JPH03293878A - Video disk reproducing system - Google Patents

Abstract

PURPOSE:To realize an additive function with sufficient effect by sending a required MUSE decoder control signal to a decoder after inserting to the free period of a MUSE signal in a player. CONSTITUTION:A decoder additive control signal 9 is generated at a player operation control circuit 7, and it is inserted to the free period of the MUSE signal to be outputted at a decoder additive control signal insertion circuit 10. Required additive control for the decoder is performed by the decoder additive control signal 9 to effectively realize various kinds of additive functions of the player other than decoder operation control by a control signal of MUSE transmission signal form. In such a manner, it is possible to control the operation of the MUSE decoder appropriately without connecting the player to the MUSE decoder with a specific wire, and to realize the additive function with sufficient effect.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The method of the present invention relates to a method for interconnecting a video disc player and a subsample decoder for reproducing television signals using a subsample transmission method.

(Prior Art) As a frequency band compression transmission method for high-definition television signals, there is a method using multiple sub-sampling transmission technology.

(Unexamined Japanese Patent Publication No. 81-284889 ``Multiple subsample transmission method''.Hereinafter, this method will be referred to as the MUSE method, and the transmission signal will be referred to as the MU
It is written as SE signal. ) This transmission method is used not only for broadcasting systems, but also for
It can also be applied to a recording/playback system using a video disc, and while a practically sufficient playback time can be obtained, a subsample decoder (hereinafter referred to as a MUSE decoder or simply a decoder) is required for broadcast reception and video disc playback. By sharing the image receiving device, it is possible to efficiently configure the image receiving device.

When playing a video disc in such a configuration, it is desirable to provide the following additional functions as in the case of a conventional NTSC television.

(1) Freezing of the played video or special playback based on this by the viewer's selection operation (2) Text display on the screen of information regarding the playback status etc. by the viewer's selection operation (3) Startup and termination , suppression of video and audio signals when normal signals are not being played, such as during video searches.In this case, these functions are not realized only by processing the playback signal on the video disc player (hereinafter referred to as the player) side. It is clear that a greater effect can be obtained by controlling the operation of the MLISE decoder to change appropriately depending on the situation, considering that the player side can only handle MUSE signals, that is, sub-sample encoded signals. In particular, screen character display can be performed with sufficient definition only by superimposing a character signal on a decoded video signal. Conventionally, for this reason, as shown in Fig. 1, a method was adopted in which the player sent a control signal to the MUSE decoder using a dedicated signal line separate from the MυSE signal, or only by signal processing on the player side. The effect remained insufficient.

(Problems to be Solved by the Invention) In order to realize additional functions with sufficient effects, it was necessary to connect a special control signal line from the player to the MUSE decoder.

(Means for solving the problem) The method according to the present invention inserts a necessary MUSE decoder control signal into an empty period on the MUSE signal in the player and sends it to the decoder, thereby creating a special control signal line. The feature is that additional functions with sufficient effects can be realized without connection.

Embodiment As an embodiment of the method of the present invention, only relevant parts of the signal processing block diagram of a player and a MUSE decoder are shown in FIG. 2, and will be described in detail below.

Playback MU output from the FM demodulation circuit in the player
The transmission signal format within one frame of the SE signal 1 is shown in FIG. 3. (Reprinted from NHK Technical Research Vol. 39, No. 2, Page 30.) YC video signal, audio/additional information signal, synchronization signal consisting of HD signal and frame pulse, clamp level signal, and encoded and decoded signals during video disc recording. In addition to the control signal for controlling the operation of the line number 584, a vacant period of approximately one line is provided. This period can be used for specific purposes in various transmission systems, and in video discs, it is usually used to record image address information and information necessary for player operation control (hereinafter referred to as control address signal). The control address signal reading circuit 6 is a circuit that reads this information, and the read information is input to the player operation control circuit 7. Viewer operation/selection information is also input to the player operation control circuit 7, and player operations such as starting playback, stopping, and searching for a desired image are controlled accordingly. On the other hand, after the playback) ILIsE signal 1 is converted into a digital signal by an A/D conversion circuit 2, a time-base correction circuit 3 is used to remove time-base fluctuations caused by disk eccentricity, etc. The video memory circuit 4 that performs the following generates a MUSE signal to be output from the player.

The circuit configuration and operation described above are not particularly different from those of conventional players.

The feature of the present invention is that the player operation control circuit 7 generates a decoder additional control signal 9, and the decoder additional control signal insertion circuit 10 inserts this into the vacant period of the MUSE signal to be output. The decoder additional control signal 9 is used to control the decoder to perform necessary additional control in order to effectively realize various additional functions of the player, in addition to the decoder operation control by the control signal in the MUSE transmission signal format. An example of the signal format is shown in FIG.

FIG. 4(a) shows the format of signal insertion. line number 56
4 is the above-mentioned idle period, which is a period in which a control address signal of another format is inserted in the reproduced MUSE signal 1. Since this signal content has already been read by the control address signal reading circuit 6, it may disappear from the output signal from the player by being replaced with the MUSE decoder additional control signal. In the figure, the transmission sample number is one of the samples transmitted at 16.2 megasamples/second in the MUSE signal.
Indicates the number in the line. Transmission sample numbers 1 to 12 are H
This is the D signal. The MLISE decoder additional control signal 9 is
In the decoder additional control signal insertion circuit 10, bits "0" and "1" are set to a level approximately equal to black and white on the video luminance signal at a rate of 1 bit per 4 sample periods during the period of transmission sample numbers 23 to 470. N corresponding to
It is inserted using the RZ (Non Return to Zero) signal format. The format of signal insertion is synchronized to the MLISE signal transmission lock (16.2 MHz), the transmission rate is low relative to the MLISE signal transmission frequency bandwidth of 8.1 MHz, and the level for bits “O” and “1’” Since the difference is sufficiently large, this signal can be easily and reliably detected by a MUSE decoder, which will be described later.

FIG. 4(b) shows the data structure of the MUSE decoder additional control signal 9. The data is divided into 28 groups of 4 bits. The first and second groups D are M
A data identification bit pattern for identifying that it is a USE decoder additional control signal, for example, “1it
ooloo”. Group G of 3.4
is a signal source identification code, and when this method is applied to different player formats or to transmission systems other than video discs,
It is provided so that the decoder can identify it and change the contents of the additional control as appropriate. The 5.6th group S is a status code that represents the operational status of the player, and the decoder indicates that the player is in a state outside the normal playback capacity, that is, searching for a desired video, fast forwarding in the forward/reverse direction, or when the video is still. is used for identification. The seventh and eighth groups C are command codes that represent additional operation commands for the decoder, such as character display on the screen, video signal suppression (
Squelch), audio suppression (mute), video freeze, etc. to the decoder. The 9th and 10th groups Y o and Y 1 are BCD encoded program chapter number codes, which are used to display the current program chapter number during normal playback and the search target program chapter number during chapter search on the screen in the decoder. . Groups 18 from FIG. 11 are BCDq encoded video address code frame numbers or program titles.
, code), and is used to display the current video address during normal playback and the search destination video address during address search by a decoder in text on the screen. The 19th to 26th groups are optional character codes, which are used to display other information on screen characters as necessary. The 27th and 28th groups are parity codes, that is, transmission error detection codes for the codes of the 3rd to 26th groups.

MUS with decoder additional control signal inserted as above
The E signal is converted into an analog signal by the D/A conversion circuit 11 in FIG. 2 and output to the MUSE decoder.

Next, the operation of the MUSE decoder in the method of the present invention will be explained.

The input MUSE signal 12 from the player is converted to a resampling frequency (16.2MHz) in the A/D conversion circuit 13.
The signal is A/D converted and output to the video decoding circuit 16, the audio decoding circuit 18, the synchronization/control signal detection circuit 14, and the decoder-added control signal detection circuit 15. The decoder additional control signal detection circuit 15 detects the decoder additional control signal, and according to the information contents, a video decoding additional control signal 17 and an audio mute signal 1 are detected.
9. Character code squelch control signal 23 is generated.

In the video decoding circuit 16, the video decoding addition control signal 1
According to No. 7, in addition to the normal decoding operation, additional control is performed to effectively display still images. In the audio decoding circuit 18, according to the audio mute signal 19,
The output audio signal is suppressed for a necessary period. In accordance with the character code/squelch control signal 23, the character/squelch signal generation circuit 23 sends the character signal to be displayed on the screen and the required period to the superimpose circuit 21 which receives the output RGB video signal 20 of the video decoding circuit 18. Outputs a video suppression signal. By performing superimpose processing at this stage, it becomes possible to display characters of any hue with sufficient definition on the screen and to perform a squelch operation. The RGB video signal to be finally displayed is outputted to the display device via the D/A conversion circuit 24.

Effects of the Invention According to the method of the present invention, the operation of the MLISE decoder can be appropriately controlled without connecting the player and the MUSE decoder with a special signal line, and additional functions with sufficient effects can be realized. .

Further, the method of the present invention can be applied to a MUSE signal transmission system other than a video disk reproduction system, such as a reproduction system using a VTR, to obtain similar effects.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing interconnection between a conventional player and a decoder, FIG. 2 is a signal processing block diagram of a player and a MUSE decoder according to an embodiment of the present invention, and FIG. FIG. 4 is a diagram showing the transmission signal format within one frame of the MUSE signal;
It is a diagram showing an example of the format of SE decoder additional control signal insertion, and the fourth figure is a diagram showing an example of the data structure of the MUSE decoder additional control signal.

Claims (1)

[Claims] It has a video disc player and a subsample decoder for reproducing television signals based on the subsample transmission method, and the subsample decoder operation control information necessary for effectively performing additional functions in video disc reproduction is transmitted during idle periods of the transmission signal. A video disc playback system characterized in that a decoder operation is controlled by inserting and transmitting data into a video disc.