JPH08331528A - Signal discrimination method and signal discrimination device - Google Patents

Abstract

PURPOSE: To surely discriminate identification information with respect to a received video signal by providing a detection means detecting an image format signal and/or an identification signal of a broadcast system and counting the detection signal so as to secure a format of an image. CONSTITUTION: A signal discrimination device 1 is made up of a slicer 20 and a control microcomputer 30. The control microcomputer 30 outputs a setting data signal such as a horizontal line position on which an identification control signal of an EDTV 2 or a video ID are superimposed, a slice level and a sampling frequency to the slicer 20 as an output and a slice data signal in response to the setting data signal is received from the slicer 20. Furthermore, discrimination counters 30a, 30b added to the control microcomputer 30 are e.g. 4-bit counters and a hysteresis characteristic is provided to count the detection signal received from the slicer 20 so as to identify the video ID or EDTV 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal discriminating method and a signal discriminating apparatus for discriminating image format information superimposed on a vertical blanking period of a video signal and identification information of a broadcasting system.

[0002]

2. Description of the Related Art Current television systems (NTSC, P
EDTV (Extended Definition Televisio) that achieves high quality while maintaining compatibility with AL, SECAM, etc.
Various types of n) have been developed, and in recent years, main broadcasting of the second generation EDTV (hereinafter referred to as “EDTV2”) system is about to start.

The EDTV2 system is a horizontal line in the vertical blanking period of a video signal for improving image quality.
The presence / absence of the horizontal / vertical resolution enhancement signal, the aspect information of the image, and the like are transmitted as the identification control signal by using the line and the 285 line. Some have an aspect ratio of 16: 9 and a number of scanning lines of 525. When the video signal of EDTV2 is received by an existing television receiver (aspect ratio 4: 3), black bands appear at the top and bottom of the screen. It becomes a so-called letter box screen.

FIG. 8 shows an example of the identification control signal waveform of the EDTV 2 superimposed in the vertical blanking period of the video signal. As shown in this figure, the identification control signal of the EDTV 2 is a horizontal sync signal H.SYNC, a color burst signal CB, and a non-return zero waveform (hereinafter referred to as “NRZ waveform” (No.
n Return to Zero) signal (1 to 5 bits) is transmitted, followed by the color burst signal CB.
An identification signal (6 bits to 23 bits) having a frequency of 3.58 MHz is transmitted by the same color subcarrier f _SC as the above, and the identification signal is identified by the phase difference from the color burst signal CB. . Further on, EDTV2
The frequency indicating the identification control signal is 2.04MHz (4
/ 7f _SC ) sine wave signal for confirmation (25 bits to 2)
7 bits) are transmitted.

FIG. 9 shows an example of the contents and status of the identification control signal of the EDTV 2 described above. As shown in this figure, the first bit (B1) and the second bit (B1)
2) is a reference timing signal, the third bit to the first
The 7 bits (B3 to B17) are used as aspect information and identification information indicating the presence / absence of the horizontal / vertical resolution enhancement signal, and the 18th to 23rd bits (B18 to B23).
Up to 6 bits are error correction (hereinafter, “CRC” (Cyclic Redundanc) for detecting a bit error or correcting a code.
yCheck)) code. Furthermore, the 25th
Bits to 27th bits (B25 to B27) are sine wave signals for confirmation indicating that the identification control signal is superimposed in order to prevent erroneous detection with the video signal.

The fifth bit (B5) and the 12th to 17th bits (B12 to B17) are undefined bits "0". In addition, the 1st bit to the 5th bit (B1 to B5) and the 24th bit (B24) surrounded by the chain line are N
The signal of the RZ waveform is shown.

On the other hand, in addition to the above-mentioned EDTV2 broadcasting, in a package medium such as movie software, video I is used as image format information such as aspect information.
D (Video ID) has already been standardized (EIAJ CPX-1204), and this video ID uses the horizontal line of the vertical blanking period to transmit identification information such as aspect information, as in the EDTV2 system. The horizontal line positions that are overlapped are 20 lines and 283 lines.

FIG. 10 shows an example of the video ID signal waveform. As shown in this figure, the video ID signal is a horizontal sync signal.
Following H.SYNC and color burst signal CB, reference signal Ref of NRZ waveform and identification information (1 bit to 2
0 bit) is transmitted.

The identification contents of such a video ID are shown in FIG.
Shown in The video ID is WORD0 composed of 2 bits and WOR composed of 4 bits as shown in FIG.
It is formed by D1, WORD2 composed of 8 bits, and a CRC code of 6 bits. And WORD0
(Bit1, bit2) is identification information relating to the transmission format of the video signal, WORD1 (bit3 to bit6) is header information that specifies information transmitted by WORD2 described later, and WORD2 (bit7 to bit14) is WOR
The data information is designated by D1, and CRC (bit1
5 to 20) are CRC codes for error correction.

Also, bit1 which is WORD0 is shown in FIG.
As shown in 1 (b), it is used as identification information of the transmission aspect ratio. For example, when the status is "1", the full mode (1
6: 9), and when the status is “0”, it indicates normal (4: 3). Also, bit2 is identification information indicating the display format of the image, and the status is "1", for example.
Is displayed as a letterbox screen, the status is "0"
At that time, the normal screen is displayed.

[0011]

By the way, as described above, although the transmission method of aspect information and the like in the package media and the like has already been standardized as the video ID, at this stage the main broadcasting by the EDTV2 method is not performed. Therefore, from video signal to video ID or EDTV2
No decoder has been developed for discriminating the identification control signal of No. 1 and decoding the aspect information or the like.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and relates to the image format information and / or the broadcasting system which are superimposed on predetermined horizontal line positions in the vertical blanking period. A detection unit capable of detecting the identification information, and a setting data signal of a horizontal line position, a sampling frequency, and a slice level are supplied to the detection unit, and the detection unit increases / decreases in accordance with the sampling signal of the image format information. And a control means having a second counter that increases / decreases in accordance with a sampling signal of broadcast system identification information, and is configured to preferentially output image format information. did.

[0013]

According to the present invention, the image format signal and the identification signal of the broadcasting system are detected, the detection signal is counted, and the format is determined by this count value. Therefore, the identification information for the input video signal is obtained. Can be reliably determined.

Since the image format signal is preferentially output, the screen can be switched to the optimum state even when both the image format signal and the broadcast system identification signal are present.

[0015]

EXAMPLES Hereinafter, as examples of the present invention, UVIC (Univ
ersal VBI Intelligent Controller) will be described. FIG. 1 shows the UV of this embodiment.
It is a figure showing an example of composition of a signal discriminating device using IC,
The signal discrimination device 1 is composed of a slicer 20 and a control microcomputer (hereinafter, referred to as “control microcomputer”) 30.

The slicer 20 samples the identification control signal of the EDTV 2 or the video ID superimposed on a predetermined horizontal line position in the vertical blanking period at a predetermined sampling frequency, and sets the sampling data to a predetermined slice level. This is a decoder that compares and decodes.

The control microcomputer 30 outputs, to the slicer 20, setting data signals such as a video ID or a horizontal line position on which the identification control signal of the EDTV 2 is superimposed, a slice level, and a sampling frequency, and is set from the slicer 20. A slice data signal corresponding to the data signal is supplied.

Further, the judgment counters 30a and 30b added to the control microcomputer 30 are, for example, 4-bit counters, and count detection signals supplied from the slicer 20 with a hysteresis characteristic, which will be described later.
The video ID or the identification control signal of the EDTV 2 is discriminated.

The decodable horizontal line positions of the signal discriminating apparatus 1 of this embodiment are 7 to 28 lines,
The frequency that can be sampled is in the range of 500 kHz to 6 MHz. Further, the setting data signal is transmitted between the slicer 20 and the control microcomputer 30 once per field.

Hereinafter, a method of decoding the video ID and the identification control signal of the EDTV 2 in the signal discriminating apparatus 1 configured as described above will be described. First, when decoding the video ID, the control microcomputer 30 sends the video ID
The setting data signal specifying the horizontal line position (20 lines) on which is superimposed, the setting data signal of the slice level, and the setting data signal of the sampling frequency (f _SC ) are output to the slicer 20, and as a result, the slicer 20 receives the input. The position of the horizontal line on which the video ID signal is superimposed is specified based on the set data signal, and the video signal is sampled at the sampling frequency f _SC .

At this time, the slicer 20 is controlled so as to sample 8 points for 1 bit of the video ID, and the reference signal Ref of the video ID is sampled (8 points) as shown in FIG. Compared with a predetermined slice level, "1" (High
It is output to the control microcomputer 30 as a slice data signal of h) or “0” (Low).

The control microcomputer 30 is the slicer 20.
It is determined that the reference signal Ref of the video ID is present if "1" of the 8-point slice data signal supplied from is, for example, 6 points or more, and that the reference signal Ref is not present if it is 3 points or less. It is done like this.

By the way, the presence / absence of the video ID can be determined by the presence / absence of the reference signal Ref. However, in order to prevent erroneous determination from a video signal having a similar waveform, the signal discriminating apparatus 1 further uses the slicer 20 to perform CRC. A code (14 bits to 20 bits) is sampled and output to the control microcomputer 30. That is, the control microcomputer 30 uses the reference signal Re
When f is present and the CRC code is OK, it is determined that the video ID is present.

Further, when the signal discriminating apparatus 1 judges that the video ID exists, the value of the judgment counter 30a added to the control microcomputer 30 is incremented by 1 as shown in FIG. As shown in FIG. 3, when the value of the counter 30a increases and the counter value becomes "8", the judgment counter 30a has the judgment counter 3a.
It has a hysteresis characteristic such that the counter value of 0a is skipped to "15".

On the other hand, the reference signal Ref of the video ID
, Or the reference signal Ref is present but the CRC code is NG, the determination counter 30 added to the control microcomputer 30
The value of a is decreased by one. As a result, when the value of the determination counter 30a decreases and the counter value becomes "7", the counter value of the determination counter 30a becomes "0".
I'm trying to fly to.

That is, in the signal discriminating apparatus 1, the video ID is not displayed until the counter value of the determination counter 30a attached to the control microcomputer 30 becomes "15".
This video ID is judged as the format of
Therefore, for example, identification information such as aspect information is determined. This prevents the aspect ratio of the screen from becoming unstable near the switching of the video ID format.

On the other hand, when the identification control signal of the EDTV2 is to be decoded, the control microcomputer 30 sends it to the EDTV2.
The horizontal line position (22
The setting data signal for specifying the line), the setting data signal for the slice level, and the setting data signal for the sampling frequency (f _SC ) are output to the slicer 20. As a result, the slicer 20 outputs the ED based on the input setting data signal.
The horizontal line position on which the identification control signal of the TV 2 is superimposed is specified, and the video signal is sampled at the sampling frequency f _SC .

At this time, the slicer 20 performs sampling of 7 points for 1 bit of the NRZ waveform signal (B1 to B5) as shown in FIG. 4A, and compares this sampling signal with a predetermined slice level. And then "1"
A slice data signal of (High) or “0” (Low) is output to the control microcomputer 30.

Then, the control microcomputer 30 judges that the NZR waveform signal is "High" if "1" is 5 points or more among the 7-point slice data signals input from the slicer 20, and if it is 3 points or less. Determines that the NRZ waveform signal is "Low". Therefore, the reference signal (B
If the first bit (1, B2) is "High" and the second bit is "Low", it is determined that the reference signal is present.

Normally, when the presence or absence of the identification control signal of the EDTV 2 is detected to determine the aspect information, the NRZ waveform signals (B1 to B1) of the identification control signal of the EDTV 2 shown in FIG.
5) only needs to be detected, but the signal discriminating apparatus 1 eliminates erroneous discrimination.
7) is also detected.

This confirmation sine wave signal (B25 to B2)
When detecting 7), the control microcomputer 30 supplies to the slicer 20 a setting data signal having a sampling frequency of (8 f _SC / 7), for example.
This is because if the sine wave signal for confirmation exists when the sampling frequency (8f _SC / 7) is twice the frequency (4.08MHz) with respect to the frequency of this sine wave signal for confirmation.
This is to obtain an 8-point inverted data string as sampling data for 1 bit as shown in (b).

Therefore, the second sine wave signal for confirmation is used.
A 24-bit inverted data string is output as a slice data signal from the 3 bits from the 5th bit to the 27th bit to the control microcomputer 30, and the control microcomputer 30 outputs the 24-bit slice data signal 15 times or more, for example. If is alternately inverted, it is determined that the confirmation sine wave signal exists.

By the way, the signal discriminating apparatus 1 is formed by simplifying the circuit configuration and transmitting the signal of the setting data between the slicer 20 and the control microcomputer 30 once per field as described above. , Data signals of the same line cannot be detected simultaneously at different sampling frequencies.

Therefore, the NRZ waveform signal of the identification control signal is set to a 4-field sequence in which 2 fields and the sine wave signal for confirmation are sampled in 2 fields, and the reference signal and the sine wave signal for confirmation are used as the NRZ waveform signal. The identification control signal of the EDTV 2 is judged to be present only when two fields are continuously present.

Furthermore, the signal discriminating apparatus 1 of this embodiment is an ED.
If it is determined that the identification control signal of the TV 2 is present, FIG.
The value of the counter 30b added to the control microcomputer 30 shown in FIG.
When the counter value of 0b is increased to "8", the judgment counter 30b has a hysteresis characteristic of skipping the counter value to "15".

On the other hand, when the reference signal and the sine wave signal for confirmation do not exist in two consecutive fields,
The value of the judgment counter 30b is decreased by one. As a result, when the counter value of the determination counter 30b decreases to "7", the counter value of the determination counter 30b is skipped to "0".

That is, the identification information such as aspect information is discriminated from the identification control signal of the EDTV 2 only when the counter value of the determination counter 30b becomes "15" and it is confirmed that the format is the EDTV 2. When the format of EDTV2 is switched,
The aspect ratio of the screen is prevented from becoming unstable in the vicinity of this switching.

Next, the procedure from the identification control signal of the EDTV 2 and the video ID in the signal discriminating apparatus 1 to discriminating aspect information, for example, will be described with reference to the flowchart shown in FIG. First, in step F101, it is determined whether or not a video ID exists for the video signal input. When the video ID is present, it is determined whether the format is confirmed by the count value of the determination counter, and if the format is confirmed, the aspect information is determined from the video ID (F102, F103). ). If the format of the video ID is not confirmed in step F102, the aspect information is determined to be normal (F104).

On the other hand, if the video ID does not exist in step F101, it is judged whether or not the identification control signal of the EDTV 2 exists (F105). Then, if the identification control signal of the EDTV2 exists, it is determined whether or not the format is determined by the determination counter of the identification control signal of the EDTV2, and if the format is determined, the EDTV2
The aspect information is discriminated from the discrimination control signal of (F106, F107). Also, in step F106, EDTV
If the format 2 is not confirmed, the aspect information is determined to be normal (F108).

Then, in step F109, if the aspect information matches four times or more consecutively regardless of the video ID or the identification control signal of the EDTV 2, the determined aspect information is newly output (F109, F11
0). On the other hand, if the aspect information does not match four times or more continuously in step F109, the aspect information that has been output up to that point is output as it is (F11.
1).

Therefore, by configuring the signal discriminating apparatus 1 in this way, it becomes possible to discriminate aspect information and the like from the input video signal irrespective of the signal system such as the video ID and the identification control signal of the EDTV 2. , It becomes possible to easily switch to the optimum screen mode.

Further, for example, after recording a program to which the identification control signal of the EDTV 2 is transmitted by a video data precoder,
If the video ID is added by the video tape recorder for playback when dubbing the tape, the video ID and E
It is conceivable that the identification control signal of the DTV 2 is transmitted at the same time.

In this case, both the video ID and the identification control signal of the EDTV 2 exist, but the signal discriminating apparatus 1 of this embodiment preferentially outputs the aspect information of the video ID as described above. There is. This is because the aspect information of the added video ID reflects the aspect information of the EDTV 2, and if the aspect information of the video ID is prioritized and discriminated, the optimum screen mode can be always set.

In this embodiment, in order to determine whether the signal is the identification control signal of the EDTV 2, the NRZ waveform signal (1st bit to 5th bit) and the sine wave signal for confirmation (25th bit to 27th bit). The discrimination control signal is discriminated by detecting the bit data of 4), but the discrimination control signal may be discriminated by also detecting the bit data of the 6th to 23rd bits.

By the way, the signal discriminating apparatus 1 as shown in FIG. 1 can be applied to, for example, an identification signal decoding apparatus previously proposed by the present applicant, and FIG. 6 shows an example of a block diagram. In this figure, a terminal 2 receives, for example, a television receiver or VTR (not shown), or a composite video signal such as a cable television signal. The low-pass filter 3 removes unnecessary high frequency components included in the identification control signal, and the trap circuit 4 is provided to remove the influence of a ghost due to the burst signal when decoding the NRZ waveform signal of the identification control signal. ing. The band pass filter 5 is provided to remove interference due to a weak electric field, a ghost, a video signal, or the like when decoding the sine wave signal (4/7 f _C ) for confirmation of the identification control signal.

The sync separation circuit 6 separates the vertical sync signal V _S and the horizontal sync signal H _S from the identification control signal from which unnecessary high frequency components are removed by the low pass filter 3. The timing control circuit 7 is controlled by the control microcomputer 30 to generate the timing control signals S _{1 to} S ₄ having a predetermined timing cycle, and the clock generation circuit 8 determines a predetermined timing based on the horizontal synchronizing signal H _S and the timing control signal S _1. The sampling clock CLK having the cycle of is generated. The switches SW1 and SW2 are switching-controlled in conjunction with each other at a predetermined timing by a timing control signal S ₂ from the timing control circuit 7.

The pedestal clamp circuit 9 is supplied with the clamp voltage V _CL and the timing control signal S ₂ so that the identification control signal input through the switch SW1 can be accurately sliced by the data detector 10. For example, only pedestal level is clamped.

The switch SW3 is a timing control signal S ₄
The switching control is performed by the contact control circuit, and the pedestal clamp circuit 9 supplies the data signal in the predetermined section of the identification control signal to the data detection unit 10 while the pedestal clamp circuit 9 is connected to the contact a only for a predetermined period. And masking voltage V _m
Is supplied to the data detection unit 10.

The data detector 10 includes a comparator 10a,
And a D flip-flop circuit 10b, and the comparator 10a outputs a signal in a predetermined bit section input through the switch SW3, for example, an identification signal (B of the NRZ waveform).
1 to B5) or a sine wave signal for confirmation (B25 to B5)
27) is compared with a predetermined slice potential V _S1 or slice potential V _S2 , converted into a digital signal, and supplied to the D flip-flop circuit 10b. The D flip-flop circuit 10b samples the digital signal with the sampling clock CLK generated by the clock generation circuit 8.

The shift register 11 temporarily stores the input sampling data and then outputs it to the slice data signal control microcomputer 30. The control microcomputer 30 receives E from the input slice data signal.
Whether or not it is the identification control signal of the DTV 2 or the video ID is determined, and if it is determined as the video ID, for example, the bit data of the aspect information of the video signal is extracted and the microcomputer of the television receiver main body (not shown) is extracted. As a result, the aspect ratio of the television receiver is controlled.

Therefore, the control microcomputer 30 determines the predetermined sampling frequency, slice level,
It is possible to easily determine the video ID or the identification control signal of the EDTV 2 by outputting the setting data signal of the horizontal line position to the timing control circuit 7 and counting the supplied data signal to make the determination.

Also, for example, the EDTV 2 as shown in FIG.
It is possible to apply the signal discriminating method of the present invention to the signal discriminating apparatus recommended for decoding the discrimination control signal. The signal discriminating apparatus shown in FIG. 7 specifies a predetermined horizontal line position in the vertical blanking period in which the video ID and the identification control signal of the EDTV 2 are superimposed, and the bit position of the identification control signal, which are not shown. Therefore, the vertical sync signal and the horizontal sync signal can be input, and the color subcarrier signal f _SC is input.
It is assumed that the color subcarrier signal f _SC is input in order to demodulate and to detect the sampling timing.

In this figure, a video ID extracted from a predetermined horizontal line position in the vertical blanking period by a pre-stage circuit (not shown) or an identification control signal of the EDTV 2 is input to the terminal 40, and this identification control signal is It is input to the identification signal decoding unit 50 and the video signal determination unit 70.

Video I input to the identification signal decoding unit 50
The identification control signal of the D or EDTV 2 is further input to the NRZ signal decoding unit 51 and the carrier signal decoding unit 52. The identification control signal supplied to the video signal determination unit 70 is further input to the confirmation signal determination unit 71 and the carrier signal determination unit 72.

The video ID or the identification control signal of the EDTV 2 input to the NRZ signal decoding unit 51 is input to the low pass filter 61 and the high pass filter 62, respectively. The low-frequency component (~ 0.5 MHz) signal D ₁ output from the low-pass filter 61 is an NRZ waveform signal (B1-B).
The data signal of 5) is used. As shown in the figure, this data signal is compared with a predetermined slice level A in a threshold circuit 63, converted into a digital signal and supplied to the shift register 53.

Signals of high frequency components (0.5 MHz to) other than the data signal output from the high pass filter 62 are input to the threshold circuit 65 via the absolute value conversion / smoothing circuit 64. Then, it is converted into a digital signal by the threshold circuit 65,
The inverted output is input to the determination circuit 55.

The video ID or the identification control signal of the EDTV 2 input to the carrier signal decoding unit 52 is also input to the bandpass filter 66.
The signal of the color subcarrier band component (f _SC ) which is the output of is demodulated in the color burst phase in the demodulation circuit 67. This demodulated signal D ₂ is compared with a predetermined slice level B in a threshold circuit 68 as shown in the figure, converted into a digital signal, and its inverted output is supplied to a shift register 53.
Then, the shift register 53 temporarily stores the data signal of the NRZ waveform at the timing cycle of the carrier signal demodulated by the carrier signal decoding unit 52, and then the data signal is supplied to the determination circuit 55 via the error correction circuit 54.

On the other hand, the video ID or the identification control signal of the EDTV 2 input to the confirmation signal determination unit 71 of the video signal determination unit 70 is a bandpass filter (BPF) 81, a band removal filter (BEF) 82, and a lowpass filter (L).
PF) 83 respectively.

The bandpass filter 81 passes the frequency band component (4 / 7f _SC ) of the sine wave signal (25 bits to 27 bits) for confirming the identification control signal of the EDTV 2 and passes the absolute value smoothing circuit 84. It is supplied to the threshold circuit 85 via the. Then, when the confirmation signal reaches the predetermined amplitude level in the threshold circuit 85, the detection signal is supplied to the AND circuit 90. The band elimination filter 82 allows signals other than the band component (4 / 7f _SC ) of the confirmation signal to pass therethrough, and supplies the threshold value circuit 87 via the absolute value conversion / smoothing circuit 86. Then, when the confirmation signal is detected to be equal to or lower than the predetermined amplitude level, the detection signal is supplied to the AND circuit 90.

Further, the low-pass filter 83 passes a signal of a low frequency component (.about.0.5 MHz), which is a data signal,
It is supplied to the threshold circuit 89 via the absolute value conversion / smoothing circuit 88. Then, when the threshold circuit 89 detects that the amplitude level of the data signal is equal to or lower than a predetermined value, the AND circuit 90 is supplied with a detection signal.

That is, when the AND circuit 90 detects the signal of the band component (4 / 7f _SC ) of the confirmation signal, and the signals other than the band component of the confirmation signal and the data signal are not detected, the AND circuit 90 discriminates from the confirmation signal. The OR circuit 73 is discriminated as a control signal.
The discrimination result is output to.

The video ID or the identification control signal of the EDTV 2 input to the carrier signal determination unit 72 is input to the bandpass filter 91 and the band removal filter 92, and the color subcarrier band component output from the bandpass filter 91. The signal (f _SC ) is supplied to the threshold circuit 94 via the absolute value conversion / smoothing circuit 93. Then, the threshold circuit 94
When the color subcarrier signal has a predetermined amplitude or more, the detection signal is supplied to the AND circuit 95.

Signals other than the carrier band component output from the band elimination filter 92 are converted into an absolute value / smoothing circuit 9.
6 is supplied to the threshold circuit 97. Then, when the threshold circuit 97 detects that the color subcarrier signal has a predetermined amplitude or less, the detection signal is supplied to the AND circuit 95 and the determination circuit 55.

The AND circuit 95 determines that it is a carrier signal when the input signal of the color subcarrier band component has a predetermined amplitude or more and the signals other than the color subcarrier band component have a predetermined amplitude or less. The determination result is output to the OR circuit 73. When the detection signal is input from the confirmation signal determination unit 71 or the carrier signal determination unit 72, the OR circuit 73 receives the EDTV.
The discrimination result that the discrimination control signal is No. 2 is output to the discrimination circuit 55.

That is, the determination circuit 55 determines the video ID or the identification control signal of the EDTV 2 from the high frequency component signal supplied from the NRZ signal decoding unit 51 and the low frequency component data signal, and at the same time, the video signal determination unit 70. From the determination result of the confirmation signal and the carrier signal, it is determined whether the signal extracted from the predetermined horizontal line position is the identification control signal of the EDTV 2. Therefore, the determination circuit 5
If there is both the video ID and the identification control signal of the EDTV 2 in 5, the identification information of the video ID may be preferentially output.

[0066]

As described above, the signal discriminating apparatus of the present invention is provided with the detecting means capable of detecting the image format signal and / or the identification signal of the broadcasting system.
Since the image format is determined by counting the detection signals, the identification information for the input video signal can be reliably determined. Further, since the identification information of the image format signal is preferentially output even when both the image format signal and the broadcast system identification control signal are present, for example, the screen mode can always be kept in an optimum state. Like

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a signal discriminating apparatus that is an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a sampling method of the video signal discriminating apparatus in the signal discriminating apparatus of the embodiment.

FIG. 3 is a diagram showing a hysteresis characteristic of a determination counter.

FIG. 4 is a diagram showing an example of a method of sampling identification information and a confirmation signal according to the embodiment.

FIG. 5 is a diagram showing an example of a signal processing sequence of the embodiment.

FIG. 6 is a diagram showing an example of a block diagram of a first signal determination device to which the present invention can be applied.

FIG. 7 is a diagram showing an example of a block diagram of a second signal determination device to which the present invention can be applied.

FIG. 8 is a diagram showing an example of a signal waveform of an identification control signal of the EDTV 2.

FIG. 9 is a diagram showing an example of contents and status of an identification control signal of the EDTV 2.

FIG. 10 is a diagram showing an example of a signal waveform of a video ID.

FIG. 11 is a diagram showing an example of contents and status of a video ID.

[Explanation of symbols]

 1 signal determination device 20 slicer 30 control microcomputer 30a, 30b determination counter

Claims (7)

[Claims] 1. When both the image format signal and the broadcasting system identification signal are superimposed on a predetermined horizontal line position in the vertical blanking period, the format information of the image format signal is preferentially output. A method for discriminating signals. 2. A detecting means capable of detecting an image format signal and / or an identification signal of a broadcasting system, which are respectively superimposed on a predetermined horizontal line position in a vertical blanking period, and a setting data signal is supplied to the detecting means. And a first counter that increases / decreases according to the detection signal sampled from the image format signal, and a second counter that increases / decreases according to the detection signal sampled from the identification signal of the broadcasting system. A signal discriminating apparatus comprising: a control unit having the above-mentioned, and configured to preferentially output the format information of the image format signal. 3. The identification information modulated by a predetermined modulation method and the confirmation signal of a predetermined frequency are sampled as the identification signal of the broadcasting method, and when the identification information and the confirmation signal are both detected, the identification of the broadcasting method is performed. The signal discriminating device according to claim 2, wherein the signal discriminating device is configured to recognize that a signal exists. 4. The detection means outputs a data signal in comparison with the slice level set by the control means when detecting the image format signal and / or the broadcast system identification signal. 2. The signal discrimination device according to 2. 5. The signal discriminating apparatus according to claim 2, wherein the detecting means is configured to sample the identification information of the broadcasting system and the confirmation signal at least twice each. 6. The signal discriminating apparatus according to claim 2, wherein the sampling frequency of the broadcast system identification information and the sampling frequency of the confirmation signal are different. 7. The signal discriminating apparatus according to claim 2, wherein the sampling frequency of the confirmation signal is at least twice as high as the frequency of the confirmation signal.