JP3352719B2 - Time-division video signal playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time-division video signal reproducing apparatus used in a pay television broadcasting system or the like and capable of outputting the same program while being shifted on a time axis.

[0002]

2. Description of the Related Art The basic concept of a pay television system in cable television (CATV) is that a transmitting side transmits a scrambled signal, and a subscriber cancels the scramble with a special terminal for viewing.

One example of such a TV signal viewing control system is a unidirectional addressable system as shown in FIG.

[0004] As shown in FIG. 1, when a subscriber requests viewing of a pay program by telephone 1 via public line 2, the center receives it via telephone 3 and registers it in host computer 4. After registration with the host computer 4, the addressable controller 5 is driven, and a command signal for instructing on / off control of the corresponding addressable terminal 7 and descrambling of the pay channel from the data transmitter 6 is sent to the CATV transmission line 8. Sent to

[0005] The addressable terminal 7 receives this command signal and selects the viewing permission mode of the pay channel. The addressable terminal 7 also has channel selection and channel conversion functions. In addition, the host computer 4 includes:
It also collects data on subscribers, channels, program types, time, etc., and performs accounting work.

A pay channel TV signal of a pay program, which is FSK-modulated by the modulator 9 from the center side and further scrambled by the scrambler 10, is descrambled by the addressable terminal 7 on the subscriber side. As a result, the television receiver 1
1 can be viewed.

Reference numeral 12 in the drawing denotes a television signal processing device, for example, a communication satellite (C).
This is for retransmitting the broadcast wave from S) via the CATV transmission line 8.

In such a pay broadcasting system such as a cable television, the same program may be broadcast at intervals of, for example, 30 minutes in order to provide a user with a wide listening time.

[0009] In this way, for example, even if it is not in time for the first program start time, by listening to the program starting 30 minutes later, it is possible to view the program from the beginning. This is a very effective method for planning.

[0010]

However, in the above-described conventional system in which the same program is broadcast while being shifted every 30 minutes, for example, a time lag occurs.
For example, a plurality of players for reproducing a video source in which a movie or the like is recorded are prepared, and the respective players are sequentially reproduced with a time lag.

[0011] Therefore, for example, if a time lag of 30 minutes is to be provided for a program of 2 hours, four transmissions are required, and four players are required. This hinders cost reduction when constructing a system.

The present invention divides information from an optical disc on which the same program is recorded by one reproducing apparatus into four systems, and outputs the divided systems with a time lag, thereby providing a C signal.
It is an object of the present invention to provide a time-division video signal recording disk and a reproducing apparatus thereof, which can reduce the cost when constructing an ATV system.

[0013]

According to the time-division video signal reproducing apparatus of the present invention, the entire video data is transmitted at a predetermined time interval.
In (T), the block is divided into N blocks.
Subdivided into n sub-blocks at predetermined time intervals (T / n)
And each sub-block is subjected to 1 / N time compression.
Recorded in a specified order.
Time-division video signal playback device
And the recording disk is moved to the predetermined time interval (T).
A reproducing means for repeating the reproduction N times every time,
Selector to select time-compressed sub-block
And a 1 / N time-compressed signal from the selector.
The sub-block size is extended by N times
N decoders, each of said N decoders
Connected to each other and for a predetermined time for each corresponding channel
At intervals (T), video data in blocks is output from each decoder.
Data selectors for selecting and outputting data
Characterized in that it.

[0014] The predetermined order may be determined when 1 / N is satisfied.
Inter-compressed sub-blocks
It is characterized by being in an interleaved state.

[0015]

According to the time-division video signal reproducing apparatus of the present invention,
With respect to the recording disk, the entire video data is divided into N blocks at a fixed time interval, and the video data in each of the N blocks is further subdivided into a sub-block at a fixed time interval to form a sub-block. After performing time axis compression on sub-blocked video data,
Rearranged in a predetermined order in a time-division manner, and
Since the time axis compressed video data is recorded at / N, the reproduction time can be reduced to 1 / N.

When the selector selects video data for each sub-block that has been time-compressed to 1 / N, N decoders demodulate and perform time-base expansion for each selected video data. , A data selector selects the transmission timing of the video data from these N decoders to the output line. Therefore, a single reproducing apparatus can output, for example, four systems of video signals whose time axes are shifted from the optical disk on which the same program is recorded.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows an embodiment of the reproducing apparatus of the present invention. As shown in the figure, an optical disk 2 described later on which a time-compressed video signal is recorded in a time-division manner.
The reproduced RF signal from 0 is demodulated by the digital demodulator 21 into a digital video signal. The demodulated digital video signal is sent to a data selector 23 after an error correction process is performed by an error correction processing unit 22.

The data selector 23 receives a select signal of compressed video data. Data selector 23
Are distributed to the video decoders 24, 25, 26 and 27 according to the select signal.

Each of the video decoders 24, 25, 2
The video signals distributed to the data selectors 28, 29, and 3 are subjected to the time axis expansion by N times here.
0,31.

The video signals sent to the data selectors 28, 29, 30, and 31 are output with time lags of 0, T, 2T, and 3T, respectively, as described later.

FIG. 3 shows a recording state of a video signal on the optical disk 20 of FIG.

First, as shown in FIG. 1 (a), the same program of a video signal including an audio signal is transmitted at time T intervals.
To D are divided into four blocks. Further, as shown in FIG. 3B, the blocks A to D respectively include A1 to An, B1 to Bn, C1 to Cn, and D1 to D every T / n time.
It is subdivided (sub-blocked) into n.

At the time of recording on the optical disk 20, as shown in FIG. 3C, each of the subdivided data A1 to An
, B1 to Bn, C1 to Cn, and D1 to Dn are recorded in a state where they are subjected to time compression and further interleaved for each block.

The operation of the reproducing apparatus having such a configuration is described below.
This will be described with reference to FIG. First, the first reproduction of the optical disc 20 is performed. At this time, the data to be reproduced is recorded in the state shown in FIG.
The blocks are reproduced in order from the block of 1, B1, C1, D1.

The reproduced data is sent to the digital demodulator 2
1 and is sent to a data selector 23 after being subjected to error correction processing by an error correction processing section 22.

At this time, the data selector 23 receives a select signal of the compressed video. The data selector 23 selects a video signal based on the select signal as shown in FIG.
4, 25, 26 and 27 are sent out.

Each video decoder 24, 25, 2
6 and 27, the video data shown in FIG.
As shown in (b), the time axis is extended N times.

The video signal whose time axis is expanded by N times is
Each video decoder 24, 25, 26, 27 sends the data to a data selector 28, 29, 30, 31.

At this time, first, the select signal is input only to the data selector 28, so that the video signal of the A block is output from CH1.

Next, the second reproduction of the optical disk 20 is performed. At this time, as described above, the video data is reproduced in order from the blocks A1, B1, C1, and D1 shown in FIG.

The reproduced data is demodulated by the digital demodulator 21 in the same manner as described above.
2, after the error correction processing is performed, the data is sent to the data selector 23.

The data selector 23 selects a video signal based on the compressed video select signal in the same manner as described above, and sends it to the video decoders 24, 25, 26 and 27.

Each video decoder 24, 25, 2
The video data fetched by the 6, 6
The time axis is extended twice and each data selector 28, 2
9, 30, and 31.

At this time, first, a select signal for selecting a B block is input to the data selector 28, so that a video signal of the B block is output from CH1. Further, for the data selector 29,
When a select signal for selecting the A block is input, a video signal of the A block is output from CH2.

At this time, the transmission timing of the video signal of block A output from CH2 is T delayed from the transmission of the video signal of block A of CH1.

Subsequently, the third reproduction of the optical disk 20 is performed. In the same manner as described above, the video data of each block which has been subjected to the time axis expansion by N times is supplied to each data selector 28,2.
9, 30, and 31.

At this time, first, a select signal for selecting the C block is input to the data selector 28, so that the video signal of the C block is output from CH1. For the data selector 29,
When a select signal for selecting a B block is input, a video signal of the B block is output from CH2. Further, for the data selector 30, A
When a select signal for selecting a block is input, a video signal of the A block is output from CH3.

At this time, the transmission timings of the video signals of the B block and the A block output from CH2 and CH3 are delayed by T and 2T from the transmission of the video signal of the B block of CH1.

Subsequently, the fourth reproduction of the optical disk 20 is performed. In the same manner as described above, the video data of each block which has been subjected to the time axis expansion by N times is supplied to each data selector 28,2.
9, 30, and 31.

At this time, when a select signal for selecting a D block is input to the data selector 28, a video signal of the D block is output from CH1. When a select signal for selecting the C block is input to the data selector 29, the video signal of the C block is output from CH2. When a select signal for selecting the B block is input to the data selector 30, a video signal of the B block is output from CH3.
When a select signal for selecting the A block is input to the data selector 31, a video signal of the A block is output from CH4.

At this time, the transmission timing of the video signals of the C block, B block and A block output from CH2, CH3 and CH4 is delayed by T, 2T and 3T, respectively, from the transmission of the video signal of the C block of CH1. Time.

After the transmission of the video data from the CH1 to the blocks A to B is completed, the input of the select signal to the data selector 28 is stopped and the remaining data selectors 29, 30, 31 are stopped. Is input.

After the transmission of the video data from the CH2 to the blocks A and B is completed, the input of the select signal to the data selectors 28 and 29 is stopped, and the input of the select signal to the remaining data selectors 30 and 31. Is performed.

After the transmission of the video data of blocks A to B from CH3 is completed, the data selectors 28, 2
The input of the select signal to 9 and 30 is stopped, and the input of the select signal to the remaining data selector 31 is performed.

After the transmission of the video data from the CH4 to the A to B blocks is completed, the data selectors 28 to 3
Input of the select signal to 1 is stopped, and transmission of video data from all channels ends.

As described above, in this embodiment, the optical disk 2
The video data is divided into four for each time T with respect to 0, each block is subdivided for every T / n time, and each video data is subjected to time axis compression and then subjected to an interleaving process for recording. I did it. As a result, the playback time of the optical disc 20 per time is reduced to T by performing time-axis compression on each video data and recording.

On the other hand, when reproducing the optical disc 20,
In addition to causing the optical disc 20 to reproduce the video data four times in accordance with the division of the video data into four every time T,
At the time of each reproduction, the video data of each block subjected to the time axis compression is subjected to an N-fold decompression process to restore the original data length.

At the time of the first reproduction, the video data of the A block is output from CH1. At the time of the second reproduction, the video data of the B block is output from CH1, and the video data of the A block is transmitted with a delay of T from CH2. At the time of the third or subsequent reproduction, the video data of the C block is transmitted from CH1 and the video data is transmitted from CH2, CH3, and CH4 with a time lag of T in order.

Therefore, the information from the optical disc 20 on which the same program is recorded can be divided into four systems by one reproducing apparatus and output with a time lag, so that the cost reduction in constructing the CATV system can be reduced. I can do it.

Although the present embodiment has been described with respect to the case where the optical disc 20 is reproduced four times in accordance with the division of video data into four at each time T, the recording should be performed on the optical disc 20. Split video data into 3
The number of divisions may be less than or equal to five or more, and three or less times of reproduction or five or more times of reproduction may be performed.

[0051]

As described above, the present invention relates to a recording desk reproduced by the time-division video signal reproducing apparatus of the present invention.
In other words, the whole video data is divided into N blocks at regular time intervals, and the video data in each of the N blocks is further subdivided into regular blocks at regular time intervals to form sub-blocks. After performing time axis compression on the compressed video data, the video data is rearranged in a predetermined order in a time-division manner, so that the video data that has been time axis compressed to 1 / N as a whole is recorded. The time can be reduced to 1 / N.

Further, according to the reproducing apparatus of the present invention, when the selector selects the video data for each sub-block that has been time-axis-compressed to 1 / N, the N decoders demodulate for each of the selected video data. After the time axis expansion process, the data selector selects the transmission timing of the video data from these N decoders to the output line. For example, it is possible to output, for example, four systems of video signals shifted in time axis.

Therefore, information from the optical disc on which the same program is recorded by one reproducing apparatus is divided into four systems and output with a time lag.
Cost reduction when constructing a CATV system can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a unidirectional addressable type CATV system as an example of a conventional CATV system configuration.

FIG. 2 is a block diagram showing one embodiment of a reproducing apparatus of the present invention.

FIG. 3 is a diagram showing a recording state of video data on an optical disc reproduced by the reproducing device of FIG. 2;

FIG. 4 is a diagram illustrating a method of reproducing video data by the reproducing device of FIG. 2;

[Explanation of symbols]

 Reference Signs List 20 optical disk 21 digital demodulator 22 error correction processing unit 23 data selector 24, 25, 26, 27 video decoder 28, 29, 30, 31 data selector

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 20/02 G11B 7/005 G11B 20/12

Claims (2)

(57) [Claims] 1. The method according to claim 1, wherein the entire video data is set at a predetermined time interval
In (T), the block is divided into N blocks.
Subdivided into n sub-blocks at predetermined time intervals (T / n)
And each sub-block is subjected to 1 / N time compression.
Recorded in a specified order.
Time-division video signal playback device
Then, the recording disk is rotated N times at the predetermined time interval (T).
A reproducing means for repeatedly reproducing and a sub-block subjected to the 1 / N time compression are selected;
And a sub-block that has been subjected to 1 / N time compression from the selector.
Extend the lock N times to the original sub-block size
N decoders to return, each connected to said N decoders, corresponding to each
From each decoder at a predetermined time interval (T) for each channel
N blocks to select and output video data in block units
Time division characterized by having a data selector of
Video signal playback device . 2. The method according to claim 1, wherein the predetermined order is a time pressure of 1 / N.
For each of the reduced sub-blocks,
Claims characterized in that it is in a state of being subjected to a turive.
2. The time-division video signal reproducing device according to 1.