JPH08280012A - Method and device for data recording and data reproducing, recording medium and method and device for data transmission - Google Patents

Abstract

PURPOSE: To continuously reproduce independently encoded moving image infor mation without interrupting it by controlling a quantizing size by regarding remaining buffer capacity less than real capacity. CONSTITUTION: A controller 1A12 controls the amount of data to be generated concerning encoded data inputted to an encode buffer memory 1B but in this case, the controller 1A12 adjusts the amount of data to be generated by controlling the quantizing size based on a prescribed encoding method. Namely, the controller 1A12 samples the remaining buffer capacity and judges whether the lapse of time reaches switching time to apparently reduce the upper limit of the buffer memory 1B or not and in that case, prescribed capacity is subtracted from the real remaining buffer capacity so that virtual remaining buffer capacity can be found. Then, the quantizing size is decided on the virtually found remaining buffer capacity or the really sampled remaining buffer capacity. Thus, since the quantizing size is controlled by regarding the remaining buffer capacity less than real capacity, the amount of data to be generated can be reduced.

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 Problems to be Solved by the Invention Means for Solving the Problems Action Example (1) Principle of data encoding method (2) Basic system configuration (2-1) Overall configuration (2-) 2) Encoding device (2-3) Decoding device (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, and a data recording and reproducing device capable of reproducing a clip image having an arbitrary time length without interruption. , A recording medium, a data transmission method and a device.

[0014]

In order to solve such a problem, in the present invention, the quantization size is controlled assuming that the buffer remaining amount is smaller than the actual amount, and based on the quantization size thus obtained. To encode the moving image signal.

Further, in the present invention, independent coded data coded so that the time required for recording is equal to or less than the time required for encoding are continuously read from the recording medium or the transmission path, and the decoded data is decoded. Write to the far memory. After that, the encoded data is read at a constant rate and decoded so that no interruption occurs in the decoding result of the independent moving image signal.

[0016]

By controlling the quantization size by regarding the remaining buffer amount as being smaller than the actual amount, the amount of data generated for the moving image signal is reduced as compared with the case where encoding is performed based on the actual remaining buffer amount. Can be made.

[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) Principle of Data Encoding Method The encoder of this embodiment regards the remaining amount of the encoding buffer as less than the actual amount and quantizes the moving image signal to determine the amount of data generated in the encoding buffer memory. It has a function of suppressing the amount to a target predetermined amount. The transition of the amount of data generated in the encode buffer by the method of FIG. 1 is shown. In the figure, the vertical axis represents the amount of generated data, and the horizontal axis represents the elapsed time.

Incidentally, the straight line EBe transmits the encoded data at the rate R.
Represents the amount of data generated in the case of transmission by the above method, and the distance between the straight line EBe and the polygonal line EBf in the vertical direction corresponds to the capacity EBc of the encode buffer memory. A curve De1 with the start point O of the encoding as a starting point shows the transition of the amount of data generated in the encode buffer memory, and the distance between the curve De1 and the straight line EBf in the vertical direction shows the buffer remaining amount EBr. ing.

Normally, the encoder writes the coded data for each frame in the buffer memory, holds it until the time Te has elapsed from the start of writing, and thereafter reads the coded data at a constant rate R when the time Te elapses. Has been done. Hereinafter, this time Te will be referred to as a start-up delay time. Now, with the current encoder, when the encoding of the moving image signal of time T is completed,
Generally, the total amount of data is like point P1.

However, in order to allow the reproducing side to continuously reproduce a plurality of independent coded signals without interruption, the total amount of data generated in the encoder is a fixed amount determined by the transmission rate and the display time of the moving image, that is, Must be RxT. This is because if the total amount of data exceeds a certain amount determined by the transmission rate and the display time of the moving image as at point P1, it takes time to transmit the data, and the transfer time becomes longer than the display time. Is.

Therefore, in order to allow the reproducing side to continuously reproduce a plurality of independent coded signals without interruption, the transition curve of the data generation amount at the time when the encoding is completed must always end at the point P3. Therefore, in the encoder of this embodiment, after a certain time Tf 'in the middle of encoding, the straight line Bf indicating the upper limit of the buffer is regarded as the straight line Bf' and the data generation amount is suppressed so as not to exceed the upper limit. The amount of generation is set to converge on the point P3.

Incidentally, it is difficult to completely match the data generation amount of the encoded data with the point P3, but normally, the data is generated less than the target value like the point P2. Refill with dummy data that does not have (hereinafter referred to as stuffing data). Incidentally, the dummy data is discarded at the time of decoding. As a result of such control, the transition of the generated data amount becomes like De2, and the generated data amount becomes equal to R × T.

(2) Basic system configuration (2-1) Overall configuration FIG. 2 shows a basic system configuration of an encoding / decoding device using the encoding method of the previous section. This system comprises a recording device 1, a reproducing device 2 and a recording medium 3. The schematic configuration of each part is as follows.

The recording apparatus 1 comprises a compression / encoding processing section 1A and an encode buffer memory 1B. Of these, the compression encoding processing unit 1A is a circuit portion that performs variable amount compression encoding of the moving image signal S1 by using the encoding method of the previous section. The compression encoding processing unit 1A performs encoding so that the amount of generated data of the moving image signal S1 always coincides with a predetermined amount (R × T) determined by the transmission rate and the display time of the moving image, and sets this as encoded data S2. It is designed to be given to the encoding buffer 1B.

The encode buffer memory 1B sequentially writes the encoded data S2 which has been encoded, and outputs it at a constant rate after the start-up delay time Te has elapsed. At this time, the amount of generated data of the moving image signal generated in the recording device 1 always matches the predetermined amount (R × T) corresponding to the display time T of the moving image, so that the encoded data S3 is stored in the recording medium 2. The time required for writing is the same as the display time T. The detailed structure of the recording apparatus 1 will be described in the next section.

On the other hand, the reproducing apparatus 2 comprises a decoding buffer memory 2A and a decompression decoding processing section 2B. The decoding buffer memory 2A stores the reproduction data S4 from the recording medium 3.
Is a circuit for reading out and accumulating at a constant rate R, and is adapted to prevent the failure of the decoding operation in the decompression decoding processing unit 2B. For this reason, the decode buffer memory 2A has a capacity DBc twice as large as the capacity EBc of the encode buffer memory 1B. The reason why the capacity DBc is doubled with respect to the capacity EBc of the encode buffer memory 1B and the amount of data generated during the decoding operation will be described in the following sections.

(2-2) Encoding Device Next, the internal configuration of the compression encoding processing unit 1A will be described with reference to FIG. The moving image signal S1 input to the compression encoding processing unit 1A is first written and stored in the frame memory 1A1. The moving image signal S1 is sequentially read by the motion estimator 1A2, and the amount of motion is estimated prior to encoding. The motion amount and the picture type detected by the motion estimator 1A2 are the motion vector signal Sv and the picture type signal Sp, respectively.
Is output as

The moving image signal output from the motion estimator 1A2 is input to the subtractor 1A3 and the difference from the motion compensated previous frame image signal is obtained. The differential signal obtained by the subtractor 1A3 is orthogonally coded by a discrete cosine transform circuit (hereinafter referred to as DCT circuit) 1A4 and output to the quantizer 1A5 as orthogonal coded data. The quantizer 1A5 quantizes the orthogonal coded data and supplies it to the variable length encoder 1A6 and the inverse quantizer 1A7 as quantized data.

The variable length encoder 1A6 is a circuit for outputting data, and the inverse quantizer 1A7 is a circuit for local decoding. That is, the inverse quantizer 1A7 is used to return the quantized data to the orthogonal coded data. This orthogonally coded data is further decoded into differential data by an inverse discrete cosine transform circuit (hereinafter referred to as IDCT circuit) 1A8 and given to the adder 1A9. Further, this difference data is added to the frame memory predictor 1 in the adder 1A9.
It is added with the previous frame image signal read from A10,
It is decoded into the current frame image. This current frame image is stored in the frame memory predictor 1A10 and used for prediction of the next frame and decoding of the current frame.

The encoded data variable-length coded by the variable-length encoder 1A6 is then multiplexed by the multiplexer 1A11 with the motion vector signal Sv and the picture type signal Sp previously obtained. This data is the encoded data S
It is 2. The encoded data S2 output from the multiplexer 1A11 is the encoded buffer memory 1B as described above.
Are temporarily stored in the recording medium 3, are sequentially read out after a predetermined time, and are written in the recording medium 3.

The controller 1A12 controls the generated data amount of the encoded data input to the encode buffer memory 1B. The controller 1A12 controls the quantization size based on the above-mentioned encoding method and adjusts the generated data amount. The stuffing processing unit 1A13 is for supplementing data when the amount of generated information is short of the target value.

Subsequently, a series of encoding operations including the control procedure of the controller 1A12 are shown in FIGS. When the recording apparatus 1 starts the encoding process from step SP1, it inputs the moving image signal to the encoder, that is, the input to the compression encoding processing unit 1A in step SP2. After the quantization, the variable-length coded coded data are sequentially multiplexed and written in the encode buffer memory 1B as shown in step SP4.

These series of encoding processes are performed in step SP5.
It continues until a positive result is obtained in. That is, when a positive result is obtained and it is detected that the start-up delay time Te has elapsed from the start of encoding, the recording device 1 moves to step SP6 and starts transmitting encoded data from the encode buffer memory 1B. . When the transmission of the encoded data is started, the controller 1A12 starts controlling the amount of generated data. The processing of this step SP7 is shown in FIG.

The controller 1A12 first samples the remaining amount of buffer EBr (= EBf-EDe) in step SP22, and in the next step SP23, determines whether the elapsed time reaches the switching time Tf 'at which the upper limit of the buffer memory appears to be small. To determine. When a positive result is obtained, in step SP24, a predetermined amount (actual buffer memory upper limit EBf-virtual buffer memory upper limit EBf ') is subtracted from the actual buffer remaining amount EBr to obtain the virtual buffer remaining amount EBr' (= EBf '. -EDe). Then, the process proceeds to step SP25. On the other hand, when a negative result is obtained, the process directly moves from step SP23 to step SP25.

At step SP25, the quantization size is determined based on the virtually obtained buffer remaining amount EBr 'or the actually sampled buffer remaining amount EBr', and this value is fed back to the quantizer 1A5 at step SP26. It is done like this. These controllers 1A
The sequence of operations for determining the quantization size in 12 is repeated until a positive result is obtained in step SP8 in FIG.
Incidentally, the determination process of step SP8 is a determination process of whether or not the elapsed time exceeds the display time T of the moving image signal to be encoded.

When a positive result is obtained, the recording apparatus 1 moves to the processing of step SP9 and determines whether the total amount of data generated from the start of encoding to the present time is smaller than the target amount of data, that is, R × T. Move to judgment processing. If an affirmative result is obtained at this time, in step SP10, the stuffing data corresponding to the difference between the target value (= R × T) and the generated data amount is added to the stuffing processing unit 1A.
It is output from 13, and the encoding operation for one moving image signal is completed in step SP11. If a negative result is obtained in step SP9, the amount of generated data matches the target value (= R × T), and there is no need for supplementation, and therefore the process directly moves to step SP11 to complete the encoding operation. .

By encoding the moving image signal through these procedures, the encoded data amount of the moving image signal can be always limited to a fixed amount according to the display time T of the moving image. Thus, the writing of data to the recording medium 3 can be completed within the same time as the time T required for encoding. This is particularly effective when it is desired to reproduce a plurality of moving image signals that require strict time management without interruption on the screen.

(2-3) Decoding Device Next, the decoding operation of the reproducing device 2 for reading and reproducing the encoded data from the recording medium 3 recorded by the recording device 1 in the preceding paragraph will be described. Incidentally, it is assumed that an arbitrary number n of moving images at time Tn are independently encoded and recorded on the recording medium 3, and the reproducing apparatus 1 uses the independent moving image data ( Hereinafter, it is assumed that a clip) is arbitrarily selected and the decoding process is continuously performed.

First, the clips to be continuously read are C1 and C.
2 and C3, the transition in the decode buffer memory when the data of these clips C1, C2, and C3 are sequentially read into the decode buffer memory 2A is shown in FIG. Incidentally, the straight line DBe in the figure represents the amount of data received by the decode buffer memory 2A at the rate R.
Between f and the capacity DBc of the decode buffer memory 2A
Equivalent to.

Since each clip C1, C2, C3 is encoded independently, the start-up delay Te in the encode buffer memory 2A and the transition of data generation in the encode buffer memory 2A are all different, but The amount of data generated is R × Tn. The changes of these clips are shown as Dd1, Dd2, Dd.
When it is set to 3, the distance between this curve and DBf in the vertical direction indicates the buffer remaining amount DBr. Further, when the capacities of the encoding buffers at the time of encoding are overlapped and expressed, they are EBf1-EBe1, EBf2-EBe2 and EBf3, respectively.
-It becomes EBe3.

Now, the transition of the amount of data generated in each clip C1, C2, C3 in the decode buffer memory 2A differs depending on each start-up delay Te. For example, when the start-up delay Te is very short as in the clip C1, the buffer remaining amount DBr of the decode buffer memory 2A changes to a large amount, and when the fluctuation width is the maximum, it is the buffer capacity at the time of encoding.
In the figure, it falls within EBf1 -EBe1.

On the contrary, when the start-up delay Te is very long as in the clip C2, the buffer remaining amount DBr of the decode buffer memory 2A shifts to a small value, and when the fluctuation width is maximum, the buffer capacity at the time of encoding is large. It will be a minute. In the figure, it falls within EBf2 -EBe2. In the decode buffer memory 2A, it is necessary for the transition and the fluctuation width to fall within the buffer capacity DBc for any clip.

Assuming that the time Td from the reception of data to the start of transmission is the time from the start of data reception to the same as the encoder buffer capacity EBc where the remaining buffer capacity DBr is, Td is given by the following equation.

[Equation 4] Becomes

At this time, the following two things can be said. 1
Considering the buffer remaining amount DBr at the time when each clip data is received by the decode buffer memory 2A and at the time when the reception is finished, the total data amount of the clip is equal and the reception amount received by the buffer. Since the rates are equal, the buffer remaining amounts at the start point and the end point are equal, and even if an arbitrary number of clips are continuously reproduced, those points are on the straight line DBh.

The other is, considering the transition of generated data, the buffer remaining amount DBr of the decode buffer memory 2A.
In the case where the maximum amount of data has changed, as shown in FIG.
When the buffer remaining amount DBr of the decode buffer memory 2A has changed to the minimum, the lower limit EBe1 of the generated data amount of the emitter buffer memory 1B is the decode buffer memory 2A as shown in FIG. That is, it overlaps with the straight line DBf that represents the upper limit of the capacity.

For the above two reasons, if the decode buffer memory 2A is provided with a capacity larger than the swing width of EBf1 and EBe2 in the vertical direction from the straight line DBh, continuous reproduction is possible regardless of any clip. You can see that you can. That is, the capacity DBc should be the encode buffer capacity BEc above and below the straight line DBh in the vertical axis direction. From this, the following equation

(Equation 5) That would be good.

As described above, the decode buffer memory 2A has twice the capacity of the encode buffer memory 1B, so that any clip encoded by the encoding method described in this embodiment can be continuously reproduced without interruption. It becomes possible. However, when the start-up delay Te is the same for each clip as shown in FIGS. 7 and 8,
The capacity of the decode buffer memory 2A may be the same as the capacity of the encode buffer memory 1B.

(3) Application system Next, an example of system configuration to 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. 9 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 is provided with 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 section 13C controls the data supply source 12, the encoder 13A and the server section 14 according to the control signal S _CTL and manages the operation state of each section.

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. Incidentally, 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. 10 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 as compressed encoded data to the artificial satellite 24 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 as a moving image signal to each home 27. 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 embodiments, the case where the moving image signal is DCT-encoded has been described, but the present invention is not limited to this.
It can be widely applied when other orthogonal transform coding method or other coding method is used. In the above 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.
It can also 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.

[0063]

As described above, according to the present invention, the variable size encoding is performed based on these quantization sizes by controlling the quantization size by regarding the buffer remaining amount as being smaller than the actual amount. It is possible to suppress the amount of generated data of the generated moving image signal.

Further, according to the present invention, independent coded data coded so that the time required for recording is equal to or less than the time required for encoding are continuously read from the recording medium or the transmission path, and are decoded. By reading out at a constant rate through the buffer memory and decoding, it is possible to prevent interruption in the decoding result of independent moving image signals.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a data generation state in an encode buffer memory.

FIG. 2 is a block diagram showing an example of a basic system using the encoding method according to the present invention.

FIG. 3 is a block diagram showing a configuration inside a compression encoding processing unit.

FIG. 4 is a flow chart showing an operation procedure at the time of encoding.

FIG. 5 is a flow chart showing an operation procedure at the time of encoding.

FIG. 6 is a schematic diagram for explaining a data generation state during continuous reproduction.

FIG. 7 is a schematic diagram showing a data generation state in the case of continuously reproducing coded data that is coded with a fixed start-up delay.

FIG. 8 is a schematic diagram showing a data generation state in the case of continuously reproducing coded data that is coded with a fixed start-up delay.

FIG. 9 is a block diagram showing a configuration example of an AV server system.

FIG. 10 is a block diagram showing a configuration example of an AV server system.

[Explanation of symbols]

1 ... Recording device, 1A ... Compression encoding processing unit, 1A1 ...
... Frame memory, 1A2 ... Motion estimator, 1A4 ...
DCT circuit, 1A5 ... Quantizer, 1A6 ... Variable length encoder, 1A7 ... Inverse quantizer, 1A8 ... IDCT circuit, 1A10 ... Frame memory predictor, 1A11.
Multiplexer, 1A12 ... Controller, 1A13 ... Stuffing processing section, 1B ... Encode buffer memory, 2
...... Playback device, 2A …… Decode buffer memory, 2B
... Decompression / decoding processing unit, 3 ... Recording medium, 11, 21 ...
... AV server system, 12 ... data supply source, 13 ...
... encoder section, 14 ... server section, 14A ... recording / reproducing section, 14B ... decoder section, 15A1-15AN ...
Terminal, 22 ... Production station, 23 ... Key station, 24 ... Artificial satellite, 25 ... Cable station, 26 ... Branch office, 27 ... Home.

Claims (15)

[Claims] 1. A data recording method for reading a moving image signal coded in a variable amount by variable control of quantization size at a constant rate through an encoding buffer memory and recording a recording medium, wherein the quantization size is A data recording method, characterized in that, when performing control based on the buffer remaining capacity of the encoding buffer memory, the quantization remaining size is controlled by regarding the buffer remaining capacity as less than the actual value. 2. The process of controlling the quantization size by regarding the remaining buffer amount as being smaller than the actual amount is started after a lapse of a certain time from the start of encoding the moving image signal, and until then, the actual process is performed. The data recording method according to claim 1, wherein the control is performed based on the remaining buffer capacity. 3. A quantizer which encodes a moving image signal by a variable amount by variable control of a quantization size and outputs it as quantized data, and a quantizer which inputs and stores the quantized data and outputs them sequentially at a constant rate. A data recording device comprising: an encoding buffer memory; and a controller for variably controlling the quantization size by regarding the remaining buffer capacity of the encoding buffer memory as being actually smaller. 4. A dummy that inserts dummy data to match the generated amount with the target value when the generated amount of the quantized data generated by the variable control of the quantization size by the controller falls below a target value. The data recording device according to claim 3, further comprising a data processing unit. 5. Independently coded data coded such that the time required for recording is equal to or less than the time required for encoding are continuously read from a recording medium and written in a decode buffer memory, and then the code is written. A data reproducing method, characterized in that, by reading out the encoded data at a constant rate and decoding it, no interruption occurs in the decoding result of the independent moving image signal. 6. An independent coder having the same capacity as the encode buffer memory provided on the recording device side, each coded so that the time required for recording is less than the time required for encoding. And a decoding processing unit for decoding the coded data read out from the decoding buffer memory at a constant rate. apparatus. 7. The capacity of the encoding buffer memory provided on the recording device side is twice as large as that of the encoding buffer memory,
Decode buffer memory that continuously reads independent coded data encoded so that the time required for recording is less than or equal to the time required for encoding, and read at a constant rate from the above-mentioned decode buffer memory A data reproducing apparatus, comprising: a decoding processing unit that decodes encoded data. 8. A recording medium, wherein one or a plurality of pieces of coded data encoded so that the time required for recording is equal to or less than the time required for encoding are recorded. 9. A data transmission method for reading a moving image signal, which is encoded in a variable amount by variable control of a quantization size, at a constant rate via an encoding buffer memory and outputs it to a transmission line, wherein the quantization size is the above-mentioned. A data transmission method characterized in that, when performing control based on the remaining buffer capacity of an encoding buffer memory, the quantization size is controlled by regarding the remaining buffer capacity as being less than the actual value. 10. The process of controlling the quantization size by regarding the remaining buffer amount as being smaller than the actual amount is started after a lapse of a certain time from the start of encoding the moving image signal, and until then, the actual process is performed. Control based on the remaining buffer capacity. 10. The data transmission method according to claim 9, wherein: 11. A quantizer which encodes a moving image signal by a variable amount by variable control of a quantization size and outputs it as quantized data, and a quantizer which inputs and stores the quantized data and then encodes the quantized data. And a controller for variably controlling the quantization size by regarding the remaining amount of the buffer in the encoding buffer memory as being smaller than the actual value. Characteristic data transmission device. 12. A dummy for inserting dummy data to match the generated amount with the target value when the generated amount of the quantized data generated by the variable control of the quantization size by the controller is below a target value. The data transmission device according to claim 11, further comprising a data processing unit. 13. Independently coded data encoded so that the time required for recording is equal to or less than the time required for encoding are continuously read from a transmission line and written in a decode buffer memory, and then the above-mentioned code is used. A data transmission method, characterized in that the encoded data is read at a constant rate and decoded so that no interruption occurs in the decoding result of the independent moving image signal. 14. An encoding buffer memory provided on the transmitting device side, having the same capacity as each other, and encoded so that the time required for transmission is less than the time required for encoding. And a decoding processing unit for decoding the coded data read out from the decode buffer memory at a constant rate. Data transmission equipment. 15. An encoding buffer having a capacity twice as large as the capacity of an encoding buffer memory provided on the side of the transmitting device, and encoding is performed such that the time required for transmission is less than the time required for encoding. And a decoding processing unit for decoding the coded data read out from the decoding buffer memory at a constant rate. Data transmission device.