JPH065943B2 - Method and apparatus for determining recording mode of reproduced video signal - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for discriminating a recording mode of a reproduced video signal, and in particular, recording recorded by switching a carrier frequency of a frequency-modulated video signal according to a selected mode. The present invention relates to a method and apparatus for determining a recording mode of a reproduced video signal when reproducing a medium.

2. Description of the Related Art In a home VTR, a carrier wave of a frequency-modulated luminance signal is higher than that of a current VTR standard (for example, VHS (registered trademark)) in combination with recent improvements in magnetic tape performance and magnetic head performance. By setting a high frequency and recording / reproducing, a high-quality image having a higher resolution than an image recorded / reproduced in the current VTR standard mode (hereinafter, this mode is referred to as a standard mode) is obtained. A recording / reproducing method for obtaining a high image quality mode has been considered.

Problems to be Solved by the Invention However, since the standard mode and the high image quality mode are not completely compatible with each other, it is necessary to determine which of the above modes the video signal to be reproduced is recorded. , It is necessary to perform playback in the same mode as when recording.

For this reason, for example, a changeover switch for switching between the standard mode recycled yarn and the high quality mode recycled yarn is provided in the VTR, the recorded signal of the magnetic tape is first reproduced in either mode, and then the reproduced image is monitored while monitoring the reproduced image. The changeover switch is changed so that the reproduced image can be reproduced in a mode in which the reproduced image is reproduced correctly.

However, this method is not very user-friendly, and when reproduced in a different mode, there is a problem in that the reproduced image quality is extremely deteriorated and the user may mistake this as a failure of the VTR.

Therefore, the present invention was created in view of the above points,
An object of the present invention is to provide a method and an apparatus for discriminating a recording mode of a reproduced video signal, which automatically discriminates in which of a plurality of modes a reproduced signal is recorded.

Means for Solving the Problems A method of discriminating a recording mode of a reproduced video signal according to the present invention is a method of discriminating n types (n is an integer of 2 or more) of different carrier frequencies of a frequency-modulated video signal. , The reproduced frequency-modulated video signal obtained by reproducing the recording medium on which the frequency-modulated video signal is recorded is supplied, and corresponds to both the sync tip level and the pedestal level of the reproduced frequency-modulated video signal. The energy of the frequency band including the carrier frequency to be extracted is extracted, and the recording mode is determined based on the extraction result. Further, the recording mode discriminating apparatus for the reproduced video signal according to the present invention according to claim 2 has n types (n is an integer of 2 or more) in which the carrier frequencies of the frequency-modulated video signals are different from each other. N band filters for separately passing signals in a frequency range including both carrier frequencies corresponding to at least the sync tip level and the pedestal level of the frequency-modulated video signal, n detection circuits, and the reproduced frequency-modulated video signal The recording mode discriminating signal is output.

Further, the recording mode discriminating apparatus for reproducing video signals according to the present invention according to claim 4 allows a signal in the frequency range of a frequency-modulated video signal of one of two modes to pass. It is composed of a single bandpass filter, a single detection circuit, and means for outputting a recording mode discrimination signal.

In the method for determining the recording mode of the reproduced video signal according to claim 1, the frequency-modulated video signal recorded on the recording medium in any one mode is reproduced from the recording medium, and then the sync chip. The energy of the frequency band including the carrier frequency corresponding to both the level and the pedestal level is extracted, and the recording mode is determined based on the extraction result. Further, according to the invention described in claim 2, the reproduced frequency-modulated video signal is separately separated by the n band-pass filters to separate the carrier frequencies of the frequency-modulated video signal of each mode, and then, the above-mentioned correspondence is provided. It is supplied to a detection circuit, where envelope detection is performed. Each detection signal extracted from each of the n detection circuits is obtained by comparing the detection signal levels with each other by the recording mode determination signal output means, and the detection signal level and the preset reference level are respectively set as levels. Based on at least one of the comparison results, it is output as the recording mode determination signal of the reproduced frequency-modulated video signal.

Further, in the reproducing video signal recording mode discrimination device according to claim 4, the frequency-modulated video signal recorded in one of the two modes is reproduced and is reproduced by a single bandpass filter. After the carrier wave frequency including at least the pedestal level and the sync tip level of the frequency-modulated video signal of the mode is separated and supplied to the output means through the detection circuit, the level is compared with a preset reference level, Based on the result, it is converted into a recording mode determination signal and output.

Embodiment FIG. 1 to FIG. 5 show block system diagrams of an apparatus to which the method of the present invention is applied or each embodiment of the apparatus of the present invention. In each figure, the same reference numerals are given to the same components. The device of the present invention is a device provided in a video signal reproduction system of a VTR,
The video signal to be reproduced is recorded in either the standard mode or the high image quality mode. Here, a video signal, particularly a luminance signal, is recorded and reproduced on a magnetic tape in a signal form of a frequency-modulated luminance signal (FM luminance signal) obtained by frequency-modulating (FM) a carrier wave. In the standard mode, the frequency spectrum is as shown by I in FIG. 7, and in the high image quality mode, the carrier frequency is set higher than in the standard mode as shown by II in FIG.

In the frequency spectrum I of the FM luminance signal shown in FIG. 7,
f _AS , f _AP and f _AW indicate carrier frequencies at the sync tip level S, pedestal level P and white peak level W of the luminance signal shown in FIG. 6, and similarly, f _BS , f _BP in the frequency spectrum II. And f _BW are carrier frequencies at the sync tip level S, the pedestal level P and the white peak level W of the luminance signal. For example, the carrier frequency f _AS in the standard mode is 3.4 MHz,
f _AP is 3.8 MHz, f _AW is 4.4 MHz, and the carrier frequency f _BS is 5.0 MHz and f _BP is 5.6 MH in the high image quality mode.
z and f _BW are 6.7 MHz.

As can be seen from FIG. 7, in the carrier frequencies f _AS and f _BP corresponding to the sync chip level and the carrier frequencies f _AP and f _BP corresponding to the pedestal level, the frequency of the waveband of the FM luminance signal in the other mode. Although there are components, carrier frequencies f _AS , f _BS and f _AP , f _BP
Is much larger than the energy of the waveband component of the same frequency in the other mode. Focusing on this point, the present invention extracts the energy of the frequency band including the carrier frequency corresponding to both the sync tip level and the pedestal level, and performs the mode discrimination based on the extraction result. Examples will be described below.

In the first embodiment shown in FIG. 1, the FM luminance signal reproduced from the magnetic tape is supplied to a bandpass filter (hereinafter referred to as BPF) 2 and 3 via an input terminal 1, respectively. BP
F2 has a relatively wide band pass characteristic including the carrier frequency f _AP corresponding to the pedestal level and the carrier frequency f _AS corresponding to the sync tip level in the standard mode.

Similarly, the BPF 3 has a relatively wide band pass characteristic including the carrier frequency f _BP corresponding to the pedestal level and the carrier frequency f _BS corresponding to the sync tip level in the high image quality mode.

Here, the BPF is usually composed of passive elements such as a coil, a capacitor, and a resistor, and it is difficult to make them into an IC (integrated circuit). Although modularization can be considered at the actual mass production level, the narrower the pass band characteristic, the stronger the influence of the variation of the passive element, and the higher the yield. However, in the present invention, as described above, B
Since the pass band characteristics of PF2 and PF3 are selected to be relatively wide band, as compared with the case where the narrow pass band characteristics such that only carrier frequencies f _AP and f _BP or only f _AS and f _BS are separated and separated, are used. It is not affected by the dispersion of passive elements and is suitable for mass production. However, the sensitivity may be lowered by selecting the pass band characteristics of the BPFs 2 and 3 to a relatively wide band. However, if the carrier frequencies of the standard mode and the high image quality mode are separated to some extent, the peak in the detection circuit described later will occur. By appropriately selecting the time constant of the hold circuit, it is possible to make a sufficiently stable determination, so that there is no influence of the above-mentioned decrease in sensitivity.

By selecting the pass band characteristics of the BPFs 2 and 3, when the input reproduction FM luminance signal is recorded in the standard mode, the output signal of the BPF 2 is extracted with a larger amplitude than the BPF 3 and recorded in the high image quality mode. If so, BPF
The output signal of the BPF 3 has a larger amplitude than 2.

Both output signals of the BPFs 2 and 3 are supplied to the rectification and peak hold circuits 4 and 5 in order to avoid the influence of the signal in the video section, and are peak-held after the rectification. The peak hold is not affected by the signal in the video section as the time constant is longer, but the FM signal extracted at the same time has a larger amplitude than it actually is, and as a result, the output of the comparator 8 described below is inverted. On the contrary, under such conditions, the time required for recovery will be longer, so an appropriate time constant should be selected in consideration of both factors.

The output signals of the rectification and peak hold circuits 4 and 5 are supplied to low pass filters (hereinafter referred to as LPF) 6 and 7.
This is because the rotary head scans a plurality of tracks in sequence during special playback such as during search or still, so that a track recorded by a rotary head with an azimuth angle different from that of the rotary head being played (so-called reverse track). This is because the amplitude of the reproduced FM luminance signal may be greatly reduced during the period of scanning) and malfunction may occur.

The LPF 6 constitutes another detection circuit together with the rectification and peak hold circuit 4, and the LPF 7 constitutes the second detection circuit together with the rectification and peak hold circuit 5.

The envelope detection signals extracted from the LPFs 6 and 7 are respectively supplied to the comparator 8 where they are compared in level.
That is, the comparator 8 compares the envelope levels of the carrier frequency components of the two modes obtained from the reproduced FM luminance signal, and when the reproduced FM luminance signal is recorded in the standard mode, the first logical level is obtained. If the image is recorded in the high image quality mode, a mode discrimination signal having the second logic level is generated and output to the output terminal 9.

When the amplitudes of the FM signals output from both BPFs 2 and 3 are substantially equal and the amplitudes are not stable due to noise or the like,
The output signal of the comparator 8 reciprocates between the first logic level and the second logic level at high speed, so-called chattering may occur, and the screen may be difficult to see. In consideration of such a case, the comparator 8 may be provided with a known hysteresis characteristic by a known means.

Next, a second embodiment of the device of the present invention will be described.

This embodiment is an example in which only one BPF is used.
The same components as those in the figure are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 2, the output signal of the LPF 6 is supplied to the comparator 10, where it is compared in level with the reference voltage from the reference voltage source 11. When the input reproduction FM luminance signal is recorded in the standard mode, the output signal of the LPF 6 becomes larger than the reference voltage, while when it is recorded in the high image quality mode, it becomes smaller than the reference voltage. The reference voltage from the voltage source 11 is preset.

Therefore, from the comparator 10 to the output terminal 9, the LPF
A mode discrimination signal is output by comparing the level of the output signal of 6 and the reference voltage from the reference voltage source 11. In addition, BP
Of course, BPF3 may be used instead of F2.

Next, a third embodiment of the device of the present invention will be described with reference to FIG. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 3, the input terminal 1
The reproduced FM luminance signal is supplied to the BPFs 2 and 3 while being supplied to the demodulation circuit 13. BPF 2 and 3
Both output signals of are respectively supplied to the detection circuits 14 and 15,
The envelope is detected here. The detection circuit 14 is a circuit including the rectification and peak hold circuit 4 and the LPF 6 shown in FIG. 1, and the detection circuit 15 is a circuit including the rectification and peak hold circuit 5 and the LPF 7.

On the other hand, the demodulation circuit 13 is composed of a standard mode FM demodulation circuit, a high image quality mode FM demodulation circuit, and a switch circuit for switching the outputs of both FM demodulation circuits, as shown in FIG. The reproduced luminance signal obtained by demodulating and reproducing in either mode is output to the output terminal 16. This reproduction luminance signal is also supplied to the sampling pulse generating circuit 17 shown in FIG. 3, and here, for example, based on the reproduction horizontal synchronizing signal, a sampling pulse which has a predetermined level only during the horizontal blanking period and the vertical blanking period. Generate.

This sampling pulse is simultaneously supplied to sample hold circuits (hereinafter referred to as S / H circuits for convenience) 18 and 19, respectively. Here, in the detection signals from the detection circuits 14 and 15, the horizontal blanking period and the vertical blanking period are eliminated. The signal level of the period is sampled and held. Therefore, the reproduction FM
If the luminance signal was recorded in standard mode, S / H
The output signal of the circuit 18 is at the carrier frequency corresponding to the sync tip level and the pedestal level in the standard mode, and is the detection signal in the sync tip level and the pedestal level transmission section.
The output signal of the circuit 19 is the sideband component of the reproduced FM luminance signal in the standard mode equal to the carrier frequency corresponding to the sync tip level and the pedestal level in the high image quality mode,
In addition, since it is a detection signal in the sync chip level and pedestal level transmission section, it becomes a small level. When the reproduced FM luminance signal is recorded in the high image quality mode, the level of the output signal of the S / H circuit 19 is S / H contrary to the above.
The level becomes higher than the output signal level of the circuit 18.

The comparator 20 compares the output signal levels of the S / H circuits 18 and 19 with each other, and when the reproduced FM luminance signal is recorded in the standard mode, it is recorded in the first logical level and the high image quality mode. If so, a mode discrimination signal having the second logic level is generated and output to the output terminal 9.

BPF2 and 3 are F in standard mode and high quality mode, respectively.
Since the carrier frequency of the M luminance signal is separated over the entire signal section, the output detection signal level of the detection circuits 14 and 15 becomes lower in the video section than in the blanking period. By devising the circuit configuration of the detection circuits 14 and 15, the influence of the decrease in the detection signal level in this video section can be reduced, but in this case, as in the first and second embodiments,
For example, when the mode switching is performed because the signal section recorded in the standard mode and the signal section recorded in the high image quality mode are adjacent to each other on the same magnetic tape, the switching response speed becomes slow.

Therefore, according to the present embodiment, only the detection signal levels in the horizontal and vertical blanking periods, which can take only two values of the pedestal level and the sync tip level, are sampled and held, and the levels are compared. A clear level comparison result can be stably obtained, and the switching response speed can be increased. Further, the circuit can be easily integrated into an IC, which leads to cost reduction.

Next, a fourth embodiment of the device of the present invention will be described with reference to FIG. In the figure, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, the detection signals of the detection circuits 14 and 15 are level-compared by the comparator 21, and only the signal levels of the output signals of the horizontal and vertical blanking periods are sampled and held by the S / H circuit 22. It is said that.

According to the present embodiment, the mode discrimination operation equivalent to that of the first embodiment can be performed with the configuration having one less S / H circuit than the first embodiment.

Further, as the S / H circuit 22, a D flip-flop or the like in which the output signal of the comparator 21 is applied to its data input terminal and the output signal of the sampling pulse generating circuit 17 is applied to its clock input terminal is used. You may In this case, since the mode discrimination signal can be obtained by the digital circuit, the circuit configuration is most suitable for IC.

Next, a fifth embodiment of the device of the present invention will be described with reference to FIG. In the figure, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 5, the comparator 24 compares the level of the output signal of the S / H circuit 18 with the first reference voltage from the reference voltage source 25. The comparator 26 compares the level of the output signal of the S / H circuit 19 with the second reference voltage from the reference voltage source 27. Accordingly, when the input reproduction FM luminance signal is recorded in the standard mode, the output signal level of the S / H circuit 18 becomes higher than the first reference voltage, and the output signal of the comparator 24 becomes high level. Moreover, since the output signal level of the S / H circuit 19 becomes lower than the second reference voltage, the output signal of the comparator 26 becomes low level (hereinafter, the output state of such comparators 24, 26 will be H
/ L). On the other hand, when the image is recorded in the high image quality mode, the output signal of the comparator 24 is low level and the output signal of the comparator 26 is high level (hereinafter, the output state of the comparators 24 and 26 is L
/ H).

The respective output signals of the comparators 20, 24 and 26 are supplied to the discrimination matrix circuit 28. The discrimination matrix circuit 28 outputs a signal of a predetermined level to the output terminal 9 as a discrimination signal from the combination of the logical levels of the above three input signals. The output signals of the comparators 24, 26 and 20, and the discrimination matrix circuit 28 are summarized in the following table.

However, x: any H / L: H or L output As can be seen from the above table, when the output logic levels of the comparators 24 and 26 are different from each other, the comparator 2
The output signal of the discrimination matrix circuit 28 is a signal of the same logic level as the output signal of the comparator 24 regardless of the output of 0. On the other hand, when both the output signals of the comparators 24 and 26 are at the same logic level, the discrimination matrix circuit 28 follows the output signal of the comparator 20 and selects one of the output signals of the S / H circuits 18 and 19 whichever has the higher level. The discrimination signal of is output.

According to the present embodiment, the two-frequency component equal to the carrier frequency of the FM luminance signal specified in the two modes,
In addition, two types of detection information obtained by comparing the envelope level of only the sync tip level and pedestal level transmission section with the reference voltage, and further the above two frequency components, the envelope level of the sync tip level and pedestal level transmission section. Since the detection information from the comparator 20 for detecting the magnitude relation of (1) is added to determine the mode, the more stable mode determination can be performed as compared with each embodiment.

Although the S / H circuits 18 and 19 are provided on the input sides of the comparators 20, 24 and 26 in the embodiment shown in FIG. 5, a single matrix is provided on the output side of the discrimination matrix circuit 28. An S / H circuit may be provided. Further, the comparator 20 may not be provided, and the discrimination matrix circuit 28 may be configured to discriminate the mode from both output signals of the comparators 24 and 26.

Next, a reproducing system of a two-head helical scan type VTR having the above mode discriminating device will be described with reference to FIG. In the figure, the frequency division multiplexed signal of the FM luminance signal and the low frequency conversion carrier color signal recorded on the magnetic tape 30 is
It is alternately reproduced by the rotary heads 31 and 32, and is supplied to a switch circuit 35 which is switched by a head switching pulse of a two-field cycle from a terminal 36 through preamplifiers 33 and 34, where a post high-pass filter (continuous signal) is generated. Hereinafter referred to as HPF) 37 and LPF
53. The reproduced FM luminance signal separated by the HPF 37 is separately supplied to the switch circuit 40 through the equalizer circuit 38 in the standard mode and the equalizer circuit 39 in the high image quality mode.
It is supplied to the limiter 42 and the mode discrimination device 43 according to the present invention via 1.

Limiter 43, FM demodulators 44, 47, LPF 45, 4
8, the de-emphasis circuits 46 and 49 and the switch circuit 50 constitute the demodulation circuit 13 shown in FIGS. 1 to 5. Further, the mode discriminating circuit 43 is shown in FIGS.
In the mode discriminating device of each embodiment shown in the drawings, the reproduced FM luminance signal from the AGC circuit 41 is supplied to the input terminal 1 in the circuit except the demodulation circuit 13, and the switch circuit 5
The output reproduction luminance signal of 0 is supplied to the sampling pulse generating circuit 17 provided therein.

Reproduced FM from which the amplitude fluctuation component is removed by the limiter 42
The luminance signal is a standard mode reproduction system FM demodulator 44, LP.
While being supplied to the switch circuit 50 via the F45 and the de-emphasis circuit 46, it is supplied to the switch circuit 50 via the FM demodulator 47 of the high image quality mode reproducing system, the LPF 48 and the de-emphasis circuit 49.

On the other hand, as described above, the reproduction F
The mode discriminating signal obtained by automatically discriminating whether the M luminance signal is recorded in the standard mode or the high image quality mode is supplied to the system controller 51, and is further supplied to the switch circuits 40 and 50 as a switching pulse. Supplied. As a result, the switch circuits 40 and 5
0 is connected to the terminal A side in the standard mode determination, and is switched and connected to the terminal B side in the high image quality mode determination.

Further, the reproduction signal extracted from the switch circuit 35 is separated into the low-frequency conversion carrier color signal by the LPF 53, and thereafter the reproduction chroma processing circuit 54 removes the jitter by a known means and the original band. Is returned to the reproduced carrier color signal. The adder circuit 52 adds this reproduction carrier color signal,
The reproduction luminance signal reproduced and demodulated by the reproduction system of the same mode as that at the time of recording, which is taken out from the switch circuit 50, is added and combined and output to the output terminal 55 as a reproduction color video signal.

It should be noted that the present invention is not limited to the above-described embodiment, and even when there are three or more recording / reproducing modes, the mode determination can be performed in the same manner as above. Further, it goes without saying that the signal section to be sampled and held may be only one of the horizontal blanking period and the vertical blanking period.

EFFECTS OF THE INVENTION As described above, according to the invention described in the first aspect, it is possible to automatically discriminate which mode among a plurality of modes is recorded, based on the reproduced video signal. There is no need to switch the manual switch like this, the usability can be improved, the user will not be mistaken for a failure, and the sync chip that does not change depending on the pattern in the video signal and always exists in a predetermined cycle. Since the energy of the frequency band including the carrier frequency corresponding to both the level and the pedestal level is extracted and the mode determination is performed based on the extraction result, there is a feature that the mode determination can be surely performed.

Further, according to the invention described in claims 2 to 5, in addition to the above-mentioned features, the pass band characteristic of the filter circuit separates only the carrier frequency corresponding to the pedestal level or the sync tip level. Since it has a wider band than the band characteristic, it is not easily affected by the variations in the passive elements that make up the filter circuit and is suitable for mass production.
The carrier frequency of each mode is detected after the separated wave, and the discrimination information is obtained by using the signal obtained by sample-holding the detection signal level in both the horizontal and vertical blanking periods or only in one period. In this case, it is possible to obtain the output of the sample and hold circuit that clearly identifies the mode, and the response speed at the time of mode switching compared to when using a detection circuit configured to correct the decrease in the detection output level in the video section. It is possible to quickly output an accurate mode discrimination signal without spoiling the signal, and because the sampling pulse generator circuit can be built into an integrated circuit, it has many advantages such as cost advantages. is there.

[Brief description of drawings]

1 to 5 are block system diagrams showing respective embodiments of the device of the present invention, FIG. 6 is a diagram showing a video signal waveform, and FIG. 7 is a frequency spectrum of an FM signal in a standard mode and a high image quality mode. Each of the figures and FIG. 8 is a block system diagram showing an example of an apparatus to which the method of the present invention is applied or a video signal reproducing apparatus having the apparatus of the present invention. 1 ... Reproduction FM luminance signal input terminal, 2, 3 ... Bandpass filter (BPF), 4, 5 ... Rectification and peak hold circuit,
6, 7 ... Low-pass filter (LPF), 8, 10, 20, 2
1 ... Comparator, 9 ... Mode discrimination signal output terminal, 11
... Reference voltage source, 13 ... Demodulation circuit, 14, 15 ... Detection circuit, 17 ... Sampling pulse generation circuit, 18, 19,
22 ... Sample hold circuit (S / H circuit), 43 ... Mode discrimination circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Isobe 3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Japan Victor Company of Japan (72) Inventor Masahiko Tsuruta 3--12 Moriya-cho, Kanagawa-ku, Yokohama Address inside Victor Company of Japan, Ltd.

Claims (5)

[Claims] 1. A method for discriminating n types (n is an integer of 2 or more) of different carrier frequencies of a frequency-modulated video signal, wherein the frequency-modulated video signal is recorded in one mode. Is reproduced to extract the energy of the frequency band including the carrier frequency corresponding to both the sync tip level and the pedestal level of the reproduced frequency-modulated video signal, and the reproduced frequency-modulated video signal is extracted based on the extraction result. The method for discriminating the recording mode of the reproduced video signal is characterized by discriminating the recording mode. 2. A recording medium on which a frequency-modulated video signal is recorded is reproduced in one of n types (n is an integer of 2 or more) of different carrier frequencies of the frequency-modulated video signal. The obtained reproduced frequency-modulated video signal is supplied, and signals in a frequency range including at least carrier frequencies corresponding to at least a sync tip level and a pedestal level of each frequency-modulated video signal of the n types of modes are separately passed. n bandpass filters and each output signal of the n bandpass filters are provided separately,
A total of n detection circuits that detect the envelope, the results obtained by comparing the signal levels of the output detection signals of the n detection circuits, and the detection signal and a preset reference level. And a reproduction mode signal recording mode determination signal based on at least one of the results obtained by comparing apparatus. 3. The means for outputting the discriminating signal of the recording mode is a detection signal level in a horizontal blanking period and / or a vertical blanking period among the output detection signals of the detection circuit. 3. The recording mode discriminating apparatus for the reproduced video signal according to claim 2, wherein the levels are compared with each other. 4. A reproduced frequency-modulated video obtained by reproducing a recording medium on which the frequency-modulated video signal is recorded in one of two modes in which the carrier frequencies of the frequency-modulated video signal are different from each other. A single signal is supplied to pass a signal in a frequency range including both carrier frequencies corresponding to at least a sync tip level and a pedestal level of a frequency-modulated video signal in one of the two modes set in advance. The result obtained by comparing the level of the bandpass filter, the detection circuit that is supplied with the output signal of the bandpass filter and detects the envelope, and the signal level of the output detection signal of the detection circuit and the preset reference level. Recording of the reproduced video signal, which comprises means for outputting a discrimination signal of the recording mode of the reproduced frequency-modulated video signal based on Over de discrimination device. 5. A means for outputting the discriminating signal of the recording mode indicates a detection signal level of a horizontal blanking period and / or a vertical blanking period of the detection signal output from the detection circuit. The recording mode discrimination device for reproducing video signals according to claim 4, wherein the levels are compared.