JP6426648B2 - Moving picture predictive decoding method and moving picture predictive decoding apparatus - Google Patents

Description

  The present invention relates to a moving picture predictive decoding method and apparatus, and more particularly to a moving picture predictive decoding method and apparatus for managing the maximum number of reproduced images that can be stored in a decoded picture buffer.

  A compression encoding technique is used to efficiently transmit and store moving image data. In the case of moving pictures, MPEGs 1 to 4 and H.264 are used. 261-H. The H.264 scheme is widely used.

  In these encoding methods, the image to be encoded is divided into a plurality of blocks, and the encoding and decoding processes are performed. The following predictive coding method is used to enhance coding efficiency. In prediction coding in a screen, a prediction signal is generated using an adjacent already reproduced image signal (a restored image data compressed in the past) in the same screen as the target block, and then the target is generated. The difference signal subtracted from the block signal is encoded. In inter-picture prediction coding, reference is made to a reproduced image signal in a picture different from that of the target block, the displacement of the signal is searched, the movement is compensated to generate a prediction signal, and the target block is generated. Encoding the difference signal subtracted from the The reproduced image referred to for motion search and compensation is referred to as a reference image.

  In addition, in interactive inter-screen prediction, not only images in the past in the order of display time but also future images displayed after the target image may be referred to together (this future image is coded before the target image Need to be reproduced in advance). By averaging the predictions obtained from past and future images, it is useful for predicting the signal of hidden and emerging objects, while reducing the noise contained in both predictions Have an effect.

  Furthermore, H. In H.264 inter-frame prediction coding, a prediction signal for a target block refers to a plurality of reference images that have been encoded and reproduced in the past, and an image signal with the least error while performing motion search is used as an optimum prediction signal. select. The difference between the pixel signal of the target block and this optimum prediction signal is determined, discrete cosine transformation is performed, quantization is performed, and entropy encoding is performed. At the same time, information (also referred to as a reference index and a motion vector, respectively) regarding which region of which reference image the optimal prediction signal for the target block is to be obtained is encoded together.

  By the way, H. In H.264, it is possible to refer to a plurality of reproduced images. These reproduced images are stored as a reference image used for prediction in a decoded picture buffer (DPB) which is an image buffer memory. The size of the decoded image buffer (DPB) is defined by a profile and a level, and is defined not as the number of reference images but as a bit amount. That is, the number of images changes in accordance with the frame size of the image even with the same profile and level. For example, in the case of Main profile, level 3.2, the maximum size (MaxDPBSize: Maximum Decoded Picture Buffer size) of the image buffer for storing the reference image used for prediction is defined as 7680.0 × 1024 [bytes]. In the case of 1280 × 720 4: 2: 0, five reproduced images that can be stored in the decoded image buffer (DPB), and in the case of 1280 × 1024 4: 2: 0, the reproduced images that can be stored in the decoded image buffer (DPB) The maximum number of cards is four. Decoding when the maximum number of reproduced images that can be stored in Fig. 1 is 4 (Fig. 1 (a)), 5 (Fig. 1 (b)) and 6 (Fig. 1 (c)) according to the frame size of the image Fig. 6 shows an image arrangement of an image buffer. As described above, the image buffer memory prepared in advance is used while devising the memory arrangement by variably arranging the memory pointer in accordance with the frame size of the reproduced image.

H.264: Advanced video coding for generic audiovisual services, Joint Video Team of ITU-T VCEG and ISO / IEC MPEG, ITU-T Rec. H.264 and ISO / IEC 14496-10 (MPEG4-Part 10), November 2007

  Here, in such a definition, H. Since the H.264 decoding device needs to be able to decode an image of any frame size defined by the profile or level of the range supported by the decoding device, a memory used when storing a reproduced image in the image buffer memory How to place and store can not be fixed. Therefore, since it is necessary to change the memory pointer indicating the memory position where each reproduced image is stored according to the frame size of the image to be decoded, memory control and mounting become complicated.

  As a solution to this, a method of fixing the maximum number of reproduced images (max_dec_pic_buffering) that can be stored in the image buffer memory regardless of the actual frame size of the decoded image can be considered. Since the memory arrangement of the decoded image buffer (DPB) is uniquely determined by the maximum frame size as shown in FIG. 2A by this solution, the memory pointer can also be fixed. That is, memory control is easier than variable memory pointer control. However, in this solution, when the frame size of the decoded image is smaller than the maximum frame size or when the vertical width of the image is half of that of the frame image as in the field image of the interlaced image, FIG. As shown in FIG. 2, an unused memory area occurs, and there is a problem that the memory can not be used effectively. Furthermore, by storing more reproduced images, the possibility of improving the coding efficiency by increasing the number of reference images is lost.

  The present invention solves the above-mentioned problems, and utilizes the image buffer memory efficiently by determining the maximum number of reproduced images that can be stored in the image buffer memory according to the frame size of the reproduced image. An object of the present invention is to provide a moving picture prediction / decoding method and apparatus capable of improving coding efficiency.

In order to achieve the above object, a moving picture predictive decoding method according to the present invention is a moving picture predictive decoding method to be executed by a moving picture predictive decoding device, and a plurality of pictures constituting a moving picture are displayed on the screen. Input to input encoded data indicating compressed image data which is encoded by either prediction or inter-frame prediction and which includes information on the maximum frame size as the target image frame size, the maximum number of stored reproduction images, and the encoding setting Decoding compressed image data showing information about the step, compressed image data and target image frame size, maximum number of stored reproduced images and maximum frame size, and reproducing image, target image frame size and reproduced image can be stored The decoding step to restore information about the maximum number and the maximum frame size, the reproduced image, and the subsequent image Storing at least one image as the reference image to be used by the image storage means, and storing in the frame memory based on the relationship between the maximum frame size of the image and the frame size of the input image The present invention is characterized in that the maximum number of possible reproduced images is determined to be equal to, double or quadruple of a predetermined value .

Further, in the moving picture prediction decoding method according to the present invention, when the frame size of the input image is 1/2 or less of the maximum frame size of the image, the maximum number of reproduced images that can be stored in the frame memory is specified. It may be characterized in that it is determined to be twice the value of .

Further, in the moving picture prediction decoding method according to the present invention, when the frame size of the input image is 1⁄4 or less of the maximum frame size of the image, the maximum number of reproduced images that can be stored in the frame memory is specified. It may be characterized in that it is determined to be four times the value of .

The moving picture prediction / decoding apparatus according to the present invention encodes a plurality of images constituting a moving picture by either intra-frame prediction or inter-frame prediction, and the maximum number of target image frame sizes and the number of reproduction images that can be stored. And input means for inputting encoded data indicating compressed image data including information on maximum frame size as encoding setting, information on compressed image data, target image frame size, maximum number of stored reproduced images, and maximum frame size Decoding means for decoding compressed image data representing the reproduced image, and information relating to the reproduced image and information on the target image frame size, the maximum number of images that can be stored and the maximum frame size, and the reproduced image Image storage means for storing one or more as a reference image used for image processing; Based on the relationship between the frame size's and the input image, magnification of a predetermined value the maximum number of storable reproduced image in the frame memory, and determining the double or quadruple.

  According to the moving picture predictive decoding method and apparatus according to the present invention, the image buffer memory is efficiently used by determining the maximum number of reproduced pictures that can be stored in the image buffer memory according to the frame size of the reproduced picture. , And can further improve the coding efficiency.

It is a figure which shows an image buffer memory, the number of stored images, and a variable memory pointer position. FIG. 5 is a diagram showing a problem of a fixed memory pointer in an image buffer memory. FIG. 1 is a block diagram showing a moving picture predictive coding apparatus according to an embodiment of the present invention. FIG. 1 is a block diagram showing a moving picture prediction decoding apparatus according to an embodiment of the present invention. 3 is a flowchart illustrating a first video predictive coding / decoding method according to an embodiment of the present invention. It is a schematic diagram for demonstrating the process of the 1st moving image predictive coding / decoding method by embodiment of this invention. It is a figure which shows the hardware constitutions of the computer for running the program recorded on the recording medium. FIG. 16 is a perspective view of a computer for executing a program stored in a recording medium.

  Hereinafter, embodiments of the present invention will be described using FIGS. 3 to 8.

  FIG. 3 is a block diagram showing a video predictive coding apparatus according to an embodiment of the present invention. Reference numeral 301 denotes an input terminal, 302 denotes a block divider, 303 denotes a prediction signal generator, 304 denotes a frame memory, 305 denotes a subtractor, 306 denotes a converter, 307 denotes a quantizer, 308 denotes an inverse quantizer, and 309 denotes an inverse transform 310 is an adder, 311 is an entropy encoder, 312 is an output terminal, and 314 is a frame memory manager (also called a buffer manager). The input terminal 301 corresponds to input means. The prediction signal generator 303, the subtractor 305, the converter 306, the quantizer 307 and the entropy encoder 311 correspond to encoding means. The inverse quantizer 308, the inverse transformer 309 and the adder 310 correspond to the decoding means. The frame memory 304 corresponds to the image storage unit. The frame memory manager 314 corresponds to memory control means.

  The operation of the moving picture predictive coding apparatus configured as described above will be described below. A moving image signal composed of a plurality of images is input to the input terminal 301. The image to be encoded is divided by the block divider 302 into a plurality of regions. In the embodiment according to the present invention, the block is divided into blocks of 8x8 pixels, but may be divided into other block sizes or shapes. Next, a prediction signal is generated for an area to be encoded (hereinafter referred to as a target block). In the embodiment according to the present invention, two types of prediction methods are used. That is, inter-screen prediction and intra-screen prediction.

  In inter-frame prediction, using a reproduced image that has been encoded in the past and restored as a reference image, motion information that gives a predicted signal with the smallest error with respect to the target block is determined from this reference image. This process is called motion detection. Also, depending on the case, the target block may be subdivided, and the inter-screen prediction method may be determined for the subdivided small area. In this case, among the various division methods, the most efficient division method and respective motion information are determined for the entire target block. In the embodiment according to the present invention, it is performed by the prediction signal generator 303, and the target block is input through the line L302, and the reference image is input through the L304. As a reference image, a plurality of images encoded and restored in the past are used as a reference image. Details are given in the prior art MPEG-2, 4, H.264. The same as H.264. The motion information and the method of dividing the small area determined in this way are sent to the entropy encoder 311 via the line L312 and encoded, and then output from the output terminal 312. Also, among the plurality of reference images, information (reference index) on which reference image the prediction signal is to be obtained from is also sent to the entropy encoder 311 via the line L312. In the embodiment according to the present invention, M (M is an integer of 1 or more) reproduced images are stored in the frame memory 304 and used as a reference image. The prediction signal generator 303 acquires a reference image signal from the frame memory 304 based on the reference image and the motion information corresponding to the division method of the small area and each small area, and generates a prediction signal. The inter-frame prediction signal thus generated is sent to the subtractor 305 via the line L303.

  In intra prediction, an intra prediction signal is generated using already reproduced pixel values spatially adjacent to the target block. Specifically, the prediction signal generator 303 acquires already reproduced pixel signals in the same screen from the frame memory 304, and generates an in-screen prediction signal by extrapolating these signals. Information on the extrapolation method is sent to the entropy encoder 311 via the line L312 and encoded, and then output from the output terminal 312. The intra prediction signal generated in this manner is sent to the subtractor 305. The prediction signal generation method in the screen in the prediction signal generator 303 is the conventional technique H.264. The same as H.264. With respect to the inter-frame prediction signal and the intra-frame prediction signal determined as described above, the one with the smallest error is selected and sent to the subtractor 305.

  As for the first image, there is no image before that, so all target blocks are processed by intra prediction.

  The prediction signal (via line L303) is subtracted from the signal (via line L302) of the target block in the subtractor 305 to generate a residual signal. The residual signal is discrete cosine transformed by the converter 306, and each coefficient is quantized by the quantizer 307. Finally, the transform coefficient quantized by the entropy encoder 311 is encoded and sent out from the output terminal 312 together with information on the prediction method.

  In order to perform intra prediction or inter prediction with respect to the subsequent target block, the signal of the compressed target block is inversely processed and restored. That is, the quantized transform coefficients are dequantized by the dequantizer 308, and then inverse discrete cosine transformed by the inverse transformer 309 to restore a residual signal. The residual signal restored by the adder 310 and the prediction signal sent from the line L 303 are added to reproduce the signal of the target block, and the signal is stored in the frame memory 304. Although the converter 306 and the inverse converter 309 are used in the present embodiment, other conversion processes may be used instead of these converters. In some cases, the converter 306 and the inverse converter 309 may not be necessary.

  The frame memory 304 is limited, and it is impossible to store all reproduced images. Only the reproduced image used for encoding the subsequent image is stored in the frame memory 304. The frame memory manager 314 controls the frame memory 304. The frame memory manager 314 controls so that the oldest one of the M (where M is an integer) reproduced images in the frame memory 304 can be erased and the latest reproduced image to be used as a reference image can be stored. Do. The maximum frame size defined by the frame size and encoding setting (profile, level) of each image is input from the input terminal 313, and the maximum number of reproduced images that can be stored in the frame memory is determined based on this information. The frame memory manager 314 operates to store the maximum number of frames. At the same time, information on the maximum frame size defined by the frame size and encoding setting of each image and the maximum number of reproduced images that can be stored in the frame memory is sent to the entropy encoder 311 via line L314 and encoded And then output along with the compressed image data. The maximum frame size defined by the frame size and the encoding setting, and the maximum number of reproduced images that can be stored in the frame memory is attached to each image, and indicates the frame size of the image as it is or the frame size It may be expressed in the form of a power. If the maximum frame size is determined in advance as the profile or level information, the maximum frame size may be input using such information. In the present embodiment, it is assumed that the value of frame size is converted to binary coding as it is, and the maximum frame size is defined as level information. The control method of the frame memory manager 314 according to the present invention will be described later.

  Next, a moving picture predictive decoding method according to the present invention will be described. FIG. 4 shows a block diagram of an image prediction and decoding apparatus according to an embodiment of the present invention. 401 is an input terminal, 402 is a data analyzer, 403 is an inverse quantizer, 404 is an inverse transformer, 405 is an adder, 408 is a prediction signal generator, 407 is a frame memory, 406 is an output terminal, and 409 is a frame memory It is a manager. The input terminal 401 corresponds to input means. The inverse quantizer 403 and the inverse transformer 404 correspond to the decoding means. Other means may be used as the decoding means. The frame memory 407 corresponds to the image storage unit. A frame memory manager 409 corresponds to memory control means. Also, the inverse converter 404 may not be necessary.

  The operation of the moving picture predictive decoding apparatus configured as described above will be described below. Compressed data compressed and encoded by the method described above is input from the input terminal 401. The compressed data includes information relating to a residual signal obtained by predicting an object block obtained by dividing an image into a plurality of blocks and encoding the same, generation of a prediction signal, and the like. The information related to the generation of the prediction signal includes information on block division (block size) in the case of inter-frame prediction, motion information and the above-mentioned reference index, and in the case of intra-frame prediction, surrounding reproduced pixels Contains information on extrapolation methods.

  In the data analyzer 402, from the compressed data, the residual signal of the target block, the information related to the generation of the prediction signal, the quantization parameter, the maximum frame size defined by the frame size of the image and the coding setting, Extract the maximum number of playback images that can be stored in. The residual signal of the target block is dequantized by the dequantizer 403 based on the quantization parameter (via line L402). The result is inverse discrete cosine transformed in inverse transformer 404.

  Information related to the generation of the prediction signal is then sent to the prediction signal generator 408 via line L406b. The prediction signal generator 408 accesses the frame memory 407 based on the information related to the generation of the prediction signal, acquires a reference signal from among a plurality of reference images, and generates a prediction signal. This prediction signal is sent to the adder 405 via the line L408, added to the recovered residual signal, reproduced from the target block signal, and output via the line L405 and simultaneously stored in the frame memory 407.

  The frame memory 407 stores a reproduced image used for decoding and reproducing the subsequent image. The frame memory manager 409 controls the frame memory 407. The frame memory 407 is controlled so as to delete the oldest one of the stored M (here, M is an integer) reproduced images and store the latest reproduced image to be used as a reference image. The frame memory manager 409 operates based on the information on the maximum frame size defined by the frame size and encoding setting of the target image sent via the line L 406a, and the maximum number of reproduced images that can be stored in the frame memory. . The control method of the frame memory manager 409 according to the present invention will be described later.

  Next, the operation of the moving picture predictive coding method and the moving picture predictive decoding method according to the present invention will be described with reference to FIGS. 5 and 6. FIG. 5 is a flow chart showing a method of moving picture predictive coding / decoding according to an embodiment of the present invention. The meaning of the variables used in the figure will be described. pic_width is the number of luminance pixels in the horizontal width of the reproduced image, pic_height is the number of luminance pixels in the vertical width of the reproduced image, MaxLumaFS is the maximum image size defined by the level information, and MFSBuffer is the decoded image buffer (DPB) defined as the level information Amount of memory buffer represented by the maximum number of reproduced images that can be stored, maxDPBsize is the amount of memory buffer represented by the maximum number of reproduced images that can be stored in the decoded image buffer (DPB), and max_dec_pic_buffering is reproduction used at the time of decoding The maximum storage number of images (memory buffer amount), DPBpointer is a variable indicating a pointer indicating a position at which a reproduced image is stored in the decoded image buffer.

In FIG. 5, the number of pixels of the width of the reproduced image pic_width, the number of pixels of the width of the reproduced image pic_height, the maximum frame size MaxLumaFS defined as the encoding setting, and the maximum number of reproduced images that can be stored in the decoded image buffer (DPB). The memory buffer amount MFSBuffer represented by is input. Next, a value obtained by integrating the number of pixels pic_width of the width of the reproduced image input and the number of pixels pic_height of the width of the reproduced image is compared with a half value (MaxLumaFS / 2) of the maximum image size MaxLumaFS defined as the encoding setting Is performed (step S502). Here, when the condition is not satisfied (when the value obtained by integrating pic_width and pic_height is larger than the value of MaxLumaFS / 2), maxDPBsize = MFSBuffer is set (step S503). If the condition is satisfied (if the value obtained by integrating pic_width and pic_height is less than or equal to the value of MaxLumaFS / 2), maxDPBsize = 2 * MFSBuffer is set (step S504).
(Formula)
maxDPBsize = 2 * MFSBuffer (when pic_width * pic_height ≦ (MaxLumaFS >> 1))
maxDPBsize = MFSBuffer (other than the above)
Note that ">>" in the above equation indicates a right shift operation, which has the same meaning as MaxLumaFS / 2.

Then, the memory buffer amount max_dec_pic_buffering represented by the maximum number of stored reproduction images used at the time of decoding is set to be equal to or less than maxDPBsize.
(Formula)
max_dec_pic_buffering ≦ maxDPBsize

  When maxDPBsize = MFSBuffer, DPBpointer = 1 is set at the top of the image memory buffer as shown in FIG. 6A, and DPBpointer = 2, 3 and 4 are twice the maximum frame size from the position of DPBpointer = 1. , 3 and 4 times the position of the memory pointer is set to the advanced position.

  Further, in the case of maxDPBsize = 2 * MFS Buffer, in addition to DPBpointers 1 to 4 already set as shown in FIG. 6B, 1/2 and 3/2 times the maximum frame size from the position of DPBpointer = 1 , 5/2 times, 7/2 times the position of the memory pointer is advanced. (Step S505).

  The set max_dec_pic_buffering and DPB pointer are used to control the frame memory in step S508 described later. That is, at the time of decoding, the reproduced image is stored in the frame memory up to max_dec_pic_buffering sheets at a maximum, and at the time of storage, control is performed so as to be stored based on the set DPBpointer. In the encoding method, it is expressed by the maximum number of reproduced images that can be stored in the decoded image buffer (DPB), the maximum image size MaxLumaFS, and the information on the luminance pixel number pic_width of the horizontal width of the reproduced image, the luminance pixel number pic_height of the vertical width of the reproduced image The level information including the memory buffer amount MFSBuffer to be generated is externally given. In FIG. 3, it is supplied from a control device (not shown) via an input terminal 313.

  On the other hand, in step S506, the image to be processed is encoded and decoded by the method described in FIG. Data of the encoded image is transmitted or accumulated outside. In step S507, it is determined whether the target image is used as a reference image in the subsequent processing. This determination is determined by the coding type of the image (intra-picture prediction coding, inter-picture prediction coding, bi-directional prediction coding). If it is not used as a reference image, the process proceeds to step S510. If it is used as a reference image, the process proceeds to step S508, the DPB pointer is controlled at the position shown in FIG. 6, the image decoded and reproduced at step S509 is stored in the frame memory, and the process proceeds to step S511. In step S511, if there is a next image, the process proceeds to S506, and if there is no next image, the process ends. Thus, the encoding process is performed up to the last image.

  The above-mentioned processing corresponds to the processing of the whole moving picture coding method of FIG. 3, but in particular, steps S502, S503, S504, S505 and S508 are performed in the frame memory manager 314 according to the present invention.

  Although FIG. 5 has been described as the moving image encoding method, it can be applied to the processing of the moving image decoding method. When the decoding process is performed, data (bit stream) of the compression-coded image is input in step S501. From the data, the maximum number of reproduced images that can be stored in the number of pixels in the horizontal width of the reproduced image pic_width and the number of pixels in the vertical width of the reproduced image pic_height and the maximum frame size MaxLumaFS defined as encoding settings and decoded image buffer (DPB) The memory buffer amount MFSBuffer to be expressed and the maximum storage number (memory buffer amount) max_dec_pic_buffering of reproduced images used at the time of decoding are extracted, and the control of steps S502 to S505 and S508 is performed in the same manner as described above. On the decryption side, it is checked whether max_dec_pic_buffering restored in step S505 is equal to or less than maxDPBsize. In step S506, the compressed data of the target image is decoded, and the image is restored. The processes after step S507 are as described above. This process corresponds to the process of the moving picture decoding apparatus shown in FIG. 4, but steps S502, S503, S504, S505 and S508 are performed in the frame memory management unit 409 of the moving picture decoding apparatus according to the present invention.

  FIG. 6 is a schematic diagram for explaining the position of the memory pointer of the frame memory in the moving picture predictive coding / decoding method according to the embodiment of the present invention. As can be seen by comparing FIGS. 6A and 6B, the positions of the memory pointer numbers 1 to 4 are fixed. If the condition is satisfied in step S503, the memory pointers 5 to 8 are newly controlled. That is, the position of the memory pointer is fixed regardless of the determination in step S503.

(Location of memory pointer)
Although the memory pointer numbers of this embodiment are alternately set to 1 to 4 and 5 to 8, the memory pointer numbers may be assigned in the order of 1 to 8.

(Number of memory divisions)
In the present embodiment, the number of pixels in the width of the reproduced image pic_width, the number of pixels in the width of the reproduced image pic_height and the half frame value (MaxLumaFS / 2) of the maximum frame size MaxLumaFS defined as the encoding setting are compared. However, the number of pixels in the width of the reproduced image pic_width and the number of pixels in the vertical width of the reproduced image pic_height may be compared with the maximum frame size MaxLumaFS / 2 ^L (L is an integer of 2 or more) defined as the encoding setting . At that time, as shown in FIG. 6, the memory pointer may be arranged at a position 1/2 ^L of MaxLumaFS while fixing the already arranged pointer, as shown in FIG.

(Definition of frame size)
In the present embodiment, the frame size is expressed by the number of pixels pic_width of the horizontal width of the reproduced image and the number of pixels pic_height of the vertical width of the reproduced image, but a value indicating the frame size integrated in advance may be used. Also, the frame size may be calculated by other methods.

  In the present embodiment, the memory buffer amount MFSBuffer represented by the maximum number of reproduced images of the maximum image size MaxLumaFS and the size of MaxLumaFS that can be stored in the decoded image buffer (DPB) is defined as level information, but the level It is not limited to being sent as information. It may be added as information other than level information.

  In the present embodiment, FSBuffer and maxDPBsize are represented by the maximum number of storable reproduced images, but may be represented as an actual memory amount. In this case, the number of reproduced images may be calculated by dividing the memory amount by the frame size.

  In particular, according to the present invention, the maximum number of reproduced images that can be stored in the image buffer memory is determined based on the relationship between the image frame size and the maximum frame size defined as the encoding condition, so that the actual frame size is maximized. When the size is smaller than the frame size, there is an effect of reducing the waste of the frame memory and securing a memory area for a reference image that can further improve the coding efficiency.

  A moving picture predictive coding program and a moving picture predictive decoding program according to the present invention for causing a computer to function as the above-described moving picture predictive coding apparatus and moving picture predictive decoding apparatus are stored and provided as a program in a recording medium. . Examples of the recording medium include a recording medium such as a floppy (registered trademark) disk, a CD-ROM, a DVD, or a ROM, a semiconductor memory, and the like.

Specifically, the moving picture predictive coding program encodes an image by an input module for inputting a plurality of images constituting the moving picture, by any of intra prediction and inter prediction, and a target image frame. A code relating to information relating to the target image frame size, the maximum number of images that can be stored in the reproduction image, and the maximum frame size is generated by generating compressed image data including the size, the maximum number of images that can store the reproduction images, and the maximum frame size as encoding settings. An encoding module for encoding with encoded data, a decoding module for decoding compressed image data and restoring it to a reproduced image, and storing one or more reproduced images as a reference image used for encoding a subsequent image Image storage module and memory control module for controlling image buffer memory in the image storage module Comprising a Lumpur, a memory control module, when the frame size of the input image with respect to the maximum frame size of the image is 1/2 L ^(L is an integer of 1 or more) or less, it can be stored in the frame memory It is a moving picture predictive coding program characterized by determining the maximum number of reproduced pictures as 2 ^L times.

Similarly, the moving picture predictive coding program is coded on the plurality of images constituting the moving picture by either intra prediction or inter prediction, and the target image frame size, and the maximum number of reproduction images that can be stored. And an input module for inputting encoded data indicating compressed image data including information on the maximum frame size as the encoding setting, information on the compressed image data, the target image frame size, the maximum number of stored reproduced images, and the maximum frame size The decoding module decodes the compressed image data representing the image data into the reproduced image and the information on the target image frame size, the maximum number of images that can be stored and the maximum frame size, and the reproduced image decodes the subsequent image Image storage module for storing one or more reference images used for image Includes a memory control module that controls the module, a memory control module, the frame size is 1/2 L of the input image with respect to the maximum frame size of the image ^(L is an integer of 1 or more) in the case of times or less, It is a moving picture predictive coding program characterized by determining the maximum number of reproduced pictures that can be stored in a frame memory to be 2 ^L times.

  FIG. 7 is a diagram showing a hardware configuration of a computer for executing a program recorded in a recording medium, and FIG. 8 is a perspective view of the computer for executing a program stored in the recording medium. The computer includes a DVD player equipped with a CPU and performing processing and control by software, a set top box, a mobile phone, and the like.

  As shown in FIG. 7, the computer 30 includes a reader 12 such as a floppy (registered trademark) disk drive, a CD-ROM drive, and a DVD drive, and a working memory (RAM) 14 in which an operating system is made resident. , A memory 16 for storing a program stored in the recording medium 10, a display device 18 such as a display, a mouse 20 and a keyboard 22 as input devices, a communication device 24 for transmitting and receiving data, etc. And a CPU 26 for controlling the When the recording medium 10 is inserted into the reading device 12, the computer 30 can access the moving picture prediction encoding / decoding program stored in the recording medium 10 from the reading device 12, and the moving picture prediction encoding / decoding The program makes it possible to operate as a video encoding device / decoding device according to the present invention.

  As shown in FIG. 8, the moving picture predictive coding program or the moving picture decoding program may be provided via a network as a computer data signal 40 superimposed on a carrier wave. In this case, the computer 30 can store the moving picture predictive coding program or the moving picture decoding program received by the communication device 24 in the memory 16 and execute the moving picture predictive coding program or the moving picture predictive decoding program. .

  In order to achieve the above object, a moving picture predictive coding apparatus according to the present invention comprises: input means for inputting a plurality of images constituting a moving picture; and any of intra prediction and inter prediction of images. To generate compressed image data including information on the maximum frame size as the target image frame size, the maximum number of stored reproduced images, and the encoding setting, the target image frame size, the maximum number of stored reproduced images and Reference means used to encode the encoded image data with respect to information on the maximum frame size, to decode the compressed image data and to reconstruct the reproduced image, and to encode the subsequent image the reproduced image An image storage unit that stores one or more images as an image, and the frame size of the input image is 1/1 of the maximum frame size of the image. If times below, and determines the maximum number of storable reproduced image to twice in the frame memory.

  In this moving picture predictive coding apparatus, the image data is stored in the image buffer memory based on the relationship between the frame size attached to each image constituting the moving picture or compression-coded image data and the maximum frame size defined by the coding setting. The maximum number of possible playback images is determined. More specifically, for example, when the frame size of the input image is larger than 1/2 of the maximum frame size defined in the encoding setting, up to N reproduced images can be stored (N is an integer of 1 or more). If the frame size of the input image is equal to or less than half of the maximum frame size, the amount of memory buffer available for storing the reproduced image is controlled to be able to store a maximum of 2 × N reproduced images. When the frame size of the reproduced image decoded by this is 1/2 or less of the maximum frame size defined in the encoding setting, the maximum number of reproduced images that can be stored can be increased, and the reference image is increased. This makes it possible to improve the coding efficiency.

  Further, the moving picture predictive coding apparatus according to the present invention can calculate the maximum number of reproduced images that can be stored in the frame memory when the frame size of the input image is 1/4 or less of the maximum frame size of the image. It may be characterized in that it is determined four times.

  The moving picture prediction / decoding apparatus according to the present invention encodes a plurality of images constituting a moving picture by either intra-frame prediction or inter-frame prediction, and the maximum number of target image frame sizes and the number of reproduction images that can be stored. And input means for inputting encoded data indicating compressed image data including information on maximum frame size as encoding setting, information on compressed image data, target image frame size, maximum number of stored reproduced images, and maximum frame size Decoding means for decoding compressed image data representing the reproduced image, and information relating to the reproduced image and information on the target image frame size, the maximum number of images that can be stored and the maximum frame size, and the reproduced image Image storage means for storing one or more as a reference image used for image processing; If the frame size of the input image relative's is 1/2 times or less, and determines the maximum number of storable reproduced image to twice in the frame memory.

  This moving picture prediction / decoding apparatus can store in the image buffer memory based on the relationship between the frame size attached to each image constituting the moving picture or compression-coded image data and the maximum frame size defined by the encoding setting. The maximum number of reproduced images is determined. More specifically, for example, when the frame size of the input image is larger than 1/2 of the maximum frame size defined in the encoding setting, up to N reproduced images can be stored (N is an integer of 1 or more). If the frame size of the input image is equal to or less than half the maximum frame size, up to 2N reproduced images can be stored. When the frame size of the reproduced image decoded by this is 1/2 or less of the maximum frame size defined in the encoding setting, the maximum number of reproduced images that can be stored can be increased, and the reference image is increased. This makes it possible to improve the coding efficiency.

  Further, the moving picture prediction decoding apparatus according to the present invention is configured such that the maximum number of reproduced images that can be stored in the frame memory is 4 when the frame size of the input image is 1/4 or less of the maximum frame size of the image. It may be characterized in that it is determined by doubling.

  A moving picture predictive coding method according to the present invention is a moving picture predictive coding method executed by a moving picture predictive coding apparatus, and an input step of inputting a plurality of images constituting a moving picture, an image Is encoded by either intra-frame prediction or inter-frame prediction to generate compressed image data including information on the target image frame size, the maximum number of sheets that can store the reproduced image, and the maximum frame size as an encoding setting, An encoding step of encoding together with encoded data relating to information on a target image frame size, a maximum number of reproduced images that can be stored, and a maximum frame size; a decoding step of decoding compressed image data and restoring it to a reproduced image; An image store for storing by the image storage means one or more as a reference image used to encode a subsequent image And determining that the maximum number of reproduced images that can be stored in the frame memory is doubled if the frame size of the input image is 1/2 or less times the maximum frame size of the image. It features.

  Further, in the moving picture predictive coding method according to the present invention, when the frame size of the input image is 1⁄4 or less of the maximum frame size of the image, the maximum number of reproduced images that can be stored in the frame memory is obtained. It may be characterized in that it is determined four times.

  The moving picture prediction decoding method according to the present invention is a moving picture prediction decoding method executed by the moving picture prediction decoding apparatus, and it is possible to perform intra prediction or inter prediction with respect to a plurality of images constituting a moving image. An input step of inputting encoded data indicating compressed image data which is encoded by any of the target image frame size, the maximum number of sheets that can store the reproduced image, and information on the maximum frame size as an encoding setting; And the compressed image data indicating information on the target image frame size, the maximum number of stored reproduced images, and the maximum frame size, and the reproduced image, the target image frame size, the maximum number of stored reproduced images, and the maximum frame size And the reconstructed image is used to decode the subsequent image. Storing at least one image storing step of storing the image by the image storing means as the reference image, and storing the image in the frame memory when the frame size of the input image is 1/2 or less of the maximum frame size of the image The present invention is characterized in that the maximum number of possible reproduced images is determined twice.

  Further, according to the moving image predictive decoding method of the present invention, when the frame size of the input image is 1/4 or less of the maximum frame size of the image, the maximum number of reproduced images that can be stored in the frame memory is 4 It may be characterized in that it is determined by doubling.

  The moving picture predictive decoding method according to the present invention is characterized in that, when determining the maximum number of reproduced pictures that can be stored in the frame memory, the memory pointer indicating the storage position of the reproduced picture in the memory is fixed. You may do it.

  In this moving picture predictive decoding method, since the memory pointer indicating the storage position of each reproduced image can be fixed at, for example, the position corresponding to the maximum frame size and half thereof, variable memory pointer control according to the frame size It is possible to implement simpler and more efficient memory control without the need for In addition, also when calculating the position of the memory pointer, it is possible to execute by shift operation because it is limited to, for example, 1/2 change, and the operation cost is small.

  Further, the moving picture prediction decoding program according to the present invention can encode a plurality of images constituting the moving picture by either intra prediction or inter prediction and store the target image frame size and the reproduced image. Maximum number of sheets and input module for inputting encoded data indicating compressed image data including information on maximum frame size as encoding setting, compressed image data, target image frame size, maximum number of frames that can store reproduced image, and maximum frame size And a decoding module for decoding compressed image data indicating information related to the reproduced image, and information on a reproduced image and information on a target image frame size, a maximum number of reproduced images that can be stored, and a maximum frame size; An image storage module for storing one or more reference images used for decoding; Provided, when the frame size of the input image with respect to the maximum frame size of the image is 1/2 times or less, and determines the maximum number of storable reproduced image to twice in the frame memory.

  The moving picture prediction decoding method and the moving picture prediction decoding program can achieve the same effect as the above-described moving picture prediction decoding apparatus.

  Reference numeral 301: input terminal, 302: block divider, 303: prediction signal generator, 304: frame memory, 305: subtractor, 306: converter, 307: quantizer, 308: inverse quantizer, 309: inverse transform , 310: an adder, 311: an entropy encoder, 312: an output terminal, 313: an input terminal, 314: a frame memory manager, 401: an input terminal, 402: a data analyzer, 403: an inverse quantizer, 404 ... inverse converter, 405 ... adder, 406 ... output terminal, 407 ... frame memory, 408 ... prediction signal generator, 409 ... frame memory manager.

Claims (4)

A moving picture prediction decoding method performed by a moving picture prediction decoding apparatus, comprising:
Information on the maximum frame size is encoded as the target image frame size, the maximum number of images that can be stored in the reproduced image, and the encoding setting, with respect to a plurality of images constituting the moving image by either intra prediction or inter prediction. An input step of inputting encoded data indicating compressed image data to be included;
The compressed image data indicating the compressed image data, the target image frame size, the maximum number of reproduced images that can be stored, and information about the maximum frame size can be decoded, and the reproduced image, the target image frame size, and the reproduced image can be stored. A decoding step for restoring information on the maximum number of images and the maximum frame size;
An image storing step of storing the reproduced image by the image storing means one or more as a reference image used to decode a subsequent image;
The maximum number of reproduced images that can be stored in the frame memory is determined to be equal to, double or quadruple of a predetermined value based on the relationship between the maximum frame size of the image and the frame size of the input image. Moving picture predictive decoding method. When the frame size of the input image is 1/2 or less of the maximum frame size of the image, the maximum number of reproduced images that can be stored in the frame memory is determined to be twice the predetermined value. A moving picture predictive decoding method according to claim 1. The maximum number of reproduced images that can be stored in the frame memory is determined to be four times the predetermined value when the frame size of the input image is equal to or less than 1⁄4 of the maximum frame size of the image. A moving picture predictive decoding method according to claim 1. Information on the maximum frame size is encoded as the target image frame size, the maximum number of images that can be stored in the reproduced image, and the encoding setting, with respect to a plurality of images constituting the moving image by either intra prediction or inter prediction. Input means for inputting encoded data indicating compressed image data to be included;
The compressed image data indicating the compressed image data, the target image frame size, the maximum number of reproduced images that can be stored, and information about the maximum frame size can be decoded, and the reproduced image, the target image frame size, and the reproduced image can be stored. Decoding means for restoring information on the maximum number of images and the maximum frame size;
Image storage means for storing the reproduced image as one or more reference images used to decode subsequent images;
The maximum number of reproduced images that can be stored in the frame memory is determined to be equal to, double or quadruple of a predetermined value based on the relationship between the maximum frame size of the image and the frame size of the input image. Moving picture prediction decoding device.

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