JPH11331752A - Video signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video signal processor, capable of reducing a circuit scale and power consumption and suppressing the increment of cost. SOLUTION: A slicer 19 detects copyright protection information which is added as a VBID signal in accordance with the reference count value of an H/V counter 18 from a filter output outputted from an LPF 16. A microcomputer(MC) I/F 20 sends the copyright protection information outputted by the slicer 19 to an MC 21 and receives a control signal from the MC 21. The MC 21 generates a control signal for controlling the decoding of a video decoder 11, based on the copyright protection information, e.g. and sends the control signal to the video decoder 11 via the MC I/F 20. Consequently, the video signal processor 1 can decode an analog video signal based on the copyright protection information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing apparatus for processing a video signal for which copyright protection has been taken.

[0002]

2. Description of the Related Art Digital video tape recorders, digital video disk recorders, and the like capable of recording video signals such as television signals in the form of digital signals have come into practical use. These digital video recorders provide high quality recording and playback,
Copying is also possible. Therefore, in order to protect the copyright, it has become necessary to add to the video signal, copy protection control information composed of a copy protection signal or a copy generation limit signal in which the number of times of copying is limited, or copyright data.

For this reason, for example, in order to control the duplication of an analog video signal of 525 lines / 60 fields,
An identification signal inserted during the vertical blanking period (Vertic
It has been proposed to use al Blanking Interval Data (VBID). The VBID signal is inserted into the 20th (first field) and 283rd (second field) horizontal sections (lines) of the vertical blanking period in the video signal of one frame period. And this VBID
Using a signal, for example, a copy generation control signal (Copy Gener
ation management system (CGMS).

In a closed caption television signal called closed caption adopted in the United States, the closed caption signal is used to generate the CGMS.
Is transmitted. The closed caption inserts 14-bit (excluding parity) data into the 21st line in the vertical blanking period of each field. Although the closed caption data is superimposed on the 21st line of each of the odd field and the even field, actually, since the first field is used to transmit the captions in two languages, the third and the other captions are transmitted. The second field prepared for transmitting the caption in the fourth language is rarely used. Therefore, it has been proposed to use the 21st line (the 284th line when a serial number is assigned to a line of one frame) in the vertical blanking period of the second field to carry various additional information. . This is called an extended data service (XDS), and some transmission contents are defined. Therefore, the CGMS may be transmitted using the XDS transmission format.

[0005] Further, the aspect ratio and presence or absence of a helper signal for widening the screen used in the next-generation television broadcasting system called PALplus system proposed in Western European countries and the like adopting the PAL system. Wide Screen Signaling
It is also considered that the CGMS is transmitted using an aling (WSS) signal.

Further, conventionally, an AGC pulse system by Macrovision has been used to prevent duplication. In the AGC pulse method, a pseudo-sync signal having a large level is inserted as a sync signal corresponding to a reference pulse of the AGC, and the pseudo-sync signal causes the AGC to operate. Ban.

FIG. 7 shows a configuration of a video signal processing apparatus for detecting such copyright protection information (hereinafter referred to as copyright protection information) and demodulating and digitizing an analog video signal in accordance with the detection result. Shown in Here, CGMS is used as the copyright protection information, for example, the VB
It is assumed that an ID signal is used.

The conventional video signal processor 50 comprises a video decoder 52, a copyright protection information detector 64, and a microcomputer 72.

The video decoder 52 includes an AGC amplifier (AMP) 53 for performing automatic gain control (AGC) on the analog composite video signal supplied from the input terminal 51 and an AGC amplifier 53 from the AGC amplifier 53.
A / D converter 54 for converting the C output into a digital signal
And a YC separator 55 for separating the digital signal from the A / D converter 54 into a luminance (Y) component and a color difference (C) component.
A color difference decoder 56 for decoding the color difference component from the YC separator 55, and an LPF for removing the high frequency component through the low frequency component of the digital signal from the A / D converter 54.
57, a synchronization separation circuit 58 for separating the horizontal synchronization signal (Hsync) and the vertical synchronization signal (Vsync) from the filter output of the LPF 57, and an H / V for counting the horizontal synchronization signal or the vertical synchronization signal from the synchronization separation circuit 58. A counter 59 outputs luminance data from an output terminal 61, color difference data from an output terminal 62, and outputs a reference count value of H / V from an output terminal 63. A microcomputer interface (I / F) 60 for performing communication with the microcomputer 72 is also provided, and the functions of the above-described units are controlled according to a control signal from the microcomputer 72.
For example, decoding for generation-limited duplication is performed.

The copyright protection information detector 64 includes an AGC amplifier 65 for applying AGC to the analog composite video signal from the input terminal 51, and an AGC amplifier 6
A / D for converting the AGC output from 5 into a digital signal
A converter 66, a slicer 67 for extracting the copyright protection information added as the VBID signal from the digital signal from the A / D converter 66 based on a reference count value of an H / V counter 71 described later, and a slicer 67; A microcomputer interface (I / F) 68 for supplying the copyright protection information detected by 67 to the microcomputer 72 and receiving a control signal from the microcomputer 72, and the A / D converter 66
An LPF 69 that passes the low-frequency component of the digital signal from
A horizontal synchronizing signal (Hs
sync) and a vertical synchronizing signal (Vsync), and an H / V counter 71 that counts the horizontal synchronizing signal or the vertical synchronizing signal from the synchronizing separator 70 and supplies a reference count value to the slicer 67. Be prepared.

The microcomputer 72 receives the copyright protection information sent from the copyright protection information detector 64 via the microcomputer I / F 68, performs error correction processing and the like, and then decodes the information. The microcomputer 72 sends a control signal to the video decoder 52 via the microcomputer I / F 60 as described above based on the copyright protection information to control the functions of the above-described units. Cause decoding.

[0012]

In the conventional video signal processing apparatus 50, the copyright protection information detector 64 is required separately from the video decoder 52, so that the circuit scale is increased and the miniaturization is prevented. At the same time, power consumption has increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a video signal processing apparatus capable of realizing a reduction in circuit size and power consumption and a reduction in cost.

[0014]

According to the present invention, there is provided a video signal processing apparatus for processing a video signal to which copyright protection information is added. A video decoding unit including a copyright protection information detecting unit for detecting information is provided.

Here, the video decoding means includes a synchronization separation section, a low-pass filter section, an automatic gain control section, an interface, an A / D conversion section, and a horizontal / vertical synchronization signal reference counter section. Also share.

For this reason, this video signal processing device does not require separate circuit configurations required for the video decoder and the copyright protection information detecting means as in the prior art.

Further, the copyright protection information detecting means detects the copyright protection information superimposed during the vertical blanking period of the video signal.

The copyright protection information includes a VBID signal, a closed caption signal, a WSS signal or an AG signal.
Superimposed on the video signal by the C pulse method.

Further, the copyright protection information detecting means may detect the copyright protection information added as watermark information on the image.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a video signal processing device according to the present invention will be described with reference to the drawings.

In this embodiment, for example, VBID (Vert
A video signal processing device that detects copyright protection information added to a video signal as an ical blanking interval data) signal and demodulates and digitizes an analog video signal according to the detection result. Applied to computer.

In FIG. 1, the video signal processing device 1
Comprises a video decoder 11 for decoding a composite video signal supplied from an input terminal 10 and a microcomputer 21. Here, the video decoder 11 has a function of detecting the copyright protection information.

The video signal processing device 50 shown in FIG.
In the above, each part constituting the video decoder 52 and each part constituting the copyright protection information detector 64 have a part that can be shared as shown by oblique lines. For this reason, in the video signal processing device 1 shown in FIG. 1, a function of detecting copyright protection information is built in the video decoder 11, thereby reducing the circuit size and the power consumption.

That is, the video decoder 11 includes an AGC amplifier (AMP) 12 for performing automatic gain control (AGC) on an analog composite video signal supplied from the input terminal 10, and an AGC amplifier 12.
A / D converter 13 for converting an AGC output from the A / D converter into a digital signal, a YC separator 14 for separating the digital signal from the A / D converter 13 into a luminance (Y) component and a color difference (C) component, A color difference decoder 15 for decoding the color difference component from the YC separator 14 and an L for removing the high frequency component through the low frequency component of the digital signal from the A / D converter 13
A PF 16, a synchronization separation circuit 17 for separating a horizontal synchronization signal (Hsync) and a vertical synchronization signal (Vsync) from the filter output of the LPF 16, and an H / V for counting the horizontal synchronization signal or the vertical synchronization signal from the synchronization separation circuit 17. The counter 18 and the VB based on the filter output from the LPF 16 according to the reference count value of the H / V counter 18.
A slicer 19 serving as a detector for detecting the copyright protection information added as an ID signal; a microcomputer I / F 20 for sending the copyright protection information from the slicer 19 to the microcomputer 21 and receiving a control signal from the microcomputer 21; Is provided.

Here, the VBID signal used for transmitting the copyright protection information will be described in detail with reference to FIG. This VBID signal is inserted in the 20th (first field) and 283rd (second field) horizontal sections (lines) of the vertical blanking period in the video signal of one frame period. A 2-bit reference and a 20-bit (bit 1 to bit 20) digital signal are inserted into an effective video signal area after the horizontal synchronization signal and the color burst signal in the line. The reference level is defined as 70 IRE, and the binary level of the digital signal is defined as 0 IRE or 70 IRE. This digital signal is used as a VBID signal.

FIG. 3 shows the structure of a transmission signal when transmitting copyright protection information using this VBID signal. The structure of the transmission signal is the same as that of the VBID signal, and changes the code assignment of the 20-bit digital signal. FIG.
As shown in (1), the 20-bit digital signal is composed of 14 information bits and a CRC code (6 bits) for error detection for the 14 bits. And 1
Word 0 is constituted by the first and second bits of the four bits, word 1 is constituted by four bits from the third bit to the sixth bit, and word 1 is constituted by the seventh bit. 8 up to the 14th bit
Word 2 is composed of bits.

Word 0 is information on the transmission format of the video signal, and has the same assignment as the VBID signal. Word 1 is a header that specifies the information transmitted in word 2. Word 1 (0000) indicates that information for the digital video recorder is transmitted by word 2. That is, when word 1 is (0000),
The copy generation control information (CGMS) used when the digital video recorder / players are interconnected to perform copying is transmitted by word 2.

As an example, as shown in FIG. 4, the first two bits (bit 7 and bit 8) of the eight bits of word 2 have contents indicating a copyable generation. When transmitting the information when the word 1 is (0000), the information is transmitted at least two frames or more in two seconds.

When the slicer 19 in the video decoder 11 of the video signal processor 1 shown in FIG. 1 reads out the first two bits of the word 2 based on the reference count value of the H / V counter 18, the result is shown in FIG. CGMS with content
Can be detected.

This copyright protection information is stored in the microcomputer I / F 2
0 is supplied to the microcomputer 21. Then, the microcomputer 21 performs, for example, the CGMS having the contents shown in FIG.
, A control signal for controlling decoding in the video decoder 11 is generated and sent to the video decoder 11 via the microcomputer I / F 20. Thus, the video signal processing device 1 decodes the analog video signal based on the copyright protection information.

Next, an algorithm for detecting copyright protection information in the slicer 19 serving as a copyright protection information detector will be described with reference to FIG.

AGC information from the AGC amplifier 12 of the video decoder 11, AGC level fluctuation information, or H / V
The information on the acquisition of the H / V synchronization signal by the counter 18 can be used to grasp the situation such as the signal / noise ratio (S / N) and the ghost. The slicer 19 can stably detect the copyright protection information from these pieces of information.

FIG. 5A shows an algorithm that uses AGC information / synchronization signal (SYNC) acquisition rate information. When the AGC gain is small / the SYNC acquisition rate is low, S
Since N is good, the averaging time constant of the detected data of the copyright protection information becomes short. At this time, since the slicer 19 has good signal quality, it is possible to detect the copyright protection information at high speed. On the other hand, when the AGC gain is large / the SYNC acquisition rate is high, the SN is bad, so that the averaging time constant of the copyright detection data is long. At this time, slicer 19
Is noise reduction by averaging even if the signal quality is poor,
Although it takes time, stable detection is possible.

FIG. 5B shows an algorithm using the peak AGC information. At peak AGCON,
Since the synchronization signal is controlled to be smaller than the standard, the slice level for taking in the copyright protection information can be lowered to enable stable detection. FIG. 6 shows a waveform of the copyright protection information which can be detected by the slicer 19 by the algorithm using the peak AGC information. When the peak AGC information is ON, the copyright protection information can be detected stably by correcting and lowering the slice level.

As described above, in the video signal processing device 1,
Since the copyright protection information detector capable of stably detecting the copyright protection information is incorporated in the video decoder 11 by sharing the circuit configuration, the circuit scale can be reduced, the power consumption can be reduced,
Cost can be reduced.

Since the quality of the image signal can be evaluated from the information held by the video decoder 11, the copyright protection information can be obtained more efficiently.

Although the slicer 19 of the video signal processor 11 detects the copyright protection information as a VBID signal, the slicer 19 may detect the copyright protection information by a closed caption signal, a WSS signal, or an AGC pulse method. .

Further, the copyright protection information represented by a watermark (Water Mark) added as watermark information on the image may be detected.

[0039]

The video signal processing apparatus according to the present invention is a video signal processing apparatus for processing a video signal to which copyright protection information has been added, and includes a copyright protection information detecting means for detecting the copyright protection information. Since the video decoding means is provided, the size of the circuit can be reduced, the power consumption can be reduced, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video signal processing device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram for explaining a VBID signal.

FIG. 3 is a format diagram for explaining a data structure of a VBID signal.

FIG. 4 is a diagram for explaining bit allocation when transmitting information for a video recorder using a VBID signal.

FIG. 5 is a diagram for describing an algorithm for detecting copyright protection information in a copyright protection information detector.

FIG. 6 is a waveform diagram of copyright protection information that can be detected by a copyright protection information detector by an algorithm using peak AGC information.

FIG. 7 is a block diagram of a conventional video signal processing device.

[Explanation of symbols]

1 video signal processing device, 12 automatic gain control amplifier,
Reference Signs List 13 A / D converter, 14 YC separator, 15 color difference decoder 16 Low-pass filter, 17 sync separation circuit, 18 horizontal sync signal / vertical sync signal counter, 19
Slicer, 21 microcomputer

Claims (5)

[Claims] 1. A video signal processing apparatus for processing a video signal to which copyright protection information has been added, comprising: a video decoding means having a copyright protection information detection means for detecting the copyright protection information. Video signal processing device. 2. The copyright protection information detecting means according to claim 2, wherein said video decoding means includes a sync separation section, a low-pass filter section, an automatic gain control section, an interface, an A / D conversion section and a horizontal / vertical synchronization signal reference counter section. 2. The video signal processing device according to claim 1, wherein the video signal processing device is also shared. 3. The video signal processing apparatus according to claim 1, wherein said copyright protection information detecting means detects said copyright protection information superimposed within a vertical blanking period of the video signal. 4. The copyright protection information includes a VBID signal,
4. The video signal processing device according to claim 3, wherein the video signal is superimposed on the video signal by a closed caption signal, a WSS signal, or an AGC pulse method. 5. The video signal processing apparatus according to claim 1, wherein said copyright protection information detecting means detects said copyright protection information added as watermark information on an image.