JPH05304658A - Pseudo video signal and pseudo video signal transmission system - Google Patents

Abstract

PURPOSE:To efficiently utilize broadcasting equipment. CONSTITUTION:In a broadcasting station 1 being a transmission side, an input video signal 21a is converted into a continuously or intermittently compressed video signal 21b, a synchronizing signal 26a which is the same as the input video signal is added, and the signal is converted into a first pseudo NTSC signal 23a to which a 3MHz discrimination signal 27a is added in a burst period. Then, this signal is continuously or intermittently recorded, and continuously reproduced, so that a second pseudo NTSC signal 24a obtained by filling a time axis can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pseudo video signal relating to a video signal and a pseudo video signal transmission system.

[0002]

2. Description of the Related Art FIG. 10 is a diagram for explaining a conventional broadcasting system and a video signal magnetic recording / reproducing apparatus (hereinafter abbreviated as "VTR") used therein. Hereinafter, a conventional technique will be described with reference to the drawings.

In FIG. 10, a transmission video signal modulated by a broadcasting station 1 is supplied from a satellite broadcasting transmitting antenna 2 to a satellite broadcasting receiving antenna 6 in each home via a satellite 4. Further, in normal VHF and UHF broadcasting, the modulated transmission video signal is supplied from the normal broadcasting transmitting antenna 3 to the normal broadcasting receiving antenna 5 in each home.

Then, the transmission video signals modulated by the reception antennas 5 and 6 for normal broadcasting and satellite broadcasting are supplied to the first and second tuners 7 and 8 in the VTR surrounded by the dotted lines, respectively. The first and second tuners 7 and 8 are tuners for normal broadcasting and satellite broadcasting, respectively, for demodulating a video signal and supplying the demodulated video signal to the first selection circuit 9, where the operator receives a selection command. Based on this, a video signal for normal broadcasting or satellite broadcasting is selected, and the signal is supplied to the first recording system 10.

The first recording system 10 separates a video signal into a luminance signal and a chrominance signal.
A first recording signal 10a obtained by subjecting the latter to so-called PS processing, recording color signal processing such as low-frequency conversion, and then frequency-multiplexing those signals
Is supplied to the head selection circuit 11.

Then, the head selection circuit 11 uses a control signal (not shown) to provide a first magnetic head pair Ha for a standard time with a wide head width or a second magnetic head pair Hb for a long time with a narrow head width. One of the above is selected and whether the selected magnetic head is connected to the first recording system 10 or the first reproducing system 12 is determined. Then, the first recording signal 10a is recorded on the magnetic tape T via one of the first and second magnetic head pairs Ha and Hb.

On the other hand, at the time of reproduction, the reproduction signal 11a reproduced from the magnetic tape T by using the same magnetic head as that used at the time of recording is the head selection circuit 1 described above.
1 is supplied to the first reproducing system 12 having a complementary relationship with the first recording system 10 through the reproducing signal 11a.
Is subjected to frequency separation to separate a reproduction signal relating to a luminance signal and a reproduction signal relating to a chrominance signal, the former is subjected to reproduction luminance signal processing such as FM demodulation and de-emphasis, and the latter is subjected to high frequency conversion and crosstalk. A reproduction luminance signal and a reproduction color signal are obtained by performing reproduction color signal processing such as removal. Then, the reproduced video signal 12a obtained by adding these is supplied to a television receiver (not shown). Further, the VTR has a timer recording function, which was used as a time shift device. In this way, the operator spends the same time as the time required for recording to reproduce the magnetic tape T at a time different from that during recording.

[0008]

However, since the above-mentioned broadcast program can be supplied with a video signal directly to a television receiver for viewing, it has the concealment of providing the program only to a specific person. There wasn't. Further, in order to improve the utilization efficiency of the equipment of the broadcasting station 1, the satellite 4, etc., it is desired to broadcast a plurality of programs in a short time.

Therefore, the present invention broadcasts a signal obtained by compressing a normal video signal by using the same equipment as the conventional one, and when this signal is recorded and reproduced in a short time at each home, this signal is reproduced. The object is to solve the above-mentioned problems by extending the data and reproducing it at the original time.

[0010]

The present invention provides the following configurations in order to solve the above problems.

A pseudo video signal obtained by subjecting an input video signal to predetermined signal processing, the pseudo video signal having the same synchronization signal as the input video signal, and having the same band as the input video signal. Alternatively, a pseudo video signal having a narrow band, and a compressed video signal obtained by band-compressing the input video signal is inserted in a period corresponding to a picture period of the input video signal specified by the synchronization signal. Video signal.

A pseudo video signal transmission system, wherein the pseudo video signal according to claim 1 is transmitted and output using a transmitting means for transmitting and outputting the input video signal.

[0013]

FIG. 1 is a block diagram showing an embodiment of a broadcasting station on the transmitting side, FIG. 2 is a waveform diagram for explaining FIG. 1, and FIG.
Is a block diagram for explaining one embodiment of the VTR according to the present invention, FIG. 4 is a block diagram for explaining a second recording system, and FIG. 5 is a block diagram for explaining a second reproducing system.
FIG. 6 is a block diagram for explaining the main part of the mechanism control system, and FIGS. 7 to 9 are conceptual diagrams for explaining the relationship between the reference speed and the reproduction track pattern. Embodiments will be described below with reference to the drawings. The same components as those in FIG. 10 are designated by the same reference numerals and the description thereof will be omitted.

The outline of the present invention is that a broadcasting station on the transmitting side transmits a compressed video signal continuously or intermittently in a pseudo NTS.
After converting to C signal, the time axis is packed and transmitted using the conventional transmission means, and the video signal compressed by the VTR in the home, which is the receiving side, is recorded in the same time or in a short time compared with the original time. The video signal compressed continuously or intermittently,
The reproduction signal is expanded.

First, with reference to FIGS. 1 and 2, a broadcasting station on the transmission side will be described. A digital VTR (not shown) digitizes an input audio signal and an input video signal to obtain a digital signal of about 1.5 Mbps. Audio signal 20a and approximately 100M
bps digital video signal 21a is compression ratio control signal aa
Are supplied to the audio signal compression means 20 and the video signal compression means 21, respectively, and these are supplied to the compression ratio control signal aa.
In accordance with the above, a compressed audio signal 20b and a compressed video signal 21b which have been subjected to known band compression such as DCT, DPCM and wavelet are output. Here, the compression ratio control signal aa controls the degree of signal compression. For example, the information amount of the encode signal 22a described later is 10 Mbps,
In this embodiment, three types of cases of 3.3 Mbps and 1 Mbps are assumed, and the respective predetermined compression ratios will be referred to as first to third compression ratios. That is, for a program such as a black-and-white program that the viewer does not expect due to high quality, the third compression ratio is selected to increase the compression degree to 1 Mbps, and when a certain degree of quality is required such as a news program, the second compression ratio is set. The compression ratio is selected to 3.3 Mbps, and when the high quality such as movies is required, the first compression ratio is selected to 10 Mbps.
The degree of compression is switched according to the content of the program. If the audio signal of a music program or the like is required to have particularly high quality, the digital audio signal 2
0a is not compressed and the digital video signal 2
You may control so that the compression ratio of 1a may be raised.

Then, the compressed audio signal 20b and the compressed video signal 21b are respectively supplied to the scramble means 220 in the digital encoder 22 which performs predetermined digital processing, where both input signals are combined and the scramble information signal bb is combined. A signal obtained by performing well-known scrambling according to a predetermined rule specified by is supplied to the ID information adding means 221. Then, the ID information adding means 221
In accordance with the ID information based on the scramble information signal bb for descramble corresponding to the scramble in the VTR on the receiving side, which will be described later, and the label information signal cc for printing the label on the VTR on the receiving side. The ID information is added to the output signal of the scramble means 220 and supplied to the error correction code adding means 222. Then, the error correction code adding means 222 supplies the encoded signal 22a obtained by generating and adding a known error correction code such as a double Reed-Solomon code to the output signal to the pseudo NTSC signal converting means 23.

Now, the encode signal 22a will be described in detail. As described above, the amount of information becomes 10, 3.3, 1 Mbps according to the first to third compression ratios, and FIG.
As shown in (C), the encoded signal 22a is 10M
When it has an information amount of bps, it is a continuous signal when viewed in frame units, and when it is 3.3 Mbps, it is an intermittent signal every three frames, and the compression ratio is further increased to 1 Mbps.
In this case, the signal is intermittent every 10 frames. Therefore, the transmission rates of the signal portions in FIGS. 9A to 9C are all the same. Then, the 1 Mbp shown in FIG.
An enlarged version of the encoded signal 22a of s for one horizontal scanning period is shown in FIG.

The encode signal 22a is pseudo NT.
The encoded signal 22a, which is a digital signal, is supplied to the SC signal conversion means 23, where it is converted into a multi-value modulated signal having a picture period defined by the synchronization signal 26a as an effective signal period, and then the synchronization signal generation means A horizontal and vertical synchronizing signal 26a supplied from the reference signal 26 is added, and a 3 MHz sine wave for determining the second pseudo NTSC signal 24a on the receiving side supplied from the determination signal generating means 27 is determined by the determination signal 27a. The first pseudo NTSC signal 23a added to the position of the color burst signal is supplied to the digital VTR 24 capable of intermittent recording. In the present embodiment, the first pseudo NTS is realized by the 8-value multi-level modulation.
The band of the C signal 23a is set to about 4.2 MHz, and the conventional equipment can be used as it is.

The VTR 24 plays a role of compressing the first pseudo NTSC signal 23a in which an effective signal period is present intermittently while maintaining the band of the first pseudo NTSC signal 23a. , Continuous or intermittent recording according to the first to third compression ratios is performed in frame units. That is, the first pseudo NTSC signal 23a relating to the first compression ratio
In the case of the first pseudo NTSC signal 23a related to the second compression ratio, the tape running is stopped for two frame periods after recording one frame, and the first pseudo NTSC signal 23a related to the third compression ratio is further recorded. In the case of the NTSC signal 23a, the tape running is stopped for 9 frame periods after recording 1 frame. still,
The recording unit described above is determined according to the delimiter unit of the compression algorithm and the capacity of the buffer memory (not shown) provided in the pseudo NTSC signal converting means 23, and is not limited to one frame, and may be one or plural. Of course, it may be in the unit of frame, or in the unit of one or more fields.

In this way, continuous recording tracks are formed on the magnetic tape in any case, and by continuously reproducing the magnetic tape, the time-axis-compressed second track shown in FIG. 2 (E) is formed. The pseudo NTSC signal 24a can be obtained. Since the VTR 24 is for aligning effective signals on the time axis without any gap, it goes without saying that it may be a large-capacity memory.

The second pseudo-NTS thus obtained
The C signal 24a is, for example, 10 when the digital video signal 21a is
In the case of a program of 0 Mbps and 1 hour, when the third compression ratio is selected, the time axis is compressed to 1/10 of the time and the signal becomes 6 minutes. Since this signal simply corresponds to the effective signal period of the first pseudo NTSC signal 23a which is continuous, its band is the pseudo NTSC signal 23a.
Since the frequency is approximately 4.2 MHz, which is the same as that of a, the conventional transmission equipment can be used as it is and transmitted to each home via the transmission means 25. In addition, the transmitting means 25 sends a second signal to each home in the form of radio waves.
The pseudo-NTSC signal 24a of
Needless to say, it may be a cable or the like and its transmission equipment. Further, it goes without saying that the above-mentioned synchronization relationship on the transmission side is controlled by a well-known synchronization control means (not shown).

Next, a VTR according to the gist of the present invention installed in each home on the receiving side will be described with reference to FIG. In particular, this VTR can be used for both recording and reproduction of a normal video signal and recording and reproduction of the second pseudo NTSC signal 24a. The same components as those in FIG. 4 described above are designated by the same reference numerals and the description thereof is omitted.

First, a recording system will be described.
The output signals of the transmitting means 25 supplied to the first and second tuners 7 and 8 in the VTR from the reception antennas 5 and 6 for normal broadcasting and satellite broadcasting (not shown) by F, UHF broadcasting or satellite broadcasting are respectively: It is demodulated here and the second pseudo NT
It becomes the SC signal 24a and is supplied from the first selection circuit 9 to the first detection circuit 30 and the second selection circuit 31. Then, the first detection circuit 30 outputs the second pseudo NTSC signal 24.
By discriminating the frequency of the discrimination signal 27a which is a sine wave of 3 MHz in a, whether the output signal of the first selection circuit 9 is a normal video signal or the second pseudo NTSC signal 2
4a is detected, and the first detection signal 30a which becomes "high level" in the former case and "low level" in the latter case is supplied to the second and third selection circuits 31, 33.

When the first detection signal 30a is "high level", the normal video signal is the second selection circuit 31, the above-mentioned first recording system 10, and the third selection circuit 33.
Is supplied to the head selection circuit 11 for recording via. On the other hand, when the first detection signal 30a is "low level", the second pseudo NTSC signal 24a is the second selection circuit 3
1, the second recording system 32, which will be described later, and the third selection circuit 33, and the data is supplied to the head selection circuit 11.

Now, the second recording system 32 will be described in detail with reference to FIG. 4. The second pseudo NTSC signal 24a supplied from the second selection circuit 31 is the same as the pseudo NTSC signal converting means 23. The pseudo NTSC signal demodulation means 320 having a complementary relationship demodulates the multi-level (8-level) modulation, and the output signal is supplied to the error correction means 321. Then, the error correction means 321 corrects the error occurring in the transmission / reception system using the error correction signal added by the first error correction signal addition means 222, and then the second error correction signal. It is supplied to the adding means 322, and after adding an error correction signal suitable for recording / reproducing of the VTR, it is supplied to the known recording modulating means 323. This recording modulation means 323
After performing known modulation such as 4-phase PSK or 8-10 to obtain a recording modulation signal, a preamble signal 323a having a constant frequency used for clock reproduction synchronized with this signal and the clock signal is added in advance to the recording modulation signal. The second recording signal 32a thus obtained is supplied to the head selection circuit 11 via the third selection circuit 33. Then, the second recording signal 32a is recorded by using the first or second magnetic head pair Ha, Hb selected by the head selection circuit 11, and continuous recording tracks are formed on the magnetic tape T.

In this way, the first and second tuners 7 and 8 for recording a normal video signal, the first selection circuit 9, the head selection circuit 11, and the first and second magnetic heads H1 and H1. H2 can also be used when recording the second pseudo NTSC signal 24a.

Next, the reproducing system will be described again with reference to FIG. 3. The signals reproduced from the first or second magnetic head pair Ha, Hb from the magnetic tape T are the head selecting circuit 11.
Is supplied to the second detection circuit 34 and the fourth selection circuit 35 via. Then, the second detection circuit 34 detects the frequency component of the preamble signal 323a in the output signal output from the fourth selection circuit 35 during a predetermined period and reproduces the signal. Is the second pseudo-NTSC
The second detection signal 34a which is "low level" when it is a reproduction signal related to the signal 24a and "high level" when it is a reproduction signal related to a normal video signal is the fourth detection signal 34a.
It is supplied to the fifth selection circuits 35 and 38.

When the second detection signal 34a is "high level", the reproduction signal related to the normal video signal is reproduced through the fourth selection circuit 35 and the first reproduction system 12 described above. The video signal 12a is supplied to a transmission line (not shown) via the fifth selection circuit 38. On the other hand, the second detection signal 3
Second pseudo NTSC when 4a is "low level"
The reproduction signal related to the signal 24a is supplied to a transmission line (not shown) via the fourth selection circuit 35, a second reproduction system 36 described later, and a fifth selection circuit 38.

Now, the second reproduction system 36 relating to the second pseudo NTSC signal 24a will be described in detail with reference to FIG. 5, in which the reproduction signal from the fourth selection circuit 35 is supplied to the second reproduction system 3.
6 is supplied to the reproduction processing means 360 in FIG. 6 and the signal obtained by applying the well-known waveform equalization for correcting the frequency characteristic of the magnetic recording / reproducing system to the input signal is supplied from a well-known clock reproducing circuit whose main part is a PLL circuit A signal obtained by latching the obtained reproduced clock signal is supplied to the demodulation means 361.

Then, the demodulation means 361 has a complementary relationship with the above-mentioned modulation means 323, and the reproduction processing means 360.
Is demodulated, the signal is supplied to the second error correction means 323, and error correction is performed using the error correction signal added by the second error correction signal addition means 322 described above. The applied signal is supplied to the ID information detecting means 363.

The ID information detecting means 363 separates the ID information added by the ID information adding means 221 from the output signal of the second error correcting means 362 and obtains the compression ratio control signal aa and the label print information signal. cc is separated, the former is supplied to the mechanism control system 37, the latter is supplied to the label printing means 39, and a signal composed of the compressed video signal 21b, the compressed audio signal 20b and the scramble information signal bb is supplied to the descramble means 364. To do.

The descrambling means 364, which has a complementary relationship with the scrambling means 220, uses the descramble information signal dd supplied by the operator's keyboard operation, etc., and the scramble information signal bb in the input signal. If they coincide with each other, they are subjected to predetermined descrambling, and then the compressed video signal 21b and the compressed audio signal 20b are complemented by the video signal expansion means 365 and the video signal expansion means 365. To the audio signal decompression means 366, and the reproduced video signal and the reproduced audio signal obtained by decompressing them respectively are supplied to the fifth selection circuit 3.
8 to a television receiver or the like.

Now, the main part of the mechanism control system 37 capable of intermittently driving the magnetic tape will be described with reference to FIG. 6, and the compression ratio control signal aa from the second reproducing system 36 will be explained. A well-known control signal CTL having phase information of the waveform-shaped reproduction track is supplied to the control circuit 370, and the read control signal 370a is supplied to the ROM 371 based on both input signals.
From this ROM 371, the capstan motor 3 described later
A speed reference signal 371 that serves as a reference for the speed at which 74 should be driven.
a is supplied to the subtraction circuit 372. Then, in the subtraction circuit 372, the frequency information signal 375a output from the frequency detection circuit 375 (FG) that detects the rotation frequency of the capstan motor 374 converts the frequency information signal 375a into a voltage F.
The speed error information signal 372a obtained by subtracting the speed information signal 376a converted into the voltage through the −V conversion circuit 376 from the speed reference signal 371a is used as the motor drive circuit 373 (M
DA) and the output signal of the motor drive circuit 373 drives the capstan motor 374.

In this way, the capstan motor 37
4 is a speed reference signal 371a output from the ROM 371.
Since the feedback loop is formed so as to have the same speed as the reference speed represented by, the speed reference signal 371
By making a a an intermittent signal, the magnetic tape can be driven intermittently.

The speed reference signal 371a corresponds to the compression ratio control signal.
The relationship between the reference speed represented by 1a and the reproduction track pattern will be described in detail by separating the case of the head width of the magnetic head used for recording and reproduction.

First, in the case where the head width of the magnetic head used for recording / reproducing is the same, the ideal reference speed is shown in FIG. As shown by the dotted line in (A), "Vo" which is the same speed as during recording is set to 1
The frame period is the reproduction speed, and the N frame period corresponding to the compression ratio is the speed "0" in the stopped state. That is, the second
In the case of the compression ratio (3.3 Mbps), N = 2, and in the case of the third compression ratio (1 Mbps), N = 9. However, since the mechanical system has a constant inertia, it is difficult to change the reference speed as a rectangular wave as shown by the dotted line. Therefore, it is assumed that the high frequency component of the rectangular wave is removed as shown by the solid line in FIG.

Here, the product of the difference between the actual reference speed and the ideal reference speed and the time is the difference in the running distance of the magnetic tape, but the running distance when the actual reference speed is taken is ideal. Since it is necessary to match the traveled distance when a different reference speed is taken, the area L1 shown by diagonal lines in FIG.
L4 needs to have a relationship of “L1 + L4 = L2 + L3”. In the present embodiment, the following description will be made assuming that “L1 = L4 = L2 = L3” in consideration of controllability.

FIG. 3B shows a reproducing track pattern for reproducing by using the first magnetic head pair Ha composed of Ha1 and Ha2 having wide azimuth angles different from each other for standard reproduction. The positions of the first magnetic heads Ha1 and Ha2 corresponding to the times A to G in FIG.
It will be position 2. That is, the first magnetic head Ha1 at the time A moves from the position a1 to the position b1 which is displaced from the normal track pattern by the distance L1 at the time B. Then, at time B, the first magnetic head H
The first magnetic head H located 180 degrees opposite to a1
a2 is at the position b2 relative to the magnetic tape T, and the time B is
By the time point C, the position is moved to the position c2 by moving the distance L2. Since the magnetic tape T is stopped between the time C and the time D, the position of the first magnetic head Ha2 at the time point of the time D is the same position d as the position c2.
2, the magnetic tape T travels a distance L3 between the time D and the time E and moves to the position e2. Since the actual reference speed is lower than the ideal reference speed during the period from time E to time F, the first magnetic head Ha2 moves from position e2 to position f2. Then, during the period from time F to time G, the magnetic tape T runs at the same speed as during recording, so that the first magnetic head Ha2 runs in the longitudinal direction without shifting, so it moves from position f2 to position g2. Hereinafter, this is repeated to intermittently reproduce the magnetic tape T.

Next, with reference to FIG. 8, a case where the wide first magnetic head pair Ha is used for recording and the narrow second magnetic head pair Hb is used for reproduction is used. explain. The reference speed in this case is the same as that in FIG. 7A described above, and is the one shown in FIG. 8A. Then, as in the case of FIG. 7B, the magnetic tape T is driven to use the recording tracks recorded by Ha1 and Ha2 by using Hb1 and Hb2 having the same azimuth angle, respectively.
As shown in (B), the reproduction is always performed in the on-track state. This is indicated by the dashed line H in FIG.
It may be assumed that a part of a2 is Hb2.

When the head width of the second magnetic head pair Hb is, for example, 1/3 of that of the first magnetic head pair Ha, reproduction is performed at 1/3 speed using a conventional mechanism control system. By doing so, in the case of the second compression ratio, continuous reproduction is possible,
Of course, it is possible to obtain a linear reproduction track pattern.

Further, a case where recording is performed by using the narrow second magnetic head pair Hb at the time of recording and reproduction is performed by using the wide first magnetic head pair Ha will be described with reference to FIG.
In this case, the head width of the first magnetic head pair Ha is the second
The magnetic head pair may be 1.5 to 2.2 times as large as that of the magnetic head pair, but the case of 1.5 times is assumed. Also,
It is assumed that the magnetic tape is driven for one frame and then intermittently reproduced for M frames.

The ideal reference speed is "Vo", which is the same speed as during recording for one frame period, as shown by the dotted line in FIG. 9A, and M is a value corresponding to the compression ratio.
During the frame period, the speed is "0", which is a stopped state. That is, M = 2 in the case of the second compression ratio (3.3 Mbps), and M = 9 in the case of the third compression ratio (1 Mbps). However, as in the case of FIG. 7A, since the mechanical system has a constant inertia, it is difficult to change the reference speed into a rectangular wave as shown by the dotted line. Therefore, FIG.
It is assumed that the high frequency component of the rectangular wave is removed as shown by the solid line in (A). Further, the product of the difference between the actual reference speed and the ideal reference speed and the time is the difference in the running distance of the magnetic tape, which is the same as in the case of FIG.
It is illustrated in L1 to L4. Hereinafter, the reproduction track pattern shown in FIG. 7B will be represented by positions a1 to 1b of the second magnetic heads Hb1 and Hb2 corresponding to times A to J in FIG.
An explanation will be given using j2.

First, since the actual reference speed is lower than the ideal reference speed during the period from time A to time B, the running distance of the magnetic tape T is shortened by L1, so Ha1 changes from position a1 to position b1. The recording track T1 is moved and reproduced.

Then, Ha1 at time B and Ha2 where the mounting height of the rotary drum overlaps are at position b2,
Further, the magnetic tape T is separated by the distance L during the period from the time B to the time C.
Since it travels only 2 times, the position of Hc2 at time C is position c
It becomes 2. Since the magnetic tape T is stopped during the period from time C to time D, the position of Hc2 is the position c2.
And the same position d2 as. Then, during the period from time D to time E, the magnetic tape T runs the distance L3, so
The position 2 moves from the position d2 to the position e2.

Since the actual reference speed is lower than the ideal reference speed during the period from time E to time F, the running distance of the magnetic tape T is shortened by L4, so that Ha2 changes from position e2 to position f2. It moves and reproduces the recording track T2.

Since the actual reference speed and the ideal reference speed match during the period from time F to time I, the first magnetic head pair Ha moves parallel to the recording track and moves on the recording track T2. The remaining part and the front part of the recording track T3 are reproduced.

Since the actual reference speed is lower than the ideal reference speed in the period from time I to time J,
Since the running distance of the magnetic tape T is shortened by L1,
1 moves from position I1 to position j1 and recording track T3
Play the rest of. In this way, during the period from time Z to time B, the recording track T1 is moved from time E to time X.
The recording track T2 is reproduced during the period up to and the recording track T3 is reproduced during the period between time X and time J. Thereafter, by repeating this, the magnetic tape T is reproduced intermittently, so that a large capacity memory is not required for the second reproducing system.

In the above-described embodiments, the normal video signal (input video signal) has been described as an example of the signal related to the NTSC system, but the PAL system, the SECAM system, or the high-definition system (including the muse system). Of course, in such a case, the band of the input signal of the transmission means 25 and the synchronization signal correspond to the respective systems.

In the above embodiment, the second and fourth
Although the selection circuits 33 and 34 are used, they may be configured without using them. In this case, the output signal of the first selection circuit 9 is directly supplied to the first and second recording systems 10 and 32, and the output signal is switched in the third selection circuit 33, and the head selection is performed. The output signal of the circuit 11 is
The second reproducing systems 12 and 36 are directly supplied, and the fifth selecting circuit 38 switches the output signals thereof.

In the above-mentioned embodiment, the discrimination signal 2
7a has been described as a 3MHz sine wave added in the burst period specified by the synchronization signal 26a, but this signal is used for the receiving side to determine whether it is the second pseudo NTSC signal 24a or a normal video signal. Therefore, the added period is not limited to the burst period,
Needless to say, it may be a picture period, and the signal form thereof may be a digital signal having the same or narrow band as a normal video signal.

In the above-mentioned embodiment, the band of the second pseudo NTSC signal 24a is limited by the transmitting means 25 for transmitting the normal video signal. Needless to say, it may be narrow and can be set appropriately by controlling the compression ratio.

In the above-described embodiment, by detecting the frequency of the preamble signal 323a at the time of reproducing the VTR, the reproduced signal is the signal related to the second pseudo NTSC signal 24a or the signal related to the normal video signal. Although it has been detected whether or not there is an error correction means 32 in the second recording system 32.
A discriminating signal adding means for adding a second discriminating signal is provided on the path from the output of 1 to the input of the recording modulating means 323, the second discriminating signal is detected at the time of reproduction, and the result is used to obtain the fourth and the fourth signals. Of course, the selection circuits 35 and 38 of No. 5 may be switched.

As described above, according to the present embodiment, a predetermined program can be transmitted in a short time using the conventional transmission path, so that it is possible to effectively use the broadcasting equipment, and it is possible to set a specific VTR. It is possible to provide confidentiality of a program that cannot be viewed without intervention. Further, since the first and second tuners in the VTR are used also as the conventional magnetic head, the structure of the device can be simplified.

[0054]

As described above, according to the configuration of the present invention,
The pseudo video signal has the same synchronization signal as the input video signal and has the same or narrow band as the band of the input video signal,
Since the compressed video signal obtained by band-compressing the input video signal is inserted in the period corresponding to the picture period of the input video signal specified by the synchronization signal, the conventional broadcasting facility can be used as it is, Since the program related to the input video signal can be transmitted in time, there is an effect that the utilization efficiency of the conventional broadcasting facility can be improved and a program having confidentiality can be provided.

As described above, according to the configuration of the present invention, the pseudo video signal corresponds to the period corresponding to the picture period of the input video signal or the burst period of the input video signal specified by the synchronization signal. Since a discrimination signal for discriminating the pseudo video signal and the input video signal is included in the period,
There is an effect that the receiving side can determine whether the input signal is the input video signal or the pseudo video signal.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a broadcasting station on the transmitting side.

FIG. 2 is a waveform diagram for explaining FIG.

FIG. 3 is a block diagram for explaining one embodiment of a VTR according to the present invention.

FIG. 4 is a block diagram for explaining a second recording system.

FIG. 5 is a block diagram for explaining a second reproduction system.

FIG. 6 is a block diagram for explaining a main part of a mechanism control system.

FIG. 7 is a conceptual diagram for explaining a relationship between a reference speed and a reproduction track pattern when the head width of a magnetic head is the same.

FIG. 8 is a conceptual diagram for explaining a relationship between a reference speed and a reproduction track pattern when recording is performed using a wide magnetic head and reproduction is performed using a narrow magnetic head.

FIG. 9 is a conceptual diagram for explaining a relationship between a reference speed and a reproduction track pattern when recording is performed using a narrow magnetic head and reproduction is performed using a wide magnetic head.

FIG. 10 is a block diagram for explaining a conventional broadcast format and VTR.

[Explanation of symbols]

 22a Encode signal (compressed video signal) 24a Second pseudo NTSC signal (pseudo video signal) 25a Transmission means 26a Synchronous signal

Claims (2)

[Claims] 1. A pseudo video signal obtained by subjecting an input video signal to predetermined signal processing, the pseudo video signal having the same synchronization signal as the input video signal, and a band of the input video signal. A compressed video signal that is band-compressed to the input video signal is inserted in a period corresponding to the picture period of the input video signal specified by the synchronization signal. A pseudo video signal having a discrimination signal for discriminating the pseudo video signal from the input video signal in a burst period of the input video signal specified by a signal. 2. A pseudo video signal transmission system, wherein the pseudo video signal according to claim 1 is transmitted and output using a transmitting means for transmitting and outputting the input video signal.