JP3284680B2 - Digital video transmitter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video transmission apparatus for transmitting a digital video signal of HDTV.
Things.

[0002]

2. Description of the Related Art The spread of high definition television (HDTV) is expected. HD in broadcast studios
A standard for digitally transmitting TV video signals has been set,
It is published as BTA (Broadcasting Technology Development Council) standard S-002. FIG. 5A shows an analog video signal and a BTA.
The timing relationship with the standard S-002 is shown in FIG.
5 shows a video timing reference code of the standard S-002.

In this standard, in order to clarify the timing between a video signal and an analog synchronizing signal waveform, FIG.
As shown in (a), an SAV (Start of Active Video) is placed at the beginning of each video data block, and an EAV (End of Active Video) is placed at the end of each video data block. Each video device detects SAV and EAV from the transmitted digital video signal, detects horizontal synchronization and vertical synchronization timing, and establishes synchronization.

Hereinafter, a conventional digital video receiving apparatus will be described with reference to the drawings. FIG. 4 is a block diagram of an example of a conventional digital video receiving apparatus.

In FIG. 4, when a digital video signal of BTA standard S-002 is input, a horizontal synchronization detecting circuit 1
In step 3, the EAV and SAV patterns are detected, the timing of horizontal synchronization is detected, and a horizontal synchronization timing signal is output. On the other hand, the field information detection circuit 20 detects information about the field from the horizontal synchronization timing signal output from the horizontal synchronization detection circuit 13 and the input digital video signal.

In the BTA standard S-002, as shown in FIG. 5 (b), an F bit indicating whether the field is a first field or a second field in a video signal timing reference code, and a field blanking period or another period. Are multiplexed. Here, the case where the field information detection circuit 20 detects the F bit in the video signal timing reference code will be described.
The F bit output from 0 is input to the synchronization establishment determination circuit 15. When the F bit is input to the synchronization establishment determining circuit 15, a change point between 0 (first field period) and 1 (second field period) of the F bit is detected, and the establishment of a video frame is determined. When established, it outputs a synchronization frame synchronization signal.

[0007]

However, in the above conventional configuration, when the input digital video signal changes (when synchronization of the video signal must be newly established), the F bit changes from 0 to 1. 1 point per frame
Therefore, it takes one or more frames to establish frame synchronization of a newly input digital video signal.

Further, F of the input digital video signal
If a bit is entered incorrectly, it will detect synchronization incorrectly,
Next, synchronization cannot be established until an accurate F bit is input, that is, until a correct F bit change point is input.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and provides a digital video transmitting apparatus and a digital video receiving apparatus capable of establishing accurate frame synchronization of a digital video signal at an early stage.

[0010]

Means for Solving the Problems] In order to forming the object reaches, in a digital video transmission apparatus of the present invention, before transmitting
The HDTV digital video signal is a BTA (broadcast technology)
Development Council) Luminance signal and color difference signal of S-002 standard
Time multiplexing of the luminance signal and the two color difference signals
Input signal to input the
And the luminance signal input to the input circuit at the same timing
And a signal obtained by temporally multiplexing two color difference signals
During the horizontal blanking period that exists for each line,
Line number multiplexing circuit for multiplexing numbers
Configuration.

Further, in the digital video transmitting apparatus of the present invention,
Means that the HDTV digital video signal to be transmitted is B
Primary color signal of TA (Broadcasting Technology Development Council) S-002 standard
So that a plurality of primary color signals are
Input to the input circuit and the input circuit at the same timing
Water that exists for each line of the multiple primary color signals
Lines that multiplex line numbers during the flat blanking period
And a number multiplexing circuit.

[0012]

[0013]

According to the present invention, a BTA (broadcasting technology)
Technical Development Council) Luminance signal of S-002 standard and BTA
(Broadcasting Technology Development Council) The two colors of the S-002 standard
The difference signal and the time-multiplexed signal are
Input at the same timing
A signal obtained by temporally multiplexing a signal and two color difference signals
A line number is multiplexed (added) and transmitted during a horizontal blanking period existing for each line.

Further , the present invention relates to a BTA (Broadcasting Technology Development Council).
) A plurality of primary color signals of the S-002 standard
Input at the same time,
Horizontal blanking that exists for each line of primary color signal
During the logging period, the line number is multiplexed (added) and transmitted.

[0015]

[0016]

[0017]

[0018]

(Embodiment 1) A digital video transmitting apparatus and a digital video receiving apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a digital video transmitting device and a digital video receiving device according to a first embodiment of the present invention. As components shown in FIG. 1, 11 is an input terminal, 12 is a line number multiplexing circuit, 13 is a horizontal synchronization detection circuit, 14 is a line number detection circuit, and 15 is a synchronization establishment determination circuit.

The signal input from the input terminal 11 is BT
It is assumed to be an HDTV digital video signal of A-standard S-002. In the transmitting section (transmitting device), the line number multiplexing circuit 12 converts the digital video signal input during all horizontal blanking periods (digital line blanking period, between EAV and SAV) of the input digital video signal. And multiplex the line numbers.

When a digital video signal to which a line number is added is input to a receiving unit (receiving device), a horizontal synchronization detection circuit 13 detects an EAV pattern of the digital video signal and outputs a horizontal synchronization timing signal. . On the other hand, the line number detection circuit 14 receives the horizontal synchronization timing signal output from the horizontal synchronization detection circuit 13 and detects the line number added by the transmission unit from the input digital video signal. Synchronization establishment judgment circuit 15
Establishes frame synchronization based on the line number value output from the line number detection circuit 14 and outputs a frame synchronization signal.

As described above, according to the present embodiment, the establishment of frame synchronization is determined based on the detected line number, and when the frame synchronization is established, a frame synchronization signal is output. When the digital video signal changes, frame synchronization can be established early.

(Embodiment 2) Next, a digital video transmitting apparatus and a digital video receiving apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of the digital video transmitting device and the digital video receiving device of the present embodiment. 2, 11 is an input terminal, 12 is a line number multiplexing circuit, 13 is a horizontal synchronization detection circuit, 14 is a line number detection circuit, 20 is a field information detection circuit, and 21 is a synchronization establishment determination circuit.

In FIG. 2, a signal input from an input terminal 11 is a digital video signal of HDTV of BTA standard S-002. In the transmitting section (transmitting device), the line number multiplexing circuit 12 converts the digital video signal input during all horizontal blanking periods (digital line blanking period, between EAV and SAV) of the input digital video signal. And multiplex the line numbers.

When a digital video signal to which a line number is added is input to the receiving section (receiving apparatus), the horizontal synchronization detecting circuit 13 detects an EAV pattern of the digital video signal and outputs a horizontal synchronization timing signal.
On the other hand, the line number detection circuit 14 receives the horizontal synchronization timing signal output from the horizontal synchronization detection circuit 13, and detects the line number added by the transmission unit from the input digital video signal.

The field information detecting circuit 20 receives the horizontal synchronizing timing signal output from the horizontal synchronizing detecting circuit 13 and converts the F bit of the input digital video signal (first field when 0, second field when 1; Show)
Is detected. The synchronization establishment determination circuit 21 compares the line number detected and output by the line number detection circuit 14 with the F bit detected and output by the field information detection circuit 20, and the value of the detected line number is accurately determined. It determines whether frame synchronization has been established and outputs a frame synchronization signal.

As described above, according to the present embodiment, the receiving unit detects the line number added by the transmitting unit and the field information of the video signal, and establishes frame synchronization based on the detected line number and the field information. Therefore, frame synchronization can be more accurately established.

(Embodiment 3) Next, a digital video transmitting apparatus and a digital video receiving apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration of the digital video transmitting device and the digital video receiving device of the present embodiment. As components shown in FIG. 3, 31 and 32 are input terminals, 12 is a line number multiplexing circuit, 13 is a horizontal synchronization detecting circuit, 33 is a first line number detecting circuit, 34 is a second line number detecting circuit, 22 Is a synchronization establishment determination circuit.

In FIG. 3, a signal input from an input terminal 31 is a luminance signal Y of an HDTV digital video signal of BTA standard S-002, and a signal input from an input terminal 32 is an HDTV digital signal of BTA standard S-002. Pb / which is obtained by temporally multiplexing two color difference signals of the digital video signal of
Let it be a Pr signal.

First, in the transmitting section (transmitting apparatus), the input terminal 31 and the input terminal 32 are Pb / Pr obtained by temporally multiplexing the luminance signal Y and two color difference signals at the same timing.
A signal is input. The line number multiplexing circuit 12 performs all horizontal blanking periods (digital line blanking periods, Pb / Pr signals) obtained by temporally multiplexing the luminance signal Y of the input digital video signal and the two color difference signals. (Between EAV and SAV) and multiplexes the line numbers of the input digital video signals and transmits them.

Next, a Pb / Pr signal obtained by temporally multiplexing a luminance signal Y of a digital video signal to which a line number of the digital video signal is added and two color difference signals is input to a receiving unit (receiving device). Then, the horizontal synchronization detecting circuit 13 detects the EAV pattern of the luminance signal Y and outputs a horizontal synchronization timing signal. Further, the first line number detection circuit 33 receives the horizontal synchronization timing signal output from the horizontal synchronization detection circuit 13 and detects and outputs the line number added by the transmission unit from the input luminance signal Y.

The second line number detecting circuit 34
Receives the horizontal synchronization timing signal output from the horizontal synchronization detection circuit 13 and
A transmission unit detects and outputs a line number added from a Pb / Pr signal obtained by temporally multiplexing two color difference signals.
The synchronization establishment determination circuit 22 is detected and output from the Pb / Pr signal obtained by temporally multiplexing the luminance signal Y and two color difference signals by the first line number detection circuit 33 and the second line number detection circuit 34. The values of the line numbers are compared, it is determined whether the detected value is correct, the establishment of frame synchronization is determined, and a frame synchronization signal is output.

As described above, according to this embodiment, the receiving unit detects the line numbers added to the plurality of channels by the transmitting unit, and establishes the frame synchronization by the line numbers detected from the plurality of channels. Thus, accurate frame synchronization of a digital video signal can be established early.

In the above description, the BTA standard S-0
02, a luminance signal Y of an HDTV digital video signal;
Although a Pb / Pr signal obtained by temporally multiplexing two color difference signals is used, the present invention can be applied to the case of primary color signals G, B, and R of an HDTV digital video signal of BTA standard S-002.

[0034]

As described above, according to the present invention, simultaneous input
For each of the input multi-channel video signals,
To add a line number for each line and send it,
In a receiving device that receives video signals of multiple channels,
Using line numbers of video signals of multiple channels
Enables early and accurate HD by enabling frame synchronization
The frame synchronization of the digital video signal of the TV can be established.

[0035]

[0036]

[Brief description of the drawings]

FIG. 1 is a block diagram showing a digital video transmitting device and a digital video receiving device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a digital video transmitting apparatus and a digital video receiving apparatus according to one embodiment of the present invention.

FIG. 3 is a block diagram showing a digital video transmitting apparatus and a digital video receiving apparatus according to one embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional digital video receiver.

5A is a diagram showing a timing relationship between an HDTV digital video signal of the BTA standard S-002 and an HDTV analog video signal. FIG. 5B is a diagram showing a video timing reference code in the HDTV digital video signal of the BTA standard S-002. Diagram shown

[Explanation of symbols]

 11, 31, 32 Input terminal 12 Line number multiplexing circuit 13 Horizontal synchronization detection circuit 14 Line number detection circuit 15 Synchronization establishment judgment circuit 20 Field information detection circuit 21 Synchronization establishment judgment circuit 22 Synchronization establishment judgment circuit 33 First line number detection circuit 34 Second Line Number Detection Circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N ^7/ 00-7/088 H04N 5/04

Claims (2)

(57) [Claims] 1. An HDTV digital video signal is transmitted.
A digital video transmitting apparatus, wherein the HDTV digital video signal is
Technical Development Council) Luminance signal and color difference signal of S-002 standard
A is, the luminance signal and the temporally multiplex two of said color difference signals
Input signal to input the
And the luminance signal input to the input circuit at the same timing.
Signal and a signal obtained by temporally multiplexing the two color difference signals.
All horizontal blankins that exist for each video line
Multiple line numbers during the
Digital video transmission characterized by having a double circuit
Communication device. 2. An HDTV digital video signal is transmitted.
A digital video transmitting apparatus, wherein the HDTV digital video signal is
(Technical Development Council) A plurality of primary color signals which are S-002 standard primary color signals are input at the same timing.
Input circuit, and a plurality of the input circuit input to the input circuit at the same timing
All horizontal lines that exist for each video line of each primary color signal
Lines that multiplex line numbers during the blanking period
A digit multiplexing circuit.
Tal video transmission device.