JPH0799637A - Video signal transmission method - Google Patents

Abstract

PURPOSE:To always reproduce a stable picture of high picture quality. CONSTITUTION:In this video signal transmission method which transmits (transmits and receives) a series of video signals of high definition broadcast having an aspect ratio (16:9) different from that (4:3) of the current broadcast system and has the compatibility with the current system, an effective video area 20A of a specific horizontal line is provided with all of video additional information (for example, signaling bits 20c where various video additional information including discrimination information of the aspect ratio are stored and other reference amplitude information 20d and 20e as video additional information required for amplitude synthesis).

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art FIG. 6 is a diagram for explaining a PALplus reproduced image, FIG. 7 is a diagram for explaining a PALplus encoding basic algorithm, and FIG. 8 is a PALplus.
FIG. 9 is a diagram for explaining the s decoding basic algorithm, and FIG. 9 is a diagram for explaining the operation of the PALplus decoding basic algorithm.

The EDTV is compatible with the current broadcasting system and improves the shortcomings of the current system. And
As one of such technologies, there is a so-called "PALplus" system which aims to widen a screen (an image having an aspect ratio of 16: 9) in addition to improving the image quality of the PAL broadcasting system.

Although PALplus has introduced a wide screen, it can be viewed on an existing TV receiver. Therefore, here, the PALplus is displayed above and below the current screen a1 which is a reduced wide screen original image. The letterbox method is used to generate the widescreen original image a (shown in FIG. 6A) by providing the portions a2 and a3 having no image. However, when the original image a widened by the letterbox method is received by a current TV receiver having an aspect ratio of 4: 3, the same image b (shown in FIG. 6B) is obtained, but the aspect ratio is 16 : 9, a wide-screen image c (shown in FIG. 6 (C)) with deteriorated vertical resolution is obtained.

While PALplus looks similar to current TV receivers, PALplus-capable TV receivers (aspect ratio 16: 9) produce such vertical resolution when receiving images from current TV receivers with an aspect ratio of 16: 9. Is a signal for improving the definition of the wide screen image a1 in the image-free portions a2 and a3 at the top and bottom of the screen based on the above letterbox method (that is, "helper signal"). The encoded video signal in which is superimposed is transmitted.

The PALplus encoding basic algorithm A is shown in FIG. That is, the TV camera 1 capable of capturing a widescreen image (aspect ratio 16: 9) uses a widescreen image signal (625/5).
0/2: 1 system) is output. The wide-screen video signal of 575 effective scanning lines / frame output from the camera 1 is supplied to the vertical low-pass filter 2, where the number of scanning lines is converted (4-3 conversion) and the effective scanning lines 431. The main signal, which is a wide-screen video signal of the book / frame, is output to one input side of the video synthesizing circuit 3. The widescreen video signal output from the camera 1 is supplied to the vertical high-pass filter 4, where the number of scanning lines is converted (4-1 conversion) to obtain a widescreen video signal of 144 effective scanning lines / frame. Then, the AM modulation circuit 5 performs AM modulation with the same frequency signal as the color burst signal, and the level adjustment circuit 6 forms a helper signal adjusted to a small amplitude level (40IREp-p). It is output to the other input side of the video composition circuit 3. The video synthesizing circuit 3 described above outputs an encoded video signal obtained by synthesizing the main signal and the helper signal.

Thus, the video signal encoded as described above is used in the current TV receiver (aspect ratio 4: 3).
, The effective scanning lines are changed from 575 lines to 431 lines, and the full screen d of the main signal in which the vertical resolution is deteriorated can be seen (illustrated in FIG. 6D). In the figure, d2 and d3 are parts without an image in which a helper signal is inserted. In this case, the helper signal is Y / C (not shown) in the TV receiver.
Since it is regarded as a color signal by the separation circuit, it is not noticeable on the screen. The color signal is only for the main screen. Also, when it is supplied to a PALplus compatible TV receiver,
The vertical resolution, whose definition is reinforced by the helper signal, is not deteriorated (has the same effective scanning lines as the 575 effective scanning lines output from the camera 1 and has the same effective scanning lines), and has a high definition. The full screen e of the signal is visible (illustrated in FIG. 6 (E)).

Now, the above-mentioned PALplus-compatible T
A screen e (FIG. 6) having an aspect ratio of 16: 9 is obtained by decoding the above-mentioned encoded video signal by a decoding basic algorithm B shown in FIG. 9 which is built in the V receiver and is passed through a video processing circuit of a known TV receiver. It is needless to say that this algorithm B has a configuration complementary to the encoding basic algorithm A shown in FIG. 7 when receiving the image shown in (E).

Here, the decoding basic algorithm B of PALplus is shown in FIG. That is, when the above-mentioned encoded video signal is supplied (for example, a broadcast signal is received), this signal is branched into the main signal system and the helper signal system, respectively, and the encoded video signal supplied to the main signal system is vertically filtered. The wide-screen video signal f is supplied to the pass filter 10 and inversely converted (3-4 converted) in the number of scanning lines to convert from 431 effective scanning lines to 575 effective scanning lines.
(As shown in FIG. 9A) is output to one input side of the video synthesizing circuit 13. Waveforms f to j shown in FIGS. 9A to 9E respectively represent a screen k (illustrated in FIG. 9F) corresponding to the above-mentioned encoded video signal, and a central portion thereof has a “white” level, The respective level changes in the vertical direction of the screen when the upper and lower parts are set to the “black” level are shown. The encoded video signal supplied to the helper signal system is supplied to the AM demodulation circuit 11 where it is AM demodulated,
It is supplied to the vertical high-pass filter 12 where the number of scanning lines is inversely converted (1-4 conversion) and the wide screen video signal g of 144 effective scanning lines to 575 effective scanning lines (see FIG. 9).
(Shown in (B)) is output to the other input side of the video synthesizing circuit 13. The video synthesizing circuit 13 synthesizes a wide-screen video signal f of 575 effective scanning lines of the main signal system and a wide-screen video signal g of 575 effective scanning lines of the helper signal system to obtain a decoded video signal h (Fig. 9
(Illustrated in (C)) is output.

[0010]

The PAL signal AGC (auto gain control) in the current PAL system TV receiver uses the amplitude level (horizontal sync signal length (horizontal sync signal) of the horizontal sync signal of the video signal. The AGC of the video signal is performed with the reference level "0" IRE to "-40" IRE)) as the reference level.

In the PALplus compatible TV receiver described above, the PAL signal AGC can be used as the main signal AGC. That is, the AGC circuit used here current-amplifies the supplied encoded video signal to perform the above-described scanning line number reverse conversion circuit 10
The error voltage output from the differential amplifier according to the error between the horizontal sync signal reference level and the amplitude level of the horizontal sync signal in the supplied encoded video signal is used as the gain control signal of the VCA circuit to be output to , AGC.

However, in this AGC, the amplitude level of the horizontal synchronizing signal in the supplied encoded video signal is liable to change due to the deterioration of the linearity of the transmission / reception characteristics of the transmission system. , AGC
The amplitude level of the generated video signal also tends to change.

Further, since the helper signal of the PALplus system is modulated with the modulation signal of the same frequency as the color burst signal, the transmission method is different from that of the above-mentioned main signal, and therefore the main signal AGC cannot be used. Therefore, it is necessary to newly obtain the helper signal AGC.

Thus, in the PALplus-compatible TV receiver, a video image is synthesized from the main signal whose level is likely to fluctuate due to the deterioration of the linearity of the transmission / reception characteristics of the transmission system and the helper signal of the amplitude level as received. As the signal, the decoded video signal h (illustrated in FIG. 9C) in which the edge enhancement of the main signal is performed without excess or deficiency cannot always be stably obtained, and the decoded video signal i having the edge enhancement effect is excessive. (Shown in FIG. 9D) or the decoded video signal j (FIG.
As a result, the degree of image quality improvement fluctuates according to the deterioration of the linearity of the transmission / reception characteristics of the transmission system, etc., and there is a drawback that a stable high quality image cannot be reproduced at all times. It was

[0015]

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

(1) A video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from that of a predetermined broadcasting system and having compatibility with the predetermined broadcasting system, which is a high-quality video signal. The video signal transmission method, wherein all the video additional information signals are provided in the effective video area of the specific horizontal line.

(2) A video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from that of a predetermined broadcasting system and having compatibility with the predetermined broadcasting system, which is a high-quality video signal. A video signal transmission method, characterized in that a video additional information signal required for amplitude composition is provided in the effective video area of the specific horizontal line.

(3) A video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from that of a predetermined broadcasting system and having compatibility with the predetermined broadcasting system, which is a high-quality video signal. The auxiliary signal of the main signal and the auxiliary signal that constitutes the baseband signal is a baseband signal, and a video additional information signal that is shared when the main signal and the auxiliary signal are amplitude-combined in the effective video area of a specific horizontal line of the high-definition video signal. A method for transmitting a video signal, characterized by being provided.

[0019]

【Example】

[Embodiment 1] A video signal transmission method according to the present invention will be described below with reference to FIGS. FIG. 1 is a diagram for explaining an encoded video signal transmitted by a video signal transmission method according to the present invention, FIG. 2 is a block diagram of a main signal AGC circuit according to the transmission method of the present invention, and FIG. 3 is related to the transmission method of the present invention. Helper signal AGC circuit block diagram, FIGS. 4 and 5 are diagrams for explaining other examples of the encoded video signal, respectively.

The video signal transmission method according to the present invention is generally
For example, a PALplus system video signal, which is a series of high-definition video signals having an aspect ratio (16: 9) different from the PAL broadcast system aspect ratio (4: 3), is transmitted (transmitted / received), and the PAL broadcast system is also used. A video signal transmission method having recording / reproduction compatibility with, wherein an effective video area of a specific horizontal line (for example, the 23rd H) of a high-quality video signal,
All video additional information (for example, signaling bit 20c storing various video additional information including identification information of aspect ratio, main signal reference amplitude information 20d which is video additional information different from this, helper signal reference Amplitude information 2
0e).

The video signal transmission method according to the present invention is
Generally, for example, the aspect ratio of PAL broadcasting system (4: 3)
Video signal transmission that transmits (sends and receives) a PALplus system video signal that is a series of high-definition video signals having an aspect ratio (16: 9) different from that and that has recording / playback compatibility with the PAL broadcasting system. A method of adding a video additional information signal (main signal reference amplitude information 20d, helper signal reference amplitude information) necessary for amplitude synthesis in an effective video area of a specific horizontal line (for example, a horizontal line other than the 23rd H) of a high definition video signal. 20e).

First, the video signal portion 20 having signaling bits in a series of PALplus encoded video signals (for example, broadcast signals) will be described. As shown in FIG. 1A, this video signal portion 20 is, for example, the 23H (H) in each video frame (625H).
40) in the effective video area 20A following the horizontal sync signal 20a of the horizontal line) and the color burst signal 20b.
Bit signaling bit signal 20c, "0 IRE"
"0 IRE" level 20d1 for main signal having level,
"100 IRE" for main signal having "100 IRE" level
Level 20d2, "0 IRE" level (minimum amplitude level) 20e1 for helper signals having "0 IRE" level, the same frequency as the color burst signal 20b (4.43M)
The maximum amplitude level for the helper signal is the same amplitude in Hz) and the phase is ± (BY) or ± (u).
e2 has a signal mode in which the signals are sequentially arranged. Here, the helper signal in the broadcast signal is modulated by the u component of the color burst signal 20b at the time of encoding, and its maximum amplitude is the same as that of the color burst signal 20b. Therefore, the maximum value of the helper signal (vertical edge emphasis component Of the color burst signal 20b has a phase of ± (BY) on the vectorscope.
On the other hand, the minimum value of the helper signal (helper signal = 0. No signal) is the intersection of the RY / BY axes on the vectorscope.

Signaling bit signal 20c described above
Various image additional information such as an aspect ratio identification signal is inserted in the. Level 2 is included in the main signal reference amplitude signal 20d which is the reference amplitude during reproduction (decoding) of the main signal.
0d1 and 20d2, and the helper signal reference amplitude signal 20e, which serves as the reference amplitude during helper signal reproduction (decoding), has levels 20e1 and 20e2.

By the way, a PALplus-compatible TV receiver capable of receiving the broadcast signal in the above-mentioned signal mode is
Since a detection circuit capable of detecting various video additional information in the signaling bit signal 20c in the effective video area 20A of the video signal portion 20 is always provided, this detection circuit is provided in the signaling bit signal 20c. Along with the detection of the video additional information, the above-mentioned main signal reference amplitude signal 20
Each of the d and the helper signal reference amplitude signal 20e can also be detected.

Therefore, the detection circuits for the main signal reference amplitude signal 20d and the helper signal reference amplitude signal 20e are set to PALp.
There is an advantage that this can be done without newly providing it to the lus-compatible TV receiver. Then, as will be described later, the detected main signal reference amplitude signal 20d and helper signal reference amplitude signal 20e are used as reference levels for the main signal AGC and the helper signal AGC, respectively.

Now, the above-mentioned main signal reference amplitude signal 20d
The reproduction of the main signal in the broadcast signal with the reference amplitude by using the "0 IRE" level 20d1 for the main signal and the "100 IRE" level 20d2 for the main signal will be described.

Main signal AGC circuit 30 used for this
Is provided before the vertical low-pass filter 10 in the configuration of the decoding basic algorithm B shown in FIG. 8, and as shown in FIG. 2, the VCA circuit 30a, the horizontal sync separation circuit 30b, and the insertion position detection circuit. The circuit 30c, the sampling pulse generation circuit 30d, the "0 IRE" sampling circuit 30e, the "100 IRE" sampling circuit 30f, the comparison circuit 30g, and the differential amplifier circuit 30h.

Next, the operation of the main signal AGC circuit 30 described above will be described. First, the broadcast signal including the video signal portion 20 shown in FIG. 1 is supplied to the VCA circuit 30a and the horizontal sync separation circuit 30b, respectively. VCA circuit 3
Reference numeral 0a is a video synthesizing circuit in the next stage which is synthesized with the decoded helper signal as a video signal obtained by current amplification of the applied broadcast signal as the gain control voltage using the output signal from the differential amplifier circuit 30h. (0 IRE) sampling circuits 30e and 10
0 IRE ”to the sampling circuit 30f.

The horizontal sync separation circuit 30b outputs each horizontal sync signal separated from the broadcast signal supplied thereto to the insertion position detection circuit 30c. The insertion position detection circuit 30c outputs a detection signal indicating that the 23rd H / frame has been detected from the horizontal synchronization signal supplied from the horizontal synchronization separation circuit 30b to the sampling pulse generation circuit 30d. The sampling pulse generation circuit 30d is responsive to the detection signal from the insertion position detection circuit 30c to output the 23H horizontal synchronizing signal 20.
When counting is started using a clock of a predetermined frequency in synchronization with the fall of a, and the count number corresponding to the beginning of the position of the main signal "0 IRE" level 20d1 is reached, the "0 IRE" sampling circuit The sampling signal is output to 30e. Next, when the count number corresponding to the start of the position of the main signal "100 IRE" level 20d2 is reached, the sampling signal is output to the "100 IRE" sampling circuit 30f.

When the above-mentioned sampling signal is supplied, the "0 IRE" sampling circuit 30e samples the video signal supplied from the VCA circuit 30a in synchronism with the sampling signal, and samples it for a certain period (for example, one frame period). Hold and output this hold signal to the inverting input terminal of the comparison circuit 30g at the next stage. Similarly, when the above-mentioned sampling signal is supplied, the "100 IRE" sampling circuit 30f samples the video signal supplied from the VCA circuit 30a in synchronization with the sampling signal, and then samples this for a certain period (for example, one frame period). Hold and hold this hold signal in the comparison circuit 3
Output to 0g non-inverting input terminal.

The level comparison circuit 30g is "100 IRE".
The comparison signal of both signals obtained by comparing the output signal of the sampling circuit 30f and the output signal of the "0 IRE" sampling circuit 30e is output to the non-inverting input terminal of the differential amplifier circuit 30h. The inverting input terminal of the differential amplifier circuit 30h has a reference signal (voltage corresponding to the level of "100 IRE" = main signal "1").
00 IRE ”level 20d2) is always applied. In this way, the differential amplifier circuit 30h outputs the difference between the reference signal and the above-described comparison signal as an error signal, and uses this as a gain control voltage as the VCA circuit 30.
supply to a. Here, if the comparison signal from the level comparison circuit 30g is at "100 IRE" level, the level of the error signal from the differential amplifier circuit 30h is zero, so the VCA circuit 30a receives the input broadcast signal. Is output as is (through). As a result, the VCA circuit 30
a current-amplifies the applied broadcast signal according to the above-mentioned error signal, so that the main signal reference amplitude signal 20 is always supplied.
It becomes possible to output to the video synthesizing circuit of the next stage as a decoded video signal having a "100 IRE" level according to d.

As a result, even if the horizontal synchronizing signal level of the main signal in the above-mentioned broadcast signal does not satisfy the predetermined reference value due to signal deterioration in the transmission system, the main signal is always set to the prescribed level ( "100 IRE" level).

Now, the above-mentioned helper signal reference amplitude signal 20e (that is, the minimum amplitude level 20e for the helper signal).
1. Playback of the helper signal in the broadcast signal at the reference amplitude using the maximum helper signal amplitude level 20e2) will be described.

The helper signal AGC circuit 31 used for this purpose is provided before the vertical high-pass filter 12 in the configuration of the decoding basic algorithm B shown in FIG. Circuit 31a, helper signal demodulation circuit 31b, burst signal sampling circuit 31d, APC circuit 31e, oscillator circuit 31
As shown in FIG. 3, the VCA circuit 31c, the horizontal sync separation circuit 31g, and the insertion position detection circuit 3 are provided in the next stage of f).
1h, a sampling pulse generation circuit 31i, a helper signal minimum amplitude sampling circuit 31j, a helper signal maximum amplitude sampling circuit 31k, a comparison circuit 31l, and a differential amplifier circuit 31m. That is, helper signal A
The configuration of the GC circuit 31 is similar to that of the main signal AGC circuit 30 described above.

Next, the helper signal AGC circuit 3 described above
The operation of No. 1 will be described. First, the broadcast signal including the video signal portion 20 shown in FIG. 1 is supplied to the helper signal extraction circuit 31a, the burst signal extraction circuit 31d, and the horizontal sync separation circuit 31g, respectively. The signal extracting circuit 31a extracts only the helper signal (minimum amplitude level 20e1, maximum amplitude level 20e2) from the applied broadcast signal,
This helper signal is transferred to the helper signal demodulation circuit 31b at the next stage.
And the AM demodulated helper signal is output to VCA.
The signal is output to the circuit 31c and is output as a helper signal obtained by current amplification in accordance with the gain control voltage output from the differential amplifier circuit 31m to the video synthesis circuit in the next stage. At the same time, the differential amplifier circuit 31m outputs the minimum amplitude sampling circuit 31j and the maximum amplitude sampling circuit 31k, respectively.

The horizontal sync separation circuit 31g outputs each horizontal sync signal separated from the broadcast signal supplied thereto to the insertion position detection circuit 30c. The insertion position detection circuit 31h outputs, to the sampling pulse generation circuit 31c, a detection signal indicating that, for example, the 23rd H / frame has been detected from the horizontal synchronization signal supplied from the horizontal synchronization separation circuit 31g. The sampling pulse generation circuit 31c responds to the detection signal from the insertion position detection circuit 31h to the 23rd horizontal synchronizing signal 20.
When counting is started using a clock of a predetermined frequency in synchronization with the fall of a and the count number corresponding to the start of the position of the above-mentioned minimum amplitude level 20e1 for helper signals is reached, the maximum amplitude sampling circuit 31k outputs a sampling signal. Is output. Next, when the count number corresponding to the start of the position of the maximum amplitude level for helper signal 20e2 is counted, the sampling signal is output to the maximum amplitude sampling circuit 31j.

When the sampling signal is supplied, the minimum amplitude sampling circuit 31j samples the video signal supplied from the VCA circuit 31c in synchronization with the sampling signal, and holds it for a certain period (for example, one frame period). The hold signal is output to the inverting input terminal of the comparison circuit 31l. Similarly, when the sampling signal is supplied, the maximum amplitude sampling circuit 31k samples the video signal supplied from the VCA circuit 31c in synchronization with the sampling signal, and holds it for a certain period (for example, one frame period). The holding signal is output to the non-inverting input terminal of the comparison circuit 31l.

The level comparison circuit 311 outputs a comparison signal of both signals obtained by comparing the output signal of the maximum amplitude sampling circuit 31k and the output signal of the minimum amplitude sampling circuit 31j to the non-inverting input terminal of the differential amplifier circuit 31m. Output.
A reference signal (reference value) is constantly applied to the inverting input terminal of the differential amplifier circuit 31m. In this way, the differential amplifier circuit 31m outputs the difference between this reference signal and the above-mentioned comparison signal as an error signal, and supplies this as a gain control voltage to the VCA circuit 31c. Here, if the comparison signal from the level comparison circuit 31l is the reference value level, the level of the error signal from the differential amplifier circuit 31m is zero, so the VCA circuit 31c does not change the input broadcast signal. (Through) Output. In response, VC
The A circuit 31c current-controls the applied broadcast signal in accordance with the above-mentioned error signal, and as a result, a decoded video signal having a reference level according to the helper signal reference amplitude signal 20e is always provided, and the next-stage video synthesizing circuit is provided. Can be output to. Helper signal signal demodulation circuit 31 described above
b, burst signal sampling circuit 31d, APC circuit 31e,
The oscillating circuit 31f is a color signal demodulating circuit, a color burst signal extracting circuit, an APC in a known color signal reproducing system.
Since it has the same configuration and operation as the circuit and the oscillation circuit, description thereof is omitted here.

As a result, even if the horizontal sync signal level of the helper signal in the broadcast signal does not satisfy the predetermined reference value due to signal deterioration in the transmission system,
The helper signal can always be reproduced at the specified level. In this way, the demodulated video signal portion 21 obtained by synthesizing the output signals of the main signal AGC circuit 30 and the helper signal AGC circuit 31 described above can be obtained.

This video signal portion 21 corresponding to the above-mentioned video signal portion 20 has a horizontal synchronizing signal 21a, a signaling bit signal 21c, a main signal reference amplitude signal 21d ("0 IRE" as shown in FIG. 1B. Level (Signal width about 5
μsec) 21d1, “100 IRE” level (signal width about 5μ
sec) 21d2), helper signal reference amplitude signal 2
1e (reference level (“0” level) (signal width about 5 μsec)
21e1, maximum amplitude level (signal width of about 5 μsec) 21e
2). Here, a certain DC value is added to the reference level 21e1 and the maximum amplitude level 21e2 so that the maximum amplitude level 21e2 does not fall below "0 IRE" (not shown).

Since the four types of reference potential signals 21d1, 21d2, 21e1, 21e2 of the video signal portion 21 all have a signal width of about 5 μsec, for example, the 23rd H.
It is possible to perform accurate voltage sampling with reference to the timing of the horizontal synchronizing signal 21a. In addition to this, the signaling bit signal 21c may be sampled with a pulse for detection.

As described above, all of the video additional information (video additional information regarding the signal line signal 21c and video additional information regarding the reference potential signals 21d1, 21d2, 21e1, 21e2) is collected in one specific horizontal line, The same information can be detected at the lowest cost.

As shown in FIG. 1 (B), two types of reference potentials are provided in a limited area with a signal of a width unit of about 5 μsec, which is not always a sufficient length in consideration of waveform distortion.

The video signal portion 22 is, as shown in FIG. 4, the above-mentioned video signal portion 20 (shown in FIG. 1A).
The main signal reference amplitude signal 20d and the helper signal reference amplitude signal 20e are replaced with each other in order (there is no other change), and thus there is no problem even if the two signals are replaced with each other. In addition, the reference potential signal 21
It does not matter if the order of d1 and 21d2 is exchanged with each other, and similarly, the order of reference potential signals 21e1 and 21e2 is exchanged with each other. Thus
The video signal portion 22 is shown in FIG.
5H), for example, the 23rd horizontal synchronizing signal 20
a, the effective image area 20 following the color burst signal 20b
In A, signaling bit signal 20c, helper signal reference amplitude signal 20e (helper signal "0 IRE" (minimum amplitude) level 20e1, helper signal maximum amplitude level 20e2), main signal reference amplitude signal 20d (for main signal) This is a signal mode in which a "0 IRE" level 20d1 and a main signal "100 IRE" level 20d2) are sequentially arranged. The same components as those described above are designated by the same reference numerals and the description thereof is omitted.

The above-mentioned video signal portions 20 and 22 are respectively
All the video additional information necessary for the amplitude composition of the main signal reference amplitude signal 20d and the helper signal reference amplitude signal 20e described above is mounted in each frame period. The video signal 23 described below is a main signal reference amplitude. The signal 20d and the helper signal reference amplitude signal 20e are alternately mounted on the same specific horizontal line for each frame and transmitted. As a result, the reproduced reference signals 20d and 20e
The potential detection of is more stably performed. That is, the video signal portion 23a (shown in FIG. 5A) that constitutes the series of video signals 23 is, for example, the 23rd frame of n frames (n is a multiple of 2).
Immediately after the signaling bit 20c in H, the helper signal reference amplitude signal 20e (“0 IRE” for helper signal)
(Minimum amplitude) level 20e1 (signal width about 10 μsec), maximum amplitude level for helper signal 20e2 (signal width about 10 μsec)
sec)) only. The video signal portion 23b (shown in FIG. 5B) paired with the video signal portion 23a is (n
+1) Immediately after the signaling bit 20c in the 23rd H, for example, the main signal reference amplitude signal 20d (main signal “0 IRE” level 20d1 (signal width 10 μsec),
Main signal "100 IRE" level 20d2 (signal width 10μ
sec)) only.

The video signal transmission method according to the present invention described above is based on the encoding basic algorithm A (shown in FIG. 7).
In the above, since the luminance signal of the main signal is a baseband signal and the helper signal is AM-modulated with a modulation signal of the same frequency as the color burst signal, the transmission method of the helper signal is different from that of the main signal. Therefore, the transmitting side needs two reference signals (a main signal reference amplitude signal 20d and a helper signal reference amplitude signal 20e) to be multiplexed on a specific horizontal line of the encoded video signal obtained by combining the main signal and the helper signal. As a result, in the decoding basic algorithm B (shown in FIG. 8), the AGC operation for the main signal and the helper signal cannot be performed only by the main signal AGC circuit 30 (shown in FIG. 2). For this reason,
As described above, it is necessary to newly obtain the helper signal AGC circuit 31 (shown in FIG. 3).

[Embodiment 2] Therefore, according to the present invention, for example, in the encoding basic algorithm AA (shown in FIG. 10 described later), the helper signal is a modulation signal having the same frequency as the color burst signal and is not modulated by AM, but the brightness of the main signal is obtained. An encoded video signal obtained by synthesizing with the main signal is generated as a baseband signal similar to the signal (in the form after demodulation of the helper signal). As a result, both the main signal and the helper signal can be subjected to the same signal processing as the baseband signal (that is, the transmission method is the same). As a result, accordingly, on the transmission side, the reference signal multiplexed on the specific horizontal line of the encoded video signal obtained by combining the main signal and the helper signal is only the main signal reference amplitude signal 20d (or only the helper signal reference amplitude signal 20e). ) Is good. As a result, in the decoding basic algorithm BB (illustrated in FIG. 11 described later), AGC of the main signal and the helper signal is performed only by the main signal AGC circuit 30 described above (or only the helper signal AGC circuit 31 described above). As a result, it is possible to obtain the same effect as that of the above-described [Embodiment 1], but also to simplify the circuit configuration required for encoding and decoding.

Another video signal transmission method according to the present invention will be described below with reference to FIGS. Figure 10 is PALp
11 is a diagram for explaining a basic encoding algorithm for lus, FIG. 11 is a diagram for explaining a basic decoding algorithm for PALplus, and FIG. 12 is a diagram for explaining an encoded video signal transmitted by the video signal transmission method according to the present invention. FIG. 13, FIG. 13 and FIG. 14 are diagrams for explaining other examples of the encoded video signal, respectively. The same components as those described above are designated by the same reference numerals, and the description thereof will be omitted.
Hereinafter, for convenience of description, only the AGC of the main signal and the helper signal in the main signal AGC circuit 30 using the main signal reference amplitude signal 20d as the reference signal will be described, but the reference signal is the helper signal reference amplitude signal. Of course, it is also possible to perform AGC of the main signal and the helper signal by the helper signal AGC circuit 31 using 20e.

The video signal transmission method according to the present invention is generally
For example, a PALplus system video signal, which is a series of high-definition video signals having an aspect ratio (16: 9) different from the PAL broadcast system aspect ratio (4: 3), is transmitted (transmitted / received), and the PAL broadcast system is also used. A video signal transmission method that is compatible with recording and playback with a main signal and an auxiliary signal (helper signal) that compose a high-definition video signal, and the auxiliary signal is a baseband signal. In the effective video area of the horizontal line (for example, the 23rd H), a video additional information signal (for example, the reference amplitude information 20d or the reference amplitude information 20e) that is shared when the main signal and the auxiliary signal are amplitude-combined is provided.

Now, as shown in FIG. 10, the PALplus encoding basic algorithm AA is as shown in FIG.
In the configuration of the PALplus encoding basic algorithm A shown in FIG. 3, the AM modulation circuit 5 is deleted, and the vertical high-pass filter 4 has the same configuration as that of the output side directly connected to the input side of the level adjusting circuit 6, It comprises a low-pass filter 2, a video synthesizing circuit 3, a vertical high-pass filter 4, and a level adjusting circuit 6.

Next, the operation of the PALplus encoding basic algorithm AA will be described. That is, the widescreen video signal of 575 effective scanning lines / frame (625/50/2: 1 system) output from the camera 1 is supplied to the vertical low-pass filter 2, where the scanning line number conversion (4- (3 conversion) to form a main signal which is a wide-screen video signal of 431 effective scanning lines / frame, and then output to one input side of the video synthesizing circuit 3. Similarly, the above-described wide screen video signal output from the camera 1 is supplied to the vertical high-pass filter 4, where the number of scanning lines is converted (4-1 conversion) to 144 effective scanning lines /
After being converted into a wide-screen video signal of the frame, the level adjusting circuit 6 outputs, for example, a small amplitude level (40IREp-p).
The adjusted helper signal is output to the other input side of the video synthesizing circuit 3 described above. The video synthesizing circuit 3 described above outputs an encoded video signal obtained by synthesizing the main signal and the helper signal, both of which are baseband signals.

The PALplus decoding basic algorithm BB is, as shown in FIG. 11, the PALplus encoding basic algorithm B shown in FIG.
In the configuration, the AM demodulation circuit 11 is deleted and the reproduced encoded video signal can be directly supplied to the vertical high-pass filter 12, and the vertical low-pass filter 10 and the vertical high-pass filter 12 are provided. Video synthesis circuit 1
It consists of three.

Next, the operation of the PALplus decoding basic algorithm BB will be described. That is, when the above-mentioned encoded video signal is supplied (for example, a broadcast signal is received), this signal is branched into the main signal system and the helper signal system, respectively, and the encoded video signal supplied to the main signal system is vertically filtered. The signal is supplied to the pass filter 10 and inversely converted (3-4 converted) in the number of scanning lines to be output to one input side of the image synthesis circuit 13 as a widescreen image signal of 431 effective scanning lines to 575 effective scanning lines. To be done. Also,
The encoded video signal supplied to the helper signal system is level-adjusted and then directly supplied to the vertical high-pass filter 12 where the number of scanning lines is inversely converted (1-4 conversion) and the effective scanning lines 14 are converted.
It is output to the other input side of the image synthesizing circuit 13 as a wide screen image signal of four effective lines 575 effective scanning lines. The video synthesizing circuit 13 includes an effective scanning line 57 of the main signal system.
A decoded video signal obtained by synthesizing the five widescreen video signals and the 575 widescreen video signals of the effective scanning lines of the helper signal system is output.

Signaling in a series of PALplus encoded video signals (for example, broadcast signals)
The video signal portion 20 'having bits will be described.
As shown in FIG. 12, this video signal portion 20 'is, for example, the 23rd H in each video frame (625H).
In the effective video area 20A following the horizontal synchronizing signal 20a (H is a horizontal line) and the color burst signal 20b, for example, a 40-bit signaling bit signal 20c, "0 I
"0 IRE" level 20d1 for main signal having "RE" level
And "100 I" for main signal with "100 IRE" level
RE "main signal reference amplitude signal 20d consisting of level 20d2
Is a signal mode in which is sequentially arranged.

By the way, a PALplus-compatible TV receiver capable of receiving the broadcast signal in the above-mentioned signal mode is
Since the detection circuit capable of detecting various kinds of video additional information in the signaling bit signal 20c in the effective video area 20A of the video signal portion 20 'is always provided, this detection circuit is in the signaling bit signal 20c. Of the above-mentioned main signal reference amplitude signal 2 together with the detection of the video additional information
It is possible to detect 0d.

Now, the above-mentioned main signal reference amplitude signal 20d
The reproduction of the main signal and the helper signal in the broadcast signal by using the main signal "0 IRE" level 20d1 and the main signal "100 IRE" level 20d2 will be described.

Main signal AGC circuit 30 used for this
Has the same configuration as that shown in FIG.
In the decoding basic algorithm BB shown in FIG. 11, it is provided before the vertical low-pass filter 10 and the vertical high-pass filter 12.

Next, the main signal AGC shown in FIG.
The operation of the circuit 30 will be described. First, as shown in FIG.
The encoded video signal including the video signal portion 20 'shown in FIG. 2 is the VCA circuit 30a and the horizontal sync separation circuit 3.
0b are supplied respectively. The VCA circuit 30a uses the output signal from the differential amplifier circuit 30h as the gain control voltage, and outputs the encoded video signal as an encoded video signal obtained by current-amplifying the encoded video signal.
It outputs to the "E" sampling circuit 30e and the "100 IRE" sampling circuit 30f, respectively.

The horizontal sync separation circuit 30b outputs each horizontal sync signal separated from the encoded video signal supplied thereto to the insertion position detection circuit 30c. Insertion position detection circuit 3
0c outputs a detection signal indicating that the 23rd H / frame has been detected from the horizontal synchronization signal supplied from the horizontal synchronization separation circuit 30b to the sampling pulse generation circuit 30d. The sampling pulse generation circuit 30d is an insertion position detection circuit 30c.
In response to the detection signal from, the counting is started using a clock of a predetermined frequency in synchronization with the fall of the 23H horizontal synchronizing signal 20a, and the above-mentioned "0 IRE" level 20d1 for the main signal and the helper signal is set. When the count number corresponding to the start of the position is reached, a sampling signal is output to the "0 IRE" sampling circuit 30e. Next, the above-mentioned "100 IRE" for main signal and helper signal.
When the count number corresponding to the start of the position of level 20d2 is reached, the "100 IRE" sampling circuit 3
The sampling signal is output to 0f.

When the sampling signal is supplied, the "0 IRE" sampling circuit 30e samples the video signal supplied from the VCA circuit 30a in synchronization with the sampling signal, and samples it for a certain period (for example, one frame period). Hold and output this hold signal to the inverting input terminal of the comparison circuit 30g at the next stage. Similarly, when the above-mentioned sampling signal is supplied, the "100 IRE" sampling circuit 30f samples the video signal supplied from the VCA circuit 30a in synchronization with the sampling signal, and then samples this for a certain period (for example, one frame period). Hold and hold this hold signal in the comparison circuit 3
Output to 0g non-inverting input terminal.

The level comparison circuit 30g is "100 IRE".
The comparison signal of both signals obtained by comparing the output signal of the sampling circuit 30f and the output signal of the "0 IRE" sampling circuit 30e is output to the non-inverting input terminal of the differential amplifier circuit 30h. A reference signal (voltage according to "100 IRE" level = voltage according to "100 IRE" level 20d2 for main signal and helper signal) is constantly applied to the inverting input terminal of the differential amplifier circuit 30h. In this way, the differential amplifier circuit 30h outputs the difference between the reference signal and the above-mentioned comparison signal as an error signal, and supplies this as a gain control voltage to the VCA circuit 30a. Here, if the comparison signal from the level comparison circuit 30g is "100 IRE" level, the level of the error signal from the differential amplifier circuit 30h is zero, so the VCA circuit 30a receives the input encoded image. Output the signal as it is (through).

As a result, the VCA circuit 30a current-amplifies the applied encoded video signal in accordance with the above-mentioned error signal, whereby the "100 IRE" level corresponding to the main signal and the helper signal reference amplitude signal 20d is always maintained. It becomes possible to output as a decoded video signal equipped with.

As a result, even if the horizontal sync signal level of the main signal and helper signal in the above-mentioned encoded video signal does not satisfy the predetermined reference value due to signal deterioration in the transmission system, the main signal is subjected to AGC processing. Reference amplitude signal 20d (that is, "0 IRE" level 20d for main signal)
1. By controlling the main signal "100 IRE" level 20d2) to have the same amplitude, the main signal and the helper signal can always be reproduced at a prescribed level ("100 IRE" level).

In this example, the two types of reference potential signals 20d1 and 20d2 of the video signal portion 20 'are both about 5 μse.
Since the signal width is c, the 23rd horizontal sync signal 20a
It is possible to perform accurate voltage sampling based on the timing of. In addition to this, the signaling bit signal 20c may be sampled with a pulse for detection.

As described above, all the video additional information (the video additional information regarding the signal line signal 20c and the video additional information regarding the reference potentials 20d1 and 20d2) is gathered in one specific horizontal line, so that the same cost can be obtained at the lowest cost. Information can be detected. Alternatively, as the reference potential, the helper signal reference amplitude signal 20e demodulated, that is, the helper signal reference amplitude signal 21e may be used instead of the main signal reference amplitude signal 20d.

Now, as shown in FIG. 13, the video signal portion 22 'has the above-mentioned video signal portion 20' (FIG. 12A).
The reference amplitude signal 20d in FIG.
Although it is separated from the bit signal 21c (there is no other change), this does not cause any problem. Further, the order of the reference potentials 21d1 and 21d2 may be interchanged with each other without any problem.

Thus, the video signal portion 22 'includes, for example, the horizontal synchronizing signal 20a of the 23rd H and the color burst signal 20 in each video frame (625H) in FIG.
The signaling bit signal 20c and the reference amplitude signal 20d (“0 IRE” level 20d1 and “100 IRE” level 20d2) are sequentially arranged in the effective video area 20A following b. The same components as those described above are designated by the same reference numerals and the description thereof is omitted.

As described above, in the other video signal transmission method according to the present invention, since the main signal and the helper signal are both transmitted as the baseband signal, the same signal processing can be performed, and in accordance with this, Therefore, only one reference signal related to the amplitude is required (main signal reference amplitude signal 20d or helper signal reference amplitude signal 20e), and only one decoding-side AGC circuit (main signal AGC circuit 3
0 or helper signal AGC circuit 31) It is possible to perform AGC of the main signal and the helper signal.

Although the above description has explained the PALplus system, the present invention is not limited to this.
It goes without saying that the same can be done with the EDTV2. Moreover, it is needless to say that the same can be done in the case of specializing in a package medium such as a VTR. Furthermore, although the description has been made regarding the 23rd H as an example of the specific horizontal line of the high-definition video signal, it goes without saying that other horizontal lines may be used.

[0070]

As described above, the video signal transmission method of the present invention transmits a series of high-definition video signals having an aspect ratio different from the aspect ratio of the predetermined broadcasting system and is compatible with the predetermined broadcasting system. A video signal transmission method having the above, since all the video additional information signals are provided in the effective video area of the specific horizontal line of the high definition video signal, for example, only one video additional information signal detection circuit in the same horizontal line is provided. Since all video additional information signals can be obtained with,
This can contribute to simplification of the receiving circuit.

The video signal transmission method of the present invention is a video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from the aspect ratio of the predetermined broadcasting system and having compatibility with the predetermined broadcasting system. However, since the video additional information signal required for amplitude synthesis is provided in the effective video area of the specific horizontal line of the high-quality video signal, the horizontal line provided with the video additional information signal required for amplitude synthesis is different from this. Since it is separately detected from the horizontal line provided with the video additional information signal, it can be detected without being affected by the reproduction state of another video additional information signal. Especially, the linearity of the transmission / reception characteristics of the transmission system is extremely poor. Even in this case, the video additional information signal necessary for amplitude synthesis can always be detected with stable potential. Therefore, for example, by using this detected reference amplitude level, transmission / reception of the transmission system is performed. Since it is possible to constantly and stably correct the amplitude levels of the main signal and the helper signal, whose levels tend to fluctuate due to the deterioration of the linearity of the image quality, the video signal obtained by combining both signals is edge-emphasized. Since it is possible to obtain a decoded video signal in a good signal state without excess or deficiency, there is an effect that a stable high-quality image can be always reproduced.

Furthermore, the video signal transmission method of the present invention is a video signal transmission method that transmits a series of high-definition video signals having an aspect ratio different from the aspect ratio of the predetermined broadcasting system and is compatible with the predetermined broadcasting system. Of the main signal and the auxiliary signal which form the high-definition video signal, the auxiliary signal is a baseband signal, and when the main signal and the auxiliary signal are amplitude-combined in the effective video area of a specific horizontal line of the high-definition video signal. Since the auxiliary signal has the same property as the luminance signal of the main signal as the baseband signal because it has the video additional information signal shared by the two, since it has two kinds of signals having different transmission characteristics, for example, two kinds of AGC circuits. Need not be provided, and only one type of reference signal as a video additional information signal is required, so PALplus as a receiving side device
The TV receiver of the system is compatible with this reference signal.
Since it is sufficient to provide only the kind of AGC circuit, there is an effect that the configuration of the decoding processing circuit on the receiving side during signal transmission can be simplified.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an encoded video signal transmitted by a video signal transmission method according to the present invention.

FIG. 2 is a block diagram of a main signal AGC circuit according to the transmission method of the present invention.

FIG. 3 is a block diagram of a helper signal AGC circuit according to the transmission method of the present invention.

FIG. 4 is a diagram for explaining another example of the encoded video signal.

FIG. 5 is a diagram for explaining another example of the encoded video signal.

[Fig. 6] Fig. 6 is a diagram for describing a reproduced image of PALplus.

FIG. 7 is a diagram illustrating a PALplus encoding basic algorithm.

FIG. 8 is a diagram for explaining a PALplus decoding basic algorithm.

FIG. 9 is a diagram for explaining the operation of a PALplus decoding basic algorithm.

FIG. 10 is a diagram illustrating a PALplus encoding basic algorithm.

FIG. 11 is a diagram for explaining a PALplus decoding basic algorithm.

FIG. 12 is a diagram for explaining an encoded video signal transmitted by the video signal transmission method according to the present invention.

FIG. 13 is a diagram for explaining another example of the encoded video signal.

FIG. 14 is a diagram for explaining another example of the encoded video signal.

[Explanation of symbols]

 20-23, 20'-23 'Video signal 20A Effective video part 20a Horizontal sync signal 20b Color burst signal 20c Signaling bit 20d Main signal reference amplitude information 20e Helper signal reference amplitude information

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Claims (3)

[Claims] 1. A video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from that of a predetermined broadcasting system and having compatibility with the predetermined broadcasting system, the method comprising: A video signal transmission method, characterized in that all video additional information signals are provided in an effective video area of a specific horizontal line. 2. A video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from the aspect ratio of a predetermined broadcasting system and having compatibility with the predetermined broadcasting system, the method comprising: A video signal transmission method comprising a video additional information signal required for amplitude synthesis in an effective video area of a specific horizontal line. 3. A video signal transmission method for transmitting a series of high-definition video signals having an aspect ratio different from that of a predetermined broadcasting system and having compatibility with the predetermined broadcasting system, wherein Of the constituent main and auxiliary signals, the auxiliary signal is a baseband signal, and is equipped with a video additional information signal that is shared when the main signal and auxiliary signal are amplitude-combined in the effective video area of a specific horizontal line of a high-quality video signal. A video signal transmission method characterized by the above.