JPH06350959A - Video signal transmission method - Google Patents

Abstract

PURPOSE:To prevent limitless dubbling or to execute picture quality improving processing for a video signal after plural pieces of frequency of dubbing by providing with an information area for storing supply source information and recording frequency information of the video signal respectively in an identification signal. CONSTITUTION:An insert synthesis circuit 20 rewrites supply source information and recording frequency information indicated by an identification signal (b) in a video signal 10 to be supplied with new information supplied from an insertion signal generating circuit 20d and provides an output of a video signal 10' having the new information on a next stage VTR recording system 21. An identification signal line detection circuit 20b detects the signal (b) inserted in the signal 10 in response to a count signal outputted from a counter circuit 20f synchronously with a prescribed count of a horizontal synchronizing signal from a synchronizing separator circuit 20e and provides an output of the signal (b) to an identification signal content detection revision circuit 20c. The circuit 20c detects the supply source information and recording frequency information stored in the signal (b) fed from the circuit 20b and provides an output of a signal to the effect of the rewrite of the information into the new information to the circuit 20d. The circuit 20d outputs the new information to the circuit 20a based on the signal supplied from the circuit 20c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal transmission method.

[0002]

2. Description of the Related Art FIG. 6 is a diagram showing a waveform of an identification signal.
A conventional technique will be described below with reference to the drawings.

In recent years, a method of transmitting a high-quality horizontally long image having an aspect ratio of 16: 9, which is compatible with a conventional television receiver having an aspect ratio of 4: 3 (hereinafter referred to as a TV receiver), has been studied. Has been done. There are various signals with different aspect ratios in the video signals input to these TV receivers, and if these can be identified automatically, the TV receiver side can easily cope with them. For this reason, there is a standard in which an identification signal for identifying at least an aspect ratio is inserted into a video signal to provide ease of transmission and future expandability. Here, the source of the video signal is VT
It is used as a package media such as R.

As an example of this standard, a provisional standard of the Japan Electronic Machinery Manufacturers Association "Identification signal of video signals having different aspect ratios and transmission method (II) (525 line system)" (EIAJ
CPX-1204). Here, various identification signals including the identification signal for identifying the aspect ratio are respectively inserted into the 20th H / 283nd H of the vertical blanking period of the video signal (H is a horizontal line). As shown in FIG. 5, the video signal 10 has the amplitude 70 IRE (“H” state) and 0 IRE (“L” state) next to the reference signal a for level matching in the effective video portion 11 of the 1H. 20 bit (bit1 to bit2)
In the period 0), it has a signal b which is transmitted by coding identification signals relating to various video information. c is a horizontal sync signal,
d is a color burst signal. Further, the identification signal b is
In order to make it easy to distinguish from other identification signals such as for character multiplex / closed captions, a signal with a relatively low bit rate is used so that malfunctions due to signal deterioration are less likely to occur even when used for recording / reproduction with a VTR or the like. ing.

The code allocation of the identification signal b is as follows. 20-bit data is the "WORD0" below.
~ It consists of "WORD2" and "CRC". "WORD0" = 6 bits (bit1 to bit6) "WORD1" = 4 bits (bit7 to bit10) "WORD2" = 4 bits (bit11 to bit14) "CRC" = 6 bits (bit15 to bit20) The above "WORD0" is , "WORD0-A" = 3 bits (bit
1 to bit3), "WORD0-B" = 3 bits (bit4 to bit)
It is divided into 6).

"WORD0" is a basic parameter intended for automatic control on the receiving side (reproducing side), "WORD0-A" is identification information on the video signal transmission format, and "WORD0-B" is associated with the video and the video. This is identification information about other signals (voice signals, etc.) that are transmitted at the same time. Among these, "WORD0-
"Bit 1" of "A" means the content of the transmission aspect ratio,
When bit1 is "H", "Full mode (16: 9)", bi
When t1 is "L", it means "4: 3". "WORD 0-
"Bit 2" of "A" means the content of the image display format,
When 2 is "H", it is "letterbox", and bit2 is "L"
Means "normal".

Here, the "full mode (16: 9)" is 5
It means that the video signal has 525 lines and an aspect ratio of 16: 9 on a standard television signal format of 25 lines and an aspect ratio of 4: 3, and "letterbox" is usually (aspect ratio). On the screen of 4: 3),
It means that the video signal is configured such that there are no video images at the top and bottom of the screen and the entire video images having different aspect ratios are displayed.

In the above, the "identification signal and transmission method of video signals having different aspect ratios" suitable for the NTSC broadcasting system have been described, but the same standard is compatible with the PAL broadcasting system, and "Aspect ratio" Different identification signals and transmission methods of different video signals, and there is a so-called "PALplus" system which is being studied in Europe (that is, 625/50/2: 1 system,
The identification signal relating to the above-mentioned video information is inserted in the 23rd H of the vertical blanking period of the video signal).

[0009]

The "WORD0" of the identification signal b in the above "identification signal of video signals having different aspect ratios and transmission method" is intended for automatic control used during reproduction of a VTR. “WORD0-A” is identification information regarding the video signal transmission format, and “WORD0-B” is video and other signals (audio signals) that are transmitted simultaneously with the video. Signal, etc., which includes source information indicating the source of the video signal indicating whether the video signal is a broadcast signal or a signal reproduced from the VTR, and the number of times of dubbing. Since there is no information area for storing the recording count information indicating the above, it is not possible to prevent, for example, unlimited dubbing by using the above-mentioned identification signal b.

[0010]

In order to solve the above problems, the present invention provides a video signal transmission method having the following configuration.

(1) A video signal transmission method for transmitting a series of video signals having a specific horizontal line obtained by inserting an identification signal related to video information into the effective video portion, wherein the video is included in the identification signal. By providing an information area for storing signal supply source information and recording number information, respectively, video signal processing is performed according to the supply source information and the recording number information updated each time the video signal is recorded. Video signal transmission method.

(2) A video signal transmission method for transmitting a series of video signals having a specific horizontal line obtained by inserting an identification signal relating to video information into the effective video portion thereof by wire, when recording the video information, Recording generation number information is progressively recorded in the error correction code area in the identification signal, and when reproducing video information,
A video signal transmission method, wherein video signal processing is performed based on the progressively recorded information on the number of recording generations.

[0013]

[Embodiment 1] A video signal transmitting method according to the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a recording system relating to a video signal transmission method of the present invention, FIG. 2 is a diagram for explaining "VTR bit" and "copy bit", and FIG. 3 is a detection operation of an identification signal content detection circuit. 4 is a flow chart for
FIG. 5 is a diagram for explaining rewriting of “R bit” and “copy bit”. FIG. 5 is a “VTR” by dubbing different from FIG.
It is a figure for demonstrating rewriting of a "bit" and a "copy bit." The same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

The video signal transmission method according to the present invention is generally
As will be described later, in the effective video portion of a specific horizontal line in the video signal, the video signal supply source information "VTR bit" and the recording number information "copy bit" are included in the identification signal composed of the video information such as the aspect ratio. Information area to store respectively (eg bit4, bit5, or bit4, bit15)
Is a video signal transmission method for performing video signal processing (for example, processing for limiting unlimited dubbing) according to the supply source information and the recording count information. Hereinafter, the case where the VTR recording system (shown in FIG. 1) according to the video signal transmission method of the present invention is applied to the VTR recording system will be described.

First, the video signal 10 will be described. As described above, the video signal 10 (shown in FIG. 6) is a “WORD
It has an identification signal b of 20 bit data composed of "0" to "WORD3". In the identification signal b, as the area for storing the source information and the recording frequency information of the video signal,
It has a bit. That is, as shown in FIG. 2, among the "WORD0-B" forming the "WORD0" of the identification signal b,
"VTR bit" that indicates the source of video signal 10 in bit 4
And bit5 is used as a "copy bit" indicating the number of times of dubbing. Bit 4 is “L” (broadcast signal) when the source of the video signal 10 is wired or wireless “broadcast”, and the source of the video signal 10 is “VT”.
If it is “R”, it is regarded as “H” (VTR playback),
This state is updated in the recording system 20 described later.

Bit 5 is a broadcast signal, but "L" (first generation), V when the video signal 10 is first recorded in the VTR.
It is set to "H" (second generation) when the video signal 10 reproduced in TR is recorded again in VTR, and is updated in the recording system 20 described later. Of course, other video information stored in bits other than bit4 and bit5 is the same as the conventional one.

Next, the recording system 20 relating to the video signal transmitting method of the present invention will be described. As shown in FIG. 1, the recording system 20 is provided in front of a VTR recording system 21 having a well-known configuration, and has an insertion synthesis circuit 20a, an identification signal line detection circuit 20b, an identification signal content detection circuit 20c, and an insertion signal. It is composed of a generation circuit 20d, a sync separation circuit 20e, and a counter circuit 20f. Reference numeral 22 is a video signal input terminal into which the video signal 10 described above comes in.

The operation of the recording system 20 will be described. The video signal 10 input to the video signal input terminal 22 is supplied to the insertion synthesis circuit 20a, the identification signal line detection circuit 20b, and the sync separation circuit 20e, respectively.

The inserting / synthesizing circuit 20a described above is arranged so that bit 4 in the identification signal b in the video signal 10 supplied thereto is
The bit 5 supply source information and recording count information are rewritten with new supply source information and recording count information of new bit 4 and bit 5 supplied from the insertion signal generation circuit 20d. Then, the video signal 10 'having the newly rewritten video signal supply source information and recording frequency information is transferred to the VTR recording system 21 of the next stage.
Output to.

The above identification signal line detection circuit 20b
Is 20 counts or 283 horizontal sync signals cc obtained by sync separation of the video signal 10 by the sync separation circuit 20e.
According to the count signals respectively output from the counter circuit 20f in synchronization with the start of counting, the second signal of the video signal 10
Identification signal b inserted in 0th / 283rd H respectively
Is detected and is output to the identification signal content detection / change circuit 20c.

The above-mentioned identification signal content detection / change circuit 20
c is the identification signal b supplied from the identification signal line detection circuit 20b as in the detection flowchart shown in FIG.
The source information and the recording frequency information stored in it4 (“VTR bit”) and bit5 (“copy bit”) are detected respectively, and these source information and recording are recorded according to the procedure of the above-mentioned detection flowchart. A signal for rewriting (updating) the number-of-times information to new information is inserted into the insertion signal generation circuit 2
Output to 0d.

That is, first, the supply source information stored in bit 4 is detected, and when bit 4 is "L", the video signal 10 input to the video signal input terminal 22 is recognized as a "broadcast signal" ( (Illustrated in Fig. 3), bit4 is from "L" to "H"
To the insertion signal generation circuit 20d, which outputs a signal indicating that bit 5 is rewritten to "L" (information of the current video frame period (bit 4 "L", bit 5 "L") is rewritten to generate new information (bit 4 "H", bit5 "L")).
Also, the source information of bit4 is detected, and when the bit4 is "H", the recording frequency information of bit5 is detected. When bit 5 is "L", the video signal 10 input to the video signal input terminal 22 is recorded (dubbed) once by the VTR 1 and is reproduced as a "first generation reproduction signal" (shown in FIG. 4). And outputs a signal for rewriting bit4 to "H" and bit5 from "L" to "H" to the insertion signal generation circuit 20d (information of the current video frame period (bit4 "H", bit5 "L") is rewritten to new information (bit4 "H", bit5 "H"). Further, when bit4 is "H" and bit5 is "H", the video signal 10 input to the video signal input terminal 22 is set to VTR1, VTR.
The TR2 recognizes the recorded signal that has been recorded (dubbed) twice in total as the "second-generation reproduced signal" (shown in Fig. 4), and sets bit4 to "H" and bit5 to "H" (bit4). , Bit5 information not updated) is output to the insertion signal generation circuit 20d (both current and next video frame period information is bit4 "H", bit5 "H". In this case, in VTR3 The third dubbing will not be possible).

The above-mentioned insertion signal generation circuit 20d is based on the above-mentioned signal supplied from the identification signal content detection 20c, and is a signal ("H", "L") corresponding to the new bit 4 and bit 5 supply source and recording frequency information. Each state) is inserted and synthesized circuit 20
Generate and output to a. In this way, the insertion synthesis circuit 2 described above
0a indicates the 20th H / in the current video frame period.
Bit of the identification signal b inserted in the 283rd H
It is possible to rewrite 4, bit 5.

The above-mentioned video signal 10 having the source information and the recording frequency information is a signal included in the luminance signal system obtained by Y / C separating the composite video signal.
After passing through a well-known VTR luminance signal recording system (mainly a pre-emphasis circuit, a clamp clip circuit, a frequency modulation circuit, a high-pass filter circuit) in the R recording system 21, a well-known VTR color signal recording system (mainly an ACC circuit, It is frequency-multiplexed with the carrier color signal output from the frequency conversion circuit and the low-high pass filter circuit. Then, this frequency-multiplexed signal is amplified by a recording amplifier and then alternately supplied to a pair of video heads mounted on a rotating drum, so that the magnetic tapes 1 are successively continuously recorded as shown in FIG. And recorded (neither is shown).

Here, the VTR recording system 21 described above is provided with the following supply source / recording number information change detection circuit and recording signal limiting circuit (both not shown) in addition to the above configuration. This supply source / recording number information change detection circuit is connected to an appropriate portion of the VTR luminance signal recording system described above, and is connected to the 20th H / 283th H in the current video frame period of the video signal 10. Source information and recording frequency information of bit 4 and bit 5 of the identification signal b respectively inserted in the video signal and the bit of the identification signal b inserted in the 20th H / 283H of the next video frame period.
Compare the source information and recording frequency information of 4, bit 5,
Bit 4 for both current and next video frame period information
The detection signal is output only when it is "H" and bit5 "H". The above-mentioned recording signal limiting circuit is connected to an appropriate portion of the above-mentioned VTR luminance signal recording system or VTR color signal recording system, and is output from the above-mentioned supply source / recording number information change detection circuit. Depending on the detection signal,
The output of the recording signal in the VTR luminance signal recording system or the VTR color signal recording system is stopped. By this, VTR
In the recording system 21, the third dubbing cannot be performed. Although the dubbing is impossible due to the stop of the output, the dubbing may be possible by deteriorating a part of the reproduced image such as stopping the output of the color signal recording system.

The above has described the case where the present invention is applied to the "identification signal of a video signal having a different aspect ratio and the transmission method" suitable for the NTSC broadcasting system. When the video signal is composed of the main signal and the vertical information reinforcing signal, only the vertical information reinforcing signal may be prohibited instead of stopping the output. That is, the video signal consisting of the main signal and the vertical information reinforcement signal is
If bit3 = "L", "H", "H", and only the main signal (letterbox), bit1 to bit3 =
“L”, “H”, “L”, bit 4 is source information, b
When it5 is used as the recording count information, as a dubbing prevention measure, when the output of the video signal consisting of the main signal and the vertical information reinforcement signal is stopped, bit1 to bit5 = "L",
Rewrite bit3 = "H" of "H", "H", "H", and "H" as "L", and bit1 to bit5 = "L", "H",
By setting "L", "H", and "H", there may be a case where only the main signal obtained by degrading a part of the video signal formed by the main signal and the vertical information reinforcing signal is output.

Here, as shown in FIG. 4, "broadcast signal"
Is supplied to the VTR 1 (“state 2” shown in FIG. 5),
Bit1 to bit5 of "state 1" shown in Fig. 5 = "L",
Rewrite bit4 = “L” (broadcast signal) of “H”, “H”, “L”, and “L” as “H” (VTR playback), bit1
The video signal with bit 5 = “L”, “H”, “H”, “H”, “L” is recorded in the VTR 1. After that, when the "first generation reproduction signal" reproduced from the VTR1 is supplied to the VTR2 ("state 3" shown in the figure), the bit1 of the "state 2"
~ Bit5 = "L", "H", "H", "H", "L" bit5 of "first generation playback signal" from "L" (first generation) to "H" (second generation) ) Rewrite, bit1 to bit
5 = Record the video signal with “L”, “H”, “H”, “H”, and “H” in the VTR 2. Further, when the "second generation reproduction signal" reproduced from the VTR2 is supplied to the VTR3 ("state 4" shown in the figure), bits 1 to b of "state 3"
it5 = "L", "H", "H", "H", "H" bit
Rewrite 3 from "H" to "L", bit1 to bit5 =
The video signals of only the main signals which are “L”, “H”, “L”, “H”, and “H” are recorded in the VTR 3.

Here, "CRC" = 6 bits (bit15-
The error correction code of bit20 is the data area ("WORD
It is necessary to recalculate 0 ”to“ WORD2 ”= 14 bits (bit1 to bit14) according to the contents to be rewritten, and rewrite sequentially. Although the case where bit5 is used as the "copy bit" has been described above, bit6 to bit1
It goes without saying that any one unused bit of 4 may be used.

As described above, as the "copy bit", any one of bit6 to bit14 in the data area or bit1 in the "CRC" area is used.
Although the case where the 1st and 2nd generation reproduced signals can be identified by using any one of 5 to 20 bits (identifies the second dubbing) has been described, in addition to this, as the “copy bit”, Bit6 to bit14 in the data area
N bits (n is an integer. For example, n = 2)
As, bit5, bit6), or any n bits of Bit15～ bit20 of the "CRC" area (e.g., as n = 2, bit15, bit16) using a first-generation reproduction signal, second 2 ⁿ Of course, it is possible to identify the generation reproduction signal as necessary.

As a result, in general, the first generation (1
Although the S / N of the reproduced signal of the second dubbing does not deteriorate much as compared with the original signal (for example, a broadcast signal),
The dubbing by the VTR is repeated, and, for example, the reproduction signal of the fifth generation (fifth dubbing) has extremely deteriorated S / N as compared with the original signal. Therefore, a constant for changing the noise reduction effect such as expanding the so-called coring width of the noise reduction circuit (not shown) of the VTR reproduction system is changed according to the recording frequency information of the "copy bit", for example, S / It goes without saying that it is also possible to appropriately implement the fifth generation reproduction signal having a poor N as close to the S / N of the original signal as possible so as to obtain a reproduced image having a good S / N.

The above is the "high-definition broadcasting system EDT" which is suitable for the NTSC broadcasting system "identification signal and transmission method of video signals having different aspect ratios".
The case where the present invention is applied to V2 has been described, but the "PALplus" system, which is compatible with the PAL broadcasting system as a similar standard, and is suitable as the "identification signal and transmission method of video signals having different aspect ratios" (62
It goes without saying that the same can be applied to the 5/50/2: 1 system). In the above example, the case where bit 5 is used as the “copy bit” has been described, but it goes without saying that any unused 1 bit of bit 6 to bit 14 may be used.

[Embodiment 2] Now, another video signal transmitting method according to the present invention will be described with reference to FIGS. Figure 7
Is a block diagram of a recording processing circuit for recording the recording generation number information, FIG. 8 is a block diagram of an image quality improving circuit using the recording generation number information, and FIGS. 9 and 10 explain the operations of the image quality improving circuit and the recording processing circuit, respectively. It is a flowchart to do. The same components as those described above are designated by the same reference numerals and the description thereof will be omitted. The video signal transmission method according to the present invention is generally, as will be described later,
Recording generation number information is progressively recorded in the error correction code “CRC” area in the identification signal b which is unnecessary in wired transmission, and based on the recorded generation number information that is progressively recorded during reproduction,
The image quality of the reproduced video signal is improved. Hereinafter, a case where the VTR recording system (shown in FIG. 7) according to the video signal transmission method of the present invention is applied to the VTR recording system will be described.

Now, the identification signal b inserted into the above-mentioned "broadcast signal" contains an error correction code "CRC" for compensating for signal deterioration on the receiving side, and the receiving side transmits the "CRC". Is detected and error detection and correction based on this is performed. By the way, when the "broadcast signal" is recorded / reproduced by the VTR and then sent to a TV receiver (not shown) by cable, the signal S / N is not always significantly deteriorated as in the case of receiving a weak electric field broadcast. In this case, it can be said that the "CRC" is unnecessary because this transmission is more reliable and less error-prone than time. Of course, VTR reproduction involves signal loss due to dropout, but transmission is certain because it does not generally extend over a plurality of frames. Therefore, in the "CRC" area of the identification signal b whose error has been corrected at the time of recording with the VTR,
Unlike the above-mentioned "copy bit", it stores the number of recording generations information that means a greater number of dubbing times (copying number, recording generation number), and utilizes the data area where "CRC" is unnecessary in wired transmission. Is.

As a result, the "CR
By sequentially rewriting (progressing) the recording generation number information in the “C” area, the reproduction process of the VTR or the T
The V receiver can detect this recording generation number information and improve the image quality accordingly (generally, the larger the recording generation number information, the more the image quality deteriorates. As a result, an appropriate processing method according to the number of VTR recording generations = image quality becomes possible.

When using this method, it is necessary to determine whether or not the reproduced video signal output from the VTR is a reproduced signal obtained by dubbing the VTR. Therefore, it is necessary to record some identification signal indicating this in an area other than the "CRC" area and transmit this (hereinafter, this identification signal is referred to as "VTR-ID"). For example, a dedicated signal line for supplying "VTR-ID" or the identification signal b in the reproduced video signal may have "VTR-I"
A dedicated area for storing “D” may be provided to transmit “VTR-ID”.

Thus, when the reproduced video signal output from the VTR is supplied to the TV receiver together with the "VTR-ID", the TV receiver first detects the "VTR-ID" and then supplies it based on this. Identification signal b in the video signal to be reproduced
The information stored in the "CRC" area can be detected as the recording generation number information. Thus, VTR
It is possible to perform an appropriate image quality improvement process according to the number of recorded generations = image quality. When the reproduced video signal output from the VTR is supplied to another VTR together with the "VTR-ID", another VTRTV not shown first detects the "VTR-ID" and then supplies it based on this. The information stored in the "CRC" area in the identification signal b in the generated video signal can be detected as the recording generation number information. In this way, it is possible to dubb a video signal with an appropriate image quality improvement according to the number of VTR recording generations = image quality.

Now, the recording of the recording generation number information at the time of recording the VTR will be described. FIG. 7 is a diagram showing the configuration of a recording processing circuit for recording the recording generation number information.
That is, as shown in the figure, the recording processing circuit 30 is provided in the preceding stage of the VTR recording system 21 having the above-described well-known configuration, and the identification signal rewriting circuit 30a, the identification signal extracting circuit 30b, and the error correction circuit 30c. , A recording generation number counting circuit 30d. Reference numeral 31 is a video signal input terminal into which the video signal 10 described above comes in. here,
"VTR-ID" is, for example, bit 6 to bit in the identification signal b
Unused 1 bit of any one of 14 is set to "VTR-I
A case where "VTR-ID" is stored here as the "D" dedicated area will be described.

The video signal 10 input to the video signal input terminal 31 is supplied to the identification signal rewriting circuit 30a and the identification signal extracting circuit 30b (flow 51 shown in FIG. 10). The identification signal rewriting circuit 30a uses the recording generation number information stored in the "CRC" area of the identification signal b in the video signal 10 supplied here as new recording generation number information supplied from the recording generation number counting circuit 30d. Rewrite Then, the video signal 10 ″ having the newly rewritten recording generation number information is transmitted to the VTR recording system 21 of the next stage.
Is output to. The identification signal extracting circuit 30b outputs the horizontal synchronizing signal obtained by synchronously separating the video signal 10 by the synchronous separating circuit from a counter circuit (neither shown) in synchronization with the start of 20 or 283 counts. According to the count signal, the identification signal b inserted in each of the 20th H / 283th H of the video signal 10 is detected, extracted, and output to the error correction circuit 30c (FIG. 52, flow 52). . The error correction circuit 30c first puts “VT” in the “VTR-ID” dedicated area in the identification signal b.
R-ID ”is stored (see FIG.
Flow 53).

When the "VTR-ID" is not stored, the error correction circuit 30c determines that the incoming video signal 10 is the first
Recognizing that it is the recording of the generation, first, the error correction of the data bit is performed. Next, a control signal to count up "1" is output to the recording generation number counting circuit 30d so that "1" is stored therein as the recording generation number information stored in the "CRC" area. As a result, the recording generation number counting circuit 30d counts up "1" and outputs "1" as the recording generation number information to the "CRC" area to the identification signal rewriting circuit 30a. As a result, "1" is recorded in the "CRC" area as the number-of-generations information.
Is stored (flow 54 to flow 57 in the figure).

If "VTR-ID" is stored,
The "CRC" area is no longer the error correction information. The error correction circuit 30c receives the "CRC" of the incoming video signal 10.
The generation number information of the recording generation number information stored in the area is detected, and the recording generation number counting circuit 30d is further incremented by "1" to the recording generation number information stored in the "CRC" area.
In response, a control signal indicating that "1" is incremented is output. As a result, the recording generation number counting circuit 30d
Counts up "1" and outputs a count signal of "(previous recording generation number) +" 1 "as recording generation number information to the identification signal rewriting circuit 30a in the" CRC "area. As a result, the new recording generation number information (“previous recording generation number” +
“1”) is stored (flow 55 to flow 5 in the figure).
7).

As described above, the "VTR-ID" is the unused 1 bit in the identification signal b, for example, any of bit6 to bit14, as the "VTR-ID" dedicated area, and the "VTR-ID" is set here. However, the video signal 10 does not have a "VTR-ID",
When the "VTR-ID" is supplied by a dedicated signal line, the identification signal extraction circuit 30b of the recording processing circuit 30 is removed, and the "VTR-ID" dedicated signal line is directly connected to the error correction circuit 30c. Similar to the above, "V
It goes without saying that the "TR-ID" can be rewritten. Although not shown here, this recording processing circuit 3
0 may be connected to the preceding stage or the latter stage of the recording system 20 shown in FIG.

Now, here, description will be given on how to improve the image quality based on the information of the number of recording generations reproduced at the time of reproducing the VTR. FIG. 8 is a diagram showing the configuration of an image quality improving circuit using the recording generation number information. That is, the image quality improvement circuit circuit 33
Is a VT having the above-described well-known configuration as shown in FIG.
VTR reproduction process or VT in the latter stage of the R reproduction system 32
It is provided in, for example, a TV receiver connected to the R reproduction system 32 by wire, and includes a noise reduction circuit 33a, an identification signal extraction circuit 33b, and a recording generation number detection circuit 33c. Here, the "VTR-ID" to be reproduced is, for example, an unused 1 bit of bit 6 to bit 14 in the identification signal b as a "VTR-ID" exclusive area.
The case of being stored here will be described.

The video signal 11 output from the VTR reproducing system 32 having a well-known structure for reproducing the video signal recorded by the recording processing circuit 30 and the VTR recording system 21 is a noise reduction circuit 33a and an identification signal extracting circuit. Three
3b respectively (flow 41 shown in FIG. 9). The noise reduction circuit 33a noise-reduces the video signal 11 according to the recording generation number information output from the recording generation number detection circuit 33c, and outputs a video signal 11 'whose image quality is improved satisfactorily. This noise reduction circuit 3
3a changes a constant for varying a noise reduction effect such as expanding a so-called coring width according to the number of generations of "VTR-ID", for example, a reproduction signal of a fifth generation with poor S / N is compared with an original signal. It is configured so as to obtain a reproduced image having a good S / N as it approaches the S / N.

The identification signal extracting circuit 33b outputs a horizontal synchronizing signal obtained by synchronously separating the video signal 11 by the synchronous separating circuit from a counter circuit (not shown) in synchronization with the start of 20 or 283 counts. The 20th H of the video signal 11 /
The identification signals b respectively inserted in the 283rd H are detected, extracted, and output to the recording generation number detection circuit 33c (FIG. 9, flow 42).

The recording generation number detection circuit 33c detects the recording generation number information stored in the "CRC" area of the incoming video signal 11 and outputs it as a control signal to the noise reduction circuit 33a.

For example, when it is detected that the number of generations is the fifth generation, the control signal output to the noise reduction circuit 33a becomes "5", and as a result, the noise reduction circuit 33a has a poor S / N ratio. Generation reproduction signal 11
Noise reduction operation to bring the noise reduction circuit 33a closer to the S / N of the original signal is performed.
Can output a reproduction signal 11 'having a good S / N (flows 43 and 44 in the same figure). In this way, processing such as automatic selection of the noise reduction effect may be performed based on this generation information.

Although not described in detail here, in the case of movie software or the like, the generation number information described above can be used for copy prevention, and the generation number detection of the recording processing circuit 30 shown in FIG. For example, when the VTR recording system 21 is forcibly unable to record when the third generation is reached, "one-time copy"
Is possible.

The above is the "high-definition broadcasting system EDT" for "the identification signal and transmission method of video signals having different aspect ratios" suitable for the NTSC broadcasting system.
The case where the present invention is applied to V2 has been described, but the "PALplus" system, which is compatible with the PAL broadcasting system as a similar standard, and is suitable as the "identification signal and transmission method of video signals having different aspect ratios" (62
It goes without saying that the same can be applied to the 5/50/2: 1 system).

[0049]

As described above, according to the video signal transmission method of the present invention, a video signal for transmitting a series of video signals having a specific horizontal line obtained by inserting an identification signal related to video information into its effective video portion. A transmission method, wherein the supply source information and the recording frequency information are updated every time the video signal is recorded by providing an information area for storing the supply source information and the recording frequency information of the video signal in the identification signal. Since the video signal processing is performed in accordance with the above, the source information and the recording count information are used to appropriately perform the necessary video processing (for example, unlimited dubbing prevention or video after dubbing multiple times. It is possible to improve the image quality of the signal). Further, the video signal transmission method of the present invention is
A video signal transmission method for transmitting by wire a series of video signals having a specific horizontal line obtained by inserting an identification signal related to video information into an effective video portion thereof, wherein an error in the identification signal when recording the video information. Recording generation number information is progressively recorded in the correction code area, and video signal processing is performed based on the progressively recorded recording generation number information during video information reproduction. In this case, the error correction code "CRC" is not necessary because extremely reliable transmission can be performed as compared with the transmission.
In place of the error correction code, it is possible to store recording generation number information indicating the number of dubbings (copy number, recording generation number) in the “C” area.
Playback process or TV receiver), for example, this recording generation number information can be used as information for improving the image quality. Therefore, the image quality of the reproduced video signal deteriorated according to the recording generation number is changed to the original image quality. There is an effect that the image quality can be improved such as reproduction by.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording system related to a video signal transmission method of the present invention.

FIG. 2 is a diagram for explaining a “VTR bit” and a “copy bit”.

FIG. 3 is a flowchart for explaining a detection operation of an identification signal content detection circuit.

FIG. 4 is a diagram for explaining rewriting of “VTR bit” and “copy bit” by dubbing.

5] "VTR bit" by dubbing different from FIG.
6A and 6B are diagrams for explaining rewriting of "copy bit".

FIG. 6 is a diagram showing a waveform of an identification signal.

FIG. 7 is a configuration diagram of a recording processing circuit that records information on the number of recording generations.

FIG. 8 is a configuration diagram of an image quality improvement circuit using recording generation number information.

FIG. 9 is a flowchart illustrating the operation of the image quality improvement circuit.

FIG. 10 is a flowchart illustrating an operation of a recording processing circuit.

[Explanation of symbols]

 10 video signal 11 effective video part 20 recording system 30 recording processing circuit 33 image quality improving circuit b identification signal cc horizontal synchronization signal CRC error correction code dd color burst signal

Claims (2)

[Claims] 1. A video signal transmission method for transmitting a series of video signals having a specific horizontal line obtained by inserting an identification signal related to video information into an effective video portion thereof, wherein the video signal is included in the identification signal. By providing information areas for respectively storing the supply source information and the record count information, the video signal processing is performed according to the supply source information and the record count information updated every time the video signal is recorded. Video signal transmission method. 2. A video signal transmission method for wiredly transmitting a series of video signals having a specific horizontal line obtained by inserting an identification signal relating to video information into an effective video portion thereof, said video signal recording method comprising: A video signal transmission method characterized in that recording generation number information is progressively recorded in an error correction code area in an identification signal, and video signal processing is performed based on the progressively recorded recording generation number information when reproducing the video information. .