JPH08279989A - Method and device for recording data, method and device for reproducing data, recording medium, and method and equipment for transmitting data - Google Patents

Abstract

PURPOSE: To complete recording within a fixed time regardless of the quantity of data and to attain continuous data reproduction by converting compressively coded data into packet data of a prescribed size at the time of recording the data on a recording medium and recording the converted data on the medium at a prescribed data rate. CONSTITUTION: Data S2 obtained by compressively encoding a moving image signal S1 at an average rate Re in a recorder 1 are stored in a buffer memory 1A2 with capacity Be, and when the storage of the data S2 reaches fixed quantity, the stored data are outputted to a packeting processing part 1B at a rate Re and necessary information is written in a packet header and inputted to an FIFO buffer memory 1C to be a data rate converting buffer with capacity Bw at the rate Re. The data stored in the memory IC for a prescribed period Tw are read out at a rate Rw higher than the rate Re and recoded in the recording medium 3. Consequently the recording of data can be completed within a clip period, so that continuous data can be decoded at the time of reproducing them.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology Problem to be Solved by the Invention Means for Solving the Problem Action Example (1) Principle of recording method and reproducing method (2) Basic system configuration (2-1) Recording device and reproducing Device Configuration (2-2) Recording Procedure and Reproduction Procedure (3) Application System (3-1) Integrated System (3-2) Separation Type System (4) Other Embodiments Effects of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording device, a data reproducing device, etc. for compressing and coding a moving image signal for recording or reproducing. The present invention also relates to a data transmission device for compressing and encoding a moving image signal and transmitting it to a remote place.

[0003]

2. Description of the Related Art Generally, in a system for recording / reproducing a digital moving image signal or a system for transmitting to a remote place,
In order to efficiently use the capacity of the recording medium and the transmission path, a method of compressing and coding an image signal is adopted. On this occasion,
It is general to compress and code a moving image signal by utilizing intra-frame correlation or inter-frame correlation. For these compression encoding formats, MPEG1, MPE
G2, H. 261 etc. Now, in a compression coding apparatus or the like which operates based on these coding formats, coding is performed so that the data amount of a moving image signal generated within a certain time becomes constant.

[0004]

However, the amount of data generated by compression coding is not usually constant, and the amount of data generated differs for each frame. However, if the amount of data generated per hour is not constant, it is extremely difficult to directly record or directly transmit the generated data to a recording medium. This is because the data recording rate or the data transmission rate is generally constant.

Therefore, usually, a buffer memory is installed between the moving image compression encoding processing unit and the medium recording unit or between the moving image compression encoding processing unit and the transmission unit, and is output to a recording device, a transmission line or the like. The data rate of the variable amount of encoded data is constant. At this time, the moving image compression encoding processing unit adjusts the amount of encoded data generated so that the buffer memory will not be unlocked.

Therefore, the average rate of the amount of data generated in a unit time in the moving picture compression coding processing unit at the time of moving picture compression coding is the same as the data rate of the coded data output from the buffer memory. In general, a device that performs these operations is called an encoder including a buffer memory.

On the other hand, on the side of the device that decodes the compression-coded data into the original moving image signal, the buffer memory similar to the above is placed between the output end of the recording device or the transmission path and the decompression decoding processing section. It is designed to be done. In general, a device that performs these operations is called a decoder including a buffer memory. As described above, in the conventional encoder or decoder, the compression encoding processing is performed so that the data amount of the moving image signal approaches a certain amount in a certain time unit or approaches the target encoded data generation amount according to the application. There is.

[0008] Here, the moving image signal is obtained by recording the encoded data obtained by compressing and encoding the moving image signal of the time length T on the recording medium at the write rate R, and then reading and decoding this recording data at the read rate R. Consider the case of playing. In this case, the target encoded data generation amount E
i is

[Equation 1] Becomes

However, the actual data generation amount Er is

[Equation 2] As shown in, the constant value R × T is not obtained. Here, B is the capacity of the buffer memory provided in the encoder.

This data is recorded on a recording medium as it is,
Considering the case of subsequent reading, the reading time t is
The following formula

(Equation 3) Becomes The read data is decoded into a moving image signal by a decoder, and the reproduction time of the decoded moving image signal is T as well. From this, it is understood that the image reproduction time and the data read time required for the image reproduction are different.

By the way, like an AV server, an arbitrary number of data (hereinafter referred to as a clip) obtained by compression-encoding a moving image signal for a certain fixed time is written in a medium, and an arbitrary number of clips are recorded from the medium. The following problems occur when reading out and continuously reproducing the image signal.

When an arbitrary number of clips obtained by compression-encoding a moving image signal for a certain fixed time are written on a medium and an arbitrary number of clip image signals are continuously reproduced from the medium, it takes time to read out necessary data. Because it is different, if the data read time becomes longer than the playback time,
There is a problem that the actual clipped image signal cannot be continuously reproduced without interruption.

The present invention has been made in consideration of the above points, and a data recording method and device, a data reproducing method and device, a recording medium, and data capable of reproducing a clip image of an arbitrary time length without interruption. An attempt is made to propose a transmission method and device.

[0014]

In order to solve such a problem, according to the present invention, packet data obtained by compressing and coding a moving image signal for a certain fixed time and then packetizing it is output to a recording medium or to a transmission line. At this time, the packet data is only written to the buffer memory of the first-in first-out system for a certain period of time after the output of the packet data is started, and the reading to the recording medium or the transmission path is prohibited. After a certain time has elapsed from the start of packet data output, the packet data that has been compressed and encoded and then packetized is written to the buffer memory of the first-in first-out system, while the packet data written to the buffer memory of the first-in first-out system is written at a data rate higher than that at the time of writing. It is read out and recorded in a recording medium or output to a transmission line.

On the other hand, recording in which compressed coded data obtained by compressing and coding a moving image signal for a certain fixed time is always converted into packet data of a fixed size and recorded regardless of the data generation amount of the compressed coded data. When reading packet data from a medium or receiving it from a transmission path, the packet data is read at a data rate higher than the data rate at which the packet data is written to the recording medium or the data rate at which the packet data is output to the transmission path, and written to the buffer memory of the first-in first-out method. To do so. After that, the packet data already written in the buffer memory of the first-in first-out system is read out and decoded at a data rate almost the same as that when packetized.

[0016]

Normally, when a moving image signal is compression-encoded, the amount of generated data fluctuates, but regardless of these fluctuations, the compression-encoded data at the time of recording on the recording medium or the time of being output to the transmission line is constant. Converted to size packet data. Therefore, recording or transmission of the moving image signal can be completed within a fixed time regardless of the amount of generated data.
On the other hand, the reproducing side or the receiving side can reproduce or receive the compression coded data of the moving image signal within a fixed time regardless of the amount of generated data.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Principles of recording method and reproducing method Data obtained by compression-encoding a moving image for a certain period of time, that is, clips are written in an arbitrary number of recording media, and an arbitrary number of image signals are recorded from the recording media. In order to perform continuous reproduction without interruption, the recording apparatus according to the present embodiment writes the packetized data after compression encoding into the FIFO buffer memory for a certain period of time, then reads the data at a data rate higher than that at the time of writing and records it on the recording medium. To do so.

Further, the reproducing apparatus shown in this embodiment extracts data from a packet read from the recording medium at the same rate as that at the time of recording or at a rate higher than that, and writes this data in a FIFO buffer memory having a capacity larger than that at the time of recording. After that, the data is read at the same rate as that at the time of encoding and the expansion decoding processing is performed.

(2) Basic System Configuration (2-1) Configuration of Recording Device and Reproducing Device FIG. 1 shows an example of the hardware configuration of the recording device 1 which realizes these recording systems and the reproducing device 2 which realizes these reading systems. Show. First, the configuration of the recording device 1 will be described. The recording device 1 includes an encoder 1A, a packetization processing unit 1B, a FIFO.
Buffer memory 1C and padding packet processor 1D
It is composed by.

The encoder 1A is a compression encoding processing unit 1A1.
And the encode buffer memory 1A2. The compression encoding processing unit 1A1 uses the moving image signal S
1 is variably compressed and encoded at the average rate Re, and the encoded data S2 is sequentially output to the encode buffer memory 1A2 of the capacity Be. Further, the encode buffer memory 1A2 outputs the coded data S2 at a rate Re when the coded data S2 is accumulated in the memory in a fixed amount. By the way, the buffer remaining amount Be of the encode buffer memory 1A2 is determined by the compression encoding processing unit 1A1.
It is designed to prevent the bank from failing.

The packet processing unit 1B sequentially inputs the encoded data S3 output from the encoder 1A, stores them in one or a plurality of packets, and outputs the packets. On this occasion,
The packet processing unit 1B determines the packet size, the type of data,
Necessary information such as time information is written in the packet header and is output to the FIFO buffer memory 1C at the same constant rate Re as when encoding.

The FIFO buffer memory 1C is a buffer memory having a capacity Bw provided for data rate conversion. The FIFO buffer memory 1C stores the packet data S4 written at the rate Re for a predetermined time Tw, then reads it at a read rate Rw higher than the rate Re at the time of writing, and records it on the recording medium 3.

As a result, the packet data S5 can always be written in the recording medium 3 within a time corresponding to the clip time T regardless of the amount of information generated during encoding. Note that the FIF at the time of this read operation
The accumulation time Tw, the read rate Rw, and the buffer capacity Bw of the O buffer memory 1C are calculated as follows.

[Equation 4]

(Equation 5)

(Equation 6)

Incidentally, the FIFO buffer memory 1C is Rw
From the relationship of> Re, there is a possibility that the internal data may be lost during the writing of the data into the recording medium 3. The padding packet processing unit 1D is provided for this situation. The padding packet processing unit 1D is a FIF
O The buffer residual amount Be of the buffer memory 1C is constantly detected, and when the buffer residual amount Be becomes 0, a meaningless packet (that is, a padding packet) not directly related to the data is output and the blank period is output. It is designed to be filled. As a result, the transmission form does not break down.

Next, the structure of the reproducing apparatus 2 will be described. The reproducing apparatus 2 is composed of a data extraction processing section 2A, a FIFO buffer memory 2B and a decoder 2C. The reproduction device 2 reads the recording data recorded on the recording medium 3 at a constant rate Rw, and reads this as reproduction data S6 into the data extraction processing unit 2A. Data extraction processing unit 2A
Removes the padding packet from the read reproduction data S6 and discards it, and extracts only the encoded data S7 corresponding to the moving image signal to read out the FIF.
The data is sent to the O buffer memory 2B.

At this time, assuming that the read rate when the data extraction processing section 2A reads the record data S6 from the recording medium 3 is Rw, which is the same as the write rate, the time Td required for the read is expressed by the following equation.

(Equation 7) That is, it can be seen that it can always be accommodated within the clip display time.

The encoded data S7 thus extracted by the data extraction processing unit 2A is written in the read FIFO buffer memory 2B, and the data rate is returned to the original data rate. The capacity Br of the read FIFO buffer memory 2B satisfies the following condition.

Generally, the capacity of the decode buffer memory 2C1 built in the decoder 2C is larger than that of the encode buffer memory 1A2. Therefore, in the case of this embodiment, the read FIFO buffer memory 2B is used.
The capacity Br of the

(Equation 8) As shown in, the FIFO buffer memory 1 for writing
The capacity Bw of B or more is used.

Finally, the decoder 2C will be described. The decoder 2C is composed of a decoding buffer memory 2C1 and a decompression decoding processing unit 2C2. The decode buffer memory 2C1 reads the coded data S8 from the FIFO buffer memory 2B at a constant rate Re and supplies it to the decompression decoding processing unit 2C2. The decompression decoding processing unit 2C2 decodes the encoded data S8 at the average decoding rate Re, and the decoding result is the moving image signal S10.
Output as

(2-2) Recording Procedure and Reproduction Procedure In the above configuration, recording operation and reproduction operation executed in the recording apparatus 1 and the reproduction apparatus 2 at the time of recording and reproduction will be described in order. First, the recording operation at the time of recording assuming that a plurality of clips can be continuously reproduced without interruption will be described with reference to FIG.

When the recording operation is started, the recording apparatus 1 moves from step SP1 to step SP2 and specifies the position on the recording medium 3 for recording the moving image signal by the write pointer. Incidentally, this pointer is used as a read pointer for reading the record data of the moving image signal during reproduction. When the designation of the write pointer is completed, the process of the recording device 1 moves to step SP3 and the encoder 1A
The moving image signal S1 is input to and the variable amount coding is started.

When the encoding is started, the recording apparatus 1 encodes the moving image signal S1 by the encoder 1A at the average rate Re, and as shown in step SP4, the code obtained by the encoding. The converted data S3 is sequentially packetized. At the same time, the recording apparatus 1 starts writing the packetized packet data S4 into the FIFO buffer memory 1C. The recording apparatus 1 confirms the elapsed time from the writing start time, as shown in the next step SP5,
It is determined whether the elapsed time is longer than the accumulation time Tw given by the equation (4).

When a positive result is eventually obtained, the recording device 1
Starts to read the packet data S5 from the FIFO buffer memory 1B as shown in step SP6.
The data rate Rw at the time of reading is a data rate higher than the data rate Re at the time of writing to the FIFO buffer memory 1C, as described in the previous section.

After this, as shown in step SP7, F
Until it is confirmed that the remaining buffer capacity Be of the IFO buffer memory 1C has reached 0, the recording apparatus 1 is in the step SP.
The process returns from step 7 to step SP6 to continue writing the packet data S5 read from the FIFO buffer memory 1C to the recording medium 3. Incidentally, when a positive result is obtained in step SP7 and it is confirmed that the FIFO buffer memory 1C has become empty, the recording apparatus 1 proceeds to step SP8.
In step S14, the process proceeds to a determination process as to whether or not all writing of the packet data S4 to the FIFO buffer memory 1B has been completed.

If a negative result is obtained at this time, the recording apparatus 1 judges that the FIFO buffer memory 1C is temporarily emptied because the read rate Rw is larger than the write rate Re, and moves to step SP8. Fill the deficiency of the packet with a padding packet. After that, the recording apparatus 1 returns to step SP7 to determine again whether or not the remaining buffer amount Be is 0. If it is not 0, writing to the recording medium 3 is restarted, and if it is 0, it is again in step SP8. It is determined whether or not the writing to the FIFO buffer memory 1C is completed.

When a positive result is obtained in step SP8, it is confirmed in step SP10 that the recording of the series of moving image signals S1 is completed, and in the next step SP11 it is determined whether or not the moving image signal S1 of the next clip is to be recorded. Move on to judgment. While the positive result is obtained here, the recording device 1
Repeats the processing from step SP2 to step SP11. When a negative result is obtained, recording of a plurality of clips is ended.

Next, the reproducing operation for reproducing the record data from the recording medium 3 thus recorded will be described with reference to FIG. When the reproducing operation is started, the reproducing apparatus 2 moves from step SP21 to step SP22, and specifies the position on the recording medium 3 from which the recording data is read out by the read pointer. When the designation of the read pointer is completed, the reading from the recording medium 3 is started as shown in step SP23.

When the reproduction apparatus 2 reads the reproduction data S6 into the data extraction processing section 2A, as shown in step SP24, the reproduction data S6 read out at a constant rate Rw to the data unrelated to the encoded data such as the padding packet. Extract and remove. After that, the reproducing apparatus 2 proceeds to step S.
In P25, the encoded data S7 of the moving image signal portion is set to F
It is given to the IFO buffer memory 2B. Next step SP
Moving to step 26, the playback device 2 becomes the FIFO buffer memory 2
The coded data S8 that has been rate-converted by B is supplied to the decoder 2C, and the moving image signal S1 is supplied by this decoder 2C.
Start playing 0.

Then, in the next step SP28, the reproducing apparatus 2 determines whether or not the data reading has been completed, and while a negative result is obtained, step SP29-step SP24-step SP25-step SP26.
-Step SP27-The processing of step SP28 is repeated. When the reading of the data for one clip is completed by repeating this processing loop, the reproducing device 2 moves from step SP28 to step SP29 and moves to the process of determining whether or not there is the next clip to be continuously reproduced.

While the affirmative result is obtained here, the reproducing apparatus 2 repeats the processing of steps SP22 to SP28, and when a negative result is obtained, moves to the processing of step SP30. Then, at step SP30, when it is confirmed that the buffer remaining amount of the decode buffer memory 2C1 has become 0, the process moves to step SP31 to end the reproducing operation.

FIGS. 4 and 5 show the relationship between the data amount and the processing time when the two clips 1 and 2 are continuously recorded as an example of the above recording / reproducing operation. First, it is assumed that the image times of the clips 1 and 2 which are continuously recorded are T and T ′, respectively, as shown in FIG. Generally, since the encoded buffer memory 1A2 of the encoder 1A has the image data encoded immediately before, the encoded data S3 of the clip 1 and the clip 2 is read out from the FIFO buffer memory 1B by using FIG.
As shown in (B), it takes T + ΔT and T ′ + ΔT ′.

When this coded data S3 is recorded on the recording medium 3 as it is as in the conventional case, the time of T + ΔT and T '+ ΔT' is also required to reproduce the clip 1 and the clip 2 from the recording medium 3, and the display time is required. It will be long against. Therefore, in the conventional reproducing apparatus, even if the two clips 1 and 2 are continuously reproduced, there is a possibility that a blank time of ΔT may occur during display.

On the other hand, the recording apparatus 1 shown in this embodiment
Is the average coding rate R from the FIFO buffer memory 1B.
Since the data is read out under the condition that the data rate is higher than e and the formula (5) is satisfied, the data portion including the clip 1 and the clip 2 is within the image time T and T ′ regardless of the amount of the buffer remaining amount Be. Then, the writing to the recording medium 3 can be completed. This is shown in FIG. 4 (C). Incidentally, the time indicated by the diagonal lines in the figure is the period during which the padding packet is filled. At the end of recording on the recording medium 3, data is recorded with the data structure shown in FIG.

On the other hand, at the time of reproduction, the reproducing apparatus 2 can read the record data of the moving image signal corresponding to the clip 1 and the clip 2 within the time T and T ', respectively, as shown in FIG. 5 (A). Moreover, since data unrelated to the encoded data such as a padding packet is extracted from the read reproduction data S6, the data read to the FIFO buffer memory 2B is truly a moving image signal as shown in FIG. 5B. Only the corresponding data will be available.

After this, the encoded data S8 is transferred from the FIFO buffer memory 2B to the decoder 2 as shown in FIG. 5 (C).
It is read by C at the original data rate Re and decoded. At this time, in FIG. 5C, although the buffer remaining amount and the apparent data reading time are longer than the display time of the clip 1 and the clip 2, the decoding operation of each encoded data is performed at the time T and T '. Since the process is completed, continuous reproduction of two clips 1 and 2 as shown in FIG. 5D is possible.

According to the above construction, the moving image signals of the two clips to be continuously reproduced are displayed at the respective display times T and T '.
By being able to read from the recording medium 3 inside,
The display delay of the clip due to the delay of the decoding operation can be avoided. As a result, it is possible to realize the recording device 1 and the reproducing device 2 capable of continuously reproducing a plurality of clips without a blank period. Moreover, the recording medium 3 capable of continuous reproduction can be realized.

(3) Application system Next, a system configuration example in which this basic system is applied will be shown. Here, an integrated system in which the recording device 1, the recording medium 3, and the reproducing device 2 are connected by communication lines, respectively,
A separation type system in which the recording device 1 and the recording medium 3 or the recording medium 3 and the reproducing device 2 are not connected by a wired path will be described.

(3-1) Integrated System As an example of the integrated system, a server system (hereinafter referred to as an AV server system) that distributes AV signals (audio signals and video signals) to a large number of terminal devices via a communication line. ) Will be described. FIG. 6 shows the overall configuration of the AV server system 11. This AV server system 1
1 comprises a data supply source 12, an encoding unit 13, and a server unit 14.
It is used to distribute AV signals from four to a large number of terminals 15A1 to 15AN. Each part is configured as follows.

The data supply source 12 is composed of a reproducing device 12A such as a video tape recorder (VTR) or a magneto-optical disk device. Each playback device 12A has an AV data signal S
D1, SD2 ... Are supplied to the encoding unit 13 through a transmission line and a signal line. Incidentally, in this example, a plurality of data supply sources 12 are provided. The encoding unit 13 is a unit corresponding to the recording device 1 of the basic system, and includes an encoder 1
3A, a FIFO buffer / packet processing unit 13B and a control unit 13C.

Of these, the encoder 13A receives the AV data signals SD1, SD2 ...
Are encoded into data format signals conforming to the MPEG2 standard, and data streams D1 and D2 ...
It is designed to be converted into. The FIFO buffer / packet processing unit 13B receives these data streams D1, D
.. are each temporarily stored in the FIFO buffer memory and subjected to rate conversion, and the rate-converted coded data is converted into packet data by the packet processing unit.

The control unit 13C controls the data supply source 12, the encoder 13A and the server unit 14 by the control signal S _CTL and manages the operation state of each unit.

The server 14 is composed of a recording / reproducing section 14A and a decoding section 14B. Recording / playback unit 1
4A is adapted to record the encoded data, which is obtained by further compressing the encoded data which has been compressed and encoded in the time axis direction, on a recording medium. When the user gives an instruction, the corresponding AV data is read and output to the decoding unit 14B. Used to do. The instruction from the user is input as the request signal S _request .

The recording / reproducing section 14A is the media control section 1
4A1 and a plurality of media units 14A2 to 14A8. Here, the media control unit 14A
Reference numeral 1 is a unit for controlling the recording / reproducing operation of the plurality of media units 14A2-14A8. Further, each of the media units 14A2 to 14A8 has a plurality of built-in hard disk devices, and can record and reproduce a plurality of signals simultaneously in parallel. Thereby, multi-access from a large number of terminals 15A1 to 15AN can be realized. Further, a clip moving image signal which requires continuous reproduction is recorded on these hard disks.

The decoding section 14B is composed of a data extraction processing section / FIFO buffer memory 14B0 and a plurality of decoders 14B1 to 14BM. Here, the decoders 14B1 to 14B provided in the decoding unit 14B
The number of BMs is the number of terminals 15A1 to 15AN finally connected.
And the number of encoded data that can be simultaneously reproduced by the recording / reproducing unit 14A.

The decoding section 14B includes decoders 14B1 to 14B1.
14BM for each media unit 14A2-14A
The encoded data read via 8 is decoded and output to each of the terminals 15A1 to 15AN. Incidentally, the AV server system 11 does not necessarily have to be provided in one room, and may be connected to each other by a LAN (Local Area Network) or the like.

(3-2) Separation-Type System Next, as an example of the separation-type system, an AV server system that distributes AV signals (audio signals and video signals) to a large number of terminal devices via physical delivery of a recording medium. Will be described. FIG. 7 shows the overall configuration of the AV server system 21. The AV server system 21 is a system including a production station 22, a key station 23, an artificial satellite 24, a cable station 25, a branch office 26, a home 27, etc., which are geographically distant from each other.

In the case of this example, the recording apparatus 1 described in the basic system corresponds to the encoder 22A of the production station 22,
The playback device 2 corresponds to the decoder 26A of the branch office 26. The production station 22 edits the video source to edit the commercial (CM).
A production company or a production room that produces a program (program), and a moving image of a program or a CM is compression-coded here and recorded on the recording medium 3. The recording medium 3 is physically delivered to the key station 23 and the cable station 25.

The key station 23 is used when the image data reproduced from the recording medium 3 is sent to the artificial satellite 24 as compression encoded data and is transmitted to the remote branch office 26. This data transmission is performed by the recording medium 3 in the basic system.
And the playback device 2 is wirelessly transmitted. on the other hand,
The cable station 25 is used when transmitting the image data reproduced from the recording medium 3 as compression encoded data to the branch office 26 at a remote place via a cable. Other than this, cable station 2
The data transmission between the 5 and the branch office 26 may be performed by the recording medium 3.

The branch office 26 is provided with a decoder 26A and a file server 26B, which is used to decode the received encoded data at the original data rate and deliver it to each home 27 as a moving image signal. The basic system can also be applied in this way. Also in this example, encoder 2
Although the number 2 is provided in the production station 22, it may be provided in the key station 23. In addition, the decoder 26A is connected to the branch 26
Although the example provided inside is shown, the example provided inside each home 27 can also be realized.

(4) Other Embodiments In the above-described embodiment, the recording apparatus 1 in which the encoder 1A, the packetization processing unit 1B, the FIFO buffer memory 1C, and the padding packet processing unit 1D are integrated. Although described, the present invention is not limited to this, and may be built in separate housings. Similarly, as the reproducing apparatus 2, the one in which the data extraction processing unit 2A, the FIFO buffer memory 2B and the decoder 2C are integrated has been described, but the present invention is not limited to this and may be incorporated in a separate housing.

Furthermore, in the above-mentioned embodiment, the case where a hard disk or a video tape is used as an example of the recording medium 3 has been described, but the present invention is not limited to this and can be applied to other recording media. For example, it can be applied to a video disk, a magneto-optical disk, an optical disk such as a phase change disk, or a so-called optical card. It can also be applied to a magnetic recording medium such as a floppy disk.

Further, in the above-mentioned embodiment, the case where the data is read from the recording medium 3 at the same rate Rw as when the data is written to the recording medium has been described, but the reading rate may be higher than this.

[0064]

As described above, according to the present invention, when a moving image signal is compression-encoded, the amount of generated data normally fluctuates, but at the time of recording on a recording medium or a transmission line regardless of these fluctuations. The compression-encoded data at the time of being output is converted into packet data of a fixed size, and recording or transmission of a moving image signal can be completed within a fixed time regardless of the amount of generated data. As a result, at the time of reproduction or reception, a moving image signal can be always reproduced or received within a fixed time regardless of the amount of generated data, and continuous reproduction of decompressed and decoded moving image signal becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a data recording device and a data reproducing device according to the present invention.

FIG. 2 is a flow chart showing a recording operation by a data recording device.

FIG. 3 is a flow chart showing a reproducing operation by the data reproducing apparatus.

FIG. 4 is a schematic diagram showing a relationship between a data generation amount and a processing time during recording.

FIG. 5 is a schematic diagram showing a relationship between a data generation amount and a processing time during reproduction.

FIG. 6 is a block diagram showing a configuration example of an AV server system.

FIG. 7 is a block diagram showing a configuration example of an AV server system.

[Explanation of symbols]

1 ... Recording device, 1A ... Encoder, 1A1 ... Compression encoding processing unit, 1A2 ... Encode buffer memory,
1B ... Packetization processing unit, 1C ... FIFO buffer memory, 1D ... Padding packet processing unit, 2 ... Playback device, 2A ... Data extraction processing unit, 2B ... FIFO
Buffer memory, 2C ... Decoder, 2C1 ... Decode buffer memory, 2C2 ... Decompression decoding processing unit, 1
1, 21 ... AV server system, 12 ... Data supply source, 13 ... Encoder section, 14 ... Server section, 14A
...... Recording / reproducing section, 14B ...... Decoder section, 15A1-1
5AN ... terminal, 22 ... production station, 23 ... key station, 2
4 ... Artificial satellite, 25 ... Cable station, 26 ... Branch office,
27 ... home.

Claims (14)

[Claims] 1. When compressing and coding a moving image signal for a certain fixed time and recording it on a recording medium, the compressed and coded data output from the coding processing unit is packetized into packet data of a fixed size, and then the packet data. For a certain time from the start of the output of the above, the packet data is prohibited to be recorded on the recording medium only by writing the packet data to the buffer memory of the first-in first-out method, and after the lapse of the predetermined time, the packet data is written to the buffer memory of the first-in first-out method. A data recording method characterized in that the packet data written in the buffer memory of the first-in first-out system is read at a data rate higher than that at the time of writing and recorded on the recording medium. 2. The data corresponding to the total capacity of the coding buffer memory is coded from a coding buffer memory provided in a coding processing unit for coding the moving image signal into compression coded data and outputting the coded data during the fixed time. 2. The reading time is set to be longer than the minimum time required for reading.
Data recording method described in. 3. The data rate at which the packet data is read from the buffer memory of the first-in first-out system after the elapse of the fixed time, the data rate is compression coded data corresponding to the moving picture signal for the fixed time and the moving picture signal is compressed and coded. 2. The data recording method according to claim 1, wherein the data rate corresponding to the total capacity of the buffer memory provided in the encoding processing unit that outputs the data is a data rate sufficient to read within the fixed time. . 4. An encoding processing unit for compressing and outputting a moving image signal for a certain fixed time, and compression encoded data from the encoding processing unit, converting the compressed encoded data into a packet, and a packet. Input packet data from the packetization processing unit and the packetization processing unit, and prohibits reading only by writing the packet data until a certain time elapses from the start of input of the packet data, and after the elapse of the certain time, the packet data The data recording device is characterized by further comprising: a first-in first-out buffer memory for reading the previously written packet data more than at the time of writing and writing the same to the recording medium while continuing to write the data. 5. The fixed time period is set to be longer than or equal to a minimum time required to read out data corresponding to the entire capacity of the encoding buffer memory from the encoding buffer memory provided in the encoding processing unit. The data recording device according to claim 4, wherein 6. The data rate at which the packet data is read from the buffer memory of the first-in first-out system after the lapse of the fixed time is set in the compression-coded data corresponding to the moving image signal for the fixed time and the coding processing section. 5. The data recording device according to claim 4, wherein the data recording device has a data rate sufficient to read data corresponding to the entire capacity of the buffer memory in the fixed time. 7. Packet data obtained by packetizing compression-encoded data obtained by compression-encoding a moving image signal for a certain period of time is stored in a buffer memory of a first-in first-out system for a certain period of time from the start of output, after which writing to the buffer memory is performed. When reproducing the packet data from a recording medium that is read and recorded at a rate higher than the writing rate while continuing, the packet data is read at a data rate that is equal to or higher than the data rate at which the recording medium was written, and the first-in first-out method is used. A data reproducing method characterized by writing to a buffer memory, and then reading and decoding the packet data written in the buffer memory of the first-in first-out system at the same data rate as when packetized. 8. A packet memory in which compressed coded data obtained by compressing and coding a moving image signal for a certain period of time is packetized is stored in a buffer memory of a first-in first-out system for a certain period from the start of output, and then writing to the buffer memory is performed. While continuing, the packet data is read from the recording medium that is read and recorded at a rate higher than the writing rate, and the packet data is sequentially input from the data extraction processing unit that extracts the compression encoded data from the packet data and the data extraction processing unit. After writing by writing, the packet data is read out at a data rate slower than the data rate at the time of reading from the data extraction processing unit, and at the same data rate as the data rate when the compression-coded data is packetized, and a buffer memory of the first-in first-out method, Above Re data reproducing apparatus characterized by comprising a decoding unit for obtaining the moving image signal by decoding the packet data read from the buffer memory of the first-out method. 9. Compressed coded data obtained by compressing and coding a moving image signal for a certain fixed time is always converted into packet data of a fixed size and recorded regardless of the data generation amount of the compressed coded data. A recording medium characterized by. 10. The recording according to claim 9, wherein the packet data is of two types: first packet data composed of header data and the compression coded data, and second packet data composed of header data and dummy data. Medium. 11. When transmitting compressed coded data obtained by compressing and coding a moving image signal for a certain fixed time through a transmission line,
The compression-encoded data output from the encoding processing unit is packetized into packet data of a fixed size, and then the packet data is written to the buffer memory of the first-in first-out system for a certain time from the start of output of the packet data to the transmission line. Of the packet data is written to the first-in first-out buffer memory while the packet data already written in the first-in first-out buffer memory is read out at a data rate higher than that at the time of writing, and the packet data is transmitted. A data transmission method characterized by outputting to a road. 12. An encoding processing unit for compression-encoding and outputting a moving image signal for a certain fixed time; a packetization processing unit for packetizing the compression-encoded data from the encoding processing unit and outputting it as packet data. Input the packet data, prohibit the output only by writing the packet data until a fixed time elapses from the start of input of the packet data, and after the elapse of the fixed time, continue inputting the packet data while writing the packet data. A data transmission device, comprising: a first-in first-out buffer memory for reading the packet data at a data rate higher than that for writing and outputting it to a transmission line. 13. A first-in first-out buffer memory is stored for a certain period of time from the start of output of packet data obtained by packetizing compression-encoded data obtained by compression-encoding a moving image signal for a certain period of time, and then writing to the buffer memory. When reading the packet data from a recording medium that is read and recorded at a rate higher than the write rate while continuing, the packet data is read at a data rate that is equal to or higher than the data rate at which the recording medium was written, and the buffer memory is a first-in first-out type buffer memory. And then read and decode the packet data written in the first-in first-out buffer memory at substantially the same data rate as when packetized. 14. A packet memory in which compressed coded data obtained by compressing and coding a moving image signal for a certain fixed time is packetized and stored in a buffer memory of a first-in first-out system for a fixed time from the start of output, and then writing to the buffer memory is performed. A data extraction processing unit that receives the packet data from a transmission path that reads and transmits at a rate higher than the writing rate while continuing, and extracts compressed encoded data corresponding to the moving image signal from the packet data, and the data extraction processing unit. After sequentially inputting and writing the packet data read from, the packet data is slower than the data rate at the time of reading from the data extraction processing unit, and at the same data rate as the data rate at the time of packetizing the data. First-in, first-out method to read A data transmission device comprising: a memory and a decoding processing unit for decoding the packet data read from the first-in first-out buffer memory to obtain the moving image signal.