JPH10126763A - Simple time difference transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate downloading and to reduce the cost of a device by using compressed transmission program data. SOLUTION: This device has at least two data storage devices 24 and 26, and when one of the data storage devices is used as a data storage device for program transmission, the other data storage device is used as a spare storage device. If one of the data storage device that is used for program transmission becomes unable to transmit, the spare data storage device is used as a substitute device. Transmission program data that is distributed is undergone data compression. The devices 24 and 26 store compressed program data. Then, a program sending side is not provided with a decoder for data compression. Because transmission program data is compressed, the download time can be shortened, and because a device side does not need an encoder for compression, the costs of the device is also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a simple VOD [N
VOD (Near Video On Demand)] system and the like. More specifically, when the transmission program data is stored in the program transmission data storage device, the required transmission program data can be downloaded to the data storage device in a short time by using the distributed compressed transmission program data. It is.

[0002]

2. Description of the Related Art NVOD broadcasting, which has recently attracted attention as a form of broadcasting service, is a simple system of VOD (Video On Demand), and is used when a same program having a length of m is reproduced on an n channel on a receiving side. Is a time difference program transmission system in which the transmission side transmits the same program at an interval of m / n minutes so that the same program can be viewed with a time difference of m / n. As a result of the same program being broadcast with a time difference of m / n, the viewer can enjoy the program from the beginning by waiting for m / n.

[0003]

Such an NVOD transmission device (simple time difference transmission device) may have a system configuration as shown in FIG. As shown in the figure, a reproducing apparatus 12 is provided, in which a tape for a transmitted program sent from a program distributor is loaded, and the transmitted program signal (signal of a movie or the like) is reproduced. The reproduced transmission program signal is converted into a digital signal (video data and audio data) by the encoder 14, and a compression process is performed. The compressed digital signal (transmitted program data) is generated by the number of transmission channels as needed and downloaded to the data storage device 16.

[0004] The downloaded transmission program data is transmitted by the transmission processor 18 into n transmission channels each having a time difference of a predetermined time as shown in FIG. 11, in this example, four transmission channels (S1 to S4). The same program data is transmitted for four channels as shown in FIG.

[0005] In the NVOD receiver, an appropriate channel is selected from the transmitted program data for four channels in relation to the current time, and a decoding process is performed to expand the program data.

By the way, such a simple time difference transmitting apparatus 1
0, the program tape (or disk) distributed to each NVOD transmission side has not been subjected to data compression processing as described above, and therefore, a data compression encoder 14 is required for each simple time lag transmission apparatus. This has led to increased system costs.

[0007] Further, it takes a long time to reproduce the transmitted program signal from the program tape and download it to the data storage device 16, so that a high-speed download process cannot be realized in a short time. This means that it takes time to deal with a failure of the transmission system, and the service to the user is reduced.

Therefore, the present invention solves such a conventional problem, and enables high-speed download.
An object of the present invention is to provide a simple time-lag transmission device that can reliably cope with a transmission failure.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a simplified time difference transmitting apparatus according to the present invention has at least two components.
When one of the data storage devices is used as a program transmission storage device,
When the other data storage device is used as a spare storage device and one of the data storage devices used for program transmission fails to transmit, the spare data storage device is used as an alternative device, The data storage device stores compressed program data.

According to the present invention, the already-compressed broadcast program tape is distributed and downloaded using the tape, so that the time for downloading can be greatly reduced.
Since at least two data storage devices for transmitting a program are prepared, one of them can be used as a spare device.
Therefore, even when the data storage device being transmitted is out of order, the same program can be transmitted without interruption using the spare data storage device, so that the service to the user is further improved.

[0011] Even when a new program is downloaded, the program is downloaded to the spare device side and switched to the new program transmission at the timing when the transmission of the old program is completed, and from the data storage device being transmitted to the data storage device of the old program. Since the copying is sufficient, the program exchange can be performed very smoothly.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a simplified time difference transmitting apparatus according to the present invention will be described in detail with reference to the drawings.

In the simplified time lag transmission device 10 shown in FIG. 1, the playback device 22 is loaded with a recording medium from a program distributor. When the recording medium is a data recording medium such as a tape streamer, a reproducing apparatus for the tape streamer that can reproduce the tape streamer is used as the reproducing apparatus 22. The distributed recording medium records compressed transmission program data (for example, video and audio data). In this example, the program is organized so that the same program can be transmitted at different times by four channels.

The transmitted program data reproduced by the reproducing device 22 is stored in at least two data storage devices 24 and 26.
Downloaded to Since the downloaded transmission program data is already compressed data, it is downloaded in a very short time and at a high speed. As the data storage devices 24 and 26, a hard disk device (HDD) having a large data storage capacity can be used.

When one of the pair of data storage devices 24 and 26 is a transmitter, the other is used as a standby device.
The transmission program data for the four channels is supplied to the transmission processor 28, the data is read out in the order corresponding to the time difference transmission (NVOD reproduction), and the data is compressed via the terminal 30 and remains in the data transmission device (not shown). ). Therefore, channel selection and data decompression processing are performed on the receiving device side.

The above-mentioned playback device 22 to the transmission processor 28 are monitored by a transmission controller 32 having a built-in CPU, and perform download processing, data storage 2
A series of processes such as selection of the data storage devices 24 and 26 and switching of the data storage devices 24 and 26 based on the transmission failure signal output from the transmission processor 28 are performed.

FIG. 2 shows a generator 40 for generating transmission program data to be distributed. In this example, a VTR 42 is prepared as a distribution source (supply side) of a program, and one or a plurality of programs are provided. The signal is reproduced. Conventionally, the program signal itself of the distribution source is distributed to the NVOD side. The program signal (video and audio data) reproduced by the VTR 42 is supplied to an encoder 44, where a data compression process is performed.

When the reproduced signal is an analog signal, it is once digitized and then compressed. Data compression is performed using a known compression processing technique (such as MPEG).

The transmitted program data is recorded by a recording device 46. As the recording device 46, a recording device for a data streamer is used in relation to the reproduction device 22 described above.

The distributed transmission program data is reproduced by the reproducing device 22 shown in FIG. 1, and one of the data storage devices 24 and 26, in this example, the data storage device 2 is used.
4, and the transmission program data of each channel is output with a predetermined time difference based on the transmission program. FIG.
Indicates this state, and the transmission program data of each channel is sequentially transmitted with a time difference of 30 minutes.

If the data storage device 24, which is a transmitter, fails for some reason during the transmission of the program data, for example, at the timing ta in FIG. 4, a transmission failure signal obtained from the transmission processor 28 is detected by the transmission controller 32. You. A switching signal is generated from the transmission controller 32 at the same time that the transmission failure signal is detected, whereby the first data storage device 24 is instantaneously switched to the second data storage device 26.

Since the second data storage device 26 is also in the standby state, even if it is switched to the standby unit as shown in FIG. 5, the program data of each channel after the failure timing ta can be continuously transmitted. . Therefore, the program is not interrupted on the way.

While the transmitter is being switched to the second data storage device 26, the first data storage device 24 is exchanged for a non-defective one, and then the transmitted program data is transmitted from the second data storage device 26. Be copied. Or playback device 2
Downloaded again from 2. From the timing when the transmission failure occurs, the first data storage device 24 functions as a standby device.

When the transmitted program circulates a specified number of times, it is switched to a new program. At this time, a data streamer for transmitted program data in which a new program is recorded is loaded into the reproducing device 22. Then, as shown in FIG. 6, at an arbitrary timing tb before the end of the program of the specific channel, for example, the first channel CH1, the second data storage device 26 serving as a standby unit is used.
The new program is downloaded. Download time is short. This is because compressed data is used.

For the first time, the data contents of the first and second data storage devices 24 and 26 differ due to the download of the new program. After the download of the new program is completed, the channel is switched to the first channel on the second data storage device 26 at a timing tc at which the transmission program (old program) of the first channel ends.

In the same manner, when the second channel CH2 on the first data storage device 24 side ends, the channel is immediately switched to the second channel on the second data storage device 26 side (time td), and the third channel at time te. Since the channel CH3 is switched to the fourth channel CH4 at time tf, the time t
At f, all channels have been switched to new programs as shown in FIG.

At an arbitrary timing after all the channels are switched to the new program, in FIG. 6, the new program is copied from the second data storage device 26 to the first data storage device 24 at time tg. You. Therefore, at time tg, both the first and second data storage devices 24 and 26 become new program data, and the first data storage device 24 now operates as a standby device. All such control relationships are ascertained and monitored by the delivery controller 32.

FIG. 8 shows an example of a processing flow when a transmission failure occurs. Data is stored in the first data storage device 24.
This indicates a case where the message has been sent. When a transmission failure occurs in the data storage device 24 during transmission, data reading is immediately switched to the second data storage device 26 (steps 52 and 54). When the switching process is performed, the first data storage device 24 is replaced with a non-defective device, and when the replacement is completed, a copy process is performed from the second data storage device 26 to the first data storage device 24 to perform trouble processing. Ends (steps 56 and 58).

In the above, an example has been described in which the same program is divided into four channels and transmitted with a time difference. However, one channel can be transmitted by compressing and multiplexing four channels for the time axis. This example will be described with reference to FIG.

FIG. 9 shows an example of a flowchart for explaining the process of switching from the old program to the new program. This is to realize the operation of FIG. 6, and the current program is the first program.
It is assumed that the data is sent out in a staggered manner using the data storage device 24 of FIG.

First, as shown in step 60 in FIG. 9, the download of new program data (compressed program transmission data) is performed to the second data storage device 26 as a standby unit, and after the download is completed. The first data storage device 24 determines whether or not the time difference transmission for the program (old program) of the channel i (CHi, in this example, the first channel CH1) has ended (step 62). When the time lag transmission is completed, the data is switched to the second data storage device 26 and the data of the new program is replaced with the data of the channel CH in place of the old program.
1 and the time difference is sent out (step 6).
4). Thereafter, i is incremented (step 6).
6).

Then, it is checked whether this transmission processing has been performed for all the channels (step 6).
8). When starting from i = 1, the same operation as described above is repeated from channel 1 to channel 4, and the process of shifting to a new program is executed.

When the process of shifting to the new program for all the channels is completed in step 68, the new program continues to be staggered using the second data storage device 26 only (step 70).

When the process of shifting to the new program is completed, the new program data being transmitted in a time lag is stored in the first data storage device 24.
(Step 72), and when all copy operations are completed, the first data storage device 24 functions as a standby device thereafter.

[0035]

As described above, according to the present invention, since the alternative device is provided, even if the data storage device during the transmission of the program becomes out of transmission due to a failure or the like, another data storage device is immediately provided. , You can continue sending the program,
The simple time difference transmission system has a feature that programs can be continued without interruption. Since the data storage device on the non-sendable side can be replaced with a non-defective one while the program is being sent out by the substitute machine, the failure recovery process is also easy.

Also, since the transmission program data to be downloaded is compressed data, downloading to the data storage device can be performed at a high speed. In addition, since the compressed transmission program data is distributed, simple time difference transmission is performed. There is no need for an encoder for data compression on the device side, which has the benefit of reducing costs in individual transmission systems.

[Brief description of the drawings]

FIG. 1 is a system diagram of a main part showing an embodiment of a simple time difference transmitting apparatus according to the present invention.

FIG. 2 is a system diagram of a main part showing an embodiment of a transmission program data generation device.

FIG. 3 is an explanatory diagram of a simple time difference transmission mode in multiple channels.

FIG. 4 is an explanatory diagram of a transmission mode when a transmission failure occurs.

FIG. 5 is an explanatory diagram of a transmission mode at the time of switching transmission.

FIG. 6 is an explanatory diagram of a transmission mode when a new program is downloaded.

FIG. 7 is an explanatory diagram of a transmission mode after downloading a new program.

FIG. 8 is a diagram illustrating an example of a flowchart illustrating an example of a restoration process.

FIG. 9 is a diagram showing an example of a flowchart when a new program is replaced.

FIG. 10 is a system diagram of a simple time difference transmission apparatus.

FIG. 11 is an explanatory diagram of simple time difference transmission.

FIG. 12 is an explanatory diagram of simple time difference transmission.

[Explanation of symbols]

10: Simple time difference sending device, 22: Reproducing device, 2
4, 26 data storage device, 28 transmission processor, 32 transmission controller, 44 data compression encoder

Claims (3)

[Claims] 1. When at least two data storage devices are used as a program transmission storage device, the other data storage device is used as a spare storage device. When one of the data storage devices used for program transmission fails to transmit, the spare data storage device is used as an alternative device and the distributed compressed program data is stored in the data storage device. A simple time difference sending device characterized by being stored. 2. The program exchange is performed on the spare data storage device, and while a new program is transmitted using the spare data storage device, the exchanged program data is replaced with the other program data. 2. The simple time difference transmitting apparatus according to claim 1, wherein the data is copied to a data storage device. 3. The simple time difference transmitting apparatus according to claim 1, wherein the data storage device is a hard disk device having a large data storage capacity.