JPH05328305A - False video signal decoder - Google Patents

Abstract

PURPOSE:To efficiently utilize broadcasting equipment by allowing a decoder for demodulating a false video signal to supply a control signal for controlling the drive of a recording medium in accordance with the operation of extension algorithm to a video signal reproducing device. CONSTITUTION:A reproducing video signal FF outputted from a VTR 15 is inputted to the 4th selection circuit 30 and a detection means 39 in the decoder 16 and the means 39 sends a control signal S3 found from a decision signal included in the signal FF to the 4th and 5th selection circuits 30, 36. At the time of detecting that the signal FF is an input video signal AB or an information signal DD by the signal S3, the circuit 30 sends the signal FF to a false NTSC signal demodulating means 31, the means 31 demodulates many-valued modulation and sends the demodulated result to an error correcting means 32, which sends a corrected signal to an ID information detecting means 33. The means 33 sends a signal obtained by removing ID information to a scrambling means 34, which sends a scrambled signal to an extension means 35. The means 35 extends the scrambled signal and sends a reproduced signal EE for the input signal to the circuit 36, which sends the reproduced signal EE to a monitor, a printer, or a computer based upon the signal S3.

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 decoder for demodulating a pseudo video signal reproduced by a video signal reproducing apparatus which is a video signal reproducing apparatus or a video signal recording / reproducing apparatus.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional broadcasting system and a video signal magnetic recording / reproducing apparatus (hereinafter abbreviated as "VTR") used therein.
FIG. 6 is a block diagram for explaining the above. Less than,
A conventional technique will be described with reference to the drawings.

In FIG. 7, 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 transmitting video signal is supplied from the terrestrial broadcasting transmitting antenna 3 to the terrestrial broadcasting receiving antenna 5 in each home.

Then, the transmission video signals modulated by the reception antennas 5 and 6 for terrestrial 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 terrestrial 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 supplies the head selection circuit 11 with a first recording signal 10a obtained by subjecting the output signal of the first selection circuit to a predetermined recording process described later.

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 recording signal 10a is the first and second magnetic head pairs Ha,
It is recorded on the magnetic tape T via either one of 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 a first reproducing system 12 having a complementary relationship with the first recording system 10 and a reproduced video signal 12a obtained by performing a predetermined reproducing process described later is received by a television receiver (not shown). Was being supplied to the machine. Further, the VTR has a mechanism control system 37 and controls the traveling of the rotary drum and the magnetic tape. Further, it has a timer recording function (not shown) and uses the VTR 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 for recording.

[0009]

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.

In view of the above, the present invention broadcasts a normal video signal or a signal obtained by compressing an information signal used for electronic publishing, etc., using the same equipment as in the past, and records the signal in each home in a short time. It is an object of the present invention to solve the above problems by expanding this signal and reproducing it in the original time during reproduction.

[0011]

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

A pseudo video signal is supplied from a video signal reproducing device for reproducing a recording medium on which a pseudo video signal subjected to a predetermined scramble process is recorded after at least compressing the input information signal. A video signal decoder, which drives the recording medium according to the operation of a decompression algorithm when performing decompression processing according to the scrambling processing on the pseudo video signal and then decompressing according to the compression processing. A pseudo video signal decoder, characterized in that a control signal for controlling is supplied to the video signal reproducing device.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining an outline of a broadcasting mode according to the present invention, FIG. 2 is a block diagram showing an embodiment of a broadcasting station on the transmitting side, and FIG. 3 is for explaining FIG. Waveform diagram, FIG. 4 is a block diagram for explaining a decoder according to the present invention, FIG. 5 is a block diagram for explaining a main part of a mechanism control system, and FIG. 6 is a relation between a reference speed and a reproduction track pattern. It is a conceptual diagram for doing. Embodiments will be described below with reference to the drawings. The same components as those in FIG. 7 are designated by the same reference numerals and the description thereof will be omitted.

An outline of an embodiment of the broadcasting mode according to the present invention will be described with reference to FIG. 1. In the broadcasting station 1 on the transmitting side,
After scrambling the compressed video / audio signal or information signal, it is converted into a pseudo NTSC signal, and the transmission video signal modulated by the conventional transmission means is transmitted from the satellite broadcasting transmission antenna 2 through the satellite 4 to It is supplied to the satellite receiving antenna 6 in each home. Also, in normal VHF and UHF broadcasting, the terrestrial broadcasting transmitting antenna 3 supplies the modulated transmission video signal to the terrestrial broadcasting receiving antenna 5 in each home. Then, the video signal compressed by the VTR 15 in the home, which is the receiving side, is recorded in the same or a short time as compared with the original time, and the video signal compressed continuously or intermittently is reproduced, and the reproduced signal is reproduced. Decompress with decoder 16 and monitor 1
7, computer 18, printer 19, etc.

First, the first input video signal A1 and the first input video signal A1 will be described with reference to FIGS.
Input audio signal A2 is digitized via the A / D converter 20 and the input video / audio signal AB (for example, approximately 100 Mb
signal of ps) is supplied to one input side of the second selection circuit 21. Further, the other input side of the second selection circuit 21 is supplied with an information signal DD which is digital information relating to electronic publishing and the like, and the input video / audio signal AB and the information signal DD are first input.
The input information signal XX obtained by selecting using the selection signal S1 of
Is supplied to the encoder 22.

The operation of the encoder 22 will be described when the input information signal XX supplied to the encoder 22 is the input video / audio signal AB. The compression means 220 in the encoder 22 has a compression ratio control signal aa and a first selection signal S1.
A scramble means 2 scrambles a compressed information signal 220a obtained by subjecting the input information signal XX to a well-known band compression algorithm such as DCT, DPCM, wavelet, etc.
22.

Here, the compression ratio control signal aa controls the degree of signal compression. For example, when the information amount of the input video / audio signal AB is about 100 Mbps, it is 10 Mbps, 3.3 Mbps, 1 Mbps. In the present embodiment, it is assumed that three types of compression are performed, and the respective predetermined compression ratios will be referred to as first to third compression ratios. That is, for programs such as black and white programs that viewers do not expect due to high quality, the third compression ratio is selected to increase the degree of compression to 1M.
bps, and if a certain quality such as a news program is required, select the second compression ratio to 3.3 Mbps,
Further, when high quality such as a movie is required, the first compression ratio is selected to be 10 Mbps, and the compression degree is switched according to the content of the program. The audio signal and the video signal may have different compression algorithms. For example, when a high quality audio signal such as a music program is required, the audio signal is not compressed. Therefore, control may be performed to increase the compression ratio of the video signal.

The memory 221 is, for example, a large-capacity disk type or semiconductor memory, and the compression means 22.
It operates as a data buffer for adjusting the timing of the desired input data that fluctuates according to the 0 compression algorithm.

Then, the compressed information signal 220a is supplied to the scramble means 222, and the scramble information signal bb specified for each program (program) of the input video signal A1 and the input audio signal B1 is used to perform a well-known scramble according to a predetermined rule. The signal obtained is the ID information adding means 22.
3 is supplied.

The ID information adding means 223 adds the ID information based on the label information signal cc for label printing in the VTR on the receiving side, which will be described later, and other ID information to the output signal 222a of the scramble means 222. The output signal 223a thus obtained is supplied to the error correction code adding means 222. Then, the error correction code adding means 223 supplies an encoded output signal 22a obtained by generating and adding a known error correction code such as a double Reed-Solomon code to the output signal 222a to the pseudo NTSC signal converting means 23.

On the other hand, when the input information signal XX supplied to the encoder 22 is the information signal DD, the same processing is performed to obtain the encoded output signal 22a. However, it goes without saying that the compression means 220 may be directly input to the scramble means 222 without going through this.

The encode output signal 22a is shown in FIG.
As shown in (A), it goes without saying that the period corresponding to the picture period defined by the later-described sync signal 26a may be a valid signal period.

Then, the encode output signal 22a is supplied to the pseudo NTSC signal converting means 23, and the synchronizing signal 26a is supplied.
After being converted into a multi-valued modulated signal whose effective signal period is the picture period defined by, horizontal and vertical synchronizing signals 26a supplied from the synchronizing signal generating means 26 are added thereto,
Further, a discrimination signal 27a for discriminating a normal video signal on the receiving side supplied from the discrimination signal generating means 27 and for specifying the kind of the signal inserted in the picture period is provided on a predetermined line in the vertical synchronizing signal. Pseudo NTSC signal 2 obtained by inserting
3a is supplied to the third selection circuit 24.

Here, the discrimination signal 27a is, for example, a 3 MHz sine wave when the encode output signal 22a is a signal related to the input video signal AB, and a 2 MHz sine wave when it is a signal related to the information signal DD. To do. The multi-level modulation described above is, for example, 8-level multi-level modulation to set the band of the pseudo NTSC signal 23a to approximately 4.2 MHz,
The existing equipment can be used as is.

Then, the third selection circuit 24 has a pseudo N
The control information signal dd, which has the program number to be paired with the TSC signal 23a and the same information as the discrimination signal 27a and is used auxiliary on the reproducing side, the second input video signal A2, and the second input audio signal. B2 and are supplied. Here, the second input video signal A2 and the second input audio signal B2 are signals inserted before the pseudo NTSC signal 23a, and scrambled with the contents such as the title of the pseudo NTSC signal 23a that follows. It is a signal for explaining a method for canceling.

Then, the second selection signal S2 shown in FIG. 7C is supplied, and while the signal is at a high level, the second input video signal A2 and the second input video signal A2 shown in FIG.
Audio signal B2 is selectively output, while the pseudo NTSC signal 23a and the control information signal dd are in the low level period.
Are selected and output, and they are recorded on the VTR 25,
A master tape for transmission is created.

Then, for example, the transmission video / audio signal YY obtained by reproducing the VTR 25 while the broadcasting facility is not used, such as at midnight, is transmitted to each home by using the conventional transmission means 26 as it is. .. The transmitting means 26 transmits to each home in the form of radio waves, but it goes without saying that it may be a cable such as CATV and its transmitting 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).

In this way, the conventional transmitting means can be used for transmission because the band of the pseudo NTSC signal 23a is approximately 4.2 MHz. Also, pseudo NTS
When the C signal 23a is a signal related to the input video / audio signal AB, for example, in the case of a one-hour program, when the third compression ratio is selected, the time axis is compressed to 1/10 of the time and the duration of 6 minutes is reduced. Become a signal.

Next, a V installed in each household on the receiving side
TR15, decoder 16, monitor 17, printer 18,
The computer 19 will be described. Since the VTR 15 is the same as the conventional VTR except that the mechanism control system 13 intermittently runs the tape during reproduction in relation to a decoder 16 described later, its description is omitted.

The operation of the decoder 16 will now be described with reference to FIG.
Will be described in detail. The reproduced video signal FF output from the VTR 15 is supplied to the fourth selection circuit 30 and the detection means 39, and the detection means 39 detects the discrimination signal 27a inserted in the vertical synchronizing signal of the reproduced video signal. The third obtained
The control selection signal S3 is supplied to the fourth selection circuit 30 and the fifth selection circuit 36.

Then, the fourth selection circuit 30 outputs the reproduction video signal only when the reproduction video signal FF is detected as the first input video signal AB or the information signal DD by the third control selection signal S3. Is supplied to the pseudo NTSC signal demodulating means 31 having a complementary relationship with the pseudo NTSC signal converting means 23, where the multi-level modulation is demodulated and the output signal thereof is supplied to the error correcting means 32.

Then, the error correction means 32 corrects the error generated in the transmission / reception system and the error generated in the recording / reproduction system of the VTR 15 using the error correction signal added by the error correction signal adding means 224. After that, it is supplied to the ID information detecting means 33.

The ID information detecting means 33 supplies a label information signal cc obtained by separating the ID information added by the ID information adding means 223 from the output signal of the error correcting means 32 to a printer (not shown). The signal from which the ID information is removed is supplied to the descramble means 34.

The descrambling means 34, which has a complementary relationship with the scramble means 222, obtains a predetermined descramble using the descrambling information signal P1 supplied by a keyboard operation (not shown) of the operator. And the supplied signal to the expansion means 35. It is assumed that the operator inquires the broadcasting company about the cancellation number to be input on the keyboard in order to obtain the scramble cancellation information signal P1 on condition that the fee is paid.

The decompressing means 35, which has a complementary relationship with the compressing means 220, decompresses the output signal of the descrambling means 34 to input the audio / video signal AB or the information signal DD.
A reproduction signal EE relating to is obtained. The decompression means 35 has a memory (not shown), but its capacity is limited. Therefore, the decompression means 35 adjusts the data amount of the input signal according to the operation of the decompression algorithm to the mechanism control system 37 in the VTR 15. It is controlled by the supplied drive control signal Q1. That is, the magnetic tape T is intermittently run according to the operation of the expansion algorithm to adjust a desired amount of data.

Now, the main part of the mechanism control system 37 capable of intermittently driving the magnetic tape T will be described with reference to FIG. 5, in which the drive control signal Q1 indicates the phase information of the waveform-shaped rotary drum. The represented drum pulse DP is supplied to the control circuit 370 to which the read control signal 370a is supplied to the ROM 371 based on both input signals. From the ROM 371, a speed reference signal 3 serving as a reference for the speed at which a capstan motor 374, which will be described later, should be driven.
71a 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 is passed through the FV conversion circuit 376 that converts the frequency into a voltage. The motor drive circuit 373 receives the speed error information signal 372a obtained by subtracting the speed information signal 376a converted into the voltage from the speed reference signal 371a.
(MDA) 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
The intermittent drive of the magnetic tape T becomes possible by using a as an intermittent signal.

The speed reference signal 371a corresponds to the drive control signal Q1.
The relationship between the reference speed represented by 71a and the reproduction track pattern will be described in detail with reference to FIG.

In the process from the running fall of the magnetic tape T to the running start, the ideal reference speed is shown in FIG.
As shown by the dotted line in the figure, "V
"" is a reproduction speed for one frame period, for example, and the speed is "0" which is a stopped state during N frame periods according to the drive control signal Q1. 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. 6B 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.

As described above, since the reproduction is performed intermittently, the expanded reproduction signal EE can be obtained without requiring a large capacity memory in the expansion means 35.

Then, the reproduction signal EE is supplied to the fifth selection circuit 36 to which the third selection control signal S2 and the reproduction video signal FF are supplied, and the monitor 17, based on the third selection control signal S2. The input signal is selectively output to the printer 18, the computer 19, and the like. That is, the third selection control signal S
When 2 detects that the reproduced video signal FF is a normal video signal, the reproduced video signal FF is supplied to the monitor 17, and when it is detected that the reproduced video signal FF is a signal related to the input video audio signal AB, the reproduction is performed. The signal EE is supplied to the monitor 17,
When it is detected that the reproduced video signal FF is a signal related to the information signal DD, the reproduced signal EE is supplied to the printer 18 and the computer 19.

In the above-mentioned embodiment, when reproducing the prerecorded magnetic tape T, it goes without saying that the VTR 15 may be a reproduction-only machine. Also, VTR
Reference numeral 15 is not limited to a VTR, as long as it can record and reproduce a video signal, and may be, for example, a device for reproducing a disc such as a magneto-optical disc or an optical disc (CD). Needless to say, it is only necessary to control the disk as a recording medium so as to be driven intermittently.

In the above-mentioned embodiments, the normal video signal (input video signal) has been described by taking the signal according to the NTSC system as an example, 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 pseudo NTS is used.
Since the band of the C signal 23a is limited by the transmitting means 25 for transmitting the normal video signal, it goes without saying that it may be narrower than the band of the normal video signal.

In the above-described embodiment, the pseudo NTSC signal 23a is the input audio / video signal for the second input video signal A2 and the second input audio signal B2 selected by the third selection circuit on the transmission side. When it is AB, it may be the first input video signal A1 and the first input audio signal B1, and these signals are appropriately inserted between the pseudo NTSC signals 23a (for example, one frame in 10 minutes). ), On the receiving side, when reproducing, the VTR 15 detects a discrimination signal, stores it in a memory, and reads it until it is updated. A magnetic tape that is reproduced by a user who does not have a decoder. Needless to say, a part of the contents of the above may be understood, and further this may be performed by the decoder.

In the above embodiment, the signal supplied to the detecting means 39 on the receiving side may be the reproduced audio signal of the VTR 15, and in such a case, the reproduced audio signal is supplied from a known audio recording / reproducing system. It goes without saying that the third selection control signal S3 may be generated based on the control information signal dd.

As described above, according to the present embodiment, it is possible to supply the compressed video / audio signal, the information signal DD such as the electronic publication, the newspaper, the computer software, etc. to each home by using the conventional broadcasting equipment. The method of descrambling can also be transmitted. Further, it is possible to provide confidentiality of information that can be viewed only through a specific decoder. In addition, these pieces of information are temporarily recorded on the magnetic tape T by the VTR 15.
Since it is recorded in, information can be obtained if necessary. Further, the VTR 15 used on the receiving side has the same configuration as the conventional VTR except that it is configured to be able to run intermittently, so that it can be used for normal recording and reproduction.

[0050]

As described above, according to the configuration of the present invention,
The pseudo video signal decoder for demodulating the pseudo video signal can adjust a desired input data amount by supplying a control signal for driving and controlling the recording medium according to the operation of the expansion algorithm to the video signal reproducing device. There is an effect that a pseudo video signal decoder with a simple configuration can be provided without requiring a large-capacity memory as
Since the pseudo video signal subjected to the predetermined scramble process after the compression process can be demodulated, the confidential information transmitted in a short time can be demodulated into effective information.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an outline of a broadcasting form according to the present invention.

FIG. 2 is a block diagram showing an embodiment of a broadcasting station on the transmitting side.

FIG. 3 is a waveform diagram for explaining FIG.

FIG. 4 is a block diagram illustrating a decoder according to the present invention.

FIG. 5 is a block diagram for explaining a main part of a mechanism control system.

FIG. 6 is a conceptual diagram for explaining a relationship between a reference speed and a reproduction track pattern.

FIG. 7 is a block diagram for explaining a conventional broadcasting system and a video signal magnetic recording / reproducing apparatus used for the conventional broadcasting system.

[Explanation of symbols]

 15 VTR (video signal reproducing device) 16 Decoder (pseudo video signal decoder) 23a Pseudo NTSC signal (pseudo video signal) T Magnetic tape (recording medium) Q1 Drive control signal XX Input information signal

Claims (1)

[Claims] 1. A pseudo video signal is supplied from a video signal reproducing device for reproducing a recording medium on which a pseudo video signal, which has been subjected to a predetermined scramble processing, after at least compressing the input information signal. A pseudo video signal decoder for performing a descrambling process according to the scramble process on the pseudo video signal, and then performing a decompression process according to the compression process, according to the operation of the decompression algorithm. A pseudo video signal decoder, which supplies a drive control signal for driving and controlling the video signal to the video signal reproducing device.