JPS62121966A - Tape recording method - Google Patents

Abstract

PURPOSE:To discriminate a pirate tape by setting data of plural prescribed bits to the prescribed bit pattern so as to take for dubbing protection data among discrimination data. CONSTITUTION:The output of an input device 3 is supplied to a decoder 4, and its output is supplied to a pattern generator 5. It supplies code word data showing a dubbing protection data mode and the data code word data corresponding to the input of the device by the desired cycles to a mixer 17 through a changeover switch 2. A discrimination data word generator 1 generates the mode code word data and the data code word, while a data generator 6 generates control word data. All said data are supplied to the switch 2. An audio signal to be recorded is supplied to an input terminal 13, and the output of the mixer 17 is recorded on a tape. In terms of a reproduction signal, a pattern detector 32 detects word data, which is compared with the pattern included in the output of the generator 5 from a pattern generator 33.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a tape recording method.

[Summary of the invention]

The present invention provides a tape recording method in which discrimination data is recorded on a tape together with information data, in which a plurality of predetermined bits of the discrimination data are set in a predetermined bit pattern and used as dubbing protection data. ,
This allows the tape to be distinguished from pirate tapes.

[Conventional technology]

Below, first, with reference to FIG.
8-199409) will be explained. This figure 3 shows the data structure of one field of a digital audio signal, where one word is 8 bits, (m-8 words) (n=132 blocks) (mxn=105
6 words). Sampling frequency is 2f)
, (where fh is the horizontal frequency) NTS
The PCM audio signal for one field in the C method is 1
050 words, 6 words of discrimination data IDo
, IDz...10s will be added. In other words, (Lo.

Ro+ Lt+ RLI L21 R2...
Ls22+R522* L523, R523)
Continuous! At the beginning of the field's worth of digital audio signals, the above-mentioned 6-word discrimination word IDo~! Mouth 5
is added.

105 including 6 words of discrimination data IDo~l1lls
The six words of data are arranged at intervals of 44 blocks in the horizontal direction, every two words. In hardware, data is written to addresses separated by 44 blocks by RAM address control. Apart from control data or parity data, two words (Li, Ri) are arranged horizontally. , like this, the horizontal direction is 3
The purpose of dividing and interleaving the digital audio signal is to lengthen the burst error length that can be corrected, for example, by mean value interpolation. In particular, by arranging (Li, R1) in the horizontal direction, the correction length can be made longer than by arranging it in the vertical direction.

Two parities, for example, an even parity, are added to the digital audio signal and discrimination data for one field. The audio data series of each row of the above-mentioned matrix structure is wo l Wl .

...W7, the first parity sequence P is formed from 8 words belonging to each data sequence separated by a horizontal distance of 14 or 15 blocks.

Further, a second parity sequence Q is formed from 9 words extracted from each of the 9 total sequences of the audio data sequence Wo=W and the parity sequence P at a distance of 12 blocks. This first parity series P is arranged at the center within one block, and the second parity series Q is arranged at the center of one block.
It is placed at the end of the block. In other words, since there is a high probability that data at the central position within one block will be uncorrectable, a parity sequence P that is less important than audio data is allocated, and this parity sequence P is generated by In order to maximize the distance between words, the parity series Q is arranged at the end of one block.

Each of the 132 blocks includes 8 words of digital audio data and 2 words of parity data, and a 16-bit CRC code for error detection, for example, is added to the data of each block. When the data of, for example, the first CRC block, which is recorded on a magnetic tape with a synchronization signal and a block address signal added thereto, is extracted, the data is shown in FIG. After this, the second block, the third block...132nd block
This will be followed by a block of

Next, the above-mentioned 6-word discrimination word data I[l.

~IQs will be explained with reference to FIG. These discrimination word data IDo=Ins are each composed of 8-bit bit data Bo=By. ID.

-104 are utility word data, of which IDo is mode code word data and IDt to ID+ are data code word data. And the data ID
Depending on the value of o, the data IDt to ID4 are used to display the tape counter; program number ■; year, month, day, and day of the week at the time of recording; hours, minutes, seconds, and frames at the time of recording; program number ■; table of contents; A multi-PCM discrimination code is displayed.

10s is control word data, and various control data are expressed by the value of each bit data. First, bit data BT is bit data Bs, which indicates dubbing protection (protection of dubbing as a digital signal) when it is 1.

B6 indicates the recording start and end points and the recording period according to its value. Bit data B3 and B4 indicate whether they are audio or other information for channel 1 (old C) and channel 2 (CH2), respectively, depending on their values. Bit data B1°B2 is determined by the value of
Mono, stereo, bilingual and other distinctions are represented. The bit data Bo indicates whether the other bit data B1 to B7 are valid or invalid according to 1.0.

[Problems to be Solved by the Invention] However, when a soft tape manufacturer uses a printer to copy a large number of slave tapes from a mask tape, the printer copies control word data 1.
It is normal to record l as bit data B7 of 0s. Therefore, if a person who wants to create a pirate tape uses the same printer to create a duplicate tape, the bit data B of the control word data 10s of that tape can be used.
Since 7 can become 1, pirate tapes cannot be distinguished from genuine tapes.

In view of this, the present invention proposes a tape recording method that can be distinguished from pirate tapes.

[Means for solving problems]

The present invention provides a tape recording method in which discrimination data is recorded on a tape together with information data, in which a plurality of predetermined bits of the discrimination data are set in a predetermined bit pattern and used as dubbing protection data. This is a characteristic feature.

[Effect]

According to the present invention, by reproducing dubbing protection data recorded on a tape, the tape can be distinguished from a pirated tape.

〔Example〕

A tape recording apparatus (VTR as a printer) to which the present invention is applied will be described below with reference to FIG. In this example, the tape is a so-called 8 mm video cassette tape. , Incidentally, the explanation regarding the digital audio data of 8 mm video refers to the explanation in the above-mentioned prior art section.

In FIG. 1, (3) is an input device consisting of a numeric keypad, etc., and its output is supplied to a decoder (4) to be decoded.
The decoded output is supplied to a pattern generator (5).

Then, from the pattern generator (5), the mode code word data ■Do indicates the dubbing protection data mode, for example, Bv Bs . . . B IB o −
rIIIIIIJ is obtained, and as data code word data 101 to 104, the input device (3)
For example, r 0110001011...
・1011J (this bit pattern can be different depending on the manufacturer) is obtained, and this is passed through the changeover switch (2) to the mixer (17
). (1) is a discrimination data word generator,
From now on, mode code word data ID.

As a result, the seven mode data mentioned at the beginning are obtained, and the data code word data IO1 to IO104 in each mode are obtained and supplied to the mixer (17) via the changeover switch (2). (6) is a data generator, and from this, as control word data 10s, for example, B7B6...BI BO=r 100IIO
IIJ (Bt is always 1, Bs to Bo are as stated at the beginning) is obtained and supplied to the mixer (17) via the changeover switch (2).

The audio signal to be recorded on the tape (signal from which the master tape has been played) is sent from the input terminal (13) to A through the low-pass filter (14) and the noise removal circuit (15).
The digital audio signal is supplied to a /D converter (16) for digitization, and the digital audio signal is supplied to a mixer (17) to be mixed with the output of the changeover switch (2).

The mixed output from the mixer (17) is supplied to the FM modulator (20) through the interleaving circuit (18) and the error correction encoder (19), where it is modulated, and the FM modulated P
The CM audio signal is supplied to a switch circuit (21). This switch circuit (22) has an input terminal (22
) is provided with an FM modulated luminance signal and a low frequency converted carrier chrominance signal.

The output of the switch circuit (21) is connected to the recording/reproducing amplifier (24).
) and (25), the distribution is supplied to a pair of recording and reproducing rotary magnetic heads (26) and (27), respectively. And these magnetic heads (26), (2
In step 7), signals are recorded (printed) so as to form inclined tracks on the magnetic tape.

Next, how to record the discrimination word data will be explained with reference to FIG. Figure 2A shows the switch circuit (2
1) shows the head switching pulse supplied to 1). 2B shows the audio signal supplied to the input terminal (13), and FIGS. 2C and 2D show the recording/reproducing rotary magnetic head (26), respectively.
), to be recorded on tape by (27),
Compressed digital audio signal per field (
(including discrimination word data).

E, F, and G in Figure 2 are mixed from the selector switch (2)! (17) Discrimination word data IDo-I supplied to
FIG. 2 E shows mode code word data 1 bit 0, and FIG. 2 F shows data code word data ■D.
□〜■口→, these data are generated by the pattern generator (5
) or from the data generator (11) via the switch (2) to the mixer (17). FIG. (2) through mixer (17)
supplied to Then, these discrimination word data IDo
=I port 5 is incorporated into the digital audio signals shown in FIGS. 2C and 2D.

Next, the identification device (30) shown in FIG. 1 for distinguishing between genuine tapes and pirated tapes will be explained. This identification device (30) is provided as part of a VTR (printer). *Rotating magnetic head (26) for recording and reproducing the tape to be separated (8mm video cassette tape),
(2'?), and the reproduced signal is recorded and reproduced by the amplifiers (24), (25) and the switch circuit (21).
) is supplied to the reproduction circuit (31). Regeneration circuit (
The reproduced signal from 31) is supplied to the pattern detection circuit (32), word data IDo~104 is detected,
This is supplied to the minus number circuit (34), and the output of the pattern generator (5) from the pattern generator (33) is compared with the dubbing protection data of the same pattern. (35)
is a display device, and a display is performed according to whether or not there is a match between both data in the minus number circuit (34). Therefore, if both data match, it is determined that the tape is a genuine tape, and if they do not match, it is determined that the tape is a pirated tape.

〔Effect of the invention〕

According to the present invention described above, it is possible to obtain a tape that can be easily distinguished from a pirate tape.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a timing chart for explaining the same, FIG. 3 is an explanatory diagram of the data structure of a digital audio signal, and FIG. 4 is an explanatory diagram of the block structure. , FIG. 5 is an explanatory diagram of the discrimination word data. Timing chart figure 2 extra 1! III Word Data Nishiki Ikumi August Map Figure 5

Claims (1)

[Claims] A tape recording method in which discrimination data is recorded on the tape together with information data, characterized in that a plurality of predetermined bits of the discrimination data are set in a predetermined bit pattern to serve as dubbing protection data. How to record tape.