CN1882097B

CN1882097B - Moving picture signal coding method, decoding method, coding apparatus, and decoding apparatus

Info

Publication number: CN1882097B
Application number: CN 200610099959
Authority: CN
Inventors: 铃木芳典
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2002-01-24
Filing date: 2003-01-24
Publication date: 2012-04-11
Anticipated expiration: 2023-01-24
Also published as: CN1882097A; CN1882100A; CN1856106A; CN1882098A; CN100493201C; CN100508616C; CN100508615C; CN100546385C; CN100493200C; CN1882095A; CN1882099A; CN100508614C; CN1882096A

Abstract

The invention relates to a moving picture signal coding method, decoding method, coding apparatus and decoding apparatus. Moving picture motion compensation coding/decoding predicts a motion vector in a coding block from a motion vector of the adjacent position and codes a differential motion vector calculated from the motion vector to be coded and its prediction motion vector. The coding is performed by switching the coding accuracy between a coding accuracy of the differential motion vector (1) and a coding accuracy of the prediction motion vector and the coding motion vector (2) for each block. Moreover, when decoding the motion vector from the differential motion vector coded by the aforementioned coding, a reversed processing with respect to the coding is performed.

Description

The coding method of moving image, coding/decoding method, code device and decoding device

The application is that application number is 200610084483.3, and the applying date is on January 24th, 2003, and denomination of invention is divided an application for " coding method of moving image, coding/decoding method, code device and decoding device ".

Technical field

The present invention relates to, the coding method of moving image, coding/decoding method, code device and decoding device particularly relate to the coding and the decoding technique of motion vector.

Background technology

The summary that the coding and decoding of moving image is handled describes.The coding of moving image generally is that the code device by Figure 13 carries out.Become 1 frame of the moving image of coded object, that kind as shown in Figure 3, by 1 luminance signal (Y-signal: 61) and 2 color difference signals (Cr:62, the Cb signal: 63) constitute, the image size of color difference signal all is 1/2 of luminance signal in length and breadth.In general video standard, each frame of moving image is divided into fritter, be that unit carries out reproduction processes with the piece that is called as macro block.

Above-mentioned macro block, that kind as shown in Figure 5 is by 1 Y-signal piece 30 of 16 * 16 pixels, spatially Cr block 31 and the Cb block 31 of 8 * 8 pixels consistent with it constitutes.The coding of picture signal is that unit handles with above-mentioned macro block.In coding, roughly be divided into intraframe coding (mode intra coding in the frame) and predictive coding (interframe mode inter coding).

In the code device of the picture signal of Figure 13, under the situation of intraframe coding, the input macroblock image 201 of coded object is divided into the DCT encoding block and directly carries out DCT203 by dct transform device 203, is transformed into the DCT coefficient.Each conversion coefficient is quantized by quantizer 204, is encoded by demultiplexing device 206.

The DCT coded block size is generally 8 * 8 pixels in coded system in the past, but in MPEG-4 Part10 (Advanced Video Coding) etc., has also discussed the dct transform that utilizes 4 * 4 pixel sizes recently.

That kind as shown in Figure 6, each macro block are divided into 24 4 * 4 block of pixels, are transformed into 16 DCT coefficients respectively by dct transform device 203.Its part of DCT coefficient that is quantized is decoded into the input macro block by inverse DCT of local decoder 220 207 and anti-DCT device 208, and is synthesized in the frame memory 210.Local decoder 220 process with after the same decoded picture of decoding device stated.Be stored in the prediction of the time orientation of stating after image in the frame memory 210 is used to.This intraframe coding is configured in the macro block (also comprising the 1st coded frame) of not similar with previous frame part, or desire is eliminated the part of the storage arithmetic eror of following DCT etc.

Under the situation of interframe (predictive coding) coding, input macroblock image 201 and be stored in the motion compensation process between the decoded picture (reference frame) of the coded frame in the frame memory 210 is undertaken by motion compensator 211.Motion compensation is meant from reference frame and retrieves and the part of the similar content of target macroblock (generally be the absolute value of selecting the predictive error signal in the piece with or square error and less part), and the compress technique of the time orientation that its amount of exercise (motion vector) is encoded.

The processing structure of motion compensation shown in Fig. 4.Fig. 4 is expression about the luminance signal piece 72 of the present frame 71 that surrounds with thick frame, the predict blocks 75 on the previous frame 73 (reference frame) and the figure of motion vector 76.Motion vector 76 expression spatially is equivalent to amount of movement (the motion vector length that color difference signal is used in predict blocks 75 zones of piece (dotted line) 74 to the present frame on the previous frame of same position from the thick frame piece for present frame; Be made as the half the of luminance signal, do not encode).Detected motion vector, and the motion vectors (predicting) that obtains from MV fallout predictor 215 from the motion vector of adjacent block between carried out encoding by demultiplexing device 206 after the difference processing.The predicted macroblock image 213 that extracts from previous frame through motion compensation, and carry out difference processing by difference engine 202 between the input macroblock image 201 of present frame, and generate the difference macroblock image.

The difference macroblock image, that kind as shown in Figure 6 is divided into 24 4 * 4 block of pixels, is transformed into 16 DCT coefficients respectively by dct transform device 203.Each DCT coefficient is quantized by quantizer 204, is encoded by demultiplexing device 206.Under the situation of interframe encode also be by the inverse DCT of local decoder 220 207 and anti-DCT device 208 with quantization DCT coefficient, be decoded into the difference macroblock image, undertaken being synthesized in the frame memory 210 after the addition by adder 209 and predicted macroblock image.In addition, the number of the motion vector that here will in 1 macro block, encode is made as 1, but generally is that macro block further is divided into fritter, each fritter is calculated motion vector carry out Methods for Coding.For example, in MPEG-4 Part10 (Advanced Video Coding), the macroblock partition type in the time of will carrying out motion compensation (brightness composition) is made as Fig. 7 and considers.Basically be 4 kinds of type 51～type 54.Type 54 is respectively to 48 * 8 54-0～54-3, further from 5 kinds of type 54a, 54b, 54c, 54d and intraframe codings, selects.

And then as the motion compensation process of predictive coding, the information that is divided into the frame that use passes by in time carries out the forward predictive coded of motion compensation and uses pass by the bi-directional predictive coding that carries out motion compensation with the information of the frame in future in time.In the motion compensation of above-mentioned forward predictive coded; Only carry out forward prediction; But in the motion compensation of alternating binary coding, except forward prediction, also handle back forecast, bi-directional predicted and utilize motion vector information in following in time frame from the two-way direct prediction of predicting.

The encoding precision of motion vector is generally handled integer pixel or the precision below it.For example, in the Advanced of MPEG-4 Part 2 Simple Profile, can select 1/2 pixel precision and 1/4 pixel precision to each bit data.Computational methods about integer-pel precision or the predicted value below it; Save explanation; In 1/2 pixel precision, adapt to the linear filter that ground uses 2 taps, in 1/4 pixel precision, adapt to ground and use 8 tap filters and 2 tap filters according to location of pixels according to location of pixels.In addition, in MPEG-4 Part 10, also discussed and come the expressive movement vector, used 6 tap filters and 2 tap filter calculations to go out predicted value with 1/4 pixel precision.Like this, through the filter that uses long tap number estimated performance is improved.

To be suitable for the frame that intraframe coding obtains to whole macro blocks and be called I-Picture, will be called P-Picture, will be called B-Picture by alternating binary coding or frame that intraframe coding constituted by forward predictive coded or frame that intraframe coding constituted.In P-Picture or B-Picture,, judge each macro block is carried out with which of predictive coding and intraframe coding, and encode by 206 pairs of result of determination 218 of demultiplexing device by the INTRA/INTER determinant 214 of Figure 13.

The decoding of the code signal of moving image is to carry out with the opposite step of coding.Generally be that decoding device by Figure 14 carries out.

Code is deciphered portion 501, and the coded data of being imported is analyzed, and motion vector related information and macro block type information are given MV fallout predictor 508, and quantization DCT coefficient information is given inverse DCT 502.At macro block (mb) type is under the situation of intraframe coding, in inverse DCT 502 and anti-DCT device 503, decoded quantization DCT coefficient information is carried out the anti-DCT of inverse quantization to each 4 * 4 block of pixels handle, and reproduces macroblock image.Prediction mode at macro block is under the situation of predictive coding, calculates decoding motion vectors by MV fallout predictor 508 from decoding differential motion vector and motion vectors, and is input to motion compensator 504.In motion compensator 504, extract the predicted macroblock image from the frame memory 507 of the decoded picture of storing previous frame according to amount of exercise.

Then, in inverse DCT 502 and anti-DCT device 503,, each 4 * 4 block of pixels is carried out the anti-DCT of inverse quantization handle, reproduce the difference macroblock image the coded data relevant with predictive error signal.Then, carry out addition by 505 pairs of predicted macroblock images of adder and difference macroblock image and handle, reproduce macroblock image.The macroblock image of being reproduced synthesizes the decoded frame image by synthesizer 506.In addition, the decoded frame image is that the prediction of next frame is with being stored in the frame memory 507.

As the document related, the open communique (the Japan Patent Publication Laid-Open is put down the 11-46364 communique) of patent is arranged with the present invention.In this document, recording, being that unit carries out preparing several motion vector precision in the coding-decoding method of the moving image that coding and decoding handles with the piece, is the means of the encoding precision of unit motion switch vector with a plurality of pieces that bind together.

In the motion compensation encoding of known moving image in the past, to have discussed and prepared the multiple motion vector number in the piece that is included in, the encoding precision of motion vector is the such high coded system of 1/8 pixel precision.But, because the relation of the size of code of motion vector even in piece, comprise under the situation of a plurality of motions, also has selection to carry out the tendency of Methods for Coding with few motion vector number.In addition, generate at the filter that uses long tap number under the situation of integer-pel precision or the predict pixel below it, just produce for generate 1 predict blocks used become the problem of big such storage access with reference to the pixel count in the image.This problem particularly just becomes problem when carrying out motion compensation.

Thereby the object of the invention just provides, and can cut down the size of code of motion vector and can cut down coding method, coding/decoding method, code device and the decoding device that is increased the motion image signal of the prediction error information that causes by the piece number in the encoding block.

Other purposes of the present invention are exactly, in code device and decoding device, and storage access scope when reducing motion compensation.

Summary of the invention

The present invention provides a kind of coding method of moving image, has following steps,

Image segmentation is become a plurality of encoding blocks; Come the motion vector of predictive coding piece through motion vector from adjacent block; Wherein with the motion vector of this adjacent block as motion vectors; With the piece is that unit encodes to the differential motion vector that is calculated by the motion vector that should encode and motion vectors thereof, wherein adds that through the motion vector in this adjacent block differential motion vector is used as the motion vector of encoding block

It is characterized in that: this method also has following steps,

Prepare the precision of several differential motion vector,, and the information of selected precision and the differential motion vector of this precision encoded the precision of the selected differential motion vector of each encoding block.

It is characterized in that: this method also has following steps,

Prepare the precision of several motion vectors; To the precision of the selected motion vector of each encoding block, and encode to the information of above-mentioned selected precision and by the differential motion vector that the motion vector computation of motion vectors that is modified to above-mentioned selected precision and selected precision goes out.

The present invention provides a kind of coding/decoding method of moving image, has following steps,

Image segmentation is become a plurality of decoding blocks, comes the motion vector of prediction decoding piece, calculate decoding motion vectors by decoding differential motion vector and motion vectors from the decoding motion vectors of adjacent block,

It is characterized in that: this method also has following steps,

Prepare the precision of several differential motion vector; To the precision information of each decoding block decoding differential motion vector and the differential motion vector of this precision; After the precision of the differential motion vector of will decoding is modified to the precision identical with motion vectors, the motion vector that calculates decoding block from the decoding differential motion vector of carrying out the precision correction and motion vectors.

It is characterized in that: also have following steps:

Prepare the precision of several motion vectors; To the precision information of each decoding block decoding motion vectors and the differential motion vector of this precision; After the precision with motion vectors is modified to the precision identical with decode precision information, calculate the motion vector of decoding block from decoding differential motion vector and the motion vectors of having carried out the precision correction.

In order to achieve the above object; The present invention provides a kind of coding method of moving image; Comprising image segmentation is become a plurality of encoding blocks, come the motion vector in the predictive coding piece from the motion vector of adjoining position, is the step that unit encodes to the differential motion vector that is calculated by the motion vector that should encode and motion vectors thereof with the piece; Motion vector is encoded; Have: the precision of several differential motion vector is prepared in (1), to the precision of the selected differential motion vector of each encoding block, and the step that the differential motion vector of the information of selected precision and this precision is encoded; Perhaps the precision of several motion vectors is prepared in (2); Precision to the selected motion vector of each encoding block; And to the information of selected precision, and the step of encoding by the differential motion vector that the motion vector computation of motion vectors that is modified to selected precision and selected precision goes out.

Here; In the situation of above-mentioned (1) and (2), comprise the decision and the encoding process of the accuracy value (below abbreviate the mv_shift value as) of the coding of following differential motion vector, except in whole macro blocks, carrying out; The type of also utilizing macro block (for example; The size of the number of encoding motion vector) or situation on every side (for example), omit the situation of coding of the mv_shift value of specific macroblock in abutting connection with the situation of macro block.

The situation of above-mentioned (2) also can be distributed different precision on the horizontal composition of motion vector and vertical composition, for each composition the differential vector that the motion vector computation from the precision of being distributed goes out is encoded.

The code utilize moving image encoding of the present invention is used in the decoding of moving image of the present invention, through with the opposite step of step of coding, carry out the reconstruction of image of encoding block.Promptly; Prepare the precision of a plurality of motion vectors; On the horizontal composition of motion vector and vertical composition, distribute different precision, each composition is modified to this precision that is assigned with, and the differential motion vector that the motion vector computation from this corrections motion vectors and the precision of being distributed goes out is encoded.

And then, under the situation of decoding, the setting of mv_shift value, the processing procedure that the code of corresponding decoding is encoded is carried out.For example, when the code that the mv_shift value is not encoded under the type of macro block or the situation on every side in coding was reproduced, the mv_shift value is made decision, handled to the type of decoded macroblock or situation on every side.

The explanation of the embodiment of the structure of the object of the invention, characteristic, code device and decoding device through following following accompanying drawing will further obtain clearly.

Description of drawings

Fig. 1 is the figure of example of the data syntax of expression forward predicted frame.

Fig. 2 is the figure of example of the data syntax of expression bi-directional predicted frames.

Fig. 3 is the figure of explanation macroblock partition.

Fig. 4 is the figure of the principle of account for motion compensation.

Fig. 5 is illustrated in being included in the block structured figure that is utilized when encoding that has or not of meaningful DCT coefficient in the macro block.

Fig. 6 illustrates expression to carry out that DCT handles and the figure of the macroblock structure of the block unit of encoding process.

Fig. 7 illustrates the figure of structure of luminance block that the block unit of motion compensation is carried out in expression.

Fig. 8 is the figure of the generation of explanation motion vectors.

Fig. 9 is the figure of example of the code table of expression motion vector precision.

Figure 10 is the figure of the Forecasting Methodology of account for motion vector accuracy.

Figure 11 representes that the code table and 8 * 8 of the macro block (mb) type among the P-Picture according to an embodiment of the invention divides the figure of the code table of types.

Figure 12 representes that the code table and 8 * 8 of the macro block (mb) type among the B-Picture according to an embodiment of the invention divides the figure of the code table of types.

Figure 13 is the block diagram of the general structure of expression dynamic image encoding device.

Figure 14 is the block diagram of the general structure of this moving image decoding apparatus of expression.

Figure 15 is the figure of example of the code table of the macro block (mb) type of explanation in the previous methods.

Figure 16 is the figure of the configuration example of expression versatility code table.

Figure 17 is the figure of configuration example of the macro block of the frame structure in the representative domain signal.

Figure 18 is the flow chart of processing that comes the encoding precision of motion switch vector by block size.

Figure 19 is by the assign to flow chart of processing of encoding precision of motion switch vector of the one-tenth of the motion vector in the embodiments of the invention.

Figure 20 is the flow chart of processing that comes the encoding precision of motion switch vector by the composition of the motion vector in the embodiments of the invention and macroblock structure.

Figure 21 is the flow chart of processing that comes the encoding precision of motion switch vector by the composition of the block size in the embodiments of the invention, motion vector and macroblock structure.

Figure 22 is other example of flow chart of processing that comes the encoding precision of motion switch vector by the composition of the block size in the embodiments of the invention, motion vector and macroblock structure.

Figure 23 is the example by the flow chart of the processing of the encoding precision of the motion switch vector that becomes to assign to of block size in the embodiments of the invention and motion vector.

Figure 24 is other example by the flow chart of the processing of the encoding precision of the motion switch vector that becomes to assign to of block size in the embodiments of the invention and motion vector.

Figure 25 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 26 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 27 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 28 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 29 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 30 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 31 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 32 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 33 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 34 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 35 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 36 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 37 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 38 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 39 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 40 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 41 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 42 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 43 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 44 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 45 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 46 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Figure 47 is the structure chart according to the embodiment of the encoding section of the motion vector of dynamic image encoding device of the present invention.

Figure 48 is the structure chart according to the embodiment of the lsb decoder of the motion vector of moving image decoding apparatus of the present invention.

Embodiment

Before the explanation embodiments of the invention,, the data syntax of the code data created by the demultiplexing device of code device is described for the understanding that makes following explanation is easy.

Fig. 1 representes the part of the data syntax of P-Picture, and Fig. 2 representes the part (owing to identical Therefore, omited with Fig. 1 after the CBP15) of the data syntax of B-Picture.In addition, establish data (motion vector precision information) 13 here, do not appear in the data syntax and describe.In addition, about I-Picture, owing to be not included in Therefore, omited explanation in the characteristic of the present invention.

In picture header10, comprise the data relevant such as image size, the reproduction moment with the information reproduction of frame.Picture type11 is a frame type information, and the kind of I-Picture, P-Picture, B-Picture is encoded at this.From MB type12 to Tcoeff chroma17 to each macro block data, undertaken repeatedly by the macroblock number in the frame.In MB type12, from the table 95 (P-Picture) of Figure 15 or the macro block mode shown in the table 96 (B-Picture), select a mode to encode to each macro block.

The SKIP mode means, isolates the macroblock image that spatially is equivalent to same position from the decoded picture of previous frame and copies.Block sizes when M, the N of the IntraM * N in the table representes to carry out spatial prediction.Little block unit when M * N representes to carry out motion compensation, the mode 1～mode 4 of corresponding diagram 7 respectively.

Direct means direct prediction.Blcok1 and Block2, the mode 2 of identification Fig. 7 or 2 fritters in the mode 3, which of Forward (forward prediction), Backward (back forecast), Bi-directional (bi-directional predicted) be the prediction direction of representing each fritter be.About in MB type12, having selected the macro block of 8 * 8 (split), then 8 * 8Partition18 produces.In macro block mode in addition, then 8 * 8Partition18 does not produce.In 8 * 8Partition18, from 8 * 8 dividing mode shown in the table 94 (B-Picture) of the table 92 (P-Picture) of Figure 11 or Figure 12 each 8 * 8 is divided and select a mode, encode.Intra representation space prediction in the table.Little block unit when M * N representes to carry out motion compensation, the division 1～division 4 of corresponding diagram 7 respectively.Direct means direct prediction.

Prediction representes that which of Forward (forward prediction), Backward (back forecast), Bi-directional (bi-directional predicted) be the prediction direction of each fritter be.MVD14 representes the coded data of the differential motion vector among the P-Picture.Thereby, be under the situation of IntraM * N at MB type12, then these data do not produce.At MB type12 is under the situation of M * N, and MVD14 encodes by the vector number shown in MB type and the 8 * 8Partition repeatedly.For example, under 16 * 8 situation, the differential motion vector number that should encode is 2, and each motion vector is made up of level, 2 vertical compositions, and 4 MVD are encoded continuously.MVDFW23 and MVDBW24 represent the coded data of the differential motion vector among the B-Picture.MVDFW23 produces under the situation of the macro block that comprises the motion vector of following the forward prediction shown in MB type12 and the 8 * 8Partition 18 (also comprising bi-directional predicted).Equally, MVDBW24 produces under the situation of the macro block that comprises the motion vector of following the back forecast shown in MB type12 and the 8 * 8Partition 18 (also comprising bi-directional predicted).Thereby, be under the situation of IntraM * N or Direct at MB type12, then these data do not produce.At MB type12 is M * N; Follow under the situation that the motion vector of forward prediction (also comprising bi-directional predicted) exists; MVDFW23 is by following the vector number of (also comprising bi-directional predicted) of the forward prediction shown in MB type and the 8 * 8Partition (differential motion vector number * 2, horizontal vertical power) to encode repeatedly.Equally; At MB type12 is M * N; Follow under the situation that the motion vector of back forecast (also comprising bi-directional predicted) exists; MVDBW24 is by following the vector number of (also comprising bi-directional predicted) of the forward prediction shown in MB type and the 8 * 8Partition (differential motion vector number * 2, horizontal vertical power) to encode repeatedly.

CBP15 is expression, and about 24 DCT pieces shown in Figure 6, whether the quantization DCT coefficient (meaningful coefficient) beyond 0 is included in 16 coded datas in the coefficient.But, because if about 24 each DCT pieces respectively to meaningful coefficient have or not information to encode then additional information will increase, so here, that kind as shown in Figure 6 is that unit encoded to having or not of meaningful coefficient to have gathered 8 * 8 of 4 DCT pieces.

Tcoeff luma16 representes the coded data of the quantization DCT coefficient in the luminance block 40.Coding is from 4 * 4 40-0 to 4 * 4 40-15, respectively 16 quantization parameters is encoded by the little order of numbering.But about represented not have 8 * 8 of meaningful coefficient by CBP, encoding process just is omitted.

Tcoeff chroma17 representes the coded data of the quantization DCT coefficient in the luminance block 40.Coding is respectively 16 quantization parameters to be encoded by the order of 4 * 4 41-0,41-2,41-3,42-0,42-1,42-3.But about represented not have the signal component of meaningful coefficient by CBP15, encoding process just is omitted.

Coding method about the coded data of macroblock level illustrated in figures 1 and 2; Consider only to use the Universal VLC (UVLC) of a kind of variable-length codes table, the coding method of having made up fixed-length code (FLC) and variable length code (preparing the code table different) and arithmetic coding (for example, with reference to non-patent literature 1) etc. to each coding elements.The structure of the table 83 expression UVLC of Figure 16, the value of Xn is " 0 " perhaps " 1 ".The example of the variable-length codes table of expression reality in table 84.As the concrete grammar of arithmetic coding, consider everybody to be carried out Methods for Coding according to the occurrence Probability Model of each generation probability of 0 and 1 of expression with the connotation of each code of binary data displacement of number bit.The method is called as CABAC (Context-basedAdaptive Binary Arithmetic Coding) (Witten et al.; " ArithmeticCoding for Data Compression ", Comm.of the ACM, 30 (6); 1987, pp.520-541).

The present invention particularly has characteristic on the encoding section/lsb decoder of motion vector.That is, on by the structure of the MV portion 508 of the decoding device of MV prediction section 215, dynamic compensating unit 211 and Figure 14 of the code device of the processing of the data M VD grammer MVD precision13 portion of Fig. 1 and Fig. 2, Figure 13, dynamic compensating unit 504 and information processing method, has characteristic.The structure of other parts and signal processing method are substantially identical with in the past device, method, and the embodiment in the face of characteristic of the present invention describes down.

< embodiment 1 >

Present embodiment is the encoding section at motion vector; Image segmentation is become a plurality of encoding blocks; Predict the picture signal of above-mentioned encoding block and the motion vector in the above-mentioned encoding block from the motion vector of adjoining position; Be in unit the moving image encoding that the differential motion vector that is calculated by the motion vector that should encode and motion vectors thereof the is encoded motion compensation encoding of moving image (below abbreviate as) with the piece; Prepare the precision of several differential motion vector,, and the information of selected precision and the differential motion vector of this precision information carried out Methods for Coding the precision of the selected differential motion vector of each decoding block.

At first, use Fig. 8 that the generation of above-mentioned motion vectors is described.Here, the fritter of establishing the object that motion vector is encoded is 50.In fritter 50, respectively to the horizontal vertical composition of motion vector, 3 the motion vector that will be positioned at adjoining position A, B, C calculates its median as candidate, and the motion vector of median is made as motion vectors.But the piece of position C perhaps is positioned under the situation outside the image for the preceding situation of coding in the relation of coded sequence and macro block position, and the motion vector that the position of substitution C will be positioned at the piece of position D uses as one of candidate motion vector.In addition, do not have under the situation of motion vector, its motion vector is made as 0 vector carries out prediction processing at the piece of position A, B, C, D.At this moment, under the situation that 2 do not have a motion vector among 3 candidate pieces, a remaining candidate motion vector is made as motion vectors.Above-mentioned Forecasting Methodology to the piece 51-0 of the mode 1 (51) of Fig. 7, fritter 54a-0,54b-0,54b-1,54c-0,54c-2 and the 54d-0～54d-3 of mode 4 (54), is used identical Forecasting Methodology.

About 2 fritters (52-0,52-1) of mode 2 (52), 2 fritters (53-0,53-1) of mode 3 (53), the motion vector that will be positioned at the piece at arrow root place shown in Figure 8 is made as predicted value.In addition, in arbitrary mode, the motion vector that the aberration composition is used is not encoded, and the motion vector of brightness composition is used divided by 2 grades.

In present embodiment 1, the candidate of at first establishing the precision of differential motion vector is 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision.Be set as the value after 4 times if establish MV for the motion vector composition that 1/4 pixel precision is expressed; If PWV is set as the value after 4 times for the motion vectors composition that 1/4 pixel precision is expressed; Then in this expresses, as following, limit for the value of the MV that is equipped with the precision candidate.

1 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 4 multiple.

1/2 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 2 multiple.

1/4 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 1 multiple.

Thereby, for the effect that makes this mode is reflected in coding characteristic in motion vector is inferred, prepare the absolute value of predictive error signal or square error with on added the impact assessment function of the size of code of motion vector.At this moment; Each precision of (MV-PMV) is calculated the optimum evaluation of estimate of each fritter; The motion vector of the whole fritters in macro block infer handle be through with after; Through the addition value to the mean value of each accuracy computation fritter, the precision decision that the summation of mean value is less is the precision of differential motion vector.The differential motion vector MVD that encodes calculates with formula (1).

MVD＝(MV-PMV)＞＞mv_shift......(1)

Mv_shift in the formula (1) is the value shown in the table 81 of Fig. 9.Formula (1) expression will deduct the value behind the motion vectors composition PMV from motion vector composition MV, and the value of having carried out to the right behind the arithmetic shift position by the number shown in the mv_shift is differential motion vector composition MVD.Here, deduct value that motion vectors composition PMV obtains from motion vector composition MV and be 1＜＜multiple of mv_shift, carried out the value that differential motion vector composition MVD that the right bit shift of arithmetic handles just becomes 1 multiple.

At Picture type is under the situation of P-Picture, and mv_shift is as the coded data key element shown in the data M VD precision13 of Fig. 1, and MVD is encoded as the coding elements shown in the data M VD14.At Picture type is under the situation of B-Picture; Mv_shift is as the coded data key element shown in the data M VD precision13 of Fig. 2, and MVD will usually encode as the coded data shown in data M VDFW23 (being under the situation of differential motion vector of forward prediction at MVD) or the data M VDBW24 (being under the situation of differential motion vector of back forecast at MVD).In addition, then be omitted in the macro block that the coded data that is coded in differential motion vector of MVD precision (MVD14 or MVDFW23 and MVDBW24) does not produce.Specifically; Be exactly P-Picture:MB type be IntraM * N perhaps; MB type is that 8 * 8partition of 4 fritters of 8 * 8 (split) all is the situation of Intra; B-Picture:MB type is the situation of IntraM * N or Direct, and then MB type is that 8 * 8 partition of 4 fritters of 8 * 8 (split) all are the situation of Intra or Direct.

Such shown in example in the past, adopt UVLC or arithmetic coding etc. as coding method.Mode shown in the table 81 of Fig. 9 is to have used the example of the coded system under the UVLC situation.Under the situation of arithmetic coding, the generation value of the motion vectors of the MB that for example encodes (7C of Figure 10) is encoded according to the urgent MB of keeping left (7A of Figure 10) with near the generation probability tables that the mv_shift value of last MB (7B of Figure 10) calculates.

In the decoding side, from decoding mv_shift value and decoding MVD and PMV, according to following formula,

MV＝(MVD＜＜mv_shift)+PMV......(2)

Carry out the decoding of each motion vector composition, promptly the MV value is reproduced (decoding).Formula (2) is illustrated in differential motion vector composition MVD has been carried out left adding that the value behind the motion vectors composition PMV becomes decoding motion vectors composition MV on the value behind the arithmetic shift position by the number shown in the mv_shift.Handle through this arithmetic left dislocation position, decoded differential motion vector composition MVD just from 1 multiple become 1＜＜multiple (corresponding to the MV-PMV of the side of encoding) of mv_shift.Through adding that on this value PMV decoding motion vectors composition MV just is recovered to the value of original precision.

Then, be that the situation that 1/8 pixel precision, 1/4 pixel precision, 1/2 pixel precision, 1 pixel precision are 4 kinds is narrated to the candidate of the precision of differential motion vector.Be set as the value after 8 times if establish MV for the motion vector composition that 1/8 pixel precision is expressed; If PWV is set as the value after 8 times for the motion vectors composition that 1/8 pixel precision is expressed; Then in this expresses, as following, limit for the value of the MV of each precision candidate.

1 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 8 multiple.

1/2 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 4 multiple.

1/4 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 2 multiple.

1/8 pixel precision: the value horizontal vertical composition of (MV-PMV) in the whole fritters in the macro block all is the MV of 1 multiple.

The method of inferring about motion, since identical with the situation of 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision, the Therefore, omited explanation.Differential motion vector MVD calculates with formula (1).Here, the value that deducts motion vectors composition PMV from motion vector composition MV is 1＜＜multiple of mv_shift, carried out the value that differential motion vector composition MVD that the right bit shift of arithmetic handles just becomes 1 multiple, calculate with above-mentioned formula (1).Mv_shift in the formula (1) is the value shown in the table 82 of Fig. 9.

Coding method about mv_shift and MVD; Because with the candidate of the precision of differential motion vector is that the situation of 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision is identical; Therefore, omited explanation has used code under the UVLC situation just according to table 82 rather than table 81.

The processing of decoding side is that the situation of 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision is identical with the candidate of the precision of differential motion vector also; From decoding mv_shft value and decoding MVD and PMV; According to above-mentioned formula (2), the decoding MV value of each motion vector composition is reproduced.Formula (2) is illustrated in differential motion vector composition MVD has been carried out left by the number shown in the mv_shift adding that the value of motion vectors composition PMV becomes decoding motion vectors composition MV on the value of arithmetic shift position.Handle through this arithmetic left dislocation position, decoded differential motion vector composition MVD just from 1 multiple become 1＜＜multiple (corresponding to the MV-PMV of the side of encoding) of mv_shift.Through adding that on this value PMV decoding motion vectors composition MV just is recovered to the value of original precision.

< embodiment 2 >

Present embodiment 2 is in the motion compensation encoding of moving image; Prepare the precision of multiple motion vector; Precision to the selected motion vector of each macro block; To selected precision information, and carry out Methods for Coding by the motion vectors that is modified to this precision of having selected and the differential motion vector that the encoding motion vector that is modified to this precision of having selected calculates.

The candidate of at first, establishing the precision of motion vectors and encoding motion vector is 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision.Be set as the value after 4 times if establish MV for the motion vector composition that 1/4 pixel precision is expressed; If PWV is set as the value after 4 times for the motion vectors composition that 1/4 pixel precision is expressed; Then in this expresses, as following, limit for the value of the MV of each precision candidate.

1 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 4 multiple.

1/2 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 2 multiple.

1/4 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 1 multiple.

Thereby, for the effect that makes this mode is reflected in coding characteristic in motion vector is inferred, prepare the absolute value of predictive error signal or square error with on added the impact assessment function of the size of code of motion vector.At this moment; Each precision of MV is calculated the optimum evaluation of estimate of each fritter; The motion vector of the whole fritters in macro block infer handle be through with after; Through the addition value to the mean value of each accuracy computation fritter, precision decision that just can the summation of mean value is less is the precision of differential motion vector.The differential motion vector MVD that encodes calculates with formula (3).

MVD＝(MV-((PMV＞＞mv_shift)＜＜mv_shift))＞＞mv_shift......(3)

Mv_shift in the formula (3) is the value shown in the table 81 of Fig. 9.Formula (3) expression is to deducting from motion vector composition MV; Motion vectors composition PMV has been carried out the value behind the arithmetic shift position to the right behind the arithmetic shift position at once left by the number shown in the mv_shift, and the value of further having implemented the right bit shift of the 2nd arithmetic by the number shown in the mv_shift becomes differential motion vector composition MVD.Here, handle and handle the left dislocation position for the continuous right bit shift of motion vectors composition, play that value with motion vectors composition PMV is identical with MV to be transformed into 1＜＜effect of the value of the multiple of mv_shift.In addition, handle through the right bit shift of the 2nd arithmetic, differential motion vector composition MVD just becomes the value of 1 multiple.

Like this, in the method for the precision of switching encoding motion vector, when motion is inferred, just need not consider the precision of PMV, but when the generation of MVD is handled, need carry out the precise decreasing of PMV motion vectors is arrived the processing of the precision of mv_shift.But formula (3) just can be cut down the computing step number through as following, simplifying.When the realization of circuit design etc. just effectively.In this formula, implement difference processing after motion vector composition MV and motion vectors composition PMV being transformed into the value of 1 multiple." will be transformed into predictive vector composition behind 1 the multiple be set as 1＜＜mv_shift value doubly " with following formula in " be transformed into 1＜＜the motion vectors composition of mv_shift value doubly " be equal to; In addition since motion vector composition MV be 1＜＜multiple of mv_shift, so the disappearance of the information that following formula caused of use just can not take place.

MVD＝(MV＞＞mv_shift)-(PMV＞＞mv_shift)......(4)

About distribution and the coding method of the data syntax of mv_shift and MVD to Fig. 1 and Fig. 2 since with the method identical Therefore, omited explanation of the precision of switched differential motion vector.

MV＝(MVD＜＜mv_shift)+((PMV＞＞mv_shift)＜＜mv_shift)......(5)

Decoding MV value to each motion vector composition is reproduced.This formula (5) expression; On the back value of differential motion vector composition MVD having been carried out the arithmetic shift position by the number shown in the mv_shift left, add, motion vectors composition PMV is become decoding motion vectors composition MV by the value that the number shown in the mv_shift has carried out behind the arithmetic shift position behind the arithmetic shift position at once to the right left.Here; Handle and the processing of left dislocation position for the continuous right bit shift of motion vectors composition; With differential motion vector composition MVD is carried out the processing of arithmetic shift position left by the number shown in the mv_shift, play that each composition is transformed into 1＜＜effect of the value of the multiple of mv_shift.Thereby that decoding motion vectors composition MV just becomes is original 1＜＜multiple of mv_shift.In addition, formula (5) just can be cut down the computing step number through as following, simplifying.When the realization of circuit design etc. just effectively.In formula (5), expression is to the value of the decoded differential motion vector DMV of addition on the motion vectors composition PMV of the value that is transformed into 1 multiple, and the value of having implemented left arithmetic shift position by the number shown in the mv_shift becomes decoding motion vectors composition MV.In " the predictive vector composition that will be transformed into 1 multiple be set as 1＜＜mv_shift value doubly " and the following formula " be transformed into 1＜＜the motion vectors composition of mv_shift multiple " be equal to; In addition because differential motion vector components D MV is 1 multiple, so the disappearance of the information that the following formula of use (6) is caused just can not take place.

MV＝(MVD+(PMV＞＞mv_shift))＜＜mv_shift......(6)

1 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 8 multiple.

1/2 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 4 multiple.

1/4 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 2 multiple.

1/8 pixel precision: the value horizontal vertical composition of the MV in the whole fritters in the macro block all is the MV of 1 multiple.

The method of inferring about motion, since identical with the situation of 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision, the Therefore, omited explanation.The differential motion vector MVD that encodes calculates with following formula.

MVD＝(MV-((PMV＞＞mv_shift)＜＜mv_shift))＞＞mv_shift......(3)

Mv_shift in the formula is the value shown in the table 82 of Fig. 9.This formulate is to deducting from motion vector composition MV; Motion vectors composition PMV has been carried out the value behind the arithmetic shift position to the right behind the arithmetic shift position at once left by the number shown in the mv_shift, and the value of further having implemented behind the right bit shift of the 2nd arithmetic by the number shown in the mv_shift becomes differential motion vector composition MVD.Here, handle and handle the left dislocation position for the continuous right bit shift of motion vectors composition, play that value with motion vectors composition PMV is identical with MV to be transformed into 1＜＜effect of the value of the multiple of mv_shift.

In addition, handle through the right bit shift of the 2nd arithmetic, differential motion vector composition MVD just becomes the value of 1 multiple.

Coding method about mv_shift and MVD; Because with the candidate of the precision of differential motion vector is that the situation of 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision is identical; Therefore, omited explanation has used code under the UVLC situation just according to table 82 rather than table 81.But following formula just can be cut down the computing step number through as following, simplifying.When the realization of circuit design etc. just effectively.In this formula, implement difference processing after motion vector composition MV and motion vectors composition PMV being transformed into the value of 1 multiple.In " the predictive vector composition that will be transformed into 1 multiple be set as 1＜＜mv_shift value doubly " and the following formula " be transformed into 1＜＜the motion vectors composition of the multiple of mv_shift " be equal to; In addition since motion vector composition MV be 1＜＜multiple of mv_shift, so the disappearance of the information that following formula caused of use just can not take place.

MVD＝(MV＞＞mv_shift)-(PMV＞＞mv_shift)......(4)

The processing of decoding side is that the situation of 3 kinds of 1/4 pixel precisions, 1/2 pixel precision, 1 pixel precision is identical with the candidate of the precision of differential motion vector also, from decoding mv_shift value and decode MVD and PMV, and according to following formula,

MV＝(MVD＜＜mv_shift)+((PMV＞＞mv_shift)＜＜mv_shift)......(5)

The decoding MV value of each motion vector composition is reproduced.This formulate; Add on the value after differential motion vector composition MVD has been carried out the arithmetic shift position left by the number shown in the mv_shift, motion vectors composition PMV is become decoding motion vectors composition MV by the value that the number shown in the mv_shift has carried out behind the arithmetic shift position behind the arithmetic shift position at once to the right left.Here; Handle and the processing of left dislocation position for the continuous right bit shift of motion vectors composition; With differential motion vector composition MVD is carried out the processing of arithmetic shift position left by the number shown in the mv_shift, play that each composition is transformed into 1＜＜effect of the value of the multiple of mv_shift.Thereby that decoding motion vectors composition MV just becomes is original 1＜＜multiple of mv_shift.In addition, this formula just can be cut down the computing step number through as following, simplifying.When the realization of circuit design etc. just effectively.In this formula; Expression is to the value behind the decoded differential motion vector DMV of addition on the motion vectors composition PMV of the value that is transformed into 1 multiple, and the value of having implemented behind the left arithmetic shift position by the number shown in the mv_shift becomes decoding motion vectors composition MV." being transformed into the motion vectors composition of mv_shift multiple " in " the predictive vector composition that will be transformed into 1 multiple be set as 1＜＜mv_shift value doubly " and the following formula is equal to; In addition because differential motion vector components D MV is 1 multiple, so the disappearance of the information that following formula caused of use just can not take place.

MV＝(MVD+(PMV＞＞mv_shift))＜＜mv_shift......(6)

If the foregoing

description

1 and 2 relatively, then because embodiment 1 is actually the precision of adjusting the differential motion vector of encoding, so the computing of comparing with embodiment 2 is simple.With respect to this,, just do not rely on predictive vector so supposed the exploration pixel under the situation of each precision because embodiment 2 is precision of the motion vector that should encode of adjustment.Thereby embodiment 1 is effective under the situation of only pursuing coding efficiency, but after in the storage access cutting method stated, embodiment 2 is effective.

< embodiment 3 >

Present embodiment 3 is the codings of not doing one's utmost to carry out the mv_shift value, and, prevents in the high zone of the selection rate of macro block the method that the size of code of mv_shift value increases according to coding method and coding/decoding method that block mode is predetermined.That is, in the few mode of the motion vector number of following macro block, carry out the coding and the decoding processing of differential motion vector with the default motion vector precision of defined in advance.Handle through this, just omit the coding and the decoding processing of motion vector precision information.

For example, set in coding side and decoding side so that in MB type is 16 * 16 macro block, encode and decoding processing, in the macro block of these modes, just omit the coding and decoding of precision information and handle with 1/4 pixel precision or 1/8 pixel precision.Here, it is 16 * 16 macro block that the mode of handling as the coding and decoding that omits precision information is only set MB type, but can further expand its object.For example, set in coding side and decoding side and make that be that 16 * 16,16 * 8 and 8 * 16 macro block is encoded and decoding processing also is effective with 1/4 pixel precision or 1/8 pixel precision to MB type.In addition; In P-Picture; It is 16 * 16 macro block that the mode of handling as the coding and decoding that omits precision information is only set MB type; In the many B-Picture of the motion vector number of encoding, can be used as also that mode that the coding and decoding that omits precision information handles sets until MB type is 16 * 16,16 * 8 and 8 * 16 macro block.

In addition, the default value of above-mentioned motion vector precision can be set in the scope of 0-3 (at 1/4MC type time be 0-2) with mv_shift equally, switches with bit stream unit or frame unit.At this moment, establish the code of default value, under the situation of bit stream unit, be included in the initial head portion of data, under the situation of frame unit, be included in the picture header data.In addition, under the situation of bit stream unit,, then need not be included in the coded data if determine in advance in coding side and decoding side.

And then through replacing table 95 and the table 96 of Figure 15, the macro block (mb) type of the mv_shift value shown in the table 93 of table 91 and Figure 12 of Figure 11, the additional information that just can cut down the coding of following the mv_shift value have been stipulated in preparation.In addition, when the mv_shift value was carried out arithmetic coding, the motion vector number that comprises through being based in the macro block adapted to ground and switches the used probabilistic model of coding, and code efficiency is improved.In addition,, the switching unit of mv_shift is made as macro block unit here, but also considers per 8 * 8 situation about switching.Such processing just can realize through the mode that per 8 * 8 modes and per 16 * 16 handled handle is set in MB_type.In addition, carry out switching way, and then per 8 * 8 pairs of 4 mv_shift values are carried out Methods for Coding and also can be realized through in table 81 or table 82, being provided with per 8 * 8.

In addition further, switch unit, also can in all frames, be set as fixing or in total sequence, be set as fixing as the selection of differential motion vector or motion vector precision.Unit is switched in the selection of fixed precision, will simplify coding/decoding and handle.Thereby, realize in the simple coding/decoding mode of cost having considered, be effective with the switching unit of frame unit or sequence unit fixed precision.

< embodiment 4 >

This form of implementation 4 is to judge the method for shift value uniquely from situation on every side.That is,, cut down the size of code of mv_shift value through from come the mv_shift value of predictive coding target macroblock in abutting connection with macro block.For example, the urgent macro block that keeps left (7A), the mv_shift value of coming predictive coding target macroblock (the macro block 7C of Figure 10) near the mv_shift value of last macro block (7B).Have from the addition value of the mv_shift value of 7A and 7B as Forecasting Methodology and to carry out forecast method.As the concrete means of utilizing; Having at addition value is 0; The MB type of 7C is under 16 * 16 the situation; Omit the coding of mv_shift value (MVD precison) and use perhaps 1/4 pixel precision of 1/8 pixel precision as setting, under the situation of the combination of in addition addition value and MB type, carry out the control device of the coding of mv_shift value the both sides of coding and decoding side.In addition, this concrete example is an example, and the combination that the situation the when kind of the kind in abutting connection with macro block that forecasting institute is used, Forecasting Methodology, the MB type that controls, control is distinguished kind etc. has multiple.For example, expand to the differential motion vector below 2 or 2 through the MB type that will control, perhaps the control point with addition value expands to below 2 or 2, and the reduction of the size of code of mv_shift value just increases.In addition, also have through the such method of the prediction of motion vector, its difference value is carried out Methods for Coding etc. from mv_shift value in abutting connection with the current MB of mv_shift value prediction of MB.

Such distortion below in the encoding precision switch means of the motion vector of the foregoing description, also comprising.

Although in the present embodiment, the candidate of establishing the encoding precision of motion vector is 1/8 pixel precision, 1/4 pixel precision, 1/2 pixel precision, 1 pixel precision, is not limited thereto.Situation about for example all comprising up to 1/16 pixel precision perhaps is made as the situation of 2 kinds of 1/2 pixel precisions, 1 pixel precision.

In addition, although in the above-described embodiments, be the coding that unit carries out the encoding precision information of motion vector with the macro block, the method to the encoding precision information of each motion switch vector of a plurality of macro block groups is also arranged.

And then; Although in the above-described embodiments; The partitioning scheme of the motion compensation block in the macro block is made as shown in Figure 74 kinds; But because the motion vector encoder method of this specification can be implemented even the kind of the partitioning scheme of motion compensation block and number change also, so the encoding block structure of motion vector does not limit.

In addition,, UVLC and arithmetic coding have been described as the coded system of coded data although in the above-described embodiments, the motion vector encoder method of this specification, the kind that can be not limited to entropy coding is implemented.In addition, the structural approach of the structure of the code table of UVLC and arithmetic encoding/decoding also is not limited to the table of embodiment.In addition and then, although in the present embodiment,, utilized the default value of mv_shift value about 16 * 16,16 * 8 and 8 * 16 modes, can this default value be applicable to the Partition mode of the part of 8 * 8 (split).In addition, although in an embodiment, that establishes the default value is set at bit stream unit or frame unit, also can distribute different values about each macro block unit.For example have in 16 * 16 modes the default value is set at 1, in 16 * 8 and 8 * 16 modes, the default value is set at 0 method.If briefly say; Then about macro block mode and 8 * 8 Partition modes; Stipulate the encoding precision of the differential motion vector (perhaps motion vector) of each self application with frame unit or sequence unit; Encode to transmit and get final product (under the situation of sequence unit,, then need not carry out the coding of precision information) if determine the encoding precision in the modes in coding side and decoding side in advance.As above-mentioned, unit is switched in the selection of regular coding precision, will simplify coding/decoding and handle.Through increasing the mode of regulation default value, realize that cost just further reduces.In the coding/decoding mode of the simpler structure of needs, for more mode, the switching unit of regular coding precision is effective.

Above to being illustrated according to the coding method of moving image of the present invention and the embodiment of coding/decoding method.Code device and decoding device according to moving image of the present invention; Code device about method Figure 13 of embodiment; At first in motion compensator 211, append, come the determination processing of the coding of ON/OFF mv_shift value, the motion of having considered the mv_shift value to infer processing, follow computing and the processing of the mv_shift value being passed to demultiplexing device 206 of MVD, MVDFW, the MVDBW of mv_shift according to the combination of MB type and 8 * 8 Partition.In addition, in demultiplexing device 206, append the processing that the mv_shift value is encoded as MVDprecision.Decoding device about Figure 14; Decipher in the device 501 to be provided with at code, append the handling part that comes the determination processing of the decoding of ON/OFF mv_shift value, MVD precision is carried out process of decoding as the mv_shift value and the mv_shift value passed to the processing of MV fallout predictor 508 according to the decode value of MB type and 8 * 8 Partition.In addition, in MV fallout predictor 508, be provided with, the MVD that follows mv_shift, MVDFW, MVDBW be rendered as the handling part of MV.

Figure 25, Figure 27, Figure 29, Figure 31, Figure 33, Figure 35, Figure 37, Figure 39 and Figure 41 are the block diagram of expression according to major part (encoding section of the motion vector) structure of the embodiment of the code device of moving image of the present invention.Figure 26, Figure 28, Figure 30, Figure 32, Figure 34, Figure 36, Figure 38, Figure 40 and Figure 42 represent to correspond respectively to Figure 25, Figure 27, Figure 29, Figure 31, Figure 33, Figure 35, Figure 37, Figure 39 and Figure 41 code device, according to the block diagram of major part (lsb decoder of the motion vector) structure of the embodiment of the code device of moving image of the present invention.

In each figure, to the additional same numbering of identical function piece in fact.Structure, the action of device of each figure, the explanation through the foregoing description 1 to embodiment 4 can easily realize, so corresponding with above-mentioned each embodiment only is shown, detailed explanation is omitted.

The device of Figure 25 and Figure 26 is made up of the formula (1) of carrying out embodiment 1 and the circuit of (2) respectively, and the decision of (mv_shift) value that is shifted is only imported (obtaining when the motion vector detection) according to the outside and controlled.MV prediction section 215 is utilized the memory 101 of the motion vector MV that has stored each piece, generation forecast motion vector PMV.Subtracter 102 is obtained their difference MV-PMV.103 couples of MV-PMV of dextroposition handling part carry out dextroposition.In the decoding side, because the contrary processing of the side of encoding, so the memory 101 of having stored motion vector MV, shift left handling part 113 and adder 112 are set.

The device of Figure 27 and Figure 28; Be made up of the formula (1) of carrying out embodiment 1 and the circuit of (2) respectively, the decision of (mv_shift) value that is shifted imports (obtaining when the motion vector detection) according to the outside and the some of conditions such as type of macro block determines, controls.Selected under the situation of specific block type in shift value selection portion 104, selected the mv_shift value, from mv_shift value, used corresponding to the mv_shift value of block type and handle dextroposition handling part 103 from this one by control circuit 105.

The device of Figure 29 and Figure 30 is made up of the separate equations (1) of carrying out embodiment 1 and the circuit of (2) respectively, and the decision of displacement (mv_shift) value only determines, controls according to the conditions such as type of macro block.

The device of Figure 31 and Figure 32 is made up of the formula (3) of carrying out embodiment 2 and the circuit of (5) respectively, and the decision of (mv_shift) value that is shifted is only imported (obtaining when the motion vector detection) according to the outside and controlled.Precision correcting process portion 106, carry out formula (3) (PMV＞＞mv_shift)＜＜processing of mv_shift.

The device of Figure 33 and Figure 34; Be made up of the formula (3) of carrying out embodiment 2 and the circuit of (5) respectively, the decision of (mv_shift) value that is shifted imports (obtaining when the motion vector detection) according to the outside and the some of conditions such as type of macro block determines, controls.

The device of Figure 35 and Figure 36 is made up of the formula (3) of carrying out embodiment 2 and the circuit of (5) respectively, and the decision of (mv_shift) value that is shifted only waits according to the type of macro block and controls.

The device of Figure 37 and Figure 38 is made up of the formula (4) of carrying out embodiment 2 and the circuit of (6) respectively, and the decision of (mv_shift) value that is shifted is only imported (obtaining when the motion vector detection) according to the outside and controlled.

The device of Figure 39 and Figure 40; Be made up of the formula (4) of carrying out embodiment 2 and the circuit of (6) respectively, the decision of (mv_shift) value that is shifted imports (obtaining when the motion vector detection) according to the outside and the some of conditions such as type of macro block determines, controls.

The device of Figure 41 and Figure 42 is made up of the separate equations (4) of carrying out embodiment 2 and the circuit of (6) respectively, and the decision of displacement (mv_shift) value determines, controls according to the some of conditions such as type of macro block.

< embodiment 5 >

Figure 18 is the process chart of the coding method of embodiment 5.

Present embodiment 5 is in order to solve the problem that in the motion compensation of the filter that has used long tap number storage access zone enlarges, and the coding-decoding method that the precision of encoding motion vector is switched.

The predicted value of using long filter to generate is pixel precision or the predict pixel below it.Thereby, be defined as integer pixel through encoding precision with motion vector, just can cut down the storage access zone.But, the encoding precision of motion vector is defined as integer pixel, estimated performance will be reduced.Therefore, in present embodiment 5, the expansion that accordings to the storage access scope realizes device or software realization effect, limits pixel precision.Particularly only under the less situation of the block size when motion compensation, the encoding precision of constrained motion vector.

The influence that the associative memory accessing zone enlarges, block size is more little just to become big more.The pixel count that the less piece of size carries out access originally is just few.For this reason, if piece that relatively size is bigger and little piece, then for the ratio of the expansion accessing zone of original access range, block size is more little then big more.

The code device method of present embodiment the piece of Fig. 7 being cut apart under the situation of the motion compensation of carrying out 1/4 pixel precision, as Figure 18, is at first carried out block size and is differentiated (handling 801), selects the mv_shift value.Under the situation of present embodiment; In 8 * 8 Partition2 (8 * 4) and 8 * 8 Partition3 (4 * 8), select 1/2 pixel precision (handling 811), among 8 * 8 Partition3 (4 * 4), select integer-pel precision (handling 812), in 8 * 8 pixels and size is bigger more than this piece selection 1/4 pixel precision (processing 813 of Figure 18), and drive dextroposition handling part 103 with selected mv_shift and carry out motion compensation.When the coding of motion vector, in the piece of 8 * 4 and 4 * 8 pixel sizes, establishing mv_shift is 1, and in the piece of 4 * 4 pixel sizes, establishing mv_shift is 2, and in the piece of in addition pixel size, establishing mv_shift is 0.

In addition, in the mode of using P-picture and B-picture, also can only be suitable for above-mentioned precision and switch, in P-picture, how all carry out motion compensation with 1/4 pixel precision regardless of block size to B-picture.In addition,, only will be made as 4 * 4, also can it be expanded to 8 * 4 and 4 * 8 with the block size that integer-pel precision is carried out motion compensation although here.In the case, in the piece of 8 * 4,4 * 8 and 4 * 4 pixel sizes, establishing mv_shift is 2, and in the piece of in addition pixel size, establishing mv_shift is 0.

According to the code device of the moving image of present embodiment and the encoding section and the lsb decoder of the motion vector in the decoding device, likewise constitute with above-mentioned Figure 41 and Figure 42 respectively.

< embodiment 6 >

Figure 19, Figure 45 and Figure 46 are respectively the coding method process chart of embodiments of the invention 6, the major part structure chart of code device and the major part structure chart of decoding device.

Present embodiment is also in order to solve the problem that in the motion compensation of the filter that has used long tap number storage access zone enlarges, and through with the different coding precision each composition of vertical-horizontal of motion vector being encoded, comes the limits storage access range.

The displacement selection portion 124 of code device as Figure 19, judges that whether motion vector is vertical composition (handling 801), and select mv_shift.Type adaptation portion 124 drives dextroposition handling part 103 with selected mv_shift and carries out motion compensation.In the present embodiment; Motion compensation through 1/4 pixel precision; The vertical one-tenth of motion vector is divided into integer-pel precision (handling 812); Level is become to be divided into 1/4 pixel precision (handling 813), and the mv_shift that establishes when vertical composition carried out coding/decoding is 2, and the mv_shift that establishes when horizontal composition carried out coding/decoding is 0.

It is very big that the encoding precision of the vertical composition of the motion vector that the influence to the storage access expanded range of present embodiment is bigger is carried out the limiting method effect.View data generally is that the order by raster scan is kept at the memory towards the bottom right from upper left.For this reason, under situation about beginning from certain pixel adjacent pixels expansion access range, 1 pixel of horizontal direction means 1 pixel degree, and 1 pixel of vertical direction then means 1 stroke degree.Thereby, follow number to the storage access of vertical direction, bigger than going back of horizontal direction.And then; Not to preserve with byte unit's (1 pixel) but with word unit's (per 2 pixels) or dword unit's (per 4 pixels) in the implementation method of pixel data of 1 pixel 1byte; Because expansion to the storage access scope of horizontal direction; Take place with word unit or dword unit, so its influence is not too big.With respect to this, even in the access of 1 pixel degree of vertical direction, the storage access scope also must enlarge.Thereby, the encoding precision of the motion vector of vertical direction is carried out limiting method, it is resultful dwindling such viewpoint with the storage access scope.

In addition, also the comprehensive method of embodiment 5 and embodiment 6 is carried out the processing as Figure 23.That is, displacement selection portion 124 only to the piece of 8 * 4,4 * 8 and 4 * 4 pixel sizes, is constrained to integer pixel with the vertical composition of motion vector.And then according to block size, the means of switching the vector composition that scope is limited also are effective.

As above-mentioned, the influence that the associative memory accessing zone enlarges, block size is more little then big more, and this also is said to the aspect rate of piece.Just, under the big or small in length and breadth ratio condition of different of piece, the influence that the composition access range that size is more little enlarges just becomes big more.If cut apart with the piece of Fig. 7 and to consider, then we can say to size to be that the composition of 4 pixels applies that to limit be effective.

< embodiment 7 >

Figure 24, Figure 43 and Figure 44 are respectively the coding method process chart of embodiments of the invention 7, the major part structure chart of code device and the major part structure chart of decoding device.

Present embodiment; The shift value selection portion 124 of code device (Figure 43), decoding device (Figure 44) is such shown in the process chart of Figure 24; When block size is 8 * 4 (vertical * horizontal stroke), level one-tenth is divided into integer-pel precision (mv_shift=2) and will vertically becomes to be divided into 1/4 pixel precision (mv_shift=0); When block size is 4 * 8 (vertical * horizontal stroke), level one-tenth is divided into 1/4 pixel precision (mv_shift=0) and will vertically becomes to be divided into integer-pel precision (mv_shift=2), when block size is 4 * 4 (vertical * horizontal stroke), the horizontal vertical composition all is made as integer-pel precision (mv_shift=2).In addition, from the viewpoint of estimated performance, also can replace the processing of the horizontal vertical composition of 8 * 4 and 4 * 8 modes.This results from the more little high more effective such notion of Forecasting Methodology of composition precision of size.Be to be suitable for which method, the necessity that then limits according to storage access, coding efficiency, bit rate etc. should be used for determining.

< embodiment 8 >

Figure 20, Figure 47 and Figure 48 are respectively the coding method process chart of embodiments of the invention 8, the major part structure chart of code device and the major part structure chart of decoding device.Present embodiment is in embodiment 7, is interlace signal at input picture, and macro block is under the situation of frame structure, the vertical composition of motion vector is constrained to the method for even pixel precision.

Figure 17 representes interlace signal to be carried out the macro block under the situation of coding/decoding with frame structure.The last solid line of figure means odd field (top field), and dotted line means even field (bottomfield).The motion vector that can be known odd number value by Figure 17 is, the even field from parametric image generates the predicted value on the odd field, and the odd field from parametric image generates the predicted value on the even field.In interlace signal, because odd field shows that with even field the moment is different, so in fact the vertical one-tenth resolute of odd number value does not produce.

Therefore, in the present embodiment, be interlace signal to input picture, macro block is the situation of frame structure, and the vertical composition of motion vector is constrained to the even pixel precision.In coding/decoding device, the mv_shift that establishes when vertical composition carried out coding/decoding is 3 (processing 803,814 of Figure 20), and the mv_shift that establishes when horizontal composition carried out coding/decoding is 0 (processing 813 of Figure 20).Even under the frame structure situation of this interlace signal; Also can be such shown in the flow chart of Figure 21 and Figure 22; Make up with the method for embodiment 7, only, the vertical composition of motion vector is constrained to integer pixel the piece (processing 801 of Figure 21) of 8 * 4,4 * 8 and 4 * 4 pixel sizes.And then, as the coded system of interlace signal, the accommodation mode to each macro block switch frame structure, a structure and frame structure and a structure is arranged, also can change the method for selecting of the encoding precision of motion vector according to this method.For example, in the coding specification of handling interlace signal and progressive signal, how all identical the coded system that the frame structure arranged regardless of signal scanning situation.In the case; Also can be in a frame structure and a structure; The piece less to size; The encoding precision of the motion vector of vertical direction is defined as integer-pel precision carries out coding/decoding (processing 812 of Figure 20 and Figure 21 and Figure 22), in each macro block switch frame structure and the accommodation mode of structure, the piece less to size; Encoding precision with the motion vector of vertical direction in frame structure is defined as even pixel precision (processing 814 of Figure 20 and Figure 21), is defined as integer-pel precision in the structure on the scene and carries out the such method of coding/decoding (processing 812 of Figure 20 and Figure 21).In addition; At this moment also can be in frame structure not the size of plumber block how all the encoding precision of the motion vector of vertical direction is defined as even pixel precision (processing 814 of Figure 22), in the structure on the scene the less piece of size is defined as integer-pel precision and carries out the such method of coding/decoding (processing 801 of Figure 22 with handle 812).

In the storage access scope reduction mode of embodiment 7 and 8, do not need the coding/decoding of mv_shift value to handle.Thereby, just do not need MVD Prediction13 and the Figure 11 among Fig. 1, Fig. 2, the mv_shift among Figure 12.In addition, in Figure 13, just need the mv_shift value not passed to the processing of demultiplexing device 206 from motion compensator 211.And then, in Figure 14, just need the mv_shift value not deciphered the processing that device 501 is passed to MV fallout predictor 508 from code.The mv_shift value is determined by MV fallout predictor 508 according to prediction mode.

In addition; The storage access scope reduction mode of present embodiment 8 is; The means that use is switched the precision of encoding motion vector and predictive coding motion vector " are defined as integer pixel according to block size with the encoding precision of motion vector "; " encoding precision of the vertical composition of motion vector is defined as integer pixel or even pixel "; Block size about the encoding precision of the kind of the motion vector encoder precision of the precision of motion compensation, preparation and motion switch vector is not limited to the foregoing description.In addition; Making in the motion compensation mode that the storage access scope reduces being defined as 1/2 pixel precision through the precision with motion vector, is not that motion vector is defined as integer-pel precision but the method that is defined as 1/2 pixel precision also can realize in enough the present invention.

The present invention is transmitting, in the storage, the device that shows moving image, system, need encoding image information become in the field on the industry of technology of digital signal of size of code still less to be able to utilize.

Claims

1. dynamic image decoding method has:

With image segmentation is a plurality of decoding blocks, comes the motion vector in the prediction decoding piece from the decoding motion vectors of adjoining position, calculates the step of decoding motion vectors by decoding differential motion vector and motion vectors,

It is characterized in that this dynamic image decoding method also comprises:

Prepare the precision of multiple motion vector; Horizontal composition to motion vector distributes different precision with vertical composition; Differential motion vector is decoded; Each composition of above-mentioned motion vectors is modified to the precision that is assigned with; By above-mentioned decoding differential motion vector with revise motion vectors and each composition of motion vector with the accuracy computation of being distributed, then each composition of this motion vector is transformed into the step of the precision of above-mentioned decoding motion vectors, wherein the height of the above-mentioned vertical composition of ratio of precision of above-mentioned horizontal composition.