JP2001045371A - Method and device for switching image in tv broadcasting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent broadcasting of the partial image of a TV broadcast base material, that is, a 'glimpse' by replacing a delayed TV broadcast base material with a replacement broadcast base material which is supplied through a route different from that of the TV broadcast base material at the timing of another frame appearance. SOLUTION: A frame synchronizer 12 synchronizes an inputted video signal with the frame synchronizing signal of a receiving station, which is given from an in-station synchronizing signal generating device 13, and delays the inputted video signal and, then, outputs the video signal synchronized with an in-station synchronizing signal. Then the timing of the video signal of an originating station is made to coincide with that of the video signal of the receiving station and a CM base material transmitted from an originating station side device 1 is replaced with the CM base material of the receiving station at the point of time when a frame having a rear identifying code is changed into the frame having a front identifying code so that the 'glimpse' is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for switching video in television broadcasting.

[0002]

2. Description of the Related Art A program material (a video or audio signal constituting a program) broadcasted from a television broadcast station (hereinafter simply referred to as a "station") is composed of the material of the own station created by the station. There is a material of another station which receives a material made by another station other than the station via the relay means. The station switches the material of its own station and the material of another station as appropriate to perform temporally continuous television broadcasting. In particular, in CM broadcasting (commercial message broadcasting), most of the material is made at the first transmitting station in Tokyo (hereinafter referred to as the transmitting station), and each local city receives it via trunk lines and microwave lines (Hereinafter referred to as receiving station). At the receiving station, the C transmitted from the originating station
M broadcast material (CM material) is received and broadcast to viewers in the receiving station area, but a series of CM materials sent from the source station are partially replaced with CM materials created by the receiving station. May be broadcast. For example, one sent from the originating station is 1
When the CM material of 5 seconds is broadcasted continuously in multiple episodes,
One of them is produced at the receiving station and replaced with a 15-second commercial material to be broadcast. In the replacement of this CM material, the CM material coming from the source and the C
The switching to the M material needs to be performed at an accurate timing. For example, if the switching timing is delayed, a part of the CM material of the originating station is broadcast for a short time before the broadcast of the CM material of the receiving station starts. In this case, to the viewer, it appears that the video of the CM material from the broadcasting station appears “glickering” and then switches to the video of the CM material of the receiving station. This phenomenon is referred to in the art as "flickering". The glimpse is not only unsightly, but also affects the execution status of the CM broadcast contract if there is a competition between the sponsor of the CM material of the part of the broadcasting station and the sponsor of the replaced CM material. May be exerted. If the switching timing is too early, the broadcast time of the CM material of the preceding broadcasting station is shortened, which affects the CM broadcasting contract with the broadcasting station. In addition, there is an expert who considers the glare to be a subliminal effect to the viewer, and it is required to eliminate the problem.

Conventional methods for determining the timing of switching the CM material include the following two methods. In the first method,
The broadcast start time and end time of each of a large number of CM materials are determined in Japan Standard Time (JST), and the time information is transmitted from the originating station to the receiving station in advance. The receiving station fetches the time information into the automatic program broadcasting apparatus, and switches the CM material between the source station and the receiving station according to the time information. A program whose start time and end time are defined by the JST in this way is called a “confirmed program”.

In the second method, a CM sent from a source station to a destination station is used.
A signal of a specific code called a Q signal is superimposed in a vertical blanking period of a video signal of a material. The receiving station controls the changeover switch three seconds after detecting the Q signal, and replaces the CM material. A program in which the start and end of the CM broadcast is defined by such a Q signal is called an “untime program”.

[0005]

The first method has the following problems. The clocks of the originating and receiving stations are both JS
Since the time is adjusted to T, if the time required for transmitting the CM material from the originating station to the receiving station (transmission time) is substantially zero, the CM material can be replaced at an accurate timing. However, transmission of broadcast material including CM material between the originating and receiving stations is performed by microwave lines, digital wired lines,
It is performed on various lines such as digital optical fiber lines.
In some of these lines, an analog signal is converted into a digital signal and transmitted, and the receiving station converts the analog signal again into an analog signal. Due to these signal conversions, the transmission time from the originating station to the receiving station is the sum of the propagation time of the line and the digital / analog conversion time. In addition, the vertical synchronization signals of the originating station and the receiving station are not synchronized with each other, and use independent vertical synchronization signals. Therefore, at the receiving station, the CM material arriving from the originating station is temporarily put into a frame synchronizer to perform synchronization adjustment, and broadcast after adjusting to the vertical synchronizing signal of the receiving station.
Due to this synchronization adjustment, the received CM material is delayed by a maximum of one frame time. As described above, in the replacement of the CM material based on the time information by the JST, the timing of the CM material of the originating station and the timing of the CM material of the receiving station cannot be synchronized.
A flickering beyond the frame may occur. As a countermeasure, there is a method of delaying the clock of the receiving station by about 30 milliseconds from JST. However, the material of the program is provided to the receiving station not only by the origin of the CM material in Tokyo, but also by an unspecified number of local city stations. Therefore, delaying the clock may cause a glimpse in such a case.

In the second conventional method, switching control is performed based on the Q signal superimposed on the vertical blanking period of the CM material, so that there is no delay due to the transmission time. However, since the delay due to the synchronization adjustment at the receiving station still exists, it is not possible to completely prevent glare. As described above, the conventional technology cannot completely prevent the glare.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for switching television images, which comprises a plurality of different television broadcast materials which are successively transmitted in time, each of which is provided with a video signal of a frame of a start portion of a CM broadcast. Adding an identification code and adding a rear identification code to the video signal of the end frame, wherein the alternate frame is a frame that changes from a rear identification code to a previous identification code in the temporally continuously transmitted television broadcast material. Detecting the appearance of the TV broadcast material, delaying the TV broadcast material by a time obtained by adding a fixed time to the time required for detecting the alternate frame, and the TV broadcast material, And replacing the replacement broadcast material supplied through a different path at the timing when the replacement frame appears.

A television video switching apparatus according to the present invention adds a preceding identification code to a video signal of a start portion of each of a plurality of different television broadcast materials which are successively transmitted in time, and adds a preceding identification code to an end portion of the video signal. An identification code recording device for adding a rear identification code to a video signal of a frame, the frame being connected to a transmission path for transmitting the television broadcast material transmitted continuously in time, wherein the rear identification code is changed to a previous identification code. An identification code detection device for detecting a certain alternate frame and generating a detection output, connected to the transmission line, and delaying the television broadcast material by a time obtained by adding a certain time to the time required for the detection of the alternate frame; A frame synchronizer for synchronizing with a synchronizing signal from the generator, and a detection output of the identification code applied thereto, and the delayed television broadcast element The replacement broadcast material that is synchronized with the synchronizing signal of the synchronizing signal generating device, a switch device to replace the timing of 10H of the horizontal scanning lines of the video signal of the replacement frame.

According to the method and apparatus for switching television images of the present invention, a plurality of televisions which are continuously transmitted in time are detected by detecting a replacement frame which is a frame in which a previous identification code is changed to a rear identification code. The boundaries of the broadcast material are detected. The TV broadcast material is delayed for a predetermined time so as to be longer than the time required for detecting the boundary and to be synchronized with a replacement broadcast material that is another broadcast material that replaces the TV broadcast material. Accordingly, when the broadcast material is switched to the replacement broadcast when the replacement frame is detected, the last frame of the television broadcast material is switched to the first frame of the replacement broadcast material. Therefore, it is possible to prevent a so-called “flickering” in which a part of the video of the television broadcast material is broadcast at the time of starting the broadcast of the substitute broadcast material.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of an embodiment of a video switching device according to the present invention. FIG. 2 is a block diagram showing a configuration of a video signal applied to the video switching device of the present invention, and exemplifies a CM material having a broadcast time of 15 seconds as one video signal.

In FIG. 1, a CM material station includes an originating apparatus 1 in which a CM bank 2 is provided.
In the CM bank 2, a large number of CM materials broadcast on a predetermined schedule are recorded. The identification code recording device 3 is connected to the CM bank 2. The identification code recording device 3 stores the CM material recorded in the CM bank 2 in FIG.
Is a device for adding a front identification code A and a rear identification code B, which will be described in detail later with reference to FIG.

The receiving station is provided with a receiving apparatus 10. The receiving-side device 10 is connected to the CM bank 2 of the originating-side device 1 via, for example, an NTT line 9, and
The CM material of the CM bank 2 is transmitted to the receiving-side device 10. The receiving terminal on the line 9 is connected to the input terminal 11A of the identification code detecting device 11 of the receiving device 10 and the input terminal 12A of the frame synchronizer 12. The other input terminal 12B of the frame synchronizer 12 is connected to the output terminal of the intra-station synchronization signal generator 13. An output terminal of the identification code detecting device 11 is connected to a control input terminal 14A of the switch device 14. The output terminal of the frame synchronizer 12 and the output terminal of the CM bank 15 are connected to the other two input terminals 14B and 14C of the switch device 14, respectively. The CM bank 15 records a CM material originally created by the receiving station. Identification code detection device 1
The output terminal of the CM transmission command device 17 is connected to the input terminal 11B of the CM bank 1 and the input terminal 15A of the CM bank 15.
The output terminal of the intra-station synchronization signal generator 13 is connected to the input terminal 15B. Output terminal 14 of switch device 14
D is connected to a transmitting device (not shown) of the receiving station.

FIG. 2 is a block diagram showing the structure of one copy of the most common CM material 20 having a broadcast time of 15 seconds. C
The M material 20 is a video and audio signal whose time from the start to the end is 16 seconds, and the front margin 21 of 0.5 seconds each.
And a rear margin 22. Of the 16 seconds, 15 seconds are the video signal 23 actually broadcast, and the front margin 21 and the rear margin 22 are spare video signals. The CM material 20 is recorded in the CM bank 2 of the originating apparatus 1. Front margin 21
The CM video signal 23 is converted to C
When transmitting from the M bank 2, even if the transmission start timing is slightly shifted, the video is not interrupted and a blank screen is not broadcast. Between the time t1 at the beginning of the CM material 20 and the time t3 one second later, the previous identification code A indicating the beginning of the CM material 20 has a vertical blanking period (hereinafter abbreviated as VBI) video. The signal is superimposed on the signal (the step of adding the previous identification code). In addition, from time t6 at the end of the CM material 20 to time t4 one second before, that is, at time t4
From t to t6, the post-identification code B indicating the end of the CM material is superimposed on the VBI video signal (post-identification code adding step). The front identification code A and the rear identification code B are added to all the CM materials by a signal from the identification code recording device 3 when the CM material is recorded in the CM bank 2. The front identification code A and the rear identification code B are, for example, 4-bit code signals, and are the twelfth and fourteenth horizontal scanning lines (hereinafter, each of them is 12 bits).
H and 14H) are repeatedly recorded eight times.

Referring to FIG. 3, an operation of transmitting a CM material from the originating apparatus 1 to the receiving apparatus 10 will be described with reference to FIG. FIG. 3 shows a plurality of CM materials 23 having a time length of 15 seconds.
It is a block diagram showing the state where a, 23b, 23c ... are transmitted continuously in time. The CM bank 2 of the originating apparatus 1 deletes the front margin 21 and the rear margin 22 of the CM material 20 having a time length of 16 seconds, and removes the CM materials 23a and 23 of 15 seconds.
b, 23c... are connected in time sequence and output to the line 9. As a result of deleting the front excess length 21 and the rear excess length 22, there is a front identification code A for 0.5 seconds from the start point of each of the CM materials 23a, 23b, and 23c, and a rear identification code B for 0.5 seconds to the end point. There are CM materials 23a, 23b, 23c
At times t11 and t12 of the connection point of, the rear identification code B and the front identification code A are switched.

The CM materials 23a, 23b and 23c received by the receiving side device 10 via the line 9 are inputted to the identification code detecting device 11 and the frame synchronizer 12.
The identification code detecting device 11 includes CM materials 23a, 23b, 2
The front identification code A or the rear identification code B is detected by checking the code signals of the 12H and 14H scanning lines of the video signal 3c.

When it is detected that the identification code has changed from the rear identification code B to the previous identification code A, it is detected at time t11 that the CM material 23a is replaced with the CM material 23b. That is, a replacement frame from the CM material 23a to the CM material 23b is detected (a replacement frame detection step).
When the identification code detecting device 11 detects the replacement time, it generates a replacement signal 11C, and the control input terminal of the switch device 14 in accordance with the control of the CM transmission command device 17 which commands the transmission of the CM material of the receiving station in the CM bank 15. 14A. An intra-station synchronization signal is input from an intra-station synchronization signal generation circuit 13 to an input terminal 12B of the frame synchronizer 12. The switch device 14 selects either a CM material from the originating device 1 input to the input terminal 14B or a CM material to be input to the input terminal 14C from the CM bank 15 in the receiving device 10. And a changeover switch for outputting to the output terminal 14D.

Hereinafter, the switching operation of the image will be described in detail with reference to FIGS. 1 and 4, the video signal 30 is transmitted via the line 9 to the identification code detection device 11.
And CM of the originating station input to the frame synchronizer 12
This is a video signal of the material. The video signal 31 is a video signal output from the frame synchronizer 12 and input to the input terminal 14B of the switch device 14. Video signal 32
Is a video signal output from the CM bank 15 and input to the input terminal 14C of the switch device 14. Video signal 3
Each of the negative pulses 36 and 37 of 0, 31, and 32 is a frame synchronization signal, and indicates the starting point of the video signal of one frame. As the frame synchronization signal, for example, a vertical synchronization signal may be used. Frame synchronizer 1
Reference numeral 2 denotes a device for synchronizing the input video signal 30 with the frame synchronization signal of the receiving station provided from the intra-station synchronization signal generator 13, and synchronizes with the intra-station synchronization signal by delaying the input video signal 30. The video signal 31 is output. In the example of FIG. 4, the delay is 25H (25/525 seconds) (a CM material delay step).

At time t21, the video signal 30 is input to the identification code detecting device 11. The front identification code A or the rear identification code B is recorded at 12H and 14H, but at time t2.
In step 3, when the identification code recorded in 14H is detected, the identification code detection device 11 compares the detected identification code with the identification code detected in the immediately preceding frame by an internal comparison circuit. When the detected identification code is different from the identification code of the previous frame, that is, the rear identification code B
Is changed to the previous identification code A, the identification code detection device 11 generates a replacement signal 11C. The identification code detection device 11 is provided from the CM transmission command device 17 to the CM bank 15
Is supplied to the input terminal 11B, the alternation signal 11C is applied to the input terminal 14A of the switch device 14 at time t25. 20H from time t23 to t25 is the time required for the identification code detection device 11 to detect that the rear identification code B has changed to the previous identification code A. Alternation signal 11C at time t25
Is input to the switch device 14, the switch device 14
Cuts off the input from the input terminal 14B and outputs the input from the input terminal 14C to the output terminal 14D. That is, the transmission line receiving the input of the video signal is changed from the input terminal 14B to the input terminal 14C.
Switch to Thus, the CM material from the source station is replaced by the CM at the receiving station (broadcast material replacement step).

In television broadcasting, when a plurality of video signals are selectively switched, a signal of a previous video is cut off by a scanning line 9H and a signal of a next video is transmitted from 10H in order to prevent a disturbance of the video due to the switching. It is common. Therefore, the video signal 31 output from the frame synchronizer 12
Is 25H behind the input video signal 30,
At time t25, the video signal 31 of the originating station can be cut off. At the same time t25, if the timing of the video signal 32 of the CM bank 15 receiving the command signal of the CM transmission command device 17 is 9H, the video signal 32 is output from the next 10H to the output terminal 14D of the switch device 14. Can be sent.

[0020]

As described above, according to the present invention, according to the present invention, the timing of the video signal of the originating station and the timing of the video signal of the receiving station are matched by the frame synchronizer 12 and transmitted from the originating apparatus 1. At the time when the coming CM material changes from the frame having the rear identification code to the frame having the previous identification code, the CM material from the source station can be replaced with the CM material at the receiving station. Therefore, no glare occurs. Since the replacement is performed based on the front identification code and the rear identification code added to the CM material, any delay in the transmission line is not affected. Further, since the CM material of the receiving station is replaced while synchronizing the CM material from the source station with the intra-station synchronization signal at the receiving station, no timing deviation occurs due to the synchronization adjustment at the receiving station.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video switching device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a CM material of an originating station in the embodiment.

FIG. 3 shows C transmitted from a source station to a destination station in this embodiment.
Block diagram showing the structure of the M material

FIG. 4 is a timing chart showing the operation of the present embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 originating device 2, 15 CM bank 3 identification code recording device 10 receiving device 11 identification code detecting device 12 frame synchronizer 13 intra-station synchronization signal generating device 14 switching device 17 CM sending command device A previous identification code B rear identification code 20 CM material 21 Front extra length 22 Rear extra length 23a, 23b, 23c CM material 30, 31 Video signal 32, 33 Video signal

Claims (5)

[Claims] 1. A first identification code is added to a video signal of a frame of a start portion of each of a plurality of different television broadcast materials transmitted continuously in time, and a rear identification code is added to a video signal of a frame of an end portion. Detecting the appearance of a replacement frame, which is a frame that changes from a post-identification code to a pre-identification code of the television broadcast material that is continuously transmitted in time, A delaying step of delaying the time required for the detection by adding a fixed time, and a step of replacing the delayed television broadcast material with a substitute broadcast material that is another television broadcast material at a timing at which the alternate frame appears. A method for switching television images, comprising: 2. The method according to claim 1, wherein the front identification code or the rear identification code is
2. The method according to claim 1, wherein recording is performed on one or both of a 12H horizontal scanning line and a 14H scanning line of a video signal. 3. The method according to claim 1, wherein the delaying step is performed by setting a horizontal scanning line to 12H or 14H in a time required for detecting the alternate frame.
3. The television video switching method according to claim 2, wherein the television broadcast material is delayed by a time obtained by adding the scanning time of the number of scanning lines obtained by subtracting 9H from the TV broadcast material. 4. The method according to claim 1, wherein the television broadcast material delayed by the delay step is synchronized with the replacement broadcast material. 5. A front identification code is added to a video signal of a frame of a start portion of each of a plurality of different television broadcast materials which are successively transmitted in time, and a rear identification code is added to a video signal of a frame of an end portion. An identification code recording device for adding a frame, which is connected to a transmission path for transmitting the television broadcast material transmitted continuously in time, and detects and outputs a replacement frame that is a frame in which the rear identification code is changed to the front identification code. An identification code detection device that generates a delay from the synchronization signal generation device in the receiving station by delaying the television broadcast material received through the transmission path by a fixed time to the time required for detecting the alternate frame. A frame synchronizer that synchronizes with a synchronization signal, and a detection output of the identification code detection device is applied, and the delayed television broadcast material is The replacement broadcast material that is synchronized with the synchronizing signal of the period signal generator, the switching device of a television image having a switching device to replace the timing of 10H of the horizontal scanning lines of the video signal of the replacement frame.