JP2001054073A - Video signal receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the ringing which occurs at both ends of an analog effective line when the received video signals are outputted. SOLUTION: A blanking data replacement circuit 6 of the receiving side stores the first and last data on a digital effective line and replaces two timing reference signals of a digital horizontal blanking period are replaced with the first and last data respectively to move the changing point of data on a boundary part set between the digital effective line and the digital horizontal blanking period into this blanking period. Thus, the ringing occurring position moves to the horizontal blanking period and accordingly the influence caused in an effective period can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, SMPTE
(Society of Motion Pictur
e and Television Engineer
s) A progressive video signal (to be referred to as 720p hereinafter) having a total number of 750 scanning lines and 720 effective scanning lines conforming to 296M,
BTA (Broadcasting Technology Development Council) S-002 compliant 1125 scanning lines, 1035 effective scanning lines (hereinafter 10
35i), 1125 total scanning lines, 1 effective scanning line
The present invention relates to a video signal receiving apparatus that receives a video signal in which the analog horizontal blanking period matches the digital horizontal blanking period, such as 035 lines (to be referred to as 1080i hereinafter).

[0002]

2. Description of the Related Art Conventionally, 103 based on BTA S-002
A video signal receiving apparatus that receives a video signal in which the analog horizontal blanking period matches the digital horizontal blanking period, such as the video signals of 5i and 1080i, is described in, for example, JP-A-7-30865. Are known. The configuration of a conventional video signal receiving apparatus based on this video signal receiving apparatus will be described with reference to FIG.

In FIG. 2, reference numeral 1 denotes an added timing reference signal detected from parallel data after serial / parallel conversion of serial data SD to which a timing reference signal is added during a digital horizontal blanking period of a video signal. And a serial / parallel conversion circuit 2 for synchronizing received data to parallel data based on the detection result of the timing reference signal detection circuit 1, and 3 for an output of the serial / parallel conversion circuit 2. Among the data, a color difference data separation circuit that separates time-division multiplexed color difference data Pb / Pr data into two systems of data Pb and Pr, 4 is an output of the serial / parallel conversion circuit 2 and the output of the color difference data separation circuit 3 Digital line blanking of data It is a first blanking data replacement circuit for replacing the level of the data (blanking data).

[0004] FIG. 3 shows a 1080 based on BTA S-002.
FIG. 4 shows a position where a timing reference signal or the like is added to the digital video signal shown in FIG. 3 and a data sequence obtained by word-multiplexing the two video signals Y and Pb / Pr of the video signal handled by i. FIG.

Hereinafter, the video signals shown in FIGS. 3 and 4 will be described.

As shown in FIG. 3, a video signal handled by 1080i conforming to BTA S-002 has a data rate of 7 bits.
This is two-system digital video data of Pb / Pr with a data rate of 74.25 Msps obtained by time division multiplexing of 4.25 Msps Y, Pb and Pr. Then, a timing reference signal EAV (End of Acti) is provided at the start position and the end position of the digital horizontal blanking period (digital line blanking period) of the digital video data.
ve Video) and SAV (Startof A)
active video), line number data, error detection code data, and the like are added to form two-system data as shown in the upper part of FIG. The remaining part of the digital horizontal blanking period is undefined word data in which auxiliary data can be multiplexed. To this part, an auxiliary data packet in which various auxiliary data such as audio signals and control signals are multiplexed is added. After the two systems of data are time-division multiplexed as shown at the bottom of FIG.

Next, the operation of the conventional video signal receiving apparatus will be described with reference to FIGS. 2, 4 and 5.

The serial data described above is transmitted after being subjected to E / O (electrical / optical) conversion and the like, and then returned to the original serial data by O / E (optical / electrical) conversion and the like, as shown in FIG. Is input to the video signal receiving device. This serial data S
D is converted into parallel data by the serial / parallel conversion circuit 2. At this time, the timing reference signal added during the digital horizontal blanking period is detected by the timing reference signal detection circuit 1 to be converted into word-synchronous parallel data as shown in the lower part of FIG. Are converted into word data of two systems of Y system and Pb / Pr system as shown in FIG. For the Pb / Pr system, the color difference data separation circuit 3 further adds two Pb and Pr signals.
It is separated into word data of the system and output. afterwards,
In the first blanking data replacement circuit 3, the data in the digital horizontal blanking period is converted into data of a predetermined blanking level (040H, Pb and Pr for Y system).
The system is replaced by 200H and H represents hexadecimal notation), and the digital video data is output as three systems of data Y, Pb, and Pr as shown in FIG.

[0009]

In general, digital video data is composed of digital effective lines and digital horizontal blanking periods. Normally, there is no correlation between the amplitude levels of the data contained in the two, and the change in the amplitude level of the data from the digital effective line to the digital horizontal blanking period and vice versa may be steep.

In the case where the amplitude level of adjacent data changes sharply in the state of digital data, the amplitude is changed to D.
When the / A conversion is performed, a phenomenon called "ringing" occurs around analog data at a point of change in analog data.
When the digital horizontal blanking period is shorter than the analog horizontal blanking period as in the case of NTSC video signals,
As a method of reducing ringing, for example, a method of gradually changing the amplitude level in a step-like manner in the state of digital data so that the amplitude level does not change so sharply before and after the change point can be considered. That is, at the beginning and end of the analog effective line, there is a case where a technique called oblique blanking processing in which a change in the amplitude level of data is moderated by adding digital data of an appropriate amplitude level to the outside thereof is sometimes adopted. .

FIG. 7 shows 1035 according to BTA S-002.
6 shows the timing relationship between the data formats of i and 1080i and the analog video signal.

In FIG. 7, the upper part shows the data format of an analog video signal, and the lower part shows the data format of a digital video signal corresponding to the analog video signal.

As shown in FIG. 1, BTA S-002
In the compliant 1035i and 1080i video signals, the analog horizontal blanking period (analog line blanking period) and the digital horizontal blanking period (digital line blanking period) coincide with each other. 1 / video signal amplitude
Two level signals are allowed. Further, as a digital data format, a video data block is defined to include a digital effective line and timing reference signals EAV and SAV. That is, it can be considered that the digital video data includes four words at both ends of the digital horizontal blanking period in addition to the digital effective line data.

When such a video signal is transmitted serially, the timing reference signals EAV and SAV are added to both ends of the digital horizontal blanking period at the time of transmission, so that the data originally existing at that position, That is, as shown in FIG. 3, data YD1920, YD1921, and YD1920 at both ends of the digital horizontal blanking period.
1922, YD1923, PbD960, PrD96
0, PbD961, PrD961 and YD2196,
YD2197, YD2198, YD2199, PbD1
098, PrD1098, PbD1099, PrD10
A total of 16 words of data will be lost.
When the conventional video signal receiving apparatus receives and outputs this data, the data in the digital horizontal blanking period is converted into data of a predetermined blanking level (040H for Y system, 200H for Pb / Pr system). Replace and output.

Therefore, even if the above-described oblique blanking processing is performed, the data is lost by transmission, and the effect of the processing is lost when the received video signal is output.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a video signal receiving apparatus capable of reducing ringing generated at both ends of an analog effective line when outputting a received video signal. I do.

[0017]

In order to solve such a problem, a video signal receiving apparatus according to the first aspect of the present invention comprises:
A timing reference signal detecting circuit for receiving the serial data to which the timing reference signal is added during the digital horizontal blanking period of the video signal and detecting the timing reference signal; and receiving data based on a detection result of the timing reference signal detecting circuit. A serial / parallel conversion circuit for converting the data into parallel data by synchronizing the
The first data and the last data of the digital effective line of the output data of the parallel conversion circuit are stored, and at least one data from the last data of the digital horizontal blanking period is stored.
Replace the data above the sample with the first data,
A timing reference signal replacement circuit for replacing at least one sample or more of data from the first data with the last data, so that data does not change at a boundary between a digital effective line and a digital horizontal blanking period. I do.

Thus, when a video signal whose analog horizontal blanking period coincides with the digital horizontal blanking period is received and output, the position where ringing occurs near both ends of the analog effective line is determined by the analog horizontal blanking period. It is possible to move to a period so that the influence does not appear in the effective screen.

According to a second aspect of the present invention, in the video signal receiving apparatus, the timing reference signal replacement circuit converts the first timing reference signal SAV added at the end of the digital horizontal blanking period into the first data. And the second timing reference signal EAV added at the front end of the digital horizontal blanking period is replaced with the last data.

Thus, when receiving the serial data to which the timing reference signal is added during the digital horizontal blanking period of the video signal, and decoding and outputting the original digital video signal, the data at both ends of the digital effective line is Even when the amplitude level of the data during the digital horizontal blanking period is significantly different, it is possible to reduce the influence of the occurrence of ringing on the effective screen when converting the data into analog data and outputting it.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 3 is a block diagram illustrating a configuration of a video signal receiving device according to an embodiment.

In FIG. 1, a timing reference signal detection circuit 1, a serial / parallel conversion circuit 2, and a color difference data separation circuit 3 are the timing reference signal detection circuit 1, the serial / parallel conversion circuit 2 in the conventional video signal receiving apparatus of FIG. And the same as the color difference data separation circuit 3.
Numeral 5 stores the first data and the last data of the digital effective line of the output data of the serial / parallel conversion circuit 2 and the color difference data separation circuit 3 and at least one sample or more from the last data of the digital horizontal blanking period. A timing reference signal replacement circuit for replacing data with the first data stored earlier and replacing at least one sample or more of data from the first data with the last data stored previously; The second blanking data replacement circuit replaces the remaining digital horizontal blanking period data of the output data of the circuit 5 with data of a predetermined blanking level.

The operation of the video signal receiving apparatus according to the first embodiment of the present invention will be described below with reference to FIGS. 1, 4 and 6.

In the video signal receiving apparatus of FIG. 1, serial data SD to which a timing reference signal is added during a digital horizontal blanking period of a video signal is input to a serial / parallel conversion circuit 2. The operations of the serial / parallel conversion circuit 2 and the timing reference signal detection circuit 1 are the same as those of the conventional video signal receiving apparatus shown in FIG. And Pb / Pr word data.

The Pb / Pr system is further separated by the color difference data separation circuit 3 into two systems of word data of Pb and Pr and output. These three systems of data are input to the timing reference signal replacement circuit 5. Here, the data at both ends of the digital effective line, that is, the first data and the last data of the digital effective line are temporarily stored, and at least one sample or more of data from the last data of the digital horizontal blanking period is firstly stored. Data, that is, the same data as the data located immediately after the SAV, and at least 1
The data above the sample is replaced with the last data, that is, the same data as the data located immediately before the EAV.

The "data of at least one sample or more from the last data" and "the data of at least one sample or more from the first data" are one sample (EAV and SAV are composed of four samples). ) To the number of data included in the digital horizontal blanking period.

Thereafter, during the digital horizontal blanking period in the second blanking data replacing circuit 6, data other than the data replaced by the timing reference signal replacing circuit 5 is replaced with data of a predetermined blanking level (for example, in the Y system, 040H, 200b for Pb and Pr systems), and then the digital video data is output as three systems of data Y, Pb and Pr as shown in FIG.

That is, in the video signal receiving apparatus according to the first embodiment of the present invention, the received serial data SD
Even if the amplitude level of the blanking data that replaces the data at both ends of the digital effective line and the data in the digital horizontal blanking period is significantly different, the position where the data amplitude level changes moves within the digital horizontal blanking period. It is possible to reduce the influence of the occurrence of ringing when converting the analog data into analog data and outputting the analog data within the effective screen.

(Second Embodiment) In the video signal receiving apparatus according to the second embodiment of the present invention, the timing reference signal replacing circuit 5 is also used in the video signal receiving apparatus according to the first embodiment. The data at both ends of the effective line, that is, the first data and the last data of the digital effective line are temporarily stored, and the timing reference signal SA
Replace only V with the first data stored earlier,
Only the timing reference signal EAV is replaced with the last data previously stored.

That is, the processing of the video signal according to the present invention is minimized, and is affected when a timing reference signal is added again as a video signal of the serial digital interface standard as shown in FIG. It is not to be.

Here, the effects described above will be described.
The present invention is effective only when a video signal is converted into an analog signal and output. Considering the case of exchanging data in the state of digital data, in the present invention, data is processed into an arbitrary form that does not conform to the standard. If the process of returning to the above is not performed, the processing performed in the present invention will be permanently left. However, if the processing in the present invention is limited to only the positions of the EAV and SAV as in the second embodiment, if data is subsequently exchanged in a form conforming to the serial digital interface standard (SDI), Since EAV and SAV will be added again,
Processing in the present invention will inevitably be canceled and will have no effect. That is, it is possible to exchange data conforming to the standard.

That is, in the video signal receiving apparatus according to the second embodiment of the present invention, the amplitude level of the blanking data which replaces the data at both ends of the digital effective line of the received serial data and the data in the digital horizontal blanking period is changed. Even in the case of a large difference, the position where the data amplitude level changes moves within the digital horizontal blanking period, so that the effect of ringing when converting it into analog data and outputting it is reduced in the effective screen. It becomes possible.

In the first embodiment and the first embodiment of the present invention, Pb /
Although the data of the Pr system is separated into the two data systems of Pb and Pr, similar data may be replaced in a time-division multiplexed state. Further, the order of the timing reference signal replacement circuit 5 and the blanking data replacement circuit 6 may be reversed. Further, the blanking data replacement circuit 6 is not always necessary.

[0035]

As described above, according to the present invention, when a serial digitally transmitted video signal is received, converted into an analog signal and output, the position where ringing occurs near both ends of the analog effective line is determined. The effect is obtained that the movement can be made during the analog horizontal blanking period so that the influence does not appear in the effective screen.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a configuration of a conventional video signal receiving device.

FIG. 3 is a schematic diagram showing digital video data handled by the conventional and the video signal receiving apparatuses of the present invention.

FIG. 4 is a schematic diagram showing a Y data sequence, a Pb / Pr data sequence, and a word multiplexed data sequence of digital video data conforming to BTA S-002.

FIG. 5 is a schematic diagram showing Y, Pb, and Pr data sequences of digital video data output by a conventional video signal receiving device.

FIG. 6 is a schematic diagram showing Y, Pb, and Pr data sequences of digital video data output by the video signal receiving device of the present invention.

FIG. 7 is a timing chart showing a timing relationship between an analog video signal and digital video data according to BTA S-002.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Timing reference signal detection circuit 2 Serial / parallel conversion circuit 3 Color difference data separation circuit 4, 6 Blanking data replacement circuit 5 Timing reference signal replacement circuit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 11/24

Claims (2)

[Claims] 1. A timing reference signal detection circuit for receiving serial data to which a timing reference signal is added during a digital horizontal blanking period of a video signal and detecting the timing reference signal, and a detection result of the timing reference signal detection circuit A serial / parallel conversion circuit for converting the received data into parallel data based on word synchronization of the received data, and storing the first data and the last data of the digital effective line of the output data of the serial / parallel conversion circuit and performing digital horizontal conversion. A timing reference signal replacement circuit that replaces at least one sample or more of data from the last data of a blanking period with the first data and replaces at least one sample or more of data from the first data with the last data. Effective line and digital horizontal blank A video signal receiving device, wherein data does not change at a boundary of a king period. 2. A timing reference signal replacement circuit replaces the first timing reference signal SAV added at the end of the digital horizontal blanking period with the first data, and is added to the front end of the digital horizontal blanking period. 2. The video signal receiving apparatus according to claim 1, wherein said second timing reference signal EAV is replaced with said last data.