JP3060989B2 - Image coding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to encoding, decoding and transmission of digital video data, and more particularly to a CD-RO.
The present invention relates to a moving image encoding method and apparatus suitable for a moving image reproduction system using a package medium such as M.

[0002]

2. Description of the Related Art As a conventional moving picture coding method and apparatus, there are known a picture coding transmission system described in Japanese Patent Application Laid-Open No. Sho 62-164391, or IEE, Transaction on Communication, COM. 32, 3 (March 1984) pp. 225 to 232 (IEEE, Trans. Communications, Vol.
COM-32, No. 3, March 1984, pp 225
-232) is known.

FIG. 2 is a block diagram showing a moving picture coding transmission system according to the prior art. In FIG. 1, reference numeral 20 denotes a moving picture coding apparatus, 22 denotes an input video signal, 23 denotes an A / D conversion circuit, 24 denotes image data, 25 denotes a frame memory having a capacity of at least one frame,
26 is an image encoding circuit, 27 is encoded data, 28 is a buffer memory, 29 is an encoded data amount control circuit, and 30 is an encoded data amount control signal. 31 is a transmission medium, 21 is a moving picture decoding device, 32 is coded data, 33 is a buffer memory, 34 is an image decoding circuit,
5 is image data, 36 is frame memory, 37 is D / A
The conversion circuit 38 is an output video signal. FIG. 3 shows a data amount of encoded data generated by the image encoding circuit 26 in the conventional example shown in FIG. 2 (hereinafter, referred to as an encoded data amount).
FIG.

Next, the operation will be described. In FIG. 2, an input video signal 22 is converted into digital image data 24 by an A / D conversion circuit 23 every 1/30 second, one frame at a time, and is stored and held in a frame memory 25.
The image encoding circuit 26 efficiently encodes the image data 24 in the frame memory 25 and stores the image data 24 in the buffer memory 28. The encoded data 27 stored in the buffer memory 28 is, for example, 1M bits per second (hereinafter, 1M bits).
bps) and output to the transmission medium 31. When the motion of the video content of the input video signal 22 is small, the amount of encoded data 40 generated by the image encoding circuit 26 is reduced as in the frames a, b, c, and d in FIG.
1 is determined by the transmission speed of the transmission medium 31 because
A of the data transfer capacity 41 per frame (here,
(1 Mbps × 1/30 seconds ≒ 32 k bits). In this case, dummy data is inserted and transmitted in order to synchronize transmission with the video decoding device 21. on the other hand,
When the motion of the video content of the input video signal 22 is drastic or when there is a scene change, the amount of coded data 40 generated by the image coding circuit 26 is equal to one frame, as in the frames e and f in FIG. Data transfer capacity 41
A may be exceeded. Therefore, in this case, the amount of data in the buffer memory 28 increases, so that the encoded data amount control circuit 29 drops frames like a frame of g, or changes encoding parameters like a frame of h and i. For example, the coded data amount 40 is forcibly reduced by increasing the compression ratio.

[0005]

In the above-mentioned prior art, since the transmission speed of the transmission medium is constant, the amount of coded data is forcibly reduced by dropping frames or changing coding parameters for a video with rapid movement. Had gone. For this reason, remarkable image quality degradation may occur for such a video in a moving image. By the way, from the viewpoint of information transmission related to human perception, a video with a large motion generally contains a lot of important information like a video with a small motion. Therefore, in the prior art in which a moving image having a large motion cannot be faithfully transmitted, its use is significantly limited.

As a means for solving this problem, it is conceivable to increase the transmission speed of the transmission medium. For example, when the transmission medium is a communication line, it leads to a large increase in communication cost, and when the transmission medium is a CD. -In the case of package media such as ROM, the total recording time of images is significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the cost of the recording or minimize the total recording time so that a moving image is almost the same as a moving image. It is an object of the present invention to secure image quality and realize transmission of high-quality moving image data.

[0008]

SUMMARY OF THE INVENTION The above objects are achieved by a coding method and apparatus of the moving image, the reproduction apparatus via a transmission medium
This is achieved by variably controlling the data transfer amount of the encoded data of a plurality of frames to be transferred.

According to the present invention, data is reproduced while controlling the data transfer amount of coded data of a plurality of frames.
Since transfer location, if the the violent video with little motion video and motion are mixed, the excess portion with respect to the data transfer capacity at low partial motion, the data generated in intense portions of the front and rear movements If a part can be transferred and a part with a lot of movement continues for a long time, the data transfer capacity of the transmission medium can be increased and more data can be transferred. Therefore, image quality degradation can be reduced.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention, and shows a moving picture coding and recording system for an optical disc. In FIG. 1, reference numeral 1 denotes a moving image encoding device, and 2 denotes an optical disk manufacturing device. Also, 3
Is a moving image source such as a silver halide film or a VTR, 4 is a moving image signal, 5 is an A / D conversion circuit, 6 is image data, 7 is a frame memory having a capacity of at least n frames, 8 is an image encoding circuit , 9 is coded data, 10 is a data transfer rate calculation circuit, 11 is data transfer rate information, and 12 is a buffer memory. Reference numeral 13 denotes a mastering device for reading encoded data at a constant speed to create a master of an optical disk, reference numeral 14 denotes a master of an optical disk, reference numeral 15 denotes a press device for manufacturing an optical disk from a master of an optical disk by pressing, and reference numeral 16 denotes an optical disk.

FIG. 4 is a diagram showing a change in the amount of encoded data generated by the image encoding circuit 8 of FIG. 1, and FIG. 5 is a diagram for reproducing an optical disk created by the moving image encoding and recording system shown in FIG. FIG. 1 is a block diagram of a moving picture decoding / reproducing system that performs the above. In FIG. 4, reference numeral 45 denotes an encoded data amount generated in the image encoding circuit 8, and reference numerals 46, 47, and 48 denote data transfer capacities that change in units of n frames. Also, in FIG.
50 is an optical disk reproducing device, 51 is a moving image decoding device,
52 is an optical disk on which a moving image is encoded and recorded, 53 is a servo circuit for controlling a rotary motor and an optical pickup,
54 is a rotation motor, 55 is a motor rotation control signal, 56 is an optical pickup, 57 is a preamplifier for amplifying a signal from the optical pickup, 58 is a data processing circuit for reproducing data, 59 is reproduced encoded data, 60 is Data transfer speed information; 61, a buffer memory for storing encoded data of reproduced moving images; 62, an image decoding circuit for decoding encoded data; 63, decoded image data;
64 is a frame memory, 65 is a D / A conversion circuit, and 66 is an output video signal.

Next, the operation of the moving picture coding and recording system of FIG. 1 will be described. When encoding and recording a moving image source 3 prepared in advance on an optical disc, first, the moving image signal 4 is converted into image data 6 by an A / D conversion circuit 5 for n frames, and then stored in a frame memory 7. To memorize. The image encoding circuit 8 encodes n frames of image data 6 in the frame memory 7 to generate encoded data 9, and the data transfer rate calculation circuit 10 calculates an average data amount of the encoded data 9. To output data transfer speed information 11. That is, the calculated data transfer speed is V (t), and the encoded data amount in each frame is D (t).
(I)

[0013]

(Equation 1)

V (t) is determined so that For example, FIG.
V (t) = α (bps) for i = 1 to n V (t) = β (bps) for i = (n + 1) to 2n V (t) = for i = (2n + 1) to 3n γ (bps). This data transfer speed information 11 is stored in the buffer memory 12 together with the encoded data 9. The data read from the buffer memory 12 is edited into a format for an optical disk by a mastering device 13 and recorded on a master disk 14 of the optical disk, and an optical disk 16 is manufactured by a press device 15.

Next, the operation of the moving picture decoding / reproducing system shown in FIG. 5 will be described. The data stored on the optical disk 52 is read by the optical pickup 56 and amplified and waveform-shaped by the preamplifier 57. Then, after being demodulated by the data processing circuit 58, it undergoes a data error correction process according to a predetermined procedure. The reproduced data is separated into encoded data 59 and data transfer speed information 60. The servo control circuit 53 outputs a motor rotation control signal 55 for controlling the rotation of the rotary motor 54 according to the data transfer speed information 60 reproduced by the data processing unit 58. Here, the servo is operated so that the data transfer speed from the preamplifier 57 becomes constant. That is,
CLV (constant linear velocity) rotation control is performed so that the data transfer rate is determined by the data transfer rate information 60.
For example, as described above, the data transfer rate changes in three stages, α, β, and γ (bps). Then, the data processing circuit 5
The encoded data 59 of the moving image reproduced in 8 is stored in the buffer memory 61, decoded into the original image data 63 by the image decoding circuit 62, and written into the frame memory 64. The image data 63 is sequentially read from the frame memory 64 in accordance with the display scanning, converted into an output video signal 66 by the D / A converter 65, and output. By the way, assuming that the maximum data transfer speed is γ (bps), the capacity of the buffer memory 61 only needs to be γ × n × 1/30 (bit). It is necessary to have some extra memory in consideration of the response delay when changing the speed. In this embodiment, the processing is always performed every n frames. However, if the value of n is inversely proportional to the data transfer rate, the capacity of the buffer memory 61 can be reduced.

Although the example in which the data transfer speed is changed by controlling the rotation speed of the optical disk has been described above, it is also possible to use an optical disk reproducing device having a fixed data transfer speed. For example, a commonly used CD-
Using the ROM reproducing device, the data transfer method can be equivalently made variable by devising the data transfer method. Hereinafter, the embodiment will be described in detail.

CD-ROM (Compact Disc-Read Only)
Memory) is for recording computer data instead of digital audio data on the same optical disk as an audio CD. FIG. 6 shows the structure of this optical disk. This optical disk is a disk having a diameter of 12 cm and a thickness of 1.2 mm, and is provided with one spirally connected track 70 having a total length of about 5 km. On the track 70, pits having a width of 0.4 μm and a length of 0.9 to 3.3 μm (the length differs depending on data) are recorded. 46mm inside diameter
Starts with a lead-in area 71, followed by a program area 72 with a diameter of 50 mm to 116 mm, and a lead-out area 73 with an outer diameter of 120 mm. Then, actual digital audio data and computer data are recorded in the program area.
The lead-in area has a TOC (Table Of Content)
The table of contents of the entire disc is recorded.

FIG. 7 shows a format of data recorded on a CD-ROM disc. As shown in (a), the minimum unit of data recording is a frame 80 as in the case of an audio CD, and as shown in (b), a total of 588-bit frame 80 is composed of frame synchronization data 81 and a subcode 82 (freely). Usable auxiliary information), 24-byte digital data 83, and an error correction code ECC 84 using a double-coded Reed-Solomon code. The track 80 on the disk has this frame 80 of about 260
100,000 are recorded. It should be noted that data is not actually recorded in order, but appropriate data rearrangement (interleaving) is performed over a considerably long range in order to enhance error correction capability against burst errors caused by disk defects and dirt. It is recorded after it is done.
In the case of an audio CD, the audio signal
A 16-bit, 2-channel digital audio data sampled at 4.1 kHz has 24 bytes for one frame 80.
In the case of a CD-ROM, computer data is recorded instead.

One sector 85 of the CD-ROM is composed of 2352 bytes including a total of 98 frames of digital data 83 as shown in FIG. 3C, in which 2048 bytes of blocked computer data are recorded. . One sector 85 has 12 bytes of sync data 86 for synchronizing and 4 bytes having address and mode information.
Byte header data 87, 2048-byte computer data 88, 4-byte error detection code EDC89 by 32-bit CRC, 8-byte reserved area 90 for future expansion, 276-byte error by double-coded Reed-Solomon code It consists of a correction code ECC91. To the computer, it appears as if the computer data 88 divided into blocks of 2 kB are arranged as shown in FIG.

It should be noted that, although strong error correction has been applied to the audio CD as described above,
Since the ROM targets computer data, error correction is further performed to improve data quality. The data transfer rate of CD-ROM is 1.2Mbps,
That is, it is 150 kB / sec, and about 540 MB of computer data can be recorded.

FIG. 8 is a block diagram of a moving picture coding and recording system for recording moving pictures on a CD-ROM, and FIG. 9 is a block diagram of a moving picture decoding and reproducing system for reproducing moving pictures from a CD-ROM. First, in FIG. 8, reference numeral 100 denotes a moving picture coding apparatus, 111 denotes a CD-ROM manufacturing apparatus, and 112 denotes a CD-R.
It is an OM disk. In the moving picture coding apparatus 100, 101 is an input video signal, 102 is an A / D conversion circuit, 103 is image data, 104 is a frame memory having a capacity of one frame or more, 105 is an image coding circuit,
106 is encoded data, 107 is data rate information,
108 is a data multiplexing circuit, 109 is a buffer memory, 1
Reference numeral 10 denotes a data transfer speed information generation circuit. Next, FIG.
In the figure, 120 is a video decoding device, 121 is a CD-ROM disk, and 122 is a CD-ROM playback device. Also, in the video decoding device 120, 12
3 is a data separation circuit, 124 is encoded data, 125 is data transfer speed information, 126 is a data transfer control circuit,
27 is a buffer memory, 128 is an image decoding circuit, 12
9 is image data, 130 is a frame memory having a capacity of one frame or more, 131 is a D / A conversion circuit, and 132 is an output video signal.

First, the operation of the moving picture coding and recording system shown in FIG. 8 will be described. A video signal output from a TV camera, a video tape recorder, or the like is separated from an NTSC composite video signal into three types of component video signals (for example, luminance Y, color difference RY, and BY). Each input video signal 101 is sampled at a predetermined sampling frequency (for example, four times the color subcarrier frequency of 3.58 MHz) in an A / D conversion circuit 102, and is sequentially converted into digital image data 103. You.
Normally, the number of bits of the A / D conversion circuit 102 is set to 8 bits, so that the data amount of the image data 103 per pixel is 8 bits for each component component, that is, 24 bits in total.
Bit. The frame memory 104 has a capacity capable of storing image data for a plurality of frames, and digitized image data 103 is sequentially written by a predetermined number of frames. Although it depends on the image coding method, at least two frames are required when performing inter-frame coding, for example. The image data 103 stored and held in the frame memory 104 is encoded by the image encoding circuit 105 with high efficiency to reduce the redundancy of the encoded data 10.
6 is generated. Various image coding methods are known. For example, when a motion compensation inter-frame coding method is used, the data can be compressed to about 1/100 times on average. That is, it is possible to compress the image data 103 of 24 bits per pixel to about 0.2 bits. However, the ratio of the moving area, the movement of the intensity, depending on the pattern fineness and vividness, etc., the data compression rate varies considerably greatly, the data amount of the coded data 106 changes for each frame.

Generally, the buffer memory 10
The image encoding circuit 10 changes the encoding parameter according to the data amount of the encoded data 106 stored in the image encoding circuit 10.
5 is adopted to control the data amount of the encoded data 106 generated in FIG. This is to keep the amount of data in the buffer memory 109 as constant as possible and to match the average value of the amount of data generated per unit time to the data transfer speed of the CD-ROM. Conventionally, an encoding device and a decoding device using a communication path having a constant data transfer rate have been mainly developed, and a method of controlling an encoded data amount by changing an encoding parameter in this manner is generally used. Was. However, in this method, the amount of data generation is controlled by changing the encoding parameters according to the convenience of data transfer irrespective of the inherent amount of information of the input image, so that the variation of the encoding error for each frame becomes very large. This leads to significant degradation of image quality. Therefore, in the present embodiment, the buffer memory 109
A data transfer speed information generating circuit 110 for generating data transfer speed information 107 in accordance with the data amount of the encoded data 106 stored in the storage device, and controlling the data transfer speed from the buffer memory 109 to the CD-ROM manufacturing device 111. Control method is adopted. By using this method, the fluctuation of the encoding error is suppressed, the image quality is improved, and a long-time moving image can be recorded. The specific method will be described later in detail.

The encoded data 106 output from the image encoding circuit 105 is multiplexed with data transfer speed information 107 by a data multiplexing circuit 108 and stored and held in a buffer memory 109. Then, data is sequentially read from the buffer memory 109 and output to the CD-ROM manufacturing apparatus 111 while controlling the data transfer rate. CD-R
Since the OM is not a medium that the user can easily record on the spot, the data to be recorded is stored in the CD-ROM manufacturing apparatus 1.
Hand over to CD-ROM after creating the master disc
It is necessary to manufacture the M disk 112 by pressing.

Next, the operation of the moving picture decoding system shown in FIG. 9 will be described. The CD-ROM disk 121 is a CD
-The data reproduced and recorded by the ROM reproducing device 122 is read. The read data is separated by the data separation circuit 123 into encoded data 124 and data transfer speed information 125. This data transfer speed information 12
According to 5, the data transfer control circuit 126 controls the data transfer speed from the CD-ROM playback device 122. The specific method will be described later in detail. The encoded data 124 is temporarily written into the buffer memory 127, but since the data transfer rate is controlled, the data amount of the encoded data 124 stored in the buffer memory 127 is kept almost constant. Then, the encoded data 124 read from the buffer memory 127 is transmitted to the image decoding circuit 128.
Is returned to the image data 129. The decoded image data 129 is stored and held in the frame memory 130, and the analog output video signal 1 is output by the A / D conversion circuit 131.
32 and displayed on the CRT unit.

Now, a method for controlling the data transfer rate from the moving picture coding apparatus 100 to the CD-ROM manufacturing apparatus 111 in FIG. 8 and the data transfer rate from the CD-ROM reproducing apparatus 122 to the moving picture decoding apparatus 120 in FIG. A transfer rate control method will be described. The data transfer rate of the CD-ROM is 1.2 Mbps (that is, 150 kB /
), And a method of controlling the data transfer rate in two stages, the maximum transfer rate and the lower transfer rate, will be described in detail below.

FIG. 10 shows a first example of a data transfer rate control method. In the figure, (a) shows encoded data 10 recorded in order on a track of a CD-ROM disc.
6, (b) shows the CD-
(C) Data transfer speed in data transfer, (d) data amount of coded data 106 generated by image coding circuit 105, (e) buffer memory 109 Is the data amount of the encoded data 106 stored in.

Since the encoded data amount 152 after the moving picture is highly efficiently encoded fluctuates greatly from frame to frame as shown in (d), the data transfer speed is changed to control the data amount 153 in the buffer memory. There is a need. That is, when the data transfer of the encoded data 140 is performed at the maximum transfer speed, the data amount 153 in the buffer memory becomes lower than the lower limit threshold 154 at the time A as shown in FIG. Therefore, when the coded data 141 to 149 are transferred while switching to the low transfer rate from the time point A, the data amount 153 in the buffer memory exceeds the upper limit threshold 155 at the time point B. Therefore, the encoded data 150 is transferred again at the maximum transfer rate. Here, in order to realize data transfer at a low transfer rate, sectors 141, 143, 145, 147, and 149 are skipped from the time point A to the time point B as shown in (a) and (b). , 142, 144, 146, and 148, a low-speed transfer rate equivalent to half the maximum transfer rate (shown by a dotted line in (c)) is equivalently realized.

When skipping a sector, there is a method of transferring data other than encoded data, in addition to a method of not performing data transfer.

FIG. 11 shows a second example of the data transfer rate control method. In the figure, (a) shows the sequence of encoded data, (b) shows the state of data transfer, (c) shows the data transfer speed, (d) shows the amount of encoded data, and (e) shows the amount of data in the buffer memory. is there.

The data transfer rate is changed in accordance with the fluctuation of the encoded data amount 167, and the data amount 1 in the buffer memory is changed.
68 is controlled. That is, from the time A at which the data amount 168 in the buffer memory is below the lower threshold 169 to the time B at which the data amount 168 exceeds the upper threshold 170,
The data transfer of the encoded data 161 to 164 is performed at a low transfer rate. Here, in order to realize data transfer at a low transfer rate, the start and end of the 161, 162, 163, and 164 sectors from the time point A to the time point B as shown in (a) and (b). , A low-speed transfer rate (shown by a dotted line in (c)) that is equivalently lower than the maximum transfer rate is realized.

By adjusting the pause time, it is easy to provide more steps than just two steps. Further, instead of providing a pause for each sector as described above, a pause may be provided for a plurality of sectors.

FIG. 12 shows a third example of the data transfer rate control method. In the figure, (a) shows the sequence of encoded data, (b) shows the state of data transfer, (c) shows the data transfer speed, (d) shows the amount of encoded data, and (e) shows the amount of data in the buffer memory. is there.

The data transfer rate is changed according to the fluctuation of the encoded data amount 187 shown in FIG. 4D, and the data amount 188 in the buffer memory shown in FIG. That is,
From the time point A at which the amount of data 188 in the buffer memory falls below the lower threshold 189, the upper threshold 190
Up to the time point B, which exceeds
Data transfer at a low transfer rate. Here, in order to realize a data transfer at a low transfer rate, first, as shown in FIGS.
Data is transferred only in the sectors 182 and 184 by skipping the sectors 81 and 183, and then seek again to the point A and return to transfer data only in the sector skipped earlier. By doing so, a low transfer rate (shown by a dotted line in (c)) equivalent to the lower transfer rate than the maximum transfer rate is realized.

The ratio between the number of sectors to be skipped and the number of sectors to be transferred may be set to N instead of 1, and the seek for returning from the end to the beginning may be performed N times.

As described above, the moving picture coding apparatus 100
Three examples of the method of controlling the data transfer rate to the ROM manufacturing apparatus 111 have been described in detail with reference to FIGS. The data transfer speed from the CD-ROM playback device 122 to the video decoding device 120 is determined according to the data transfer speed information 125, as described above. Variable control is performed similarly to the data transfer rate. That is, CD-
The data transfer rate is variably controlled equivalently by the ROM reproducing device 122 skipping, pausing, or seeking during the reading of data from the CD-ROM. The control of the data transfer rate of the encoded data is performed by the moving image encoding apparatus 10.
Although the control is performed based on the data amount in the buffer memory of 0, the control may be performed by another method. For example, the amount of data in the buffer memory of the video decoding device 120 may be predicted, and control may be performed by comparing the amount of data with a predetermined threshold. Also, not the amount of data in the buffer memory, but the image encoding circuit 1
The control may be performed according to the encoded data amount generated in step 05.
For example, in the moving picture encoding apparatus 100, the frame memory 104 is provided for n frames, the acquired n frames of image data are collectively encoded, the total encoded data amount is calculated, and then the total encoded data amount is calculated. There is a method of controlling the data transfer rate in response.

The CD-ROM disk 112 includes:
It is necessary to record the data transfer speed information 107 together with the coded data 106, but the data transfer speed information is embedded in the sequence of the coded data and recorded together, or only the data transfer speed information is separately recorded. What is necessary is just to collectively record in a predetermined place. The information may be recorded in the sub-code area shown in FIG. 7B or the reserved area in the sector shown in FIG.

Although the case where encoded data is recorded on an optical disk such as a CD-ROM has been described in detail above, the present invention is not limited to this, and other data recording media may be used. For example, a CD-R that can be freely rewritten by the user
Examples include an AM disk, a hard disk, and a floppy disk. While a CD-ROM has a single spiral track, a hard disk or the like has a plurality of concentric tracks, but a method similar to the data transfer rate control method described so far can be applied.

[0039]

As described above, according to the present invention,
By transferring the data to the playback device while variably controlling the data transfer amount of the encoded data of a plurality of frames, data transfer of a moving image with higher image quality than before can be realized. In addition, if the image quality is equivalent to that of the related art, if the total amount of data to be transferred is determined, the data transfer of a moving image can be realized for a longer time than in the related art.

[Brief description of the drawings]

FIG. 1 is a block diagram of a moving picture encoding and recording system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional moving picture coded transmission system.

FIG. 3 is a graph showing a change in encoded data amount in FIG. 2;

FIG. 4 is a graph showing a change in the amount of encoded data and a change in data transfer capacity in FIG. 1;

FIG. 5 is a block diagram of a video decoding / reproducing system that is paired with FIG. 1;

FIG. 6 is a conceptual diagram showing the structure of a CD-ROM disc, which is a kind of optical disc.

FIG. 7 is a conceptual diagram showing a data format of a CD-ROM.

FIG. 8 is a block diagram of a moving picture encoding and recording system according to another embodiment of the present invention.

FIG. 9 is a block diagram of a video decoding / reproducing system that is paired with FIG. 8;

FIG. 10 is a conceptual diagram showing three examples of the data transfer method in FIG.

FIG. 11 is a conceptual diagram showing three examples of the data transfer method in FIG.

FIG. 12 is a conceptual diagram showing three examples of the data transfer method in FIG.

[Explanation of symbols]

1, 20, 100: moving picture coding apparatus, 21, 51, 120: moving picture decoding apparatus, 7, 25, 36, 64, 104, 130 ... frame memory, 12, 28, 33, 61, 109, 127 ... Buffer memory, 8, 26,105 ... Image coding circuit, 34,62,128 ... Image decoding circuit, 10 ... Average data transfer calculation circuit, 53 ... Servo control circuit, 110 ... Data transfer speed information generation circuit, 126 ... Data transfer control circuit.

Continuation of the front page (56) References JP-A-58-145284 (JP, A) JP-A-61-148987 (JP, A) Patent 2830792 (JP, B1) Patent 2907707 (JP, B1) Patent 2914952 (JP, A B1) Special Table 62-500417 (JP, A) 1987 Image Coding Symposium (PC SJ87) (1987.9) 5-6 (Video packet transmission technology) IEICE Technical Report, IN 87-39 (Jul. 7-11 (Modeling of Information Fluctuation in High Efficiency Video Coding)

Claims (2)

(57) [Claims] 1. Encoded image information to generate encoded data
Format for recording the encoded data on a recording medium.
The code for formatting means for editing into a mat
An image encoding method for transferring encoded data, comprising: obtaining an encoded data amount by encoding image information; and encoding the encoded data to be recorded on a recording medium from the encoded data amount.
The coded data transfer amount for each of a plurality of images of the data is variably set, and the coded data to be recorded on the recording medium is temporarily buffered.
And transfer the encoded data per unit time.
An image encoding method , comprising: transmitting encoded data to said formatting means . 2. Generating encoded data by encoding image information.
Format for recording the encoded data on a recording medium.
The code for formatting means for editing into a mat
An image encoding apparatus for transferring encoded data, comprising: means for obtaining an encoded data amount by encoding image information; and encoding data to be recorded on a recording medium from the encoded data amount.
It sets the coding data transfer amount for each of the plurality images of data variable
Setting means for variably setting, and temporarily storing encoded data to be recorded on the recording medium
And the amount of coded data transferred per unit time
Transferring the encoded data to the formatting means.
And a buffer for transmitting the image.