JPH0591510A - Method of receiving video - Google Patents

Abstract

PURPOSE:To provide a video receiving method allowing a user to observe a video always from its head at any time to be required in a CATV system for shifting the starting time of the video by a fixed time and independently and repeatedly distributing the same video through plural channels. CONSTITUTION:A receiving side is provided with a storage part 12 having capacity allowed to store an image for the shifting time of the video, the video is stored in the storage part 12 always from its head, and in the case of observing it, the storage part 12 is used as a video signal shifting register for a time difference between a received video and an output video from a receiver so that the video can be observed always from its head at required any time and the queuing time can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video receiving method on the receiver side in a video distribution system such as CATV.

[0002]

2. Description of the Related Art Conventionally, in a CATV system in which the same video is time-shifted by a certain amount and is independently and repeatedly distributed using a plurality of channels, the receiver side is not changed, and the same method as that for normal broadcast wave reception Was received at.

[0003]

However, in the system as described above, it is not possible to immediately start watching the video to be watched from the beginning, and it is necessary to wait until the video starts from the beginning. There was a problem that it would be the time shift time of.

The present invention has been made in view of the above points.
It is an object of the present invention to provide a video receiving method that allows the user to immediately start watching the desired video from the beginning.

[0005]

According to the present invention, a receiving side is provided with a storage section having a capacity capable of storing an image for a time shift time of an image, and the received image is always stored in the storage section from the beginning of the image. In addition, in the case of trial listening, this is a video receiving method in which this storage unit is used as a shift register for a video signal of the time difference between the received video and the output video of the receiver.

[0006]

According to the present invention, when the user wants to view an image, the present invention always reads out the image from the memory unit recorded from the beginning of the image and outputs it, and this memory unit outputs the received image and the output image of the receiver. It operates as a shift register that sequentially stores and holds the images of the time difference and continues to output, thereby eliminating the waiting time.

[0007]

1 is a block diagram of a video receiver according to a first embodiment of the present invention.

Reference numeral 10 denotes a converter section for selecting and outputting a signal of a desired channel from the distributed received signal, and 1 denotes an analog received video signal output from the converter section 10.
Reference numeral 11 is a PCM encoder for PCM-encoding the received video signal 1, 2 is code data output which is the output of the PCM encoder 11, 12 is a storage unit for storing the code data output 2, and 3 is the storage. The storage data output which is the output of the section 12, 13 is a PCM decoding section for decoding the storage data output 3 into an analog video signal, 4 is the decoded output video signal, and 14 is the same as the received video signal 1. A detection unit for detecting the beginning of the time-shifted video image, 5 is a detection signal output from the detection unit 14, 16 is an operation input unit that receives a key input or a remote control input from a human and outputs an operation signal 6. , 15 are control units that receive the detection signal 5 and the operation signal 6 and output the write address 7 and the read address 8 to the storage unit 12 in accordance with the detection signal 5 and the operation signal 6.

The operation of the video receiver of this embodiment constructed as described above will be described below.

The analog received video signal 1 is the output of the converter section 10. However, when the video of a new channel time-shifted with the same video starts, the detection unit 1
4 detects this, and the detection signal 5 is output to the converter unit 10, switched to the video of the new channel, and output as the reception video signal 1.

The received video signal 1 is converted into a digital code data output 2 by the PCM encoding unit 11 and sequentially stored in the storage unit 12. Code data output 2 at that time
The memory address that specifies the storage location of is the write address 7, which is the output of the control unit 15. The storage unit 12
Can be read simultaneously with writing, and outputs the data designated by the read address 8 which is the output of the control unit 15 as the storage data output 3. The PCM decoding unit 13 decodes the stored data output 3 into an analog output video signal 4.

The detection unit 14 detects that the time-shifted video of the new channel has started, outputs a detection signal 5 to the converter unit 10, and receives the video of the new channel from the received video signal 1 To output. At the same time, the detection signal 5 is output to the control unit 15. Upon receiving the detection signal 5, the control unit 15 converts the write address 7 to the storage unit 12 into the head address of the storage unit 12, and thereafter sequentially increases the value of the write address 7. The storage unit 12 stores the code data output 2 at that position according to the write address 7. The above operation is repeated in the state where the read operation described below is not performed. Therefore, the storage capacity of the storage unit 12 is required to be sufficient to store an image for a time shift time or more.

The operation input section 16 outputs an operation signal 6 to the control section 15 when an operation for outputting a video is applied. Upon receiving the operation signal 6, the control unit 15 sets the read address 8 to the storage unit 12 to the head address of the storage unit 12, and thereafter sequentially increases the value of the read address 8. The storage unit 12 outputs the digital data stored at that position according to the read address 8 as a storage data output 3.

However, as described above, the detection unit 14 is time-shifted after the storage data output 3 is output from the storage unit 12 in the read state, that is, after the detection unit 14 receives the operation signal 6. The operation for detecting the start of a new channel image is not performed.

FIG. 2 shows the storage unit 1 of the video receiver of this embodiment.
6 is a storage unit operation diagram schematically showing an example of positions of a write address 7 and a read address 8 in FIG.

The address relationship in the storage unit 12 will be described with reference to FIG. In FIG. 2, the horizontal bar represents the memory of the storage unit 12, the left end represents the memory start address, and the right end represents the memory end address. a) shows the moment when reading is started. By this time, the write address 7 has advanced to the position shown in the figure, while the read address 8 indicates the head address. Therefore, the shaded area indicates the portion in which a valid video signal is stored. After that, the address values of the write address 7 and the read address 8 are sequentially increased at the same speed. b) shows such a state, and it can be seen that the shaded portion moves in parallel.
The write address 7 and the read address 8
When reaches the last address of the memory, it returns to the first address and repeats the same operation. In c), the read address 8 has a larger value (closer to the final address) after the write address 7 has returned to the start address for a while. The operation of the storage unit 12 is FIFO.
It may be considered that a (first-in first-out) type shift register is configured, and this means that the image is delayed by the shift register.

It will be understood from the above operation that if the operation input section 16 is operated, the output video signal 4 can always be obtained from the beginning of the video at the desired moment.

In the video receiver of this embodiment configured as described above, the write address 7 is stored when the detector 14 detects that the video of a new channel time-shifted by the same video has started. Although it was converted to the head address of the section 12, the write address is not converted at all, and the address value is always increased to continue writing, and instead, the start address of the video of the new channel is held. Alternatively, the reading may be performed from the start address when the reading is started by the operation signal 6 from the operation input unit 16.

As described above, according to this embodiment, the storage section can be a digital memory, and the relationship between writing and reading can be handled by a digital value, so that the control section can be easily constructed.

If the PCM encoding unit 11 is provided with a digital compression function for video signals, the storage capacity of the storage unit 12 can be reduced. In this case, it is obvious that the PCM decoding unit 13 needs to have a digital expansion function for video signals.

In the case of a system in which a video signal is distributed as digital data, the PCM encoder 1 in this embodiment is used.
It suffices to consider that 1 is on the image source side, which simplifies the configuration on the receiver side.

In the case of a system in which a video signal is distributed by compressed digital data, it can be considered that the video source has a function of video compression encoding, and the receiver side does not need the PCM encoding unit 11. It is sufficient that the PCM decoding unit 13 has a video signal digital expansion function.

FIG. 3 is a block diagram of a video receiver according to the second embodiment of the present invention.

In the second embodiment, an analog rewritable optical disk is used instead of the digital storage section in the first embodiment. Therefore, as shown in FIG. 3, the PCM encoding unit 11 and the PCM decoding unit 13 are unnecessary, and the storage unit 12 is replaced by the optical disc unit 21. In addition, in FIG. 3, 23 is a control unit for controlling the optical disc unit 21, and 27 and 28 are a write head control signal and a read head control signal which are outputs of the control unit 23, respectively.

The operation in this embodiment is essentially the same except that the storing method is different between digital and analog. In the case of the first embodiment, the control unit 15 controls the memory address as digital data, but in the case of the present embodiment, the control unit 23 controls the positions of the write head and the read head of the optical disc unit 21, The same operation as the first embodiment can be realized.

In the video receiver of the present embodiment configured as described above, since an analog type optical disk is used for storing the video, a circuit such as a PCM encoding / decoding circuit is not required, and a large capacity is provided. Can be stored relatively easily.

Although the storage medium is an optical disk in the above embodiments, the same function can be realized by other analog type storage media as long as writing and reading can be performed independently.

[0028]

As described above, according to the present invention,
A CAT in which the same video is time-shifted for a certain period of time and is repeatedly delivered independently using multiple channels.
In the V system, the desired image can be viewed immediately from the beginning at any time, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing a video receiver according to a first embodiment of the present invention.

FIG. 2 is an operation diagram of a storage unit in the storage unit of the video receiver according to the first embodiment.

FIG. 3 is a block diagram showing a video receiver according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Received Video Signal 2 Code Data Output 3 Stored Data Output 4 Output Video Signal 5 Detection Signal 6 Operation Signal 7 Write Address 8 Read Address 10 Converter Section 11 PCM Encoding Section 12 Storage Section 13 PCM Decoding Section 14 Detecting Section 15 Control Section 16 Operation Input Section 21 Optical Disk Section 23 Control Section 27 Write Head Control Signal 28 Read Head Control Signal

Claims (6)

[Claims] 1. A receiver for receiving video signals of a plurality of channels, wherein the same video image is shifted by a constant time interval (hereinafter referred to as time shift) and is repeatedly transmitted independently of each other. When the video signal is not output, the video signal of the new channel is detected every time the beginning of the video is detected. When the video output command is received, the stored video signals are sequentially read out and output, and at the same time, a new video signal is detected. However, the video signal of another new channel is not received, the video signal being stored is received, the storage is continued, and the storage and read addresses are the final addresses of the storage section. If reached dress, video receiving method characterized by continuing again repeated operation from the head address, respectively. 2. The video receiving method according to claim 1, wherein the video signal is transmitted as digital data, the storage unit is a digital storage device, and the digital data is stored in the storage device as it is. 3. The video receiving method according to claim 2, wherein the video signal is compressed digital video data. 4. A video receiving method according to claim 1, wherein a rewritable optical disk player in which a writing head and a reading head can independently operate is used as a storage unit. 5. The video receiving method according to claim 1, wherein the received video signal is digitally encoded by a receiver and stored in a digital storage device. 6. The video receiving method according to claim 1, wherein the received video signal is digitally compression-encoded by a receiver and stored in a digital storage device.