse conversion as described above.

That is, when there are a plurality of (N from 0 to N−1, N <(total number of codes / 2)) forbidden codes and ID codes corresponding to them, the following is performed. It becomes a conversion rule.

For example, the input code x is a prohibited code (x = 0 to 0).
In the case of (N-1), if the special code is (FFh) as described above, the output code after conversion is (FFh · (x + N)). When the input code x is neither a prohibited code nor a special code (x = N to FEh), the output code after conversion is x. Further, when the input code x is a special code (FFh), the converted output code is (FFh · FFh).

Next, the transmission device (transmission system) of the embodiment of the present invention will be described. The above-described transmission method of the present invention is applied to the transmission apparatus (transmission system) of the present invention. The transmission device (transmission system) of the present embodiment can be used when a digital recording / reproducing device such as a digital VTR is used as a data recorder.

That is, as shown in FIG. 2, the transmission apparatus (transmission system) of the present embodiment is a transmission apparatus for transmitting data including a prohibition code that cannot be recorded by the digital recording / reproducing apparatus 104, and at least the prohibition code. To a code composed of a special code other than the forbidden code and an ID code other than the forbidden code and the special code (converts the forbidden code into a code having redundancy that does not include the forbidden code), and the above conversion device 101. And an inverse conversion device 105 that performs the corresponding inverse conversion.

The special code and the ID code are at least in byte units corresponding to the prohibition code. That is, the code converted by the conversion device 101 is a code having redundancy with respect to the code to be converted (code having redundancy such as twice or three times the original data amount).

Specifically, as shown in FIG. 2, even in the transmission apparatus (transmission system) of the present embodiment, the conversion apparatus 101 is prohibited in the same manner as the conversion rule and the inverse conversion rule in the conversion method described above. The code is converted into a special code other than the prohibited code and the ID code other than the prohibited code and the special code, and the special code is converted into a code including the special code and the special code. The code is processed so as to pass through as it is. Further, in the inverse conversion device 105, a code consisting of a special code and an ID code is converted (inverse conversion) into a prohibited code,
The special code and the code consisting of the special code are converted into the special code (reverse conversion), and the other codes are processed so as to pass through as they are.

In FIG. 2, the input terminal 100 is supplied with digital data a to be recorded in the digital recording / reproducing device 104, and this digital data a is data including all codes (that is, including prohibition codes). This digital data a is sent to the conversion device 101, and is converted by the conversion device 101 into data b that does not include the prohibition code according to the conversion rule described above (the amount of data is increased because redundancy is provided by this conversion). Will increase). The above data b is
Input / output format data c for the digital recording / reproducing device 104 via the interface device 102.
After being converted into the digital recording / reproducing device 104
Is entered and recorded.

On the other hand, on the reproducing side, the digital recording / recording
The data d reproduced and output by the reproduction device 104 is converted by the interface device 102 into the inverse conversion device 1 in the subsequent stage.
It is converted into the data e of the format for 05. This data e is sent to the inverse conversion device 105, and is converted by the inverse conversion device 105 according to the inverse conversion rule described above (inverse conversion).
Are converted to digital data f of the original data rate. The digital data f is output from the output terminal 106.

That is, the transmission apparatus of the present embodiment, for example, a digital VTR, indicates a state in which reproduced data is error data, for example, with a certain code (prohibition code).
Is applied to a device that creates and represents the error data. In this case, the code representing the error data is a prohibition code (prohibition code) on the recording side. . Further, on the reproducing side, data that is not correctly reproduced is output as a prohibition code.

As a result, for example, if the digital data (image, audio) is effective for correction of error data, the digital recording / reproducing device (digital VTR) 1
The information of the reproduction error generated in 04 is the inverse conversion device 105.
It is possible to perform correction processing on the conversion device side by utilizing the fact that data is transmitted up to (through a data transmission line without using a special route).

Here, the conversion device 101 shown in FIG. 2 can be realized by the structure shown in FIG.

In FIG. 3, the input terminal 10 has the configuration shown in FIG.
The input digital data from the terminal 100 of
This input data is sent to the FIFO memory 12. In the FIFO memory 12, the input data is written based on the input clock (clock of the input data) from the terminal 11, and the timing clock generator 1
Data is read out in the above-mentioned input order by the clock from 8. In addition, this timing clock generator 1
The clock of 8 is faster than the input clock.

The data read from the FIFO memory 12 includes the special code detector 13 and the inhibition code detector 14.
To the switched terminal A of the changeover switch 19, the ID code generator 15, the FF / ID output device 16, and the FF / FF output device 17.

The special code detector 13 detects a special code from the supplied data. The prohibition code detector 14 detects a prohibition code from the supplied data. The respective detection outputs of the special code detector 13 and the prohibition code detector 14 are sent to the changeover switch 19 as changeover control signals.

Further, the ID generator 15 generates the ID code when the supplied data is an inhibition code, and the ID code is fed to the FF / ID output unit 16
Send to. The FF / ID output device 16 outputs the special code (FF) when the supplied data is a prohibited code.
h) and a code (FFh · 01h) consisting of the ID code from the ID code generator 15 are output to output the changeover switch 19
Of the selected terminal B.

The FF / FF output device 17 is provided with the special code (FF) when the supplied data is a special code.
h) and special code (FFh)
h) is output and sent to the selected terminal C of the changeover switch 19.

The special code detector 13, the prohibited code detector 14, the ID code generator 15, the FF / ID output device 16, and the FF / FF output device 17 are based on the clock from the timing clock generator 18, respectively. It works.

The changeover switch 19 is capable of changing over the terminals A, B and C to be changed over based on the detection outputs from the special code detector 13 and the prohibition code detector 14, and the special code detector. When the special code is detected by 13, the output is output from the FF / FF output device 17 (that is, the conversion code of the special code) by switching to the switched terminal C, and when the prohibition code detector 14 detects the prohibition code. The output of the FF / ID output device 16 (that is, the conversion code of the inhibition code) is output by switching to the switched terminal B, and the special code detector 13 and the inhibition code detector 14 are output.
If there is no detection output from (i.e., if the input data is neither a special code nor a prohibition code), it is switched to the switched terminal A and the output of the FIFO memory 12 is passed through as it is.

The output of the change-over switch 19 serves as the converted output of the converter 101 of this embodiment and is output from the output terminal 20 and sent to the interface device 102 of FIG.

Further, the inverse conversion device 105 of this embodiment is specifically realized by the structure shown in FIG.

In FIG. 4, the input terminal 31 is digitally recorded / recorded via the interface device 102.
Reproduction data is supplied from the reproduction device 104. The data is sent to the byte converter 33, the switched terminal A of the changeover switch 35, and the FF / ID detector 34.

The FF / ID detector 34 operates on the basis of the clock from the timing generator clock 37 which generates a clock similar to the timing clock generator 18, and at the same time, the inhibition code is supplied from the supplied data to the conversion device 101. The code (FFh · 01h) obtained by the conversion is detected.

Further, the byte converter 33 is arranged so that the FF
-Based on the detection output of the ID detector 34 and the detection of the conversion code (FFh / FFh) of the special code performed by itself, the byte of the supplied data is converted from 2 bytes to 1 byte, and the inverse conversion is performed. Is to do. That is,
When the supplied data is a 2-byte conversion code (FFh · 01h) obtained by converting the prohibition code, the data is converted into a 1-byte conversion code based on the detection output of the FF / ID detector 34. Convert to a prohibition code (00h). When the supplied data is a 2-byte conversion code (FFh · FFh) obtained by converting the special code, based on the detection output of the conversion code (FFh · FFh) of the special code detected by itself, Special code of 1 byte of the data (FF
h). The output of the byte converter 33 is sent to the switched terminal B of the changeover switch 35. The byte converter 33 also operates based on the clock from the timing generator clock 37.

Here, the byte converter 33 can be specifically realized by the configuration shown in FIG.

In FIG. 5, the byte converter 33 concerned.
Is an FF / FF detector 42 that detects a conversion code (FFh / FFh) of the special code, a special code generator 44 that generates a special code, a prohibition code generator 45 that generates a prohibition code, and the FF A changeover switch 46 in which the detection output from the FF detector 42 and the detection output from the FF / ID detector 34 supplied via the terminal 43 are used as a changeover control signal.
And have.

The special code from the special code generator 44 is supplied to the switched terminal A of the changeover switch 46, and the prohibited code from the prohibited code generator 45 is supplied to the switched terminal B. ing.

Therefore, in the byte converter 33,
When the detection output of the conversion code (FFh · 01h) of the prohibited code from the FF / ID detector 34 is supplied through the terminal 43, the selected terminal B of the changeover switch 46 is selected, and the byte conversion concerned is performed. The 1-byte prohibition code from the prohibition code generator 45 is output from the output terminal 47 of the device 33. When the FF / FF detector 42 detects a special code conversion code (FFh / FFh), the switch terminal 46 of the changeover switch 46 is selected, so that the output terminal 47 of the byte converter 33 is selected. Will output a 1-byte special code from the special code generator 44.

The FF / FF detector 42, the special code generator 44, and the prohibition code generator 45 are connected to the terminal 48.
It operates based on the clock from the timing clock generator 37 of FIG.

The data from the output terminal 47 from the byte converter 33 of FIG. 5 as described above is supplied to the switched terminal B of the changeover switch 35 of FIG.

Returning to FIG. 4, the changeover switch 35 is
A detection output from the FF / ID detector 34 is used as a switching control signal, and a 2-byte conversion code (FFh · 0) obtained by converting the prohibition code by the FF / ID detector 34 is used.
When 1h) is detected, it is switched to the switched terminal B, and in other cases, it is switched to the switched terminal A.

Therefore, if the data supplied to the terminal 31 is not the prohibited code or the conversion code of the special code, the change switch 35 outputs the data as it is, and the data supplied to the terminal 31 is prohibited. If it is a conversion code of a code, the prohibited code is output, and if it is a conversion code of a special code, the special code is output.

The output of the changeover switch 35 is a FIFO.
It is sent to the memory 36. In the FIFO memory 36,
The data supplied based on the clock from the timing clock generator 37 is written, and the data is read out in the input order based on the same clock as the clock from the terminal 32 to the terminal 11 in FIG.

The data read from the FIFO memory 36 is outputted from the output terminal 38 of the inverse conversion device 105 as the data after the inverse conversion.

As described above, according to the present embodiment, it is possible to treat a digital recording / reproducing apparatus (digital VTR) having a prohibition code that cannot be recorded as if the prohibition code does not exist. Thus, the digital VTR can be used like a data recorder capable of recording all codes.

As for the above-mentioned special code and ID code, it is desirable to select a code having a low occurrence frequency in the occurrence frequency distribution when the occurrence frequency distribution of the code of the input data is not flat. By doing so, it is possible to suppress an increase in the amount of data after conversion. If the code occurrence frequency distribution of the input data is flat, the special code and the ID code may be selected from any code excluding the forbidden code.

By the way, in the above-described embodiment, since the redundant portion is the minimum recording unit (for example, 1 byte), the transmission method and apparatus of another embodiment in which the redundant component is further reduced and the recording capacity is effectively used. Will be described below.

In another embodiment, for example, the data is 8-bit data (00h to FFh), the prohibition code is 00h, the special code which is not the prohibition code is 01h, and the ID is 2 bits. Data. Here, as the ID in the other embodiment, 2 bits different from the 2 most significant bits (MSB side) of the prohibition code are set as the ID of the prohibition code (that is, the MSB side 2 bits of the prohibition code ≠ ID), In addition, 2 bits different from the 2 most significant bits (MSB side) of the special code are set as the ID of the special code (that is, the MSB side 2 bits of the special code ≠ ID), and the prohibition code ID ≠ the special code ID.
I am trying.

In this case, the conversion rule of the transmission method of the other embodiment is as follows.

That is, for example, when the input code is the prohibition code (00h), the special code (01h) and the ID (2 bits) of the prohibition code (00h) are paired, and the 2 bits of this ID are next. 6 bits of the MSB side of the input data is added to obtain the next output data, and thereafter, the conversion is performed in a state where the input data is bit-shifted.

When the input code is the special code (01h), the special code (01h) and the ID (2 bits) of the special code (01h) are paired, and the next input is made to 2 bits of this ID. Six bits of the MSB side of the data are added to make the next output data, and thereafter, the input data is bit-shifted and converted.

When the input code is a code other than these, the input code is passed as it is.

In the other embodiment, as described above, as the ID, 2 bits of the MSB side of the prohibition code ≠ ID and 2 bits of the special code MSB side ≠ 2.
By selecting 2 bits of the ID, which is an ID, for example, as shown in FIG. 6, redundancy can be prevented from continuing by conversion.

That is, in FIG. 6, the input code is, for example, 0000000000000001.
00000000 1010100000000010
In the case of 0 ..., According to the conversion rules of the other embodiments, 0000001010000000 01000
000 00101010 000000011000
It is converted like ...

On the other hand, the inverse conversion rule corresponding to the above conversion rule in the transmission method of the other embodiment is the following rule.

For example, when the input code is the special code (01h), the following 2 bits (ID) are looked at and 0 is set according to this ID.
It is converted into 0h or 01h (reverse conversion), and the remaining 6 bits following the ID are output as they are.

When the input code is not the special code (01h), the input code is passed as it is.

After the conversion (inverse conversion), the data is output in 8-bit units at the final stage of processing.

The conversion rules and inverse conversion rules of the other embodiments described above are also the conversion device 101 and the inverse conversion device 105 of FIG.
The conversion device 101 and the inverse conversion device 105 that specifically realize the conversion rule and the inverse conversion rule of the other embodiment are configured as shown in FIGS. 7 and 8. Can be listed in.

In FIG. 7, which is a configuration corresponding to the other embodiment of the converter 101, input digital data is supplied to the input terminal 50, and this input data is FIF.
It is sent to the O memory 52. In the FIFO memory 52, the input digital data is written based on a write control signal from a system controller (not shown) from the terminal 51. Further, from the FIFO memory 52 in which this input data is written, the controller (00h, 01h detection / counter) 57 in the subsequent stage is
The data is read based on the read control signal generated in.

The data read from the FIFO memory 52 is directly converted into data of data width × 2 as shown in FIG. 9 by the latch circuits 53 and 54 which also operate based on the control signal from the controller 57. And sent to the selector 55.

In the selector 55, the data having the data width is selected by the select signal generated from the controller 57.

For example, when the data width = 8 bits (BIT) and the upper length = 2 bits (BIT), the selection by the selector 55 is performed from the outputs of the latch circuits 53 and 54 as shown in FIG. Any one of A to E will be selected.

The data selected by the selector 55 is
It is sent to the ID adding circuit 56 and the controller 57. Here, the data selected by the selector 55 is 0
If the controller 57 detects 0h (that is, a prohibition code) or 01h (that is, a special code), the controller 57 sends information indicating that fact to the ID addition circuit 56. The ID addition circuit 56 that has received the detection information from the controller 57 converts the supplied data into the special code as described above (actually, 01h remains unchanged). Further, the next data is one selection (2
By shifting by bits, 6 bits + 2 bits of the previous data are selected, and the ID addition circuit 56 rewrites the 2 bits of the previous data to the ID and outputs from the output terminal 58.

In this example, since the selection processing operation moves to the first end (E in FIG. 9) of the selector 55 by selecting four times, the controller 57 at that time stores the data in the FIFO memory 52. The reading is skipped once, and the contents of the data selector are corrected (that is, returned to the position A in FIG. 9).

On the other hand, the specific structure of the inverse conversion device 105 corresponding to the conversion device 101 of FIG. 7 in the other embodiment is as shown in FIG. It should be noted that, in FIG. 8, constituent elements that perform operations corresponding to those in FIG.

In this inverse converter, the input terminals 50 and 51 are
7 to the selector 55 is the same as the corresponding configuration in FIG. 7, but the controller (01h detection / counter) 6
The selector 55 that selects data in response to the select signal from 2 performs selection as shown in FIG.

That is, unlike the above conversion device, the selector 55 in this inverse conversion circuit outputs data in a 10-bit width as shown in FIG.
The upper 8 bits of the output of the selector 55 are 01h
If it is selected (that is, a special code), then all the 10 bits are decoded in the next data conversion circuit 61 into 8 bits. That is, the ID added in the conversion circuit is removed, and 00h is generated according to this ID.
Alternatively, it is converted to 01h data. If the upper 8 bits are not 01h (special code), the upper 8 bits are output as they are and the remaining 2 bits are ignored.

The FIF by the controller 62 is
The control of the O memory 52 and the selector 55 is performed in the exact opposite manner to that of the conversion device.

Further, when the special code is detected, the selection in the selector 55 is shifted by one as in the above-mentioned conversion apparatus. However, this shift is started from A in FIG.
When it reaches the position D, it reads one extra from the FIFO memory 52 and returns it to the position A in FIG.

As mentioned above, in another embodiment,
The digital recording device having the prohibition code can be treated as if the prohibition code does not exist, and by taking the redundant component in bit units, the recording capacity can be effectively used.

Here, each of the above-mentioned embodiments is referred to as D
A case where the digital VTR of two formats is applied will be described.

In the D2 format, input of 00h data of digital video data which is input digital data is prohibited. That is, in the D2 format, this 00h is the prohibition code. Therefore, in order to record the bit reduction data with the D2 format digital VTR, it is necessary to transmit the data (00h) of the prohibition code in another form.

Here, in the D2 format, 1
Since the recording capacity per field has some margin,
Data can be converted with redundancy.
Therefore, the D2 format digital VTR
In this case, this property is used to
Is redundantly converted to another code, so that 00h of the prohibition code is removed. Also in this case,
As in the other embodiments described above, in order to reduce the redundancy,
The redundant component is set to 2 bits for each 00h, the data is further decomposed into bit units, and the above-mentioned conversion is performed so that 00h, which is a prohibition code, does not appear when divided by bytes.

As a conversion rule in the case of the D2 format, for example, when the input data is 00000000, the output data is converted into 10,000,000 bits of 0000000101. Also, for example, if the input data is 00000
When it is 001, the output data is 00000001 10
To 10 bits. Furthermore, when the input data is not these data, it is output as it is as output data (not converted).

When the data is converted to 10 bits as described above, the first 6 bits of the next data are added to make 2 bytes as in the other embodiment.

For example, if the input data is ... 11111110 11111111 00000000 00000001 00000000 10
When 101000 00000100 ..., 11111110 11111111 00000001 01 000000 01000000 0
0101010 00000001 10 00 ...

Furthermore, when the conversion (00h encoding) for removing the prohibition code as described above is completed within the recording area, data of all 1s is recorded in the remaining gap. When the recording area overflows, the recording area is aborted.

On the other hand, the inverse conversion (decoding) corresponding to the above conversion in the D2 format is performed as follows.

That is, the inverse conversion for restoring 00h, which is the forbidden code, may be the reverse of the above conversion.
In this case, some data cannot be collected (represented by 00h), so caution is required. In addition, in this process, an error flag is generated in addition to the 8-bit data.

As a conversion rule of this inverse conversion, for example, when the input data is 0000000101, the output data is converted to 00000000. Also, for example,
When the input data is 0000000110, the output data is converted into 00000001. Further, when the input data is 00000000, all the remaining data in the block after this byte is made an error in the output data.

When the input data is not these data, it is output as it is as output data (not converted).

[0109]

As described above, in the transmission method and apparatus of the present invention, the prohibition code is converted into a code having redundancy which does not include the prohibition code. Therefore, all codes including the prohibition code are transmitted. become able to. Therefore, for example, it becomes possible to use a digital recording / reproducing apparatus such as a digital VTR in which an unrecordable prohibited code exists, as a data recorder which requires recording of all codes. Furthermore, by taking the redundant component in bit units, it becomes possible to effectively use the recording capacity.

[Brief description of drawings]

FIG. 1 is a flowchart for explaining a transmission method according to an embodiment of the present invention.

FIG. 2 is a block circuit diagram showing a schematic configuration of a transmission device of this embodiment.

FIG. 3 is a block circuit diagram showing a specific configuration of a conversion device of the transmission device according to the present embodiment.

FIG. 4 is a block circuit diagram showing a specific configuration of the inverse conversion device of the transmission device according to the present embodiment.

FIG. 5 is a block circuit diagram showing a specific configuration of a byte converter of the inverse conversion device of the transmission device according to the present embodiment.

FIG. 6 is a diagram for explaining a conversion rule of another embodiment.

FIG. 7 is a block circuit diagram showing a specific configuration of a conversion device of a transmission device according to another embodiment.

FIG. 8 is a block circuit diagram showing a specific configuration of an inverse conversion device of a transmission device according to another embodiment.

FIG. 9 is a diagram for explaining a selecting operation of a selector in a conversion device of another embodiment.

FIG. 10 is a diagram for explaining a selecting operation of a selector in an inverse conversion device of another embodiment.

[Explanation of symbols]

 52 ... FIFO memory 53, 54 ... Latch circuit 55 ... Selector 56 ... ID addition circuit 57, 62 ... Controller 61 ... Data conversion circuit 101 ... Conversion device 102 ... Interface device 103 ... Inverse conversion device 104 ... Digital VTR

Claims (8)

[Claims] 1. A transmission method for transmitting data containing an unusable prohibition code, comprising: a conversion rule for converting at least the prohibition code into a code having redundancy without the prohibition code; and an inverse conversion corresponding to the conversion rule. And a reverse conversion rule for performing transmission. 2. A transmission device for transmitting data including an unusable prohibited code, comprising: a conversion means for converting at least the prohibited code into a code composed of a special code which is not the prohibited code and an ID code which is not the prohibited code and the special code. A transmission device comprising: an inverse conversion unit that performs an inverse conversion corresponding to the conversion performed by the conversion unit. 3. The transmission device according to claim 2, wherein the special code and the ID code are at least in byte units corresponding to the prohibition code. 4. The special code and the ID code are codes having a low frequency in an occurrence frequency distribution.
The described transmission method. 5. The transmission method according to claim 1, wherein the redundancy is less than twice the code byte. 6. The transmission device according to claim 2, wherein the ID code is less than twice the byte of the special code. 7. The transmission method according to claim 5, wherein the redundant part does not match a part of the prohibition code, and the redundant part is a part of the next data. 8. The transmission device according to claim 6, wherein the ID code does not match a part of the prohibition code, and the converting means forms the ID code as a part of the next data.