JPH05161121A - Decoder for edtv signal - Google Patents

Abstract

PURPOSE:To correctly receive the image of a reproduced signal on a TV corresponding with EDTV by adding information indicating that an EDTV encode signal is decoded to a decode output video signal, thereby recording the decoded EDTV signal onto a VTR. CONSTITUTION:A video signal inputted to a terminal 1 is fed to a decoding circuit 2 and an EDTV detection circuit 3. The circuit 3 checks an encode identification signal multiplied for a vertical blanking period and outputs the video signal without demodulation processing when the identification signal indicates an NTSC signal via a switching circuit 4. When the circuit 3 detects the signal to be the EDTV encode signal, the circuit 2 implements demodulation processing to convert the signal into a wide aspect picture. Then an identification signal addition circuit 5 adds the decode identification signal to the rear part of the encode identification signal as binary data and outputs the sum to a terminal 6 and the result is recorded on a VTR. Thus, decoding processing in duplicate is prevented and the reproduced signal is correctly received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EDTV signal decoding device for correctly displaying an EDTV decoded signal on a receiver.

[0002]

2. Description of the Related Art At present, as an EDTV system, wide aspect and high definition of a television receiver are under study. This is to change the conventional receiver having an aspect ratio of 4: 3 to the aspect ratio of 16: 9 and to transmit high-definition information in a multiplexed manner to enhance the realism of a large-screen receiver. FIG. 7 is a diagram showing an example of a conventional EDTV encoding method. FIG. 7a shows a case where the image is displayed on a receiver having an aspect ratio of 4: 3, and FIG. 7b shows a case where the image is displayed on a receiver having a 16: 9 aspect ratio. This method is called a letter box method, in which 480 effective scanning lines are compressed into 360 lines to transmit the main screen, and 480 effective scanning lines are converted into 3 lines.
In order to prevent deterioration of the vertical resolution due to compression to 60 lines and to improve the horizontal resolution, the vertical and horizontal high frequency components are multiplexed and transmitted in the non-image parts above and below the main screen.

In order to distinguish it from the NTSC signal, for example, as shown in FIG. 8a, an identification signal indicating that it is an EDTV encoded signal is added as binary data at an appropriate position in the vertical blanking period. The need arises. Also, there is a possibility that a mode in which only the aspect ratio is changed from 4: 3 to 16: 9 will exist in the future, although it is not particularly related to EDTV. For example, as shown in FIG.
It is possible to add a wide aspect identification signal in addition to the identification signal of the encoding of No. 1, but it has not been decided yet. In any case, if there is no identification signal, the display mode of the TV receiver is manually switched, which is extremely unusable for the user.

On the other hand, on the EDTV receiver side, the identification signal is determined, and if it is determined that the signal is an EDTV encoded signal, a decoding operation is performed to demodulate the encoded signal into the original baseband signal. At the beginning of EDTV broadcasting, there is always a situation where the user has an EDTV-compatible receiver but does not have an EDTV-compatible VTR. In this case, as shown in FIG. The decode output signal of the decoder is connected to the VTR and recorded. Since the VTR that does not support EDTV cannot discriminate whether the recorded signal is a normal NTSC signal or an EDTV decoded signal, the input signal is recorded and reproduced as it is. Therefore, if the EDTV identification signal added when the EDTV broadcast is transmitted is output as it is to the decoded output signal of the EDTV compatible TV, the VTR records this identification signal and the reproduction signal is output to the receiver.

In the receiver, the input signal is a normal NT signal.
It is determined whether the signal is an SC signal or an EDTV encoded signal. However, since the EDTV identification signal is included, it is E even though it is an EDTV decoded signal.
It is erroneously discriminated as a DTV encoded signal. Therefore, unnecessary decoding processing is performed and a correct image cannot be reproduced on the receiver.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
When a signal added with an identification signal indicating that it is a V-encoded signal is received and decoded into the original baseband signal and then recorded in an existing VTR, the identification signal is also recorded as it is. When the playback output signal of is input to a receiver compatible with EDTV, the receiver is likely to detect the identification signal and perform the decoding process again. In this case, the correct image cannot be reproduced on the receiver. was there. Further, it is impossible to distinguish whether the decoded signal has an aspect ratio of 4: 3 or 16: 9, and if a 16: 9 signal is erroneously discriminated as 4: 3, a vertically long image is generated. there were.

The present invention has been made in order to solve the above-mentioned problems, and a decoded EDTV signal is recorded in an existing VTR, and the reproduced signal is recorded in an EDTV compatible TV.
It is an object of the present invention to provide a decoding device for an EDTV signal that can be correctly received by the.

[0008]

E according to the invention of claim 1
The DTV signal decoding device is a decoded EDTV
In the vertical blanking period, the identification signal adding means for adding the decoding signal identification signal indicating the decoding is provided.

Further, the EDTV signal decoding apparatus according to the second aspect of the present invention is an encoding identification signal removing means for invalidating an encoding identification signal indicating an EDTV encoding signal added at the time of broadcasting, and a decoding signal. The decoding signal identification signal adding means for adding the decoding signal identification signal indicating

The EDTV signal decoding apparatus according to the third aspect of the present invention comprises an encoding identification signal removing means for invalidating the encoding identification signal indicating the EDTV encoding signal added during broadcasting. ..

[0011]

The identification signal adding means in the invention of claim 1 is
A decode signal identification signal indicating that decoding is performed is added during the blanking period of the decode output signal of the EDTV.

The encode identification signal removing means in the invention of claim 2 removes the encode identification signal indicating the EDTV encode signal added at the time of broadcasting. Further, the decode signal identification signal adding means adds a decode signal identification signal indicating that it is a decode signal to the decode signal of the EDTV.

The encode identification signal removing means according to the present invention removes the encode identification signal indicating the EDTV encode signal added during broadcasting.

[0014]

EXAMPLES Example 1. Hereinafter, the present invention will be described with reference to the drawings. The case where the EDTV encode identification signal is added to the input video signal will be described below. FIG. 1 is a block circuit diagram showing an EDTV signal decoding apparatus according to an embodiment of the present invention. In the figure, a video signal is input to a terminal 1 and supplied to a decoding circuit 2 and an EDTV detection circuit 3. The EDTV detection circuit 3 checks the encode identification signal multiplexed in the vertical blanking period of the video signal as shown in FIG. 2a to determine whether the input video signal is the EDTV encoded signal or the normal NTSC signal. EDTV detection circuit 3 is normal NTS
When it is determined that the signal is a C signal, without the demodulation process, through the switch circuit 4 controlled by the output signal of the EDTV detection circuit 3,
It is output as is.

When the signal is identified as an EDTV encoded signal, the decoding circuit 2 performs demodulation processing to demodulate various signals multiplexed in the upper and lower non-image parts to obtain an aspect ratio of 16:
9 Wide aspect image. Decode circuit 2
The output signal is then supplied to the identification signal adding circuit 5. In the identification signal adding circuit 5, as shown in FIG. 2B, the decode identification signal is added as binary data to the rear part of the encode identification signal. The output signal of the identification signal adding circuit 5 is output to the terminal 6 through the switch circuit 4. The terminal 6 is generally supplied to the video input terminal of the existing VTR and recorded, but since the decode identification signal is recorded, the receiver side can be easily discriminated by providing a detection circuit. Therefore, the receiver does not disturb the image by performing the decoding process again.

Example 2. FIG. 3 is a block circuit diagram showing an EDTV signal decoding apparatus according to an embodiment of the present invention. The case where the EDTV encode identification signal is added to the input video signal will be described below. The video signal is input to the terminal 1, and the decoding circuit 2 and the EDT are connected.
It is supplied to the V detection circuit 3. The EDTV detection circuit 3 is shown in FIG.
The encode identification signal multiplexed in the vertical blanking period of the video signal as shown in a is checked, and the input video signal is an EDTV encode signal or a normal NTSC signal.
Determine if it is a signal. EDTV detection circuit 3 is normal N
If it is determined to be a TSC signal, EDTV is used without demodulation processing.
It is output as it is through the switch circuit 4 controlled by the output signal of the detection circuit 3. When the signal is identified as an EDTV encoded signal, the decoding circuit 2 performs demodulation processing to demodulate various signals multiplexed in the upper and lower non-picture portions and convert them into a wide aspect image with an aspect ratio of 16: 9.

The output signal of the decoding circuit 2 is supplied to the encode identification signal removing circuit 7. The encode identification signal removing circuit 7 completely removes the encode identification signal superimposed as the binary data as shown in FIG. 4b. The decoded signal from which the encode identification signal has been removed is then decoded.
It is supplied to the identification signal adding circuit 5. In the decoding identification signal adding circuit 5, as shown in FIG. 4c, the decoding identification signal is added as binary data after the encoding identification signal. The decode signal added with the code identification signal is output to the terminal 6 through the switch circuit 4. The terminal 6 is supplied to the video input terminal of the existing VTR for recording, but since the encode identification signal is removed and the decode identification signal is added, a simple detection circuit should be provided on the receiver side. Since the NTSC signal and the decoded signal can be discriminated from each other, the receiver does not perform the decoding process again, and the viewer is not confused by the vertically long image. The encoding identification signal removing circuit 7 and the decoding identification signal adding circuit 5 in this embodiment may be reversed in order.

Example 3. FIG. 5 is a block circuit diagram showing an EDTV signal decoding apparatus according to an embodiment of the present invention. Hereinafter, a case where a wide aspect identification signal indicating a wide aspect signal is added to the input video signal together with the EDTV encode signal will be described. A video signal is input to the terminal 1 and supplied to the decoding circuit 2 and the EDTV detection circuit 3. EDTV
The detection circuit 3 checks the encode identification signal multiplexed in the vertical blanking period of the video signal as shown in FIG. 6a and determines whether the input video signal is the EDTV encode signal or the normal NTSC signal. When the EDTV detection circuit 3 determines that the signal is a normal NTSC signal, it is directly output through the switch circuit 4 controlled by the output signal of the EDTV detection circuit 3 without demodulation processing. Also EDTV
When it is identified as an encoded signal, the decoding circuit 2 performs a demodulation process to demodulate various signals multiplexed in the upper and lower non-image parts and convert them into a wide aspect image with an aspect ratio of 16: 9.

The output signal of the decoding circuit 2 is supplied to the encode identification signal removing circuit 7. The encode identification signal removing circuit 7 completely removes the encode identification signal superimposed as binary data as shown in FIG. 7b. The decode signal from which the encode identification signal has been removed is output to the terminal 6 through the switch circuit 4. The terminal 6 is generally supplied to the video input terminal of the existing VTR for recording, but since the encode identification signal is removed and only the wide aspect identification signal remains, the receiver side has a wide aspect detection circuit. Normal NT just prepared
The SC signal and the wide aspect signal can be discriminated from each other, and the receiver does not perform the decoding process again to disturb the image, and the aspect ratio can be displayed correctly. .

In the above-mentioned embodiments, the vertical position of the vertical blanking period is set to the position where the identification signal is inserted, but the vertical blanking period is not particularly affected as long as it does not visually affect the video signal. It is not limited to.

Although the identification signal is described as binary data, it may be digital data or multi-valued data.

Further, all the explanations so far are made in NTSC.
Although the system has been described, widening (PAL plus, wide MAC) is being studied in the PAL system or the MAC system in Europe, but it can be applied similarly to the NTSC system.

[0023]

As described above, according to the invention of claim 1, when the EDTV encode identification signal is added to the input video signal, the EDTV signal decoded in the blanking period of the decoded video signal is used. Since the decoding identification signal indicating that there is a new signal is added, it is possible to prevent double decoding processing by detecting this on the TV receiver side, and thus it is possible to prevent the existing VT from being used.
Even if the decoded signal is recorded by R and the reproduced signal is input to the TV receiver, there is an effect that it can be displayed correctly.

According to the second aspect of the invention, when the EDTV encode identification signal is added to the input video signal, the encode identification signal included in the decoded video signal is removed and the widening is performed during the blanking period. Since it is configured to add a wide aspect identification signal indicating that it is an aspect signal, even if the decoded signal is recorded by the existing VTR and the reproduced signal is input to the TV receiver,
There is an effect that can be displayed correctly.

According to the third aspect of the invention, when the input video signal is added with the EDTV encode signal and the wide aspect identification signal indicating the wide aspect signal, the encoded identification of the decoded video signal is performed. Since it is configured to remove the signal, the receiver side has a normal NTS with a wide aspect detection circuit.
The C signal and the 16: 9 wide aspect signal can be discriminated, the decoded signal is recorded by the existing VTR, and the reproduced signal is T
Even if input to the V receiver, there is an effect that it can be displayed correctly.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing an EDTV signal decoding device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an identification signal in FIG.

FIG. 3 is a block circuit diagram showing an EDTV signal decoding device according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining an identification signal in FIG.

FIG. 5 is a block circuit diagram showing an EDTV signal decoding device according to an embodiment of the present invention.

6 is a diagram for explaining an identification signal in FIG.

FIG. 7 is a diagram showing an example of a conventional EDTV encoding system.

FIG. 8 is an example of a multiplex format of an identification signal which is being studied in the EDTV encoding method.

FIG. 9 is a diagram showing a connection form of a VTR having no EDTV decoder.

[Explanation of symbols]

 1 Video signal input terminal 2 EDTV decoder 3 EDTV detection circuit 4 Switch circuit 5 Decode identification signal addition circuit 6 Decoder output terminal 7 Encode signal removal circuit

Claims (3)

[Claims] 1. An ED which has been subjected to image compression processing to realize a wide-spectrum and high-definition television image while maintaining compatibility with a television signal having an aspect ratio of 4: 3.
What is claimed is: 1. A decoding device for decoding an EDTV encoding signal to which an encoding identification signal indicating a TV encoding signal is added, wherein the decoding output video signal includes the E signal.
An EDTV signal decoding apparatus comprising a decoding identification signal adding means for adding information indicating that a DTV encoding signal has been decoded. 2. An ED which has been subjected to image compression processing to realize a wide aspect and high definition television image while maintaining compatibility with a television signal having an aspect ratio of 4: 3.
A decoding device for decoding an EDTV encoding signal to which an encoding identification signal indicating a TV encoding signal is added, which is an EDTV identification for invalidating the encoding identification signal of the decoded output video signal. An EDTV signal decoding apparatus comprising a signal removing means and a decoding identification signal adding means for indicating that an EDTV encoding signal has been decoded. 3. An ED which has been subjected to image compression processing in order to realize a wide aspect and high definition television image while maintaining compatibility with a television signal having an aspect ratio of 4: 3.
A decoding device for decoding an EDTV encoding signal to which an encoding identification signal indicating a TV encoding signal and a wide aspect identification signal indicating a wide aspect signal are added. An EDTV signal decoding apparatus comprising EDTV identification signal removing means for invalidating the first identification signal of the signal.