JPH03217182A - Moving image intermittent transmitter - Google Patents

Abstract

PURPOSE:To obtain a moving image intermittent transmitter to effectively utilize a transmission line by transmitting a highspeed moving image signal as a low-speed moving image signal. CONSTITUTION:An extracting pulse generating means 14 generates an extracting pulse to determine time for extracting a moving image from a TV external synchronizing signal, and the inputted PCM moving image signal is extracted for the designated time and written into a storing means 12. The signal written into the storing means 12 is read out by a reading means 13 at the transmission speed of the transmission line and transmitted as the low-speed moving image signal. On the other hand, the receiver receiving the low-speed moving image signal writes the signal into a storing means 22 and reads it out at the speed of the high-speed PCM signal and therefore, the moving image can be transmitted by the low-speed transmission line.

Description

[Detailed Description of the Invention] [Summary] Regarding an intermittent video transmission device that transmits video signals intermittently, in order to effectively utilize the transmission path, a video signal with a high bit rate is transferred to a video signal with a low bit rate. The purpose of the present invention is to provide a moving image intermittent transmission device that transmits a moving image signal, and the transmitting device includes an extraction pulse generation means for generating a pulse for extracting an input PCM moving image signal, and a pulse generated by the extraction pulse generation means. A pulse train extracting means for extracting a PCM moving image signal, a storage means for writing the moving image signal extracted by the pulse train extracting means, and a low-speed PCM signal transmission of the moving image signal written in the storage means for a specified time. The receiving device includes a readout means for reading according to the speed, and a synchronization pulse generation means for generating a synchronization signal to be supplied to the storage means and the readout means. The apparatus comprises a readout means for reading out the written moving image signal in accordance with the transmission speed of the high-speed PCM signal, and a synchronization pulse generation means for regenerating a synchronization pulse to be supplied to the storage means and the readout means from the input moving image signal. .

[Industrial application field]

The present invention relates to an intermittent moving image transmission device that transmits moving image signals intermittently.

3 Image monitoring is widely used in various monitoring systems such as road condition monitoring, port and ship route monitoring, and dam monitoring. Such image monitoring systems include those using still images and those using moving images, but in order to improve the accuracy of monitoring, monitoring using moving images is necessary.

Transmission of such moving images requires a broadband transmission line, but there is a demand for a moving image transmission apparatus that can transmit moving images over a low-speed transmission line.

[Conventional technology]

FIG. 6 shows a block diagram illustrating a conventional example.

(a) of the conventional example in FIG. 6 shows the configuration of a transmitting station, which includes two television cameras (hereinafter referred to as TV cameras) A and B, a changeover switch 30 that switches the output of the TV cameras A and H, and an NTSC. An image signal band compression device 40 that performs A/D conversion and band compression on the outputs of the TV cameras A and H that are output as video signals; A digital multiplexing device 40A that multiplexes the multiplexed digital signals; The receiving station in (b) includes a radio device 50 that transmits a radio signal, a radio device 5l that receives a digital radio signal, a digital multiplexer 41A that separates multiplexed digital signals, and a digital multiplexer 41A that separates the multiplexed digital signal. This example includes an image signal band compression device 4l that performs A conversion, expansion, and restoration to the original moving image, and a TV monitor 60 that monitors the output of the image signal band compression device 4l.

With the above configuration, the signals are output as digital signals from the two TV cameras A and B, and transmitted from the radio device 50 via the digital multiplexer 40A.

At the receiving station, the signal received by the radio 51 is passed through the digital multiplexer 41A, and is then processed by the image signal band compression device 4l.
The data is D/A converted and expanded, and its output is monitored on a TV monitor 60.

[Problem to be solved by the invention]

Here, the transmission rate of the output of the image signal band compression device 40 is 6. When the speed is 3 Mbps, a transmission line bandwidth of 6.3 Mbps is required, and when there are a plurality of such video monitoring systems, a proportionately wide band transmission line is required.

Furthermore, even if an attempt is made to construct such a broadband line using a private wireless line, it may not be possible to realize such a broadband line due to regulations of the Ministry of Posts and Telecommunications.

SUMMARY OF THE INVENTION An object of the present invention is to provide an intermittent video transmission device that transmits a high-speed bit rate video signal as a low-speed bit rate video signal in order to effectively utilize a transmission path.

[Means to solve the problem]

FIG. 1 shows a block diagram illustrating the principle of the invention.

In the block diagram of the principle of the present invention shown in FIG. 1, 1 is a transmitting device, and 11 is a pulse train extracting means for extracting a PCM moving image signal for a specified time using the pulses generated by the extraction pulse generating means 14. 12 is a storage means for writing the moving image signal extracted by the pulse train extracting means 1l, and 13 is a readout means for reading out the moving image signal written in the storage means 12 in accordance with the transmission speed of the low-speed PCM signal. 14 is an extraction pulse generation means for generating a pulse for extracting the input PCM moving image signal; 15 is a synchronization pulse generation means for generating a synchronization signal to be supplied to the storage means 12 and the reading means 13; 2 is a receiving device, 22 is a storage means for writing the moving image signal input from the transmission path, and 23 is a storage means for writing the moving image signal written in the storage means 22 at a high-speed PCM signal transmission speed. In addition, 17 - reading means for reading; 25 is a synchronizing pulse generating means for reproducing synchronizing pulses to be supplied to the storage means 22 and the reading means 23 from the input moving image signal; by providing such means, This is a means to solve this problem.

[For production]

Based on the TV external synchronization signal, an extraction pulse generating means 14 generates an extraction pulse that determines the time to extract a moving image, extracts the input PCM moving image signal for a specified time, and writes it into the storage means 12.

The signal written in the storage means 12 is read out by the reading means 13 in accordance with the transmission speed of the transmission line, and is transmitted as a low-speed moving image signal.

On the other hand, the receiving device that has received the low-speed moving image signal writes the signal into the storage means 22 and reads it out in accordance with the speed of the high-speed PCM signal, thereby making it possible to transmit the moving image through the low-speed transmission path.

8-1 [Example] The gist of the present invention will be specifically explained below with reference to Examples shown in FIGS. 2 to 5.

FIG. 2 is a block diagram illustrating a transmitter according to an embodiment of the present invention, FIG. 3 is a block diagram illustrating a receiver according to an embodiment of the present invention, and FIG. 4 is a moving image transmitting system according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a transmission time chart of an embodiment of the present invention. Note that the same reference numerals refer to the same objects throughout the plan.

In the description of the embodiments of the present invention, the input to the intermittent video transmission device is assumed to be 6.3 Mbps, and the transmission speed of the transmission path is 1.
．． This is an example in which there are four systems each receiving signals of 5 Mbps and switching outputs from two TV cameras.

The transmitter 1 of the embodiment of the present invention shown in FIG.
Input interface unit (hereinafter referred to as INF) IIA that interfaces with the input PCM signal of bps
and a pulse string extraction circuit 1 that extracts the input moving image signal for a specified time by the output of the extraction pulse generation circuit 14A.
1B, a memory 12A into which the moving image signal extracted by the pulse train extraction circuit 11B is written, and a memory 12A which reads out the moving image signal written in the memory 12A.
．． A readout circuit 13A transmitting at a speed of 5 Mbps, and P
/S conversion circuit 13B, an output -INF 13C that takes the INF of a digital multiplexer (not shown), and a TV synchronization signal generation circuit 15A that supplies synchronization signals to each part.
It is made up of more.

Extraction pulse generation circuit 14A, TV synchronization signal generation circuit 15
The pulses generated at A are also supplied to systems (hereinafter referred to as SYS) 2, SYS3, and SYS4 having the same configuration.

The receiving unit 2 of the embodiment of the present invention shown in FIG.
Input I that interfaces with the input PCM signal of ps
NF22A, a TV synchronization signal extraction circuit 25A that extracts a TV synchronization signal from the output of the pulse extraction circuit 22B, and a pulse generation circuit 25B that generates a pulse to control reading of the memory 22C from the output of the TV synchronization signal extraction circuit 25A. , a memory 22C in which the input moving image signal is written, and a moving image signal written in the memory 22C is read out, and 6.3M
A readout circuit 23A that outputs at a speed of bps, and a gate switch 2 that controls on/off of image signal output.
3B and an output INF 24C that takes the INF of a digital multiplexer (not shown).

FIG. 4 shows the configuration of a transmission system using the above-mentioned intermittent moving image transmission apparatus IO, and FIG. 5 shows its transmission time chart.

Video signals are provided by two TV cameras SYS 1.
(A,B), SYS2 (C,D), SYS3
(E,F) and SYS4 (G,H), and a changeover switch 30 alternately switches outputs of the two TV cameras.

The outputs of the TV cameras A to H are standard NTSC video signals, and four moving image signals are input to the image signal band compression device 40.

The image signal band compression device 40 converts the four NTSC video signals into a 6.3 Mbps PCM signal and inputs it to the intermittent moving image transmission device IO.

In the moving image intermittent transmission device IA, for example, a TV camera ASB
The output signal of 6.3 Mbps is extracted for 10 seconds,
Write the signal to memory, 1. Output takes 40 seconds at a transmission speed of 5Mbps.

Therefore, each of the four inputs of the intermittent video transmission device IO is a 6.3 Mbps signal, and each of the four outputs is a 1.5 Mbps signal.

The digital multiplexer 40A multiplexes four 1.5 Mbps signals and transmits them through the radio 50.

At the receiving station, the received 1.5 Mbps signal is written into memory and read out at a speed of 6.3 Mbps, thereby restoring it to the original moving image signal.

The TV monitor shown in Figure 5 is 1 in SYS l-SYS4.
When it is on the stand, moving images of 10 seconds each shown by diagonal lines are sequentially switched and output.

When each of SY8 1 to SYS4 has one TV monitor, for example, SYS 1 monitors the output of TV camera A for 10 seconds indicated by diagonal lines, and then monitors the video for the following 30 seconds.
It is also possible to monitor the final frame of a moving image as a still image, and the monitoring time can be freely changed within the time range shown by the broken line.

By configuring as described above, high-speed 6.3Mbp
s moving image signal can be transmitted as a low-speed 1.5 Mbps signal.

The image signal band compression device 40 used in this embodiment uses a known technique, and therefore will not be described. The output of this image signal band compression device 40 is 6. 3 Mb
ps, but the transmission speed is 1.5Mbps
, 768 kbps, 384 kbps, etc., but it goes without saying that the present invention can be applied to any speed.

Furthermore, although each SYS is configured with two TV cameras, even if there are three or more TV cameras, the video monitoring time per unit will only be shorter, and the effect of the present invention will remain the same. It is.

〔Effect of the invention〕

According to the present invention as described above, it is possible to provide an intermittent video transmission device that can effectively utilize a transmission path by transmitting a high-speed video signal as a low-speed video signal.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the principle of the present invention, FIG. 2 is a block diagram illustrating a transmitter according to an embodiment of the present invention, and FIG. 3 is a block diagram illustrating a receiver according to an embodiment of the present invention. FIG. 4 is a diagram for explaining a moving image transmission system according to an embodiment of the present invention, FIG. 5 is a diagram for explaining a transmission time chart for an embodiment of the present invention, and FIG. 6 is a block diagram for explaining a conventional example. Each is shown below. In the figure, 1 is a transmitter, 2 is a receiver, 10 is a moving image intermittent transmission device, 11 is a pulse train extraction means, 11A and 22A are input INF, 11B is a pulse train extraction circuit, 22B is a pulse extraction circuit, 12 and 22 are Storage means, 12A, 22C memory, 13, 23 are reading means, 13A, 23A reading circuit, 13B is P/S conversion circuit, 13C, 24C are output INF, 14 is extraction pulse generation means, 14A is extraction pulse generation circuit, 15, 25 are synchronization pulse generation means, 15A is a TV synchronization signal generation circuit, 23B is a gate switch, 25A is a TV synchronization signal extraction circuit, 25BO pulse generation circuit, A-H is a TV camera, 30 is a changeover switch, 40, 4l 40A and 41A are digital multiplexing devices; 50 and 51 are radio devices; and 60 is a TV monitor. -560

Claims (1)

[Claims] An intermittent moving image transmission device that intermittently transmits a moving image signal, the transmitting device (1) comprising an extraction pulse generating means (14) that generates a pulse for extracting an input PCM moving image signal. ), the time specified by the pulse generated by the extraction pulse generating means (14), P
A pulse train extracting means (11) for extracting a CM moving image signal, a storage means (12) for writing the moving image signal extracted by the pulse train extracting means (11), and the storage means (12).
readout means (13) for reading out the moving image signal written in the memory according to the transmission speed of the low-speed PCM signal; and a synchronization pulse generator for generating a synchronization signal to be supplied to the storage means (12) and the readout means (13). The receiver (2) includes a storage means (2) for writing the moving image signal input from the transmission line.
2); reading means (23) for reading out the moving image signal written in the storage means (22) in accordance with the transmission speed of the high-speed PCM signal; An intermittent moving image transmission device characterized by comprising synchronization pulse generation means (25) for reproducing synchronization pulses supplied to the reading means (23).