JPH0969982A - Video broadcast device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system of simpler constitution which broadcasts the same video broadcast program over a plurality channels in overlapped time zones with time differences as a video broadcasting device for cable broadcasting. SOLUTION: Video data of one program regarding one or plural kinds of video broadcast programs are stored on a hard disk(HD) 2a and a personal computer 3 supplies a broadcast command to the hard disk drive(HDD) 2 according to schedule data regarding the kind, broadcast time, and channel of a broadcast. The HDD 2 gains random access to video data to broadcast at each time with a time difference by a certain amount at each time and reads them out in time series and after a multiplexing transfer part 6 multiplexes the data in one time slot through a buffer memory 4, the data are transferred to respective channel signal systems through a bus 7, so that the video signal after decoding (8) and D/A conversion (9) is sent out to a transmission line 11 by an analog transmission part 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video broadcasting apparatus, and more particularly to a cable broadcasting system for handling digitized video information, and more particularly to a system for staggering the same video broadcasting program on a plurality of channels in overlapping time zones. The present invention relates to an improvement for realizing with a simple configuration.

[0002]

2. Description of the Related Art Conventionally, in cable broadcasting such as CATV,
In many cases, so-called "staggered broadcasting" is performed in which the same program is broadcast on a plurality of channels while shifting the start time. Also, with the arrival of the full-fledged multimedia era, it is required to realize time difference broadcasting with a large degree of time freedom on more channels.

The following proposals have been made as technologies related to the time difference broadcasting of the above cable broadcasting system. First, as a system for realizing an on-demand video service at a lower cost, a group of video playback devices that automatically repeats a plurality of types of analog video signals with a fixed start time offset and repeatedly output the respective output signals. Signal conversion means for converting each of the modulated signals into signals having different predetermined carrier frequencies, multiplexing means for frequency-multiplexing the signals having different carrier frequencies, and a request from the subscriber. There has been proposed a cable broadcasting system including switch means for allocating a transmission channel by selecting any one of the multiplexed signals and transmitting means for transmitting the selected signal via the allocated transmission channel.
(JP-A-7-46573).

Further, a plurality of recording media in which video / audio information of one program is sequentially divided and recorded, respective signal reproducing means provided corresponding to the plurality of recording media, and respective signal reproducing means and plural. Output switching means, which is provided between the signal output terminals and selectively outputs the output signal of each signal reproducing means to each signal output terminal, and the timing for switching each switch of the output switching means. A timing signal generating means for generating a signal is provided, and while each signal reproducing means performs endless reproduction from each recording medium, the timing signal generating means generates a timing signal so as to ensure continuity of video and audio of the program. There is a proposal of a reproducing apparatus in which each switch of the output switching means is switched to obtain a time difference broadcasting signal from each signal output terminal of the output switching means. Is (JP-A-7-78411).

[0005]

By the way, the above-mentioned Japanese Patent Laid-Open No. 7-46573 broadcasts a plurality of types of programs with a time difference. According to the proposal, the time difference between program broadcasts is shortened. When increasing the number of transmission channels by
Correspondingly, a video reproducing device (namely, video disc player or VTR) must be added. Further, when performing the staggered broadcast of the same program, it is necessary to copy the video information to a disc or a video tape by the number corresponding to the staggered broadcast number. Furthermore, since each video reproduction device handles an analog video signal as an original signal, deterioration of the video signal is caused due to abrasion of the tape or the like during 24-hour operation.

On the other hand, in Japanese Patent Laid-Open No. 7-78411, dubbing is necessary because the video / audio information of one program is divided and recorded in a plurality of recording media to obtain a plurality of time difference broadcasting signals. However, there is a problem that the number of recording media increases in principle if the time difference between program broadcasts is shortened. Also, there is no mention of the case of staggered broadcasting of a plurality of types of programs, and if it were to be realized, the information of each program would have to be recorded in a plurality of separately provided recording media. However, there arises a problem that the switch circuit of the output switching means becomes too complicated.

Therefore, the present invention enables time difference broadcasting in a cable broadcasting system which handles digitized video information, without the above disadvantages and problems, with a simple circuit configuration and a large degree of freedom in time. , Was created for the purpose of providing a video broadcasting device applicable to an on-demand video service system.

[0008]

A first invention is a video broadcasting apparatus capable of time-broadcasting the same video broadcasting program on a plurality of channels in overlapping time zones, and one or more kinds of video broadcasting. A large-capacity storage means for accumulating one piece of video data for each program, a schedule management means for managing the type, broadcast time, and broadcast channel of the video broadcast program, and the large-scale storage means based on the schedule data of the schedule management means. A data reading unit for reading a fixed amount of time-series video data at each time point of a program to be staggered while randomly accessing the capacity storage unit, and temporarily storing each video data read by the data reading unit. The buffer means and the writing and writing of each video data to the buffer means while performing address management divided for each program to be staggered. R / W control means for executing reading, and multiplex transfer means for adding channel data to each video data read from the buffer means to multiplex and transferring the multiplexed data to a signal system of each channel. The signal system of each channel takes in the video data to which the corresponding channel data is attached, converts it into an analog video signal by the D / A conversion means provided for each signal system, and the analog video signal of each signal system The present invention relates to a video broadcasting device characterized in that the signal is modulated by an analog transmission means and output to a transmission line.

According to the present invention, the large-capacity storage means is made to record one piece of video data for one or a plurality of kinds of video broadcast programs, and the data reading means makes time difference based on the schedule data of the schedule management means. The video data at each point in time of the program to be broadcast is read by a fixed amount by the random access method. Since the video data read out by the data reading means at each time point is data to be broadcast on different channels, the multiplexing transfer means multiplexes and transfers each data to which the channel data is added. Then, the signal system of each channel takes in the corresponding video data and performs D / A conversion, and the analog transmission means modulates the analog video signal of each channel and outputs it to the transmission path.

The buffer means controlled by the R / W control means is interposed between the data read means and the multiplex transfer means because the data read means operates as a large-capacity storage means when the number of programs of the time difference broadcast increases. Since the number of times of random access increases and the data transfer rate of the data reading means decreases, the data transfer rate is maintained high by increasing the amount of data to be read in one access. This is to keep the throughput constant. Further, the R / W control means enables the identification of each video data for each channel by the address management divided for each program to be staggered, and the multiplexing transfer means adds the channel data based on it.

A second aspect of the invention is a mass storage means, a schedule management means, a data reading means, a buffer means, and an R /
The respective functional means of the W control means are common to the first invention, but instead of the multiplex transfer means in the first invention, each video data read from the buffer means is distributed for each program to be staggered and dealt with. The data distribution means for separately distributing and transferring to the signal system of each channel is provided, and the video data distributed and transferred from the data distributing means is converted into an analog video signal by the D / A conversion means provided for each signal system. The present invention relates to a video broadcasting device characterized in that the analog video signal of each signal system is modulated by an analog transmission means and output to a transmission line.

According to the present invention, the video data read from the buffer means is not multiplexed, and the data distribution means buffers the data based on the fact that each video data is address-managed for each channel at the stage of storage in the buffer means. Each video data read from the means is directly and individually transferred to the signal system of the corresponding channel. In that case, as many signal lines as the number of channels are required for the transfer, but the transfer process is simplified because the signals are distributed to the transfer destination while being synchronized by a multiplexer or the like.

A third invention is the video broadcasting apparatus according to the first or second invention, wherein D / in the signal system of each channel is used.
Abnormality detection means for detecting whether or not the output video signal of the A conversion means is in an abnormal state, alternative video output means for outputting the alternative video signal, and output signals of the D / A conversion means in the signal system of each channel. Switching means for selectively switching the output signal of the alternative video output means and outputting to the analog transmission means, and switching control means for controlling the switching means based on the detection data of the abnormality detection means are provided. In the video broadcasting apparatus, the switching control means controls the switching control means to set the corresponding channel to the output state of the alternative video signal when the detection data of the detection means indicates an abnormal state for any channel. Pertain.

The present invention relates to the improvement of the first or second invention, and when the image on each channel is in an abnormal state, the abnormality detecting means immediately detects the fact, and the switching control means operates the switching means. By controlling, the output of the corresponding channel is automatically switched to the alternative video signal of the alternative video output means. Therefore, when an abnormality occurs in the video being broadcast, it is immediately switched to the alternative video, and it is possible to prevent the abnormal video from continuing for a long time. Here, "Alternative video" is "Please wait. 』
A video including a message such as, and its substitute video signal is always input to the switching means.

A fourth aspect of the present invention relates to a video broadcasting apparatus intended for a digital transmission path, and has the same large-capacity storage means, schedule management means, data reading means, buffer means and R / W as the first aspect of the invention. Although it has a control means and a multiplexing transfer means, the multiplexing transfer means transfers the video data directly to the digital transmission section.

Only the transmission system is the digital system, and the read and transfer functions of the video data relating to the time difference broadcasting are the same as those of the first invention, but since the digital transmission is performed, the video data is converted into analog data on the receiving terminal side. There is a need to.

In each of the above inventions, when the video data of the video broadcast program stored in the large-capacity storage means is compressed data, a data decompression means corresponding to the compression method is provided for each channel signal system. It should be provided. The data expansion means is provided before the D / A conversion means in the first to third inventions, and is provided before the digital transmission means in the fourth invention. However, in the fourth aspect of the invention, when the compressed data is transmitted as it is with emphasis on the transmission efficiency, a method of mounting the data decompression means on each receiving terminal side without providing the data decompression means on the video broadcasting device side is adopted. To be done.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a video broadcasting apparatus of the present invention will be described in detail below with reference to the drawings. <Embodiment 1> First, FIG. 1 is a block circuit diagram of a video broadcasting apparatus. In FIG. 1, reference numeral 1 denotes a video editing machine for converting an analog video signal of a broadcast program into a digital signal for editing and a digital video signal thereof. A video input unit composed of a personal computer equipped with a hard disk for registering and storing it and an MPEG (Moving Picture Experts Group) encoder, and 2 is a batch of video data of each broadcast program obtained from the video input unit 1. Hard disk
(HD) A hard disk device (HDD) that stores the data in the 2a and reads the stored data. The 3 manages the type of each program, the start / end time of the broadcast, and the schedule of which program to broadcast to which channel. A personal computer (hereinafter referred to as "personal computer") that is managed in a dynamic manner, 4 is a buffer memory for temporarily storing the video data read by the HDD 2, and 5 is a buffer memory for the video data read by the HDD 2.
An R / W control unit for controlling writing to 4 and reading of the data, 6 is a multiplex transfer for multiplexing video data of each broadcast program read from the buffer memory 4 at each time point and transferring to the data bus 7. Denoted by 8 is a decoding unit for decoding the transferred video data by providing an MPEG decoder for each channel, and 9 is a D / A converter for each channel to convert the decoded video data into an analog signal. D /
An A conversion unit, 10 indicates an analog transmission unit that modulates the analog-converted video signal by a predetermined method and transmits it to the transmission line 11.

In this embodiment, the video broadcasting apparatus is capable of broadcasting 14 channels, and as shown in FIG. 2, 20 channels of a program A having a reproduction time of 120 minutes on 1ch to 6ch is provided for each channel. An example will be described in which a time difference is broadcast with a time difference of one minute, and a program B having a playback time of 80 on 7ch to 14ch is time-broadcast with a time difference of 10 minutes for each channel. Therefore, the HDD 2 is the video input unit 1
Video data of one broadcast of each program A, B input from
(Compressed data in the MPEG system) is stored in the HD 2a in advance, and the personal computer 3 stores the program A shown in FIG.
Broadcast schedule data of B is registered.

First, just before the time 10:00, the personal computer 3 gives a broadcast start command to the HDD 2 to send the HD 2a.
The video data of programs A and B are read from. In that case,
The HDD 2 alternately randomly accesses each track in the HD 2a where the first video data of each program A, B is recorded, and reads the video data corresponding to several frames in a time series for each access. Here, each time the video data is read, the R / W control unit 5 designates a write address in the buffer memory 4 in synchronization with the read clock of the HDD 2, and stores each read video data in the buffer memory. However, when a certain amount of data has been accumulated, the read address is specified for the buffer memory 4, and the video data of each program is read alternately by one frame and transferred to the multiplex transfer unit 6. To do. More specifically, R
The / W control unit 5 sets a writing area in the buffer memory 4 for each video data of each program A and B, and sets FIFO (First-In Firs)
t-Out) system, and while requesting data transfer to HDD2 while monitoring the amount of accumulated data relating to each video data of programs A and B, in reading control, 14 channels × 1 frame of video data is always The video data of each program is output to the multiplex transfer unit 6 at a throughput with a transfer time of one time slot.

Next, in the multiplex transfer unit 6, a header containing channel data is added to each frame of video data read from the buffer memory 4, and each video data to which the header is added is added to one. Multiplex into the time slot and output. That is, at this stage, since only the video data relating to the broadcast of the program A of 1ch and the broadcast of the program B of 7ch starting from the time 10:00, the video data of the program A and the program B are buffered by one frame each. It is input from the memory 4, and each of those video data has 1 channel
And a header incorporating a code indicating that the channel is 7ch is added, and the frame data with headers of the programs A and B are multiplexed in the time slot and output to the data bus 7.

The contents of the multiplexed data at the start of broadcasting will be described with reference to FIG. FIG.
2 shows the contents of the multiplexed data stream assigned to one time slot immediately before each time in the left column in correspondence with the broadcast schedule in FIG. “A (or B) in each block in each data stream
(Number #); (Number T) ”, A (or B) represents the program type, (Number #) represents the broadcast channel, and (Number T) represents the elapsed time from the start of each broadcast. However, for 10 minutes from the start of broadcasting at time 10:00, only the broadcast of program A of 1ch and the broadcast of program B of 7ch, so the frame data for those 2 channels is allocated in one time slot. There is.

In this way, the multiplexed data is output to the data bus 7. The data bus 7 is connected to the MPEG decoder provided for each channel of the decoding section 8, and each MPEG decoder is multiplexed. The channel data is read from the header of the encoded data, and only the frame data relating to the own channel is fetched and decoded. At this stage, the MPEG decoder corresponding to 1ch sends the frame data relating to the broadcast of the program A to the MP corresponding to 7ch.
The EG decoder takes in the frame data relating to the broadcast of the program B and individually decodes it.

Then, the decoded frame data is input to the corresponding D / A converter of the D / A converter 9, converted into an analog signal, modulated by the analog transmitter 10, and passed through the transmission line 11. It is delivered to the receiving terminal of each subscriber. The modulation method in the analog transmission unit 10 is determined by the specifications of the transmission line 11 and the receiving terminal side.

Next, about 10 minutes after the start of broadcasting, at time 10:10, the program A of 1ch and the program B of 7ch are broadcast for 10 minutes, and the HDD 2 is HD2a.
In each of the programs A and B, the tracks on which the video data of 10 minutes have elapsed are alternately accessed at random.
However, since the broadcast of program B is started, PC 3 is HD
The command is given to D2. HDD2 that received the command
In addition to the access described above, the track in which the first video data of the program B in the HD 2a is recorded is also accessed, and the video data at the time when 10 minutes of the program A has elapsed → (the video data of the program B 10 (Video data at the time when minutes passed)
-> Random access is performed in the order of (the first video data of program B), and video data for several frames is read at each access. The order of random access does not necessarily have to be the order described above, and it is sufficient to set the order that can be most efficiently read according to the recording position of the video data of each program A, B for the HD 2a. The same is true for the case.

The R / W control unit 5 is newly added 8c.
An address area related to the video data of the program B related to h is prepared in the buffer memory 4, and the three types of video data are output to the multiplex transfer unit 6 by one frame in the above one time slot by the management of the FIFO method. , The multiplexing transfer unit 6 is 8
For the video data of program B related to ch, a header incorporating a code indicating that it is 8 ch is added, and frame data with headers related to three broadcasts are multiplexed in one time slot and multiplexed to form a data bus. Output to 7.
Therefore, the data stream of the multiplexed data at that time has the contents corresponding to the time 10:10 in FIG.
1; 10], [B7; 10], and [B8; 0] are allocated in one time slot.

Then, in the decoding unit 8 and the D / A conversion unit 9, the decoder and the D / A converter corresponding to 8ch decode and convert the video data newly added, and the analog transmission unit 10 converts the 1ch program. In addition to the video signals of Program B of A and 7ch, the video signal of Program B of 8ch is modulated and sent to the transmission line 11.

Next, when 20 minutes have elapsed from the start of broadcasting, broadcasting of program A of 2ch and program B of 9ch is started in addition to the broadcasting of the above-mentioned three channels by the broadcasting schedule of FIG. At this point, the above-mentioned 1ch program A
The program B of 7ch is broadcasted for 20 minutes, the program B of 8ch is broadcasted for 10 minutes, and the HDD2 sequentially accesses the video data corresponding to each elapsed time in the HD2a at random, but the personal computer 3 accesses the HDD2. It gives a broadcast start command for program A of 2ch and program B of 9ch. H that received the order
In addition to the above access state, DD2 also accesses the track in which the first video data of programs A and B in HD2a is recorded (video data at 20 minutes of program A) → (Program A first video data) → (Program B 20 minutes elapsed video data) → (Program B 10 minutes elapsed video data) → (Program B initial video data) Random access is executed 5 times in total, and video data is read out for several frames in each access.

Further, the management operation of the buffer memory 4 by the R / W control unit 5 and the processing operation by the multiplex transfer unit 6 are 2
Basically, the temporary storage and the generation of the multiplexed data stream are executed in the same manner as described above by only adding the operation for increasing the number of channels, as shown in FIG.
At 0:20, [A1; 20], [A2; 0], and [B7; 2 within one time slot.
The frame data of [0], [B8; 10], and [B9; 0] are assigned. Then, in the decoding unit 8 and the D / A conversion unit 9, 1ch and 7
In addition to ch and 8ch, 2 / 9ch compatible decoder and D /
The A converter decodes and analog-converts the video data, and the analog transmission unit 10 also modulates the converted video signal and sends it to the transmission line 11.

Thereafter, according to the broadcast schedule of FIG.
The number of channels started to be broadcast every 0 minutes increases, and the PC 3 issues a broadcast start command to the HDD 2 each time to increase the number of random accesses to the HD 2a. At the time when a minute has elapsed, all channels 1 to 14 are in the broadcasting state.
In that case, the HDD 2 only needs to access two locations of the HD2a within a predetermined time at the beginning of the broadcast, but it will access 14 locations within the same time.
As shown at time 11:40 and after in FIG. 3, the multiplexed data stream of one time slot is composed of video data of 14 frames. Therefore, the HDD2 must continuously perform frequent access, but the recent HDD2 has a data transfer rate of 1.5 Mbps or more, and the data transfer / processing system of the HDD2 and later has video continuity. Since it has a sufficient processing speed to secure the above, the throughput for outputting a large amount of video data of about 14 channels as the whole video broadcasting apparatus when the video data compressed by the MPEG system is targeted. It can be realized with a margin.

In this embodiment, the video data of each broadcast program is stored in the HD 2a and read by the HDD 2. However, [optical disk and optical disk device] and [large capacity semiconductor memory and its data reading device] Have the same or higher data transfer rate, they may be adopted. Further, in this embodiment, the personal computer 3 is made to execute broadcasting on each channel in advance based on the broadcast schedule data. However, the transmission path 11 should be capable of bidirectional communication and received by the video broadcasting device side. An I / F is provided so that the receiving terminal side can make a broadcast request to the video broadcasting device side specifying the program and the start time, and
An on-demand video service can be realized if 3 sequentially sets the broadcast schedule according to the broadcast request obtained from the reception I / F.

<< Second Embodiment >> A block circuit diagram of a video broadcasting apparatus according to this embodiment is shown in FIG. In the same figure, those denoted by the same reference numerals as those in FIG. 1 indicate the same functional elements, and since they have the same functions as in the case of the first embodiment, the description thereof will be omitted here. . The feature of this video broadcasting device is that a data distribution unit 15 is provided in place of the multiplex transfer unit 6 in the device of FIG. 1, and direct signal lines are provided from the data distribution unit 15 to each decoder of the decoding unit 8. Is at the point where they are connected.

As described in the first embodiment, R /
The W control unit 5 sets an address area for each video data of each staggered broadcast in the buffer memory 4, writes the read data of the HDD 2 into the buffer memory 4, and reads the data for each video data of each staggered broadcast. Therefore, by confirming the read address, it is possible to confirm to which channel the data should be transferred, and the channel data is not added to individual video data as in the first embodiment and multiplexed transfer is not performed, but directly based on the read address. It can also be distributed and transferred to the corresponding decoder of the decoding unit 8.

Therefore, in this embodiment, the data distribution unit
At 15, the read address of the R / W control unit 5 is sequentially confirmed, and each video data is distributed to the corresponding signal line and output. Specifically, for example, the data distribution unit 15 is configured by a multiplexer with 14 outputs and a switching control circuit, and the switching control circuit sequentially switches the multiplexers based on the read address from the R / W control unit 5. To

In this case, as is clear from comparison between FIGS. 1 and 4, in the multiplex transfer system (FIG. 1), one data bus is used.
It suffices to connect 7 to the decoding section 8 side, but 14 signal lines are required in the distribution transfer system of this embodiment.
However, unlike the case of the multiplexing transfer method, complicated time management and processing for creating the multiplexed data stream are not required, and the data distribution unit 15 itself can be realized with a relatively simple configuration as described above. There is an advantage. Note that this embodiment is different only in the transfer method of each video data for each channel, and the operation after the decoding unit 8 is the same as that of the first embodiment.

<< Third Embodiment >> A block circuit diagram of a video broadcasting apparatus according to this embodiment is shown in FIG. Also in this figure, the same reference numerals as those in FIG. 1 denote the same functional elements, and the description thereof will be omitted here. Further, although this embodiment can be applied to the case of the embodiment 2 shown in FIG. 4 described above, the case where it is applied to the embodiment 1 will be described here. The feature of this video broadcasting apparatus is that a switching device for switching to an alternative video is provided between the D / A conversion unit 9 and the analog transmission unit 10. The switching device includes an anomaly detection unit 21 in which an anomaly detection circuit is connected to each channel signal system between the D / A conversion unit 9 and the analog transmission unit 10, and a stationary message including a message such as "please wait for a while". An alternative video output unit 22 for outputting an alternative video signal of the screen and a switch circuit capable of selectively outputting the video signal of the broadcast program and the video signal of the alternative video output unit corresponding to each channel signal system are provided. The signal switching unit 23 and the switching control unit 3 that controls each switch circuit of the signal switching unit 23 based on the detection data of each abnormality detection circuit of the abnormality detection unit 21.

In the video broadcasting device, the HDD 2 and the individual decoders of the decoding unit 8 and the individual D / A converters 9
When the A converter fails, the broadcast image may be in an abnormal state or a non-image state. In such a case, it is desirable to display the above-mentioned alternative still screen on the receiving terminal side, but in the conventional broadcasting studio etc., it is necessary to confirm an abnormal situation on the display screen of the monitor provided for each channel. The procedure to output the alternative video signal was adopted, and there was a problem in the speed of handling.

In the video broadcasting apparatus according to this embodiment, when the video signal of a certain channel signal system becomes abnormal or in a non-video state, the corresponding abnormality detection circuit of the abnormality detection unit 21 informs the switching control unit 3 of the fact. The switching control unit 24 immediately switches the switching circuit of the signal switching unit 23 related to the signal system to the connection state to the alternative video output unit 22 side to automatically broadcast the alternative video. Therefore, it is possible to prevent a situation in which the video state or the non-video state is disturbed on the receiving terminal side for a long time due to a delay in confirmation by an operator of a broadcasting studio or the like. Each abnormality detection circuit of the abnormality detection unit 21 is configured as a circuit that sets a flag to ON or OFF according to whether or not the sync signal of the video signal after D / A conversion is detected in a predetermined cycle. In that case, the switching control unit 24 checks the flag data of each abnormality detection circuit and switches the signal system in the abnormal or non-video state.

<< Embodiment 4 >> A block circuit diagram of a video broadcasting apparatus according to this embodiment is shown in FIG. In this figure as well, those denoted by the same reference numerals as those in FIG. 1 indicate the same functional elements, and description thereof will be omitted. This video broadcasting device is of a digital transmission system, and decodes original video data compressed by the MPEG system and broadcasts it. Therefore, unlike the configuration of FIG. 1, the D / A conversion unit 9 is not provided, and the video data of each channel decoded by the decoding unit 8 is modulated by the digital transmission unit 31 and the digital transmission line
It is transmitted to the receiving terminal side via 32. Here, the modulation method in the digital transmission unit 31 is PSK (Phase Shift Keying) or ASK (Ampli) depending on the specifications of the transmission path 32 and the receiving terminal.
tude Shift Keying), MSK (Minimum Shift Keying), QAM (Quadrature Amplitude Modulation), VSB (Ve
stigial Side Band) is adopted.

In the case of this video broadcasting apparatus, the video data transmitted on the receiving terminal side which receives the video data via the transmission path 32 is demodulated by a demodulation method corresponding to the modulation method of the video broadcasting apparatus side. Needless to say, the image is displayed after being subjected to D / A conversion. Although the MPEG decoder is provided in the video broadcasting apparatus in this embodiment, it is also possible to adopt a broadcasting system in which the compressed video data of the MPEG system is directly transmitted without providing the MPEG decoder. In that case, an MPEG decoder is required for each receiving terminal, which is inevitably expensive, but the transmission efficiency is improved because compressed data is transmitted.

[0041]

The video broadcasting apparatus of the present invention has the following effects due to the above configuration. According to the first and second aspects of the present invention, the video data corresponding to one or a plurality of types of video broadcast programs can be stored in the large-capacity storage means, and the video data can be stored based on the broadcast schedule. It is possible to broadcast the same program on a plurality of channels in overlapping time zones by using the random access method, and to realize a video broadcasting apparatus having a large degree of time freedom regarding time-staggered broadcasting with a small system configuration. Claim 3
According to the invention of claim 1, in the video broadcasting device of claims 1 and 2, when an abnormality occurs in the video signal of each channel, the automatic switching to the alternative video is performed, and the video in the abnormal state is broadcast for a long time. This prevents the operator from being overloaded and reduces the burden on the operator at the broadcasting studio. The invention of claim 4 realizes a digital network-compatible video broadcasting apparatus having the same function as that of claim 1.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a video broadcasting device according to a first embodiment of the present invention.

FIG. 2 is a table showing a broadcast schedule of programs.

FIG. 3 is a diagram showing the contents of a multiplexed data stream assigned to one time slot at each time (left column) when staggered broadcasting is executed based on the broadcast schedule of FIG. 2.

FIG. 4 is a block circuit diagram of a video broadcasting device according to a second embodiment.

FIG. 5 is a block circuit diagram of a video broadcasting device according to a third embodiment.

FIG. 6 is a block circuit diagram of a video broadcasting device according to a fourth embodiment.

[Explanation of symbols]

1 ... Video input section, 2 ... HDD (hard disk device; data reading means), 2a ... HD (hard disk; mass storage means), 3 ... Personal computer (personal computer; schedule management means), 4 ... Buffer memory (buffer means) ,Five…
R / W control section (R / W control means), 6 ... Multiplex transfer section (multiplex transfer section), 7 ... Data bus, 8 ... Decode section, 9 ... D /
A converter (D / A converter), 10 ... Analog transmitter (analog transmitter), 11 ... Transmission path, 15 ... Data distributor (data distributor), 21 ... Abnormality detector (abnormality detector), 22 ... alternative video output unit (alternative video output unit), 23 ... signal switching unit (switching unit), 24 ... switching control unit (switching control unit), 31 ... digital transmission unit (digital transmission unit), 32 ... digital transmission line.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinobu Okamoto 3-12 Moriya-cho, Kanagawa-ku, Kanagawa Prefecture Victor Company of Japan, Ltd. (72) Inventor Keiko Nishimaki 3--12 Moriya-cho, Kanagawa-ku, Yokohama Address inside Victor Company of Japan, Ltd.

Claims (4)

[Claims] 1. A video broadcasting apparatus capable of time-broadcasting the same video broadcasting program on a plurality of channels in overlapping time zones, in which one video data of one kind or a plurality of kinds of video broadcasting programs is recorded. A large-capacity storage means for storing the video broadcasting program, a schedule management means for managing a type, a broadcast time, and a broadcast channel of a video broadcast program, and a staggered broadcast while randomly accessing the large-capacity storage means based on the schedule data of the schedule management means. Data reading means for reading out a fixed amount of video data at each point in time of a program to be played, buffer means for temporarily storing each video data read by the data reading means, and for each program to be staggered. An R / W control hand for writing and reading each video data to and from the buffer means while executing divided address management. And a multiplex transfer means for adding channel data to each video data read from the buffer means and multiplexing the multiplexed data and transferring the multiplexed data to a signal system of each channel. The system takes in the video data with the corresponding channel data, converts it into an analog video signal with the D / A conversion means provided for each signal system, and modulates the analog video signal of each signal system with the analog transmission means. A video broadcasting device characterized by outputting to a transmission path. 2. In a video broadcasting apparatus capable of time-broadcasting the same video broadcasting program on a plurality of channels in overlapping time zones, video data for each one type or a plurality of types of video broadcasting programs. A large-capacity storage means for storing the video broadcasting program, a schedule management means for managing a type, a broadcast time, and a broadcast channel of a video broadcast program, and a staggered broadcast while randomly accessing the large-capacity storage means based on the schedule data of the schedule management means. Data reading means for reading out a fixed amount of video data at each point in time of a program to be played, buffer means for temporarily storing each video data read by the data reading means, and for each program to be staggered. An R / W control hand for writing and reading each video data to and from the buffer means while executing divided address management. And a data distribution means for distributing the video data read out from the buffer means for each program to be staggered and individually distributing and transferring to the signal system of each corresponding channel. Distribution from the data distribution means The transferred video data is D / provided for each signal system.
A video broadcasting device characterized in that it is converted into an analog video signal by the A conversion means, and the analog video signal of each signal system is modulated by the analog transmission means and output to the transmission path. 3. An abnormality detecting means for detecting whether or not the output video signal of the D / A converting means in the signal system of each channel is in an abnormal state, an alternative video output means for outputting an alternative video signal, and each channel. Switching means for selectively switching the output signal of the D / A conversion means and the output signal of the alternative video output means in the signal system of the above to output to the analog transmission means, and based on the detection data of the abnormality detection means, Switching control means for controlling the switching means is provided, and when the detection data of the abnormality detection means indicates an abnormal state for any channel, the switching control means controls the switching control means to switch the corresponding channel to the alternative video signal. The video broadcasting device according to claim 1 or 2, wherein the video broadcasting device is set to the output state. 4. In a video broadcasting apparatus capable of time-broadcasting the same video broadcasting program on a plurality of channels in overlapping time zones, one video data for each of one type or a plurality of types of video broadcasting programs. A large-capacity storage means for storing the video broadcasting program, a schedule management means for managing a type, a broadcast time, and a broadcast channel of a video broadcast program, and a staggered broadcast while randomly accessing the large-capacity storage means based on the schedule data of the schedule management means. Data reading means for reading a fixed amount of video data at each point in time of a program to be recorded, buffer means for temporarily accumulating each video data read by the data reading means, and each of the buffer means. R / that controls writing and reading of video data
The digital transmission means is provided with W control means and multiplex transfer means for adding channel data to each video data read from the buffer means to multiplex and transfer the multiplexed data to the digital transmission means. Is a video broadcasting device characterized by modulating each video data for each channel and outputting to the transmission path.