JPS63251987A - Transmission system inspecting system - Google Patents

Abstract

PURPOSE:To display a fault of a transmission system so that a preview of the system can be performed automatically, by comparing input signals inputted to the transmission system and output signals outputted from the system with each other in a digitized state after the signals are respectively AD-converted and once stored in memories. CONSTITUTION:Input signals inputted to a prescribed transmission system are stored in memories 13 and 14 after they are AD-converted by means of AD converter circuits 11 and 12 and, at the same time, signals outputted from the transmission system are stored in memories 23 and 24 after they are AD-converted by means of AD converter circuits 21 and 22. Then the input signals stored in the memories 13 and 14 are respectively compared with the output signals stored in the memories 23 and 24 and information related to the fault of the transmission system is displayed in response to the compared results. The comparison between the input signals and output signals can be carried out in such a way that one side of the signals are made to have a complementary property and both are added to each other. When the difference with a level exceeds a prescribed value, a compared result indicating existence of abnormality can be outputted. Thus inspection of the transmission system can be carried out accurately at the same time when the system performs transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission system testing method for testing the characteristics of a transmission system typified by a video tape recorder.

[Summary of the invention]

In the present invention, the input signal input to the transmission system and the output signal output from the transmission system are each A/D converted,
Once stored in memory, they are compared digitally.

[Conventional technology]

For example, commercials broadcast on broadcast stations are one of them.
The days are recorded and prepared in the order in which they will be broadcast on one videotape. FIG. 3 is a block diagram of an editing device for editing such a video tape into one video tape. In the figure, 1 is a video tape recorder, and a plurality of video tape recorders are prepared. Each video tape recorder 1 is loaded with a magnetic tape on which at least one commercial material (program) is individually recorded. A single day's list is input from a host computer (not shown) to the control circuit 5, which is made up of a computer or the like. At this time, the control circuit 5 calculates the time code of each material from the unification list, and starts each material (each video tape recorder 1) based on the material number attached to each material and the time code of each material. Create a queue map that shows the stop time, etc.

Similarly, a cue map for the video tape recorder 4 for editing is also created.

When the creation of the cue map is completed, the control circuit 5 starts reproduction of the video tape recorder 1 in which the first material is recorded according to the cue map, and turns on the corresponding switch 2.

When the time required for the reproduction signal output from the video tape recorder 1 to become stable (for example, 3 seconds) has elapsed, the recording operation of the video tape recorder 4 is started. The reproduced signal outputted via the switch 2 is inputted to the video tape recorder 4 after its time base error is corrected by a time base collector (TBC). A plurality of video tape recorders 4 (two in the embodiment) are prepared so that a plurality of identical magnetic tapes can be produced.

Furthermore, if a plurality of the above-mentioned editing thread paths (two paths in the embodiment) are provided, different (of course they can be the same) contents (
It is possible to create multiple magnetic tapes (for multiple yen worth) at the same time.

[Problem that the invention seeks to solve]

By the way, the magnetic tape created in this way needs to be played back and previewed. That is, a person inspects the degree of dropout, tracking state, audio cutout, video signal and audio signal levels, wow and flutter, etc. while looking at the playback screen. It takes 4 to 5 hours to edit into one, so it also takes 4 to 5 hours to preview. Therefore, it is necessary to complete the unification editing on the night of the 4th day before the broadcast date, the preview by the day before, and the provider of 1 program (commercial) must be decided in advance at least 3 days in advance.

Therefore, the present invention enables such a preview to be performed automatically without relying on human labor.

[Means for solving problems]

The present invention is a transmission system inspection method in which an input signal input to a predetermined transmission system is A/D converted, the A/D converted input signal is stored in a memory, and a signal output from the transmission system is A/D converted. /D conversion, stores the A/D converted output signal in memory, compares the input signal and output signal stored in memory, and displays information regarding defects in the transmission system in accordance with the comparison result. It is characterized by

[Effect]

The input signal is output through a predetermined transmission system. After the input signal is A/D converted, it is temporarily stored in the memory. Similarly, the output signal output from the transmission system is A/D converted,
stored in memory. The input signal and output signal stored in the memory are compared, and information regarding defects in the transmission system is displayed in accordance with the comparison result.

〔Example〕

FIG. 1 is a block diagram of the case where the present invention is applied to a unifying editing device. Parts corresponding to those in FIG. 3 are given the same reference numerals, and detailed description thereof will be omitted. The signal input to the video tape recorder 4 is processed by the A/D conversion circuit 11 before being time-base corrected by the time base collector 3.
．． 12 is input. Among the input signals, the video signal is A/D
The audio signal is input to the conversion circuit 11, and the audio signal is input to the A/D conversion circuit 12. The A/D conversion circuit 11 converts the input video signal from an analog signal to a digital signal.

The digital signal is input to memory 13 and stored.

The digital signal is also input to the detection circuit 15, and the detection circuit 15 detects a predetermined timing signal included in the video signal. For example, a vertical synchronization signal is detected by the detection circuit 15, and the detection signal is supplied to the memory 13. Of course, this detection can also be performed at the analog signal stage. The memory 13 stores one field or one frame by storing the vertical synchronization signal or the signal immediately after it at a predetermined address so that the video signal at a specific position can be read out by specifying the address. Stores the video signal as a unit.

Similarly, the audio signal is converted from an analog signal to a digital signal by the A/D conversion circuit 12 and stored in the memory 14. The audio signal does not include a timing signal that can specify its location.

Therefore, a predetermined amount of signals are sequentially stored (written) at predetermined addresses based on the timing when the detection circuit 15 detects a vertical synchronization signal (or a horizontal synchronization signal).

On the other hand, the signal whose time axis has been corrected by the time base corrector 3 is input to a video tape recorder 4 as a transmission system, and is recorded on a magnetic tape. This recorded signal is immediately (simultaneously) reproduced by an auxiliary rotary head dedicated to reproduction, which is separate from the main rotary head for recording and reproduction.

Of the reproduced signals output from the video tape recorder 4, the video signal is input to an A/D conversion circuit 21, and the audio signal is input to an A/D conversion circuit 22, where the analog signal is converted into a digital signal. Similar to the case described above, specific video signals are sequentially stored (written) at specific addresses in the memory 23 based on the vertical synchronization signal detected by the detection circuit 25. The audio signal A/D converted by the A/D conversion circuit 22 is also stored in the memory 2 in the same manner as described above.
4 is stored.

The data written in the memory 13 and the memory 23 are read out and input to the comparison circuit 31. Memory 13.23 (
Memories 14 and 24 also consist of a pair of memories, each operating independently, so that one memory is written in while the other is read out, so that continuous signals can be processed. This reading is performed for each corresponding address. Therefore, the comparison circuit 31 can compare data at corresponding positions in corresponding fields or frames of the signal input to the video tape recorder 4 and the signal output from the video tape recorder 4.

Video signals in adjacent fields or frames have a relatively strong correlation and can therefore be considered to be substantially the same signal. Therefore, the memory 13 and the memory 23 may each store video signals of adjacent fields or frames (for example, an odd field and an even field). Alternatively, some of the video signals may be of the same field and some of the video signals may be of different fields.

For example, if the output signal is delayed relative to the input signal,
A delay circuit can be inserted into the input signal path, or the timing of the read clock can be delayed.

If there is a time axis error in the input signal or output signal and comparison is difficult, the input signal corrected by the time base collector 3 and the time base collector inserted in the output stage of the video tape recorder 4 are used to correct the time axis. It is also possible to compare the corrected output signal.

Each material is recorded correctly on the video tape recorder 1,
Assuming that it is reproduced correctly, the input signal and output signal of the video tape recorder 4 substantially match each other if the recording and reproduction to the video tape recorder 4 is performed correctly. On the other hand, video tape recorder 4
If recording and reproduction are not performed correctly, the two do not match.

For example, if the rotating head is clogged and the output signal cannot be obtained or the specified level cannot be obtained, or if there are dropouts, tracking deviations, wow and flutter, etc., the comparison result will show a specified pattern corresponding to the defect. It will be shown. No matter how much the video tape recorder 4 is improved, it is impossible to completely eliminate these defects, and unless these defects exceed a predetermined standard, there is little practical luck. Therefore, a pattern as a reference is stored in advance in a memory 35 made of, for example, a RAM. The comparison circuit 31 compares the comparison result of the human output signal with the pattern stored in the memory 35, and if a defect exceeding the standard has occurred, a signal corresponding to the defect is sent to the control circuit 5 (of course, a separately provided control circuit).

Similarly, in the comparison circuit 32, the memory 14 and the memory 2 are
The comparison result of the audio signal data stored in the memory 35 is compared with the reference pattern stored in the memory 35, and the result is output to the control circuit 5.

Comparisons can be made analogously, but are more accurate when done digitally. When comparing digitally, a microcomputer or the like can be used as a comparison circuit.

- The detection signal of the vertical synchronization signal outputted by the force detection circuit 25 is also input to the comparison circuit 33. Comparison circuit 33 compares this detection signal with a reference vertical synchronization signal generated by generation circuit 34. Of course, it is also possible to similarly detect the reproduction horizontal synchronization signal by the detection circuit 25 and compare it with the reference horizontal synchronization signal output from the generation circuit 34.

The comparison result of the synchronization signals is also output from the comparison circuit 33 to the control circuit 5.

The control circuit 5 receives the video signal obtained in this way.

Information regarding the defect corresponding to the comparison results of the audio signal and the synchronization signal is displayed on a display means 36, such as a printer, along with a time code if necessary. Therefore, by performing unification editing while checking the display on the display means 36, subsequent previews can be omitted. If a defect is found, the time code can be used to locate it and re-edit it.

A non-video portion (black burst portion) and a silent portion exist in the section between one material (program) and the following material (program). Comparisons in such intervals are not only meaningless, but also easily influenced by noise and the like. Therefore, in such a section, the control circuit 5 controls each comparator circuit to virtually prohibit the comparison operation. In some cases, only a 20-second portion of the video is broadcast. In such a case, the video tape recorder 4 is in a substantially stopped state (for example, a pause state) when 20 seconds of recording is completed.
become. In contrast, the video tape recorder 1 continues playing until the beginning of the next material. Therefore, if a comparison is performed during this time, an incorrect display will be made, so the comparison operation is also prohibited in this case.

The input signal and the output signal can also be compared by, for example, making one characteristic complementary to the other and adding the two. In this way, if recording and playback are performed correctly, a signal with a level of ll850% will be obtained, so if the difference from the 50% level exceeds a predetermined value, the comparison result will indicate an abnormality. Output.

In the above description, the input and output of the video tape recorder for unification editing are compared, but for example, the input and output of the video tape recorder that is recording a predetermined scene may be compared at the same time as the recording. In addition to video tape recorders, the present invention can also be applied to, for example, optical disk devices, magnetic disk devices, and the like.

FIG. 2 shows an example of yet another transmission system. For example, a playback signal from a video tape recorder 4 loaded with a videotape that has been edited into one is input to two systems 42 and 52.

The system 42 is controlled by the control circuit 41, the system 52 is controlled by the control circuit 51, and the video tape recorder 4
is controlled by the operating control circuit of the control circuit 41 or 51 via the switch 61. The output of the system 42 or 52 is input to the transmitters 43 and 53 via the switch 62, and the output of either of the transmitters 43 and 53 is supplied via the switch 63 to the antenna 64 and broadcast. If a failure or the like occurs in one system, it is possible to switch to the other system using switches 61, 62, 63. Radio waves transmitted from antenna 64 are received by receiver 66 via antenna 65.

In such a transmission system, for example, systems 42 and 52
The outputs a and b of are compared as the above-mentioned input and output signals, respectively, or the input signal C to the transmitter 43.53 is
It is also possible to compare the output signal d of the receiver 66 with the output signal d of the receiver 66.

〔effect〕

As described above, the present invention relates to a transmission system inspection method.

A/D converts the input signal input to a predetermined transmission system,
/D-converted input signal is stored in memory, and
A/D converting the signal output from the transmission system, storing the A/D converted output signal in memory, comparing the input signal and output signal stored in the memory, and responding to the comparison result. Since information regarding defects in the transmission system is displayed, it becomes possible to accurately inspect the transmission system at the same time as transmission.

[Brief explanation of drawings]

Figure 1 is a block diagram when the transmission system inspection method of the present invention is applied to an editing device, Figure 2 is a block diagram of another embodiment of the transmission system, and Figure 3 is a block diagram of a conventional editing device. be. 1... Video tape recorder 2... Switch 3... Time base collector 4... Video tape recorder 5... Control circuit 11.12... A/D conversion circuit 13.14... Memory 15...Detection circuit 21.22...A/D conversion circuit 23.24...Memory 25...Detection circuit 31.32.33...Comparison circuit 34...Generation circuit 35... Memory 36...More than display means

Claims (11)

[Claims] (1) A/D converting the input signal input to a predetermined transmission system, storing the A/D converted input signal in a memory, and A/D converting the signal output from the transmission system, A
/D converted output signal is stored in a memory, the input signal stored in the memory is compared with the output signal, and information regarding a defect in the transmission system is displayed in accordance with the comparison result. Characteristic transmission system inspection method. (2) The transmission system inspection method according to claim 1, wherein the input signal is a video signal or an audio signal. (3) The transmission system inspection method according to claim 1 or 2, wherein the input signal or the output signal is A/D converted after correcting a time axis error thereof. (4) The transmission system inspection method according to claim 1 or 3, wherein the input signal is a video signal and is stored in the memory in units of fields or frames. (5) The transmission system inspection method according to claim 4, wherein at least a portion of the input signal and the output signal stored in the memory are signals of different fields. (6) The transmission system according to any one of claims 1 to 5, wherein the input signal and the output signal are compared by being added as mutually complementary signals. Inspection method. (7) The transmission system inspection method according to any one of claims 1 to 6, wherein the input signal and the output signal are compared with a predetermined pattern prepared in advance. (8) The transmission system inspection method according to any one of claims 1 to 7, wherein the transmission system is a video tape recorder. (9) The transmission system inspection method according to claim 8, wherein the output signal is a signal obtained by recording and simultaneously reproducing the input signal. (10) Transmission according to claim 8 or 9, characterized in that when a plurality of programs are recorded by the video tape recorder, the display is prohibited between the programs. System inspection method. (11) Claim 1 characterized in that the display is prohibited when the operation of the transmission system is substantially stopped.
The transmission system inspection method according to any one of items 1 to 10.