JPH0612842A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To freely reproduce information already written while writing information, and simultaneously, to freely select a speed at which the information is reproduced. CONSTITUTION:The device is provided with an information memory means 17 having a processing speed capable of executing writing and reading information at a substantially same time, and simultaneously, an address controller 25 controlling an address for writing in the information memory means 17 and an address controller 26 controlling an address for reading. Then, since a time recording in the information memory means 17 and a time interval reproducing the information already written in the information memory means 17 can be controlled arbitrarily, an arbitrary information recorded in the information memory means 17 can be accessed even while recording. Thus, even when the information is transferred at a high speed by using a data communication line of a large capacity is recorded and reproduced, monitoring is promptly executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information storage / reproduction device for reproducing already recorded information while recording information.

[0002]

2. Description of the Related Art Conventionally, in a VTR device, a recording process and a reproducing process of information such as a television signal are performed under the concept of time shift. Specific examples of the time shift include absence recording by setting a timer, and a one-touch timer that is convenient when the user is watching TV.

As a well-known general example, an outline of the absence recording by timer setting will be described. This is to receive and record a broadcast program from a desired TV station at a desired time by a VTR device including a TV tuner, a TV signal recording / reproducing device, and timer means for controlling them. As a result, the time when a certain program is broadcast and the time when the program is viewed can be shifted.

[0004]

As described above, the VTR device can shift the time when a program is broadcast, that is, the time when certain information is transmitted and the time when it is viewed. In the case of a conventional VTR device using a tape as a recording medium, the shift time cannot be freely selected.

This is because in the case of a conventional VTR device which uses a tape as a recording medium, a data transfer time and a tape rewinding time associated therewith are required, so that an immediate monitor is performed immediately after the start of the data transfer. Because it is impossible to do.

When recording / reproducing information delivered at high speed in a large capacity communication network which is expected to develop in the future, tape is used as a recording medium because the recording and reproducing speeds are different. In the case of the conventional VTR device, there is a disadvantage that immediate monitoring cannot be performed.

In view of the above-mentioned problems, the present invention makes it possible to freely reproduce already-written information while continuing to write information, and to make it possible to arbitrarily select the speed at which the information is reproduced. The purpose is to

[0008]

An information storage / reproduction device of the present invention has an information memory means capable of simultaneously writing and reading information, and has a mode for storing information at a predetermined data rate. An information storage / reproduction device having a mode for reproducing information at the predetermined data rate, storing information at a data rate equal to or higher than the predetermined data rate, and storing the stored information. It is possible to reproduce at a data rate lower than the predetermined data rate. Another feature of the present invention is that the information reproducing process is performed a predetermined time after the storage process is started.

[0009]

According to the present invention described above, by making it possible to access any information already recorded in the information memory even during recording, while continuing the current recording,
It is possible to reproduce the already recorded information from an arbitrary recording position. In addition, even when receiving and recording information transferred at a data rate equal to or higher than the data rate at the time of information reproduction processing, the information transferred at the above-mentioned high data rate is recorded while performing standard processing. Since the information can be reproduced at various data rates, the waiting time from when the transmission request is issued until the reproduction monitor is started is significantly reduced.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the structure and operation of the first embodiment of the information storage / reproducing apparatus of the present invention will be described with reference to the structure diagram of FIG.
As shown in FIG. 1, an analog input video signal supplied from the AV receiver 11 or the like is received via the video input terminal 12, and an audio signal is received from the audio input terminal 14.

The analog video and audio signals input from the input terminals 12 and 14 are converted into digital signals by the A / D converters 13 and 15, respectively. Then, after that, the amount of data is respectively reduced by the image compressor 31 and the audio compressor 30 for compressing the data. Next, the synthesizer 16 synthesizes the video data and the audio data into a data block for each predetermined unit as composite data of video and audio, which is once written in the buffer memory 17. In this embodiment, as the buffer memory 17, a memory element capable of simultaneously accessing two or more ports is used.

The data compressor used here is
The video information is based on DCT or the like. For example, simple fixed-length coding may be used in addition to the JPEG-recommended still image processing for each screen or the MPEG-recommended advanced variable-length coding. For example, in the case of voice information, coding in consideration of auditory characteristics, adaptive transform coding based on the theory of entropy coding, and 32 to 102
What has been examined in MPEG such as band division coding of a method of subdividing into four frequency bands and analyzing a music signal in each band shows good compression characteristics at present.

By the way, JPEG and MPEG are groups for studying international standardization of images, and JPEG is J.
oint Photographic Expert
Abbreviation for Group. In addition, MPEG is Mobi
ng Picture Expert Group, which stands for still images and moving images. Details of such image compression are introduced on pages 1 to 32 of the special edition of Nikkei New Media March 4, 1991.

After that, the data read from the above-mentioned buffer memory 17 is given to the separator 18 under a predetermined control, and is separated again into a video signal and an audio signal. Then, these signals are given to the image decompressor 33 and the audio decompressor 32, respectively, and decoded into the amount of information before compression. The decoded data is converted into analog signals by the D / A converters 19 and 22, and is output from the output terminals 20 and 23 as a video signal and an audio signal with an arbitrary time delay. By supplying this output signal to the video monitor 21 and the speaker 24, respectively, the video and audio of a desired broadcast program are reproduced.

Such a predetermined control is performed mainly by the system controller 28, and the write controller 25 and the read controller 26 instructed by the system controller 28 control the buffer memory 17 and the composition described above. The operations of the container 16, the separator 18, and the like are controlled.

The data transmission side compresses the data in order to transmit the high-efficiency coded data, and stands by for the data transfer. In actuality, data compression of about 10 to 1/100 is possible, but in the present embodiment, it will be explained as 1/2 compression. When the data read time is T, 1
In the case of data compression of / N, the data transfer is completed in the time of T / N.

When the data transfer is started at time T1, the buffer memory 17 starts the recording process of the received compressed AV data. When the minimum time t1 required for the minimum processing unit of the recording process has elapsed, the reproduction monitor can be started immediately.

Data is written even while the monitor is being executed, and since N = 2 in the example, even if the amount of reproduction data is subtracted, writing equal to twice the initial time t1 plus the reproduction time is performed. Is additionally performed. This state is shown at time T3 in FIG. This is as described above because N = 2 in the present embodiment, but as described above, even with N = 10, it is possible to provide sufficiently practical image quality with the current image compression technology. The same subtraction additional recording (storage) amount as in (1) corresponds to 10 times the initial time t1 plus 9 times the reproduction time.

When N = 10, for example, when transmitting movie information for 2 hours, a data transfer time of 12 minutes is required. Therefore, when it is received by the digital VTR, after 12 minutes have elapsed (correctly, tape winding It is possible to monitor only after returning. When pursuing time reduction with this system configuration, it accelerates in the direction of increasing the image data compression rate, so it is not preferable in terms of image quality, and it did not lead to the solution of the root problem, The present invention can solve such a fundamental problem.

The recording process is continued from the start of the data transfer, and when the memory is full and the memory is full (time T4), the system is instructed to end the viewing. Recording is started for the first time when the key is input to the controller 28 from the key input unit 29 (time T5), and the recording is ended. Alternatively, the end of the sending side data (EOD:
end of data).

Next, the execution procedure of the recording / reproducing process controlled based on the start of data transfer will be described with reference to FIGS. 2 and 3. FIG. 2 shows the passage of time from time T0 to time T6, and FIG. 3 shows the state of the buffer memory 17 at each time point from time T1 to time T6, distinguishing between unrecorded, recorded, and reproduced.

In FIG. 2, time T0 is an initial state, which is a standby state for data transfer preparation. For example, a transmission request, a line or transfer mode setting, a data compression protocol, and a compression rate are set from the receiving side. At the timing of time T1, the transmitting side starts data transfer, and the receiving side starts recording the received AV information data. Here, in the initial state of the memory, all are unrecorded (displayed with φ).

At time T2 after a lapse of time t1 from time T1, monitoring becomes possible. Therefore, when a monitor instruction is input to the system controller 28 from the key input unit 29, monitor reproduction is started from this time. In the present embodiment, such a nearly simultaneous recording / reproducing process can be realized by using a memory element having two or more ports that can be simultaneously accessed.

Here, assuming that the time interval from time T2 to time T1 is t1, AV information corresponding to time t1 is recorded on the buffer memory 17 at this time. The use status of the buffer memory 17 at this time is as shown at time T2 in FIG. 3, and the rest is in the unrecorded state φ.

At time T3 after the lapse of time t2, time t2
The corresponding memory area is reproduced, and at the same time, the area corresponding to the time t2 period is further recorded in the same direction. While continuing such high-speed recording, reproduction processing is performed at the standard speed in the same direction from the time when the monitor instruction is input, and immediate reproduction processing is executed. One time point during the above-described reproduction processing is time T3, and the state of the buffer memory 17 at this time point is as shown at time T3 in FIG.

That is, at time T3, the memory area becomes a reproduced area, a recorded area, and an unrecorded area in order from the smallest address, which is illustrated as a state in which the memory capacity still has a margin. On the other hand, at time T4 when time t2 has elapsed from time T3, information is stored in the entire capacity of the buffer memory 17 as an example.

In this embodiment, the recording operation is set to end in this state. Further, at time T5 when the buffer memory 17 has a sufficient capacity, EOD indicating the completion of transfer data is received, or an instruction to end the data transfer operation is issued from the key input unit 29 to the system controller 28.
It is set to end recording when sent to.

Even after the recording process as described above is completed, the reproduction process is continuously executed, and the reproduction is performed for a total of twice as long as the above-described recording process. It should be noted that data is not erased in these reproduction processes, so that it can be reproduced as many times as necessary thereafter.

It is also possible to change the speed of the reproduction processing described above. When changed, the recording speed is constant at the above-described speed, and therefore the time interval between time T1 and time T5 does not change. In this case, the reproduction speed can be freely set as long as the reproduction (read) address does not exceed the recording (write) address.

As an example, it has a high-speed reproduction mode, and when this instruction is input from the key input unit 29, this is detected and the read address is counted faster than the standard speed (jumping is specified for every several addresses). You may perform the process to do.

Next, the control of the system controller 28 will be described with reference to the flowchart of FIG. Note that the operation flowchart of FIG. 4 includes 14 processing steps, and in the following description, the processing steps will be referred to as S01 to S14.

First, in S01, preparations for data transfer between the transmitter and the receiver, for example, a transmission request from the receiving side, selection of a line and a transfer mode, initial setting of the system such as a data compression protocol and a compression rate are performed. Next, in S02, the start of data transfer is confirmed. And if started, S03 ~
Proceed to S07 in sequence.

In step S03, the read controller 26 is initialized with the reproduction start address, and in step S04, the write controller 25 is initialized with the recording start address. In S05, recording of information supplied from the data synthesizer 16 is started. When the information recording is started, the write address of the memory 17 is sequentially incremented in S06, the write address is monitored in S07, and when the capacity is exceeded, the process jumps to S12 and the recording is stopped.

Next, in S08, the magnitudes of the transmission data rate (R _mst ) and the reception data rate (R _slv ) are compared, and if R _mst <R _slv , the data is read out at a faster rate than recording. Therefore, prohibit the playback process,
Bypassing the reproduction processes S09 to S10, the process proceeds to S11.

In S09, it is determined whether or not there is a reproduction monitor instruction. In this case, if there is an instruction, the process proceeds to S10, and if there is no instruction, S10 is bypassed. In S10, the reproduction address is counted up in response to the reproduction monitor instruction. In S11, it is monitored whether or not the data on the transmission side is completed, and EOD
Then proceed to S12, and if there is still data to be received, S
Returning to 06, the above-mentioned processing is repeated.

In S12, recording is stopped in response to a reproduction end instruction or a capacity over condition. In S13, the size relationship between the reproduction address (A _pb ) and the recording address (A _rec ) is compared. In this case, if the reproduction address (A _pb ) ≦ recording address (A _rec ), it means that the area is a recorded area, and the process returns to S08 to continue the reproduction operation.

If the reproduction address (A _pb )> the recording address (A _rec ), it means that the unrecorded area is entered.
The process proceeds to S14 to stop the reproducing operation and prevent the entry into the unrecorded area.

Next, a timing chart of the above-mentioned various processes is shown in FIG. In FIG. 6, a is a clock pulse which is the minimum unit of processing. In addition, other processes are performed in order from the top, b. First phase reception processing, c. Error correction processing of the first phase, d. First phase recording process, e. First phase regeneration process, f. Second phase reception processing, g. Error correction processing of the second phase, h. A second phase recording process, i. A second phase regeneration process, j. Third phase reception processing, k. Third phase error correction processing l. Third phase recording process, m. It is the third phase reproduction process.

The processing configuration is a three-phase configuration, and data reception, transmission error detection and correction processing in each phase, recording processing of the corrected data, and reproduction monitoring of the recorded data are performed. The processing is sequentially performed each time one clock pulse advances. In the above case, if the reception clock is the first clock, the reproduction monitor process can be started at the fourth clock. Therefore, the information storage / reproduction device of the present embodiment can realize the reproduction monitor process immediately after the start of data reception.

Since the information storage / reproduction device of the first embodiment records / reproduces information in this manner, as shown in the operation conceptual diagrams (a) and (b) of FIG. It becomes possible to provide a system capable of transferring video and audio information in a short time by using a communication line. Further, as shown in (a) of FIG. 5, it is possible to immediately monitor the data immediately after the data transfer is started, and it is possible to significantly reduce the waiting time between the start of the reproduction monitor after issuing the transmission request. To do.

Further, in the conventional information storing / reproducing apparatus, even if the image compression technique is used, a large amount of data such as video information requires a data transfer time of several minutes and a tape rewinding time. Therefore, there is a limit to the time reduction, but in the case of the information storage / reproduction device of the present embodiment, this can be dispensed with, and the effect is great.

Next, a second embodiment of the information storage / reproduction device of the present invention will be described with reference to FIGS. In the second embodiment, when data transfer is started at time T1,
The buffer memory 17 detects an error in the received compressed AV data, corrects the error data when an error is given, and then starts the recording process.

Then, after such a recording process is executed for a predetermined time, the reproduction monitor is permitted to start as shown at time T2 in FIG. The setting of the time until the start of reproduction monitoring is calculated based on the reliability of the communication path for data transfer and the total transfer data amount. For example, when the error occurrence rate is 10 ⁻³ , it is considered that 1,000 data blocks are received and an error occurs in one data block, and it takes 30 minutes to transfer 2 hours of AV data. In 1/4 compression, 30 × 60 / 1,000 = 1.8, so it is assumed that an error occurs in data corresponding to 1.8 seconds.

Therefore, the transfer time required for retransmitting the above-mentioned prediction error occurrence data and the time required for the communication procedure are estimated in advance. In addition, in order to cope with the worst case where all data cannot be corrected, in the above example, (1.8 seconds + α) is set to 2 seconds. When the predetermined time t1 (= 2 sec), which is the time for the recording process set in this way, elapses, the reproduction monitor can be immediately performed.

In the second embodiment, since the monitoring is started after a predetermined time has elapsed, the time interval t1 between the time T1 and the time T2 in FIG. 7 is the same as that shown in the first embodiment. It is longer than the time interval t1 between the time T1 and the time T2 at. Further, along with this, the recorded area at time T2 in FIG. 8 becomes longer than the recorded area in FIG.

Next, the execution procedure of the recording / reproducing process controlled based on the start of data transfer will be described with reference to the operation flowchart of FIG. In the description of the operation flowchart of FIG. 9, only the parts different from the processing shown in the flowchart of FIG. 4 will be described.

First, as is clear from FIG. 9, S01-
The processing up to S08 is the same as the processing shown in the flowchart of FIG. Then, in this embodiment, it is monitored in S09 whether or not a predetermined time has elapsed. This predetermined time is
As described above, this is a time that allows for the time required for the error correction processing and the retransmission request processing. The subsequent process is the same as the process shown in the flowchart of FIG.

In this way, the information reproducing process is performed after a predetermined time has elapsed from the start of the recording process. Therefore, as shown in the operation conceptual diagrams of FIGS. A buffer time is provided between the time when is performed and the time when reception is started. Therefore, when an error is given, it is possible to correct the error data and then start the recording process, and it is possible to satisfactorily deal with the case where all data cannot be corrected.

The processing timing of the second embodiment is shown in FIG.
Shown in. The basic processing operation is the same as in the case of the first embodiment shown in FIG. 6, but in this embodiment, when the reception clock is the first clock, the time t1 until the Nth clock is the above data. Due to the margin, it is possible to record and accumulate the error-corrected received data and start the reproduction monitor process.
It starts from the + 1st clock.

As another embodiment, the recording medium may be a rotary disc-shaped recording medium. Then, although not shown, if two or more pickups are provided on one disk-shaped recording medium and one pickup is used for recording and the other pickup is used for reproduction, recording is started. The recorded data can be reproduced immediately after that. However, since it is necessary to match the data rates of recording and reproduction, it is necessary to provide a buffer memory on the reproduction side or perform special reproduction processing.

[0051]

As described in detail above, the present invention has a structure in which any information already recorded in the information memory can be accessed even during recording, and the data rate at the time of information reproduction processing can be improved. By comparison, even if the information transferred at a data rate equal to or higher than that is received and recorded, the information reproducing process can be performed at the standard data reproducing process data rate immediately after the recording process is started. Therefore, it is possible to reproduce the already recorded information from an arbitrary recording position while continuing the current recording. Further, the waiting time from when the transmission request is issued to when the reproduction monitor is started can be significantly reduced. Therefore, it is possible to provide a system that can transfer video and audio information in a short time by using a large-capacity data communication line, and it is possible to monitor immediately after the start of the data transfer, and after the transmission request is issued. It is possible to greatly reduce the waiting time before starting the playback monitor.

Further, when a predetermined time has elapsed after the start of data transfer, the monitoring becomes possible, and the waiting time from the sending of the transmission request to the start of the reproduction monitoring can be greatly shortened, and the video caused by the transmission error can be shortened. It is possible to effectively prevent the trouble of interruption of the monitor.

Further, the reproducing process can be performed at a variable speed while the recording process is continued at a constant speed.
For this reason, for example, it is possible to skip commercial TV commercials, perform a high-speed search for a desired corner in a variety program, and watch sports news in slow motion. Playback can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an information storage / reproduction device according to an embodiment of the present invention.

FIG. 2 is a time chart for explaining the operation of the information storage / reproduction device in the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a memory area showing a usage state of the memory of the first embodiment.

FIG. 4 is a flowchart for explaining a processing procedure of the first embodiment.

FIG. 5 is an operation conceptual diagram of the information storage / reproduction device in the first embodiment.

FIG. 6 is a time chart for explaining a processing operation of the information storage / reproduction device in the first embodiment.

FIG. 7 is a time chart for explaining the operation of the information storage / reproduction device in the second example of the present invention.

FIG. 8 is an explanatory diagram of a memory area showing a usage state of the memory according to the second embodiment.

FIG. 9 is a flowchart for explaining the processing procedure of the second embodiment.

FIG. 10 is an operation conceptual diagram of the information storage / reproduction device in the second embodiment.

FIG. 11 is a time chart for explaining the processing operation of the information storage / reproduction device in the second embodiment.

[Explanation of symbols]

 10 display section 11 AV receiver 13 A / D converter 15 A / D converter 16 combiner 17 buffer memory 18 separator 19 D / A converter 25 write controller 26 read controller 27 timer section 28 system controller 29 key input Part 30 Audio compressor 31 Image compressor 32 Audio decompressor 33 Image decompressor

Claims (2)

[Claims] 1. A mode for storing information at a predetermined data rate, and a mode for reproducing information at the predetermined data rate, having an information memory means capable of both writing and reading information at the same time. An information storage / reproduction device comprising: a device for storing information at a data rate equal to or higher than the predetermined data rate, and reproducing the stored information at a data rate lower than the predetermined data rate. An information storage / reproduction device, which enables the above. 2. The information storage / reproduction apparatus according to claim 1, wherein the information reproduction processing is performed after a predetermined time has elapsed from the start of the information storage processing.