KR20130050863A

KR20130050863A - Method and apparatus for video encoding with prediction and compensation using reference picture list, method and apparatus for video decoding with prediction and compensation using reference picture list

Info

Publication number: KR20130050863A
Application number: KR1020120037555A
Authority: KR
Inventors: 박영오; 정승수; 김찬열; 박정훈
Original assignee: 삼성전자주식회사
Priority date: 2011-11-08
Filing date: 2012-04-10
Publication date: 2013-05-16

Abstract

According to the present invention, a reference is assigned to an LC reference list for an LC reference list including L0 reference list which is list information of a reference picture for predictive encoding of an image having a B slice type and at least one reference picture included in the L1 reference list. A video prediction that sets a default number of pictures for each picture and predicts and encodes the picture using an LC reference list including one or more reference pictures among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number. The coding method is disclosed.

Description

Method and apparatus for video encoding with prediction and compensation using reference picture list, method and apparatus for video decoding with prediction and compensation using reference picture list}

The present invention relates to video encoding and decoding involving video prediction and video prediction.

Background of the Invention [0002] As the development and dissemination of hardware capable of playing back and storing high-resolution or high-definition video content increases the need for video codecs to effectively encode or decode high-definition or high-definition video content. According to the conventional video codec, video is encoded according to a limited encoding method based on a macroblock of a predetermined size.

The video codec reduces the amount of data by using a prediction technique by using a feature that images of a video are highly correlated with each other temporally or spatially. According to the prediction technique, in order to predict the current image using the surrounding image, image information is recorded using a temporal or spatial distance between the images, a prediction error, and the like.

In the video prediction encoding method according to an embodiment of the present invention, an LC reference list including L0 reference list which is list information of a reference image for prediction encoding of an image having a B slice type and one or more reference images included in the L1 reference list Setting, for each picture, LC default number information indicating a basic valid number of reference pictures allocated to the LC reference list for the picture; Determining the LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information; And predicting encoding the image of the B slice type using the determined LC reference list.

The setting of the LC default number information for each picture according to an embodiment may include assigning the LC default number information to the LC reference list based on reference list active number change confirmation information indicating whether the effective number of the reference image is randomly changed for each slice. And setting LC active number change confirmation information indicating whether the effective number of the reference image is randomly changed, and LC active number information indicating the current valid number of the reference image after the random change, for each slice.

The setting of the LC default number information for each picture according to an embodiment includes setting LC change related information including information on a method of changing a reference image or a reference order of the LC reference list for each slice. can do.

According to an embodiment, the video prediction encoding method may omit transmission of the LC combination confirmation information indicating whether the LC reference list is configured using one or more reference images of the L0 reference list and the L1 reference list. .

According to an embodiment, the video predictive encoding method includes: transmitting the LC default number information along with parameters for a current picture; Transmitting the LC active number information together with parameters for a current slice; And transmitting the LC change related information together with parameters for the current slice.

In the video predictive decoding method according to an embodiment of the present invention, an LC reference list including L0 reference list which is list information of a reference image for predictive decoding of an image having a B slice type and at least one reference image included in the L1 reference list For each picture, reading LC default number information indicating a basic valid number of reference pictures allocated to the LC reference list; Determining the LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information; And predicting and decoding the image of the B slice type using the determined LC reference list.

The step of reading LC default number information for each picture according to an embodiment may include assigning to the LC reference list based on reference list active number change confirmation information indicating whether the effective number of the reference image is randomly changed for each slice. Reading LC active number change confirmation information indicating whether the effective number of reference images is randomly changed; And reading LC active number information indicating a current valid number of reference images of the LC reference list after the random change, based on the read LC active number change confirming information.

According to an embodiment, reading the LC default number information for each picture may include reading LC change related information including information about a reference image or a reference order of the LC reference list for each slice. Can be.

The determining of the LC reference list according to an embodiment may be performed without reading LC combination identification information indicating whether to construct the LC reference list using one or more reference images of the L0 reference list and the L1 reference list. The LC reference list can be determined.

According to an embodiment, a video predictive decoding method includes: extracting, from a received video stream, the LC default number information along with parameters for a current picture; Extracting the LC active number information along with parameters for a current slice; And extracting the LC change related information together with the parameters for the current slice.

According to an embodiment of the present invention, an apparatus for predicting and encoding video includes an LC reference list including an L0 reference list, which is list information of a reference image for predictive encoding of an image having a B slice type, and one or more reference images included in the L1 reference list. An LC-related information setting unit for setting, for each picture, LC default number information indicating a basic valid number of reference pictures allocated to the LC reference list; And determining the LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information, and using the determined LC reference list to determine the B reference list. It includes a prediction coding unit for predicting encoding the image of the slice type

According to an embodiment of the present invention, an apparatus for predicting and decoding video includes an LC reference list including L0 reference list, which is list information of a reference image for predictive decoding of an image having a B slice type, and one or more reference images included in the L1 reference list. An LC related information reading unit for reading LC default number information indicating a basic valid number of reference pictures allocated to the LC reference list for each picture; And determining the LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information, and using the determined LC reference list to determine the B reference list. It includes a prediction decoding unit for predicting and decoding the image of the slice type.

The present invention includes a computer-readable recording medium having a program recorded thereon for implementing the video predictive encoding method according to each embodiment. The present invention includes a computer-readable recording medium having recorded thereon a program for computerically implementing a video predictive decoding method according to each embodiment.

1A and 1B illustrate block diagrams of a video predictor encoding apparatus and a video encoder according to an embodiment.
2 is a block diagram of a video prediction decoding apparatus and a video decoder according to an embodiment.
3 shows a display order and a coding order of a picture sequence of a video.
FIG. 4 illustrates a relationship between L0, L1, and LC reference lists of pictures that are B slices in the picture sequence of FIG. 3.
5 shows syntax of LC related information set for each slice.
6 is a diagram illustrating syntax of reference list default number information according to an embodiment.
7 illustrates LC reference lists set according to LC default number information according to an embodiment.
8 and 9 illustrate syntaxes of reference list active number related information according to various embodiments.
10 is a diagram illustrating syntax of reference list change information, according to an exemplary embodiment.
11 is a flowchart of a video prediction encoding method, according to an embodiment.
12 is a flowchart of a video predictive decoding method according to an embodiment.
13 is a block diagram of a video encoding apparatus involving video prediction based on coding units having a tree structure, according to an embodiment of the present invention.
14 is a block diagram of a video decoding apparatus involving video prediction based on coding units having a tree structure, according to an embodiment of the present invention.
15 illustrates a concept of coding units, according to an embodiment of the present invention.
16 is a block diagram of an image encoder based on coding units, according to an embodiment of the present invention.
17 is a block diagram of an image decoder based on coding units, according to an embodiment of the present invention.
FIG. 18 shows a depth encoding unit and a partition according to an embodiment of the present invention.
19 illustrates a relationship between a coding unit and transformation units, according to an embodiment of the present invention.
20 illustrates encoding information according to depths, according to an embodiment of the present invention.
21 is a diagram of deeper coding units according to depths, according to an embodiment of the present invention.
22, 23, and 24 illustrate a relationship between a coding unit, a prediction unit, and a transformation unit, according to an embodiment of the present invention.
FIG. 25 illustrates a relationship between coding units, prediction units, and transformation units, according to encoding mode information of Table 1. FIG.
26 is a flowchart of a video encoding method based on coding units having a tree structure, according to an embodiment of the present invention.
27 is a flowchart of a video decoding method based on coding units, according to a tree structure, according to an embodiment of the present invention.

Hereinafter, referring to FIGS. 1A to 12, a method and apparatus for predicting a video capable of bi-prediction using a reference list, a video predictive encoding method and apparatus, and a video predictive decoding method and The apparatus is disclosed.

1A and 1B show block diagrams of a video predictor encoding apparatus 10 and a video encoder 15 according to an embodiment.

The video predictor encoding apparatus 10 according to an embodiment includes an LC related information determiner 12 and a predictor encoder 14.

The video predictor encoding apparatus 10 according to an embodiment may include a central processor (not shown) which collectively controls the LC related information determiner 12 and the predictor encoder 14. Alternatively, the LC related information determining unit 12 and the predictive encoding unit 14 are operated by their own processors (not shown), and the video predictive encoding apparatus 10 is performed as the processors (not shown) operate organically with each other. ) May be operated as a whole. Alternatively, the LC related information determiner 12 and the predictive encoder 14 may be controlled under the control of an external processor (not shown) of the video predictive encoding apparatus 10 according to an embodiment.

The video predictor encoding apparatus 10 according to an embodiment may include one or more data storage units (not shown) in which input / output data of the LC related information determiner 12 and the predictor encoder 14 are stored. The video predictive encoding apparatus 10 may include a memory controller (not shown) that controls data input / output of the data storage unit (not shown).

The video prediction encoding apparatus 10 according to an embodiment performs prediction on images of a video. The video prediction encoding apparatus 10 determines prediction information indicating a temporal or spatial distance between the current image and the surrounding image, a prediction error (ie, a residual component), and the like. Therefore, the image information may be recorded using the prediction information instead of the entire data of the image.

Prediction encoding includes inter prediction that predicts a current image using temporal and backward images, and intra prediction that predicts a current image using spatial surrounding images. Therefore, the inter-prediction image is used as a reference image temporally, and in the intra prediction, the surrounding image is spatially used as the reference image, and thus the current image can be predicted. The current image and the reference image may be image data units including pictures, frames, fields, slices, and the like.

The video predictive encoding apparatus 10 according to an embodiment may divide a current image into a plurality of blocks and perform predictive encoding on the blocks in order to quickly calculate the predictive encoding. That is, for prediction encoding on the current block among the plurality of blocks in which the current image is divided, one block of the plurality of blocks in which the reference image is divided may be referred to.

The reference list may include an L0 reference list, an L1 reference list, and an LC reference list. For example, the reference list for forward prediction of an image having a P slice type may include an L0 reference list for List 0 prediction. The reference list for an image of a B slice type capable of bi-prediction including forward prediction, backward prediction, bidirectional prediction, and the like may include an L1 reference list for List 1 prediction, in addition to the L0 reference list. have.

In addition, the reference list for pair prediction of the B slice may further include an LC reference list. The LC reference list may include one or more reference pictures of reference pictures of the L0 reference list and reference pictures of the L1 reference list.

The L0 reference list, L1 reference list, and LC reference list may each include an index indicating one or more reference images and reference order information. The basic valid number of reference pictures allocated to the reference list may be limited in advance. However, the number or reference order of reference images may be changed for each image as necessary. Accordingly, the video predictive encoding apparatus 10 may provide information about the basic valid number of reference images of the reference list, information about the change of the number of reference images, information about the change of the reference image, information about the change of the reference order, and the like. Can be set.

The prediction encoder 14 according to an embodiment may determine a reference image for prediction encoding of the current image. The prediction encoder 14 may determine an image to be currently referenced from among images allocated to the reference list of the current image, which is a B slice type. In addition, the prediction encoder 14 may determine reference information indicating at least one reference image for image prediction.

The prediction encoding unit 14 may determine a reference image among the previous image and the next image in the display order than the current image, for bi-prediction of the current image that is the B slice. In addition, the prediction encoder 14 may determine the reference image among the images processed and reconstructed before the coding order of the current image. Therefore, the prediction encoder 14 determines the similarity between the blocks of the previous image and the next image that are already coded, and the current block of the current image, and detects the block having the least error. The detected block may be determined as a reference block of the reference picture. Information indicating the reference image, for example, the number of the image, the index, etc. may be determined as the reference information. Motion information indicating a reference block among the reference pictures may also be determined as reference information.

For intra prediction, an index indicating a reference region among neighboring regions adjacent to the current region in the same image as the current image may be determined as reference information.

The prediction encoder 14 may determine a prediction error that is an error between the current image and the reference image.

The prediction encoder 14 according to an embodiment may determine a reference list indicating the reference order of the reference picture and the reference picture. The prediction encoder 14 may determine a first reference list including reference information for first direction prediction and a second reference list including reference information for second direction prediction from among reference images for pair prediction. have. For example, the L0 list may preferentially include an index for a reference picture for forward prediction, and the L1 list may preferentially include an index for a reference picture for backward prediction. However, the L0 list and the L1 list are not necessarily limited to include only reference information for forward prediction and backward prediction, respectively.

In addition, the LC list may include both an index for a reference picture for forward prediction and an index for a reference picture for backward prediction.

The prediction encoder 14 according to an embodiment may determine a reference order of reference pictures allocated to each reference list. For example, the reference order may be determined to preferentially refer to a reference picture that is closest to the current picture in display order among reference pictures allocated to the reference list.

The prediction encoder 14 according to an embodiment may determine prediction information by performing prediction encoding with reference to an image included in a reference list. The prediction encoding unit 14 may determine prediction information by performing prediction encoding on the current image by referring to the image based on the index and the reference order of the reference image included in the reference list.

For example, the prediction encoding unit 14 predictively encodes the current image of the P slice using the L0 reference list, or uses the L0 reference list, the L1 reference list, and the LC reference list to select the current image of the B slice. Predictive encoding is possible.

The prediction encoder 14 according to an exemplary embodiment may determine the number and reference order of reference images allocated to the reference list based on the reference list related information set by the LC related information setting unit 12.

According to an embodiment, the LC related information setting unit 12 may set reference list related information such as a basic valid number of reference images, a number change, a reference image change, and a reference order change.

The effective number of reference pictures allocated to the reference list means the number of pictures valid for reference. The default number of reference lists indicates the basic valid number of reference pictures allocated to the reference list. The LC related information setting unit 12 may set, for each picture, LC default number information indicating the basic valid number of reference pictures allocated to the LC reference list.

The prediction encoder 14 according to an embodiment may determine a reference list that informs the reference picture of the current image, which is a B slice.

The prediction encoding unit 14 according to an embodiment may include one or more of reference images included in the LO reference list and the L1 reference list within a basic valid number of reference images allocated to the LC reference list based on the LC default number information. The LC reference list may be determined to include the reference picture.

The LC related information setting unit 12 may set the LC default number information for each picture together with at least one of the L0 default number for the L0 reference list and the L1 default number information for the L1 reference list.

The active number of reference images of the reference list according to an embodiment indicates the current valid number of reference images when the effective number of reference images for the current image is arbitrarily changed.

According to an embodiment, the LC-related information setting unit 12 includes LC active number change confirmation information indicating whether the effective number of reference images allocated to the LC reference list is randomly changed and validity of the reference image after the random change for each slice. LC active number information indicating the number can be set.

According to an embodiment, the LC related information setting unit 12 sets LC active number change confirmation information and LC active number information based on reference list active number change confirmation information indicating whether the effective number of reference images is arbitrarily changed. It may be.

The LC related information setting unit 12 according to an embodiment may include at least one of L0 active number information for the L0 reference list and L1 active number information for the L1 reference list based on the reference list active number change confirmation information for each slice. In addition, LC active number information can be set.

The reference list change related information according to an embodiment indicates information about a method of changing reference images or changing reference sequences assigned to the reference list.

According to an embodiment, the LC related information setting unit 12 may set LC change related information about an LC reference list for each slice.

According to an embodiment, the LC related information setting unit 12 may set LC change related information with at least one of L0 change related information for the L0 reference list and L1 change related information for the L1 reference list for each slice. have.

The video prediction encoding apparatus 10 may output prediction information and reference information. Also, the video prediction encoding apparatus 10 according to an embodiment may output or transmit L0 related information and L1 related information, including LC related information set by the LC related information setting unit 12.

The video prediction encoding apparatus 10 according to an embodiment omits setting and transmission of LC combination confirmation information indicating whether to construct an LC reference list using one or more reference images included in the L0 reference list and the L1 reference list. can do.

The video predictive encoding apparatus 10 according to an embodiment may transmit LC default number information along with parameters for the current picture. The video predictive encoding apparatus 10 according to an embodiment may transmit LC active number information along with parameters for the current slice. In addition, the video prediction encoding apparatus 10 according to an embodiment may transmit LC change related information together with parameters for the current slice.

For example, the video prediction encoding apparatus 10 may signal LC default number information for each picture through a picture parameter set (PPS). For example, the video prediction encoding apparatus 10 may signal LC active number information and LC change related information for each sequence through a sequence parameter set (SPS).

The prediction encoder 14 according to an embodiment performs prediction on an image to determine reference information indicating at least one reference image. The prediction unit 22 may determine a prediction error between the current image and the reference image by performing prediction on the current image.

The video prediction encoding apparatus 10 may represent an image by using prediction information instead of the entire data of the image, and thus may be applied to a video encoding that performs video compression encoding that requires a reduction in the amount of video data.

The video prediction encoding apparatus 10 according to an embodiment may be included in or associated with a video encoder 15 that encodes a video based on coding units obtained by dividing an image of a video into spatial regions, and thus may encode the prediction encoding for video encoding. Can be performed. In addition, for prediction encoding on a coding unit, the coding unit may be divided into prediction units and partitions, and prediction encoding may be performed based on the prediction units and partitions.

The coding unit according to an embodiment may include coding units having a tree structure according to an embodiment, as well as a block of a fixedly determined form. According to an embodiment, coding units having a tree structure, prediction units, and partitions according to the tree structure will be described below with reference to FIGS. 13 to 27.

The video prediction encoding apparatus 10 according to an embodiment may perform prediction encoding on image blocks and image data of a coding unit to output a prediction error, that is, a residual component of a reference image. The video encoder 15 may generate transform coefficients for quantization of transform and quantization of residual components, and perform entropy encoding on symbols such as transform coefficients, reference information, and encoding information, and output a bitstream. The video encoder 15 according to an embodiment may encode and output symbols including L0 related information and L1 related information including LC related information.

The video encoder 15 may generate a reconstructed image by performing loop filtering on the transform coefficient by reconstructing the image of the spatial domain through inverse quantization, inverse transform, and predictive compensation. The reconstructed image may be used as a reference image for prediction of the next image. That is, the prediction encoder 14 according to an embodiment may refer to the reconstructed image generated by the video encoder 15 according to L0, L1, LC reference list, for pair prediction of the current image that is a B slice. Can be. In this way, the prediction encoding unit 14 may determine the reference information and the prediction error through the prediction encoding.

Accordingly, compression encoding of the video encoder 15 may be implemented through prediction encoding through the video prediction encoding apparatus 10.

The video encoder 15 according to an embodiment may operate in conjunction with an internal video encoding processor or an external video encoding processor to output a video encoding result, thereby performing a video encoding operation including prediction encoding. . The internal video encoding processor of the video encoder 15 according to an embodiment includes a case where the video predictive encoding apparatus 10 or the central computing unit or the graphics processing unit drives the video encoding processing module, including a separate processor. It may also include a case of implementing a video encoding operation.

2 is a block diagram of a video prediction decoding apparatus 20 according to an embodiment.

The video predictive encoding apparatus 20 according to an embodiment includes an LC related information reading unit 22 and a predictive decoding unit 24.

The video predictive encoding apparatus 10 according to an embodiment may include a central processor (not shown) that collectively controls the LC-related information reader 22 and the predictive decoder 24. Alternatively, the LC related information reading unit 22 and the predictive decoding unit 24 are operated by their own processors (not shown), and the video predictive decoding apparatus 20 is operated as the processors (not shown) operate organically with each other. ) May be operated as a whole. Alternatively, the LC related information reading unit 22 and the predictive decoding unit 24 may be controlled under the control of an external processor (not shown) of the video predictive decoding apparatus 20 according to an embodiment.

The video prediction decoding apparatus 20 according to an embodiment may include at least one data storage unit (not shown) in which input / output data of the LC-related information reading unit 22 and the prediction decoding unit 24 are stored. The video predictive decoding apparatus 20 may include a memory controller (not shown) that controls data input / output of the data storage unit (not shown).

The video prediction decoding apparatus 20 according to an embodiment may parse the received bitstream and extract encoding information for decoding an image. The video prediction decoding apparatus 20 may parse the bitstream and extract the prediction information including the reference information and the prediction error indicating at least one reference image for the prediction of the image.

The LC related information reading unit 22 according to an exemplary embodiment may read the prediction error and the reference information between the current image and the reference image based on the prediction information extracted for the current image. The LC related information reading unit 22 can read information on the reference list from the extracted encoded information. For example, the LC related information reading unit 22 can read the L0 related information, the L1 related information, and the LC related information.

The video predictive decoding apparatus 20 according to an embodiment does not need to extract LC combination acknowledgment information from the received bitstream, or the LC related information reading unit 22 does not need to read the LC combination acknowledgment information.

The LC related information reading unit 22 according to an embodiment may read LC default number information, LC active number information, and LC change related information as LC related information. According to an embodiment, the LC related information reading unit 22 may read information about LC default number information for the current picture. According to an embodiment, the LC related information reading unit 22 may read LC active number information for the current slice. Also, the LC related information reader 22 according to an embodiment may read LC change related information for the current slice.

According to an embodiment, the LC related information reading unit 22 may read information on the LC default number information along with parameters for the current picture. For example, the LC related information reading unit 22 may read the LC default number information from the PPS signaled for each picture.

According to an embodiment, the LC related information reading unit 22 may read LC active number information along with parameters for the current slice. Also, the LC related information reading unit 22 according to an embodiment may read LC change related information for the current current slice. For example, the LC related information reading unit 22 may read LC active number information and LC change related information from the SPS signaled for each sequence.

According to an embodiment, the LC related information reading unit 22 may determine an LC reference list including one or more reference images among LO pictures and reference pictures included in the L1 reference list for pair prediction. .

The LC related information reading unit 22 according to an exemplary embodiment may read the basic valid number of reference images allocated to the LC reference list from the LC default number information for each picture.

The prediction decoding unit 24 according to an embodiment may determine an LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information. The predictive decoding unit 24 may predictively decode an image having a B slice type by referring to the images allocated to the determined LC reference list.

The LC related information reading unit 22 according to an embodiment reads whether or not the effective number of reference images allocated to the LC reference list for the current image is randomly changed based on the LC active number change confirmation information for each slice. can do. In addition, the LC-related information reading unit 22 according to an embodiment reads LC active-number change confirmation information based on the reference list active-number change confirmation information for each slice, and reads the LC-active-number change confirmation information, You can also check if the valid number can be changed.

For example, the LC related information reading unit 22 according to an embodiment may read whether the effective number of reference images for the current image may be arbitrarily changed based on the reference list active number change confirmation information for each slice. have. If the number of reference images in the reference list is changed as a result of reading the reference list active number change confirmation information, the LC related information reading unit 22 together with at least one of the L0 active number information and the L1 active number information, the LC active number information Can be read.

According to an embodiment, the LC related information reading unit 22 may, based on the read LC active number change confirming information, change the valid number of reference images from the LC active number information, from the LC active number information. The current valid number of reference pictures allocated to the LC reference list can be read after a random change of the effective number of.

The LC-related information reading unit 22 according to an embodiment may read information about a method of changing the reference image or the reference order of the LC reference list from the LC change-related information for each slice.

The LC related information reading unit 22 according to an exemplary embodiment may read LC default number information together with at least one of L0 default number information and L1 default number information for the current image for each picture.

The LC related information reading unit 22 according to an exemplary embodiment may read LC change related information along with at least one of L0 change related information and L1 change related information for the current image for each slice.

The prediction decoding unit 24 may construct the LC reference list using reference images of the L0 reference list and the L1 reference list without the LC related information reading unit 22 reading the LC combination confirmation information. have.

The predictive decoding unit 24 according to an embodiment of the present invention uses the reference information read by the LC related information reading unit 22 to refer to the reference order of the reference image and the reference image for pair prediction of the image having the B slice type. One or more reference lists may be determined to include. For example, the predictive decoding unit 24 refers to the reference images indicated by the reference lists of the L0 reference list, L1 reference list, and LC reference list according to the reference order, for pair prediction of the current image having the B slice type. Motion compensation may be performed on the current image and a reconstructed image may be generated as a result of the motion compensation. The reconstructed image generated by the predictive decoding unit 24 may be output as a result image of the predictive decoding. The reconstructed image may also be used as a reference image for motion compensation of the next image.

Since the video prediction decoding apparatus 20 may reconstruct an image using prediction information instead of the entire data of the image, the video prediction decoding apparatus 20 may be applied to video decoding for performing video compression encoding that requires a reduction in the amount of video data.

The video prediction decoding apparatus 20 according to an embodiment may be included in or associated with a video decoder that decodes a video based on a block or a coding unit that divides an image of the video into a plurality of spatial regions, and thus, predictive decoding for video decoding. Can be performed. In addition, for prediction decoding on a coding unit, the coding unit may be divided into prediction units and partitions, and prediction decoding may be performed based on the prediction units and partitions.

The coding unit according to an embodiment may include not only a fixed macroblock in a fixed form but also coding units having a tree structure according to an embodiment. According to an embodiment, coding units having a tree structure, prediction units and partitions according to the tree structure will be described below with reference to FIGS. 7 to 19.

When the video prediction decoding apparatus 20 according to an embodiment receives a bitstream generated as a result of encoding video, the video prediction decoding apparatus 20 may parse the bitstream and extract encoded symbols. Entropy decoding, inverse quantization, and inverse transformation may be performed on the symbols so that a prediction error with respect to the reference image may be reconstructed. The image of the spatial region may be reconstructed through the prediction compensation using the prediction error and the reference information, and the loop filtering may be performed on the reconstructed image. Therefore, compression decoding of the video decoder may be implemented through prediction decoding through the video prediction decoding apparatus 20.

The video prediction decoding apparatus 20 according to an embodiment may operate in conjunction with an internal video decoding processor or an external video decoding processor to output a video decoding result, thereby performing a video decoding operation including motion compensation. Can be. The internal video decoding processor of the video predictive decoding apparatus 20 according to an embodiment may include a separate processor, and the basic video decoding operation may be performed by the predictive decoding unit 24 or the graphics computing apparatus driving the video decoding processing module. It may also include the case of implementing.

3 shows a display order and a coding order of a picture sequence of a video.

The indices of pictures 0, 1, 2, 3, 4, 5, 6, 7, and 8 indicate the display order of each picture. In addition, the vertical levels of pictures 0, 1, 2, 3, 4, 5, 6, 7, and 8 indicate the coding order of each picture. For example, pictures 0 and 8 are coded first, picture 4 is coded in the following order, then pictures 2 and 6 are coded, and picture 1, 3, 5 and 7 are finally coded. Between pictures of the same level, such as pictures 0 and 8, pictures 2 and 6, and pictures 1, 3, 5, and 7, the coding order of pictures preceding the display order may take precedence.

FIG. 4 illustrates a relationship between L0, L1, and LC reference lists of pictures having a B slice type in the picture sequence of FIG. 3.

Pictures 0, 1, 2, 3, 4, 5, 6, 7, and 8 are pictures of a GOP (Group of Pictures) unit consisting of eight pictures. For example, if picture 0 or 8 is I slices, picture 0, 1, 2, 3, 4, 5, which is a group of pictures before picture 8 of the next I slice type, including picture 0 of the first I slice type , 6, and 7 may constitute one GOP.

A picture having a B slice type may refer to up to four pictures, and the L0 and L1 reference lists may include up to two reference pictures, respectively.

In the table 40, the POC column lists the index of the current picture in decoding order. In the L0, L1 and LC columns of the table 40, the indices of the reference pictures allocated to the L0, L1 and LC reference lists for the current picture are listed, respectively.

In principle, among the pictures coded before the current picture, the pictures that have a leading index (following) from the current picture may be allocated as the reference picture to the L0 reference list (L1 reference list). In addition, the reference order of the reference picture may be determined in the order of closer to the current picture among the pictures that have an index (first) following the current picture.

Taking picture 6 as an example, pictures coded before picture 6 are pictures 0, 2, 4, and 8, so that pictures 4 and 2 refer to L0 of picture 6 in order of precedence and closest to picture 6 of the first coded pictures. Can be assigned to a list.

Exceptionally, when there are less than two pictures that are indexed before the current picture among the pictures coded before the current picture, the display order of the current picture among the pictures that are trailing (preceding) among the first coded pictures. The picture closest to may be adopted as the reference picture of the L0 reference list (L1 reference list).

Taking picture 4 as an example, since pictures coded before picture 4 are pictures 0 and 8, but pictures preceding picture 4 are only picture 0, the L0 reference list of picture 4 is not only the preceding picture 0 but also the following picture. 8 may also be included. Similarly, the L1 reference list of picture 4 may include not only the following picture 8 but also the preceding picture 0.

Taking picture 6 as an example, pictures coded before picture 6 are pictures 0, 2, 4, and 8, but since picture following picture 6 is only picture 0, the L1 reference list of picture 6 is not only picture 8 that follows. In addition, it may also include the close picture 4 preceding the picture 6.

The LC reference list may consist of a combination of the reference picture of the L0 reference list and the reference picture of the L1 reference list. Therefore, the relationship between the number of reference images (N_L0) of the L0 reference list, the number of reference images (N_L1) of the L1 reference list, and the number of reference images (N_LC) of the LC reference list may be determined as shown in relation (A) below. .

Relation (A): N_LC = [0, (N_L0 + N_L1)]

That is, the number N_LC of reference images of the LC reference list may be equal to or greater than zero, and may be less than or equal to the sum of the number N_L0 of reference images of the L0 reference list and the number N_L1 of reference images of the L1 reference list.

Referring to Table 400 as an example, the LC reference list may include up to four reference images, but the pictures 8, 4, 2, 6, 1, and 7 overlap some reference images of the L0 reference list and the L1 reference list. Accordingly, even if the reference pictures of the L0 reference list and the L1 reference list are combined, fewer than four reference pictures of the LC reference list may be determined.

Accordingly, the number of reference pictures and reference pictures of the LC reference list may be determined depending on the state of reference pictures allocated to the L0 reference list and the L1 reference list.

The video predictive encoding apparatus 10 according to an embodiment may transmit L0 related information, L1 related information, and LC related information. The video prediction decoding apparatus 20 according to an embodiment may read encoded information extracted from the received bitstream according to syntax, and may also read L0 related information, L1 related information, and LC related information according to the syntax. 5 through 10 illustrate syntaxes of L0 related information, L1 related information, and LC related information, according to an exemplary embodiment.

5 shows syntax of LC related information set for each slice.

The slice header (slice_header ()) 50 is set for each slice, and each slice header 50 may include various pieces of information necessary for encoding / decoding a current slice. Therefore, the various types of information included in the slice header 50 are information set for the current slice. For example, the slice header 50 may include LC related information (ref_pic_list_combination (), 51). The LC related information 51 in the slice header 50 may be information set in association with an LC reference list for the current slice.

The LC related information 51 includes LC combination confirmation information (ref_pic_list_combination_flag) 53, LC active number information (num_ref_idx lc_active_minus1, 55), and LC change related information. The LC change related information according to an embodiment may include LC change confirmation information (ref_pic_list_modification_flag_lc, 57), L0 / L1 image identification information (pic_from_list_0_flag, 58), current index information (ref_idx_list_curr, 59), and the like.

For example, if it is determined that the LC reference list is formed by combining the reference images of the L0 / L1 reference list based on the LC combination confirmation information 53, the reference assigned to the LC reference list indicated by the LC active number information 55 The current valid number of images can be read.

When the LC reference list is changed according to the LC change confirmation information 57, one or more reference images to be included in the LC reference list may be newly allocated. That is, as many reference pictures as the current valid number of reference pictures allocated to the LC reference list indicated by the LC active number information 55 may be newly allocated. For each newly allocated reference image, it is confirmed whether it is a reference image of the original L0 reference list or L1 reference list based on the L0 / L1 image identification information 58, and on the original reference list based on the current index information 59. The index can be verified.

Thus, in the case of FIG. 5, if LC related information 51 is included in slice header 50, LC combination confirmation information 53 is transmitted / read for every slice. Also, apart from the L0 / L1 related information, if the LC reference list is formed by combining the reference images of the L0 / L1 reference list according to the LC combination confirmation information 53 transmitted / read per slice, the LC active number information ( 55) LC change related information is transmitted / read.

6 is a diagram illustrating syntax of reference list default number information according to an embodiment.

PPS information pic_parameter_set_rbsp () 60 according to an embodiment may include L0 default number information (num_ref_idx_l0_default_active_minus1, 61), L1 default number information (num_ref_idx_l1_default_active_minus1, 63), and LC default number information (num_ref_idactive_min_default_min_default_min) .

Therefore, the basic validity number for the LC reference list can be set with the L0 reference list and the L1 reference list for every picture. In addition, for each PPS information 60 for each picture, the LC default number information for each picture may be stored and transmitted. In addition, since the PPS information 60 extracted from the received video stream includes LC default number information, the LC default number information for the current picture can be read from the PPS information 60 for each picture. Accordingly, the LC default number information is read with L0 default number information and L1 default number information for each picture, so that the basic valid number for the LC reference list together with the basic valid number for the L0 reference list and L1 reference list can be determined. .

In addition, although LC combination confirmation information (ref_pic_list_combination_flag, 53) is set and transmitted / read in each slice in FIG. 5, in FIG. May be implied. Therefore, as the LC default number information 65 is set for each picture according to an embodiment, the LC combination confirmation information 53 does not need to be transmitted and read for each slice.

7 illustrates LC reference lists set according to LC default number information according to an embodiment.

The LC default number information num_ref_idx_lc_default_active according to an embodiment may indicate a basic valid number of reference pictures allocated to the LC reference list.

The first chart 70 and the second chart 75 show the result of variation of the default effective number of reference pictures allocated to the LC reference list when the LC default number information (num_ref_idx_lc_default_active) is set to a different value, respectively.

Similar to the chart 40 referenced in FIG. 4, the POC columns of the first chart 70 and the second chart 75 list the index of the current picture in decoding order. The L0, L1 and LC columns of the first and second charts 70 and 75 represent the indices of reference pictures allocated to the L0, L1 and LC reference lists for the current picture, respectively.

For example, when the LC default number information (num_ref_idx_lc_default_active) is set to 0, the first table 70 shows reference images of L0, L1, and LC reference list. When the LC default number information (num_ref_idx_lc_default_active) is set to 0 according to an embodiment, the default valid number of reference images for the LC reference list is not set separately and is automatically set according to the states of the L0 reference list and the L1 reference list. The base validity number of the reference list can be determined. Therefore, in the first table 70, the LC reference list, the LC reference list for each current picture may include a combination of all reference pictures of the L0 reference list and the L1 reference list.

For example, when the LC default number information (num_ref_idx_lc_default_active) is set to 2, the second diagram 75 shows reference images of L0, L1, and LC reference list. When the LC default number information (num_ref_idx_lc_default_active) is set to a value other than 0, the basic valid number of reference images for the LC reference list may be determined as the value of the LC default number information. Therefore, since the basic valid number of reference pictures for the LC reference list in the second table 75 is determined to be two, the LC reference list for the current picture is the current picture among all reference pictures of the L0 reference list and the L1 reference list. Only two reference images close to may be included.

Also, with reference to FIG. 6, an embodiment in which the default number information of each of the L0 / L1 / LC reference lists is included in the PPS information 80, 90, and 150 has been proposed, but the features of the present invention are limited thereto. It should not be. For example, the default number information for the L0 / L1 / LC reference list according to another embodiment may include sequence parameter set (SPS) information, adaptation parameter set (APS) information, arbitrary parameter set, slice header, or sequence header (Sequence). Header) or the like.

Accordingly, the default number information for the L0 / L1 / LC reference list according to another embodiment may be transmitted / read along with sequence parameters, adaptation parameters or arbitrary parameters. The default number information for the L0 / L1 / LC reference list according to another embodiment may be set for each slice to be transmitted / read with various parameters for each slice, or set for each sequence for various parameters for each sequence. Can be transmitted / read together.

8 and 9 illustrate syntaxes of reference list active number related information according to various embodiments.

8 and 9, the slice headers (slice_header (), 80, and 90) include L0 active number related information, L1 active number related information, and LC active number related information, respectively.

Specifically, starting from the slice header 90 of FIG. 8, when the current slice is a P or B slice type, the L0 active number related information and the L1 active number related information may be read.

First, the reference list active number change confirmation information num_ref_idx_active_override_flag 81 may be read. Based on the reference list active number change confirmation information 81, it may be determined whether the effective number of reference images of the reference list is changed randomly.

When it is determined that the valid number of reference images of the reference list is randomly changed based on the reference list active number change confirmation information 81, the L0 active number information (num_ref_idx_l0_active_minus1, 83) can be read. Based on the L0 active number information 83, the current valid number of reference images allocated to the L0 reference list may be determined.

If it is determined that the effective number of reference images of the reference list has been arbitrarily changed, and the current slice is a B slice type, the L1 active number information (num_ref_idx_l1_active_minus1, 85) may be read. The current valid number of reference pictures allocated to the L1 reference list may be determined based on the L1 active number information 85.

In addition, separately from the L0 active number related information and the L1 active number related information, when the current slice is a B slice type, the LC active number related information may be read. First, LC active number change confirmation information (num_ref_idx_lc_active_override_flag) 87 may be read. Based on the LC active number change confirming information 81, it may be determined whether or not the effective number of reference images of the LC reference list is changed randomly.

Based on the LC active number change confirming information 81, if it is determined that the valid number of reference images of the LC reference list is arbitrarily changed, the LC active number information (num_ref_idx_lC_active_minus1, 89) can be read. The current valid number of reference pictures allocated to the LC reference list may be determined based on the LC active number information 89.

Next, referring to the slice header 90 of FIG. 9 in detail, when the current slice is a P or B slice type, reference list active number change confirmation information (num_ref_idx_active_override_flag) 91 may be read. If it is determined that the valid number of reference images of the reference list is randomly changed based on the reference list active number change confirmation information 91, the L0 active number information (num_ref_idx_l0_active_minus1, 93) is read and the current number of the reference images allocated to the L0 reference list is read. The effective number can be determined.

In addition, when it is determined that the effective number of reference images of the reference list is randomly changed and the current slice is a B slice type, the L1 active number information (num_ref_idx_l1_active_minus1, 95) and the LC active number information (num_ref_idx_lc_active_minus1, 97) may be read together. . The current valid number of reference images allocated to the L1 reference list is determined based on the L1 active number information 95, and the current valid number of reference images allocated to the LC reference list is determined based on the LC active number information 97. Can be.

Therefore, in the case of FIGS. 8 and 9, active number related information about the L0 / L1 / LC reference list may be set for each slice. In addition, in the embodiment described in FIG. 5, the LC active number information 55 is transmitted / read per slice separately from the active number related information for the L0 / L1 reference list. In the examples, the active count related information 87 for the LC reference list, together with the active count related information 81, 83, 85, 91, 93, 95 for the L0 / L1 reference list in the slice headers 80 and 90 , 89, 97 may be transmitted / read.

The LC active number information 89 and 97 according to the embodiment disclosed with reference to FIGS. 8 and 9 may directly indicate the current valid number of the LC reference list. Also, the LC active number information according to another embodiment may include a difference of the current valid number of the L0 reference list, the difference of the current valid number of the L1 reference list, or the sum of the current valid number of the L0 reference list and the L1 reference list. It can also represent differences.

10 is a diagram illustrating syntax of reference list change information, according to an exemplary embodiment.

In FIG. 10, the slice header slice_header () 150 includes reference list change related information ref_pic_list_modification () 151.

The reference list change related information 151 according to an embodiment may include L0 change related information, L1 change related information, and LC change related information about the current slice.

First, when the current slice is a P or B slice type, the L0 modification confirmation information ref_pic_list_modification_flag_10 and 153 may be read. Based on the L0 change confirmation information 153, it may be determined whether the reference picture of the L0 reference list is to be changed.

When it is determined that the reference picture of the L0 reference list is changed based on the L0 change confirmation information 153, the reference picture change operation information modification_of_pic_nums_idc 155 may be read. Reference image number difference information (abs_diff_pic_num_minus1, 157) or long term reference image number information (long_term_pic_num, 159) may be determined based on the reference image change operation information 155.

Next, when the current slice is a B slice type, the L1 modification confirmation information ref_pic_list_modification_flag_l1 and 161 may be read. Based on the L1 change confirmation information 161, it may be determined whether the reference picture of the L1 reference list is to be changed. When it is determined that the reference picture of the L1 reference list is changed based on the L1 change confirmation information 161, the reference picture change operation information modification_of_pic_nums_idc 163 may be read. Reference image number difference information (abs_diff_pic_num_minus1, 165) or long term reference image number information (long_term_pic_num, 167) may be determined based on the reference image change operation information 163.

The reference picture number difference information (abs_diff_pic_num_minus1, 157, 165) indicates a difference value between the video number of the reference picture to be allocated to the current index of the current reference list and the predicted value of the reference picture number. The long term reference picture number information (long_term_pic_num, 159, 167) indicates the number of the long term picture to be allocated to the current index of the current reference list. The long term image may be reference frames or reference fields, and the long term reference image number information 159 may indicate one of the reference frames or one of the reference fields.

Therefore, based on the reference image change operation information 155 and 163, the number of the reference image to be allocated to the current reference list is determined using the reference image number difference information 157 and 165 or the long term reference image number information 159 and 167. Can be determined. As the reference picture to be allocated by being moved to the current index of the current reference list is changed, the reference picture may be changed or the reference order may be changed.

When the current slice is a B slice type, LC change confirmation information (ref_pic_list_modification_flag_lc) 169 may be read. When it is determined that the LC reference list is changed according to the LC change confirmation information 169, for each reference image to be allocated to the LC reference list, L0 / L1 image identification information (pic_from_list_0_flag, 171) and current index information (ref_idx_list_curr, 173). ) Can be read. Based on the L0 / L1 image identification information 171, it is confirmed whether the reference image to be allocated currently is a reference image of the original L0 reference list or the L1 reference list, and the reference to be currently assigned in the original reference list based on the current index information 173. The index of the image can be confirmed.

Accordingly, although the reference picture to be moved and allocated to the current index of the current LC reference list is again determined among the reference pictures of the L0 reference list or the L1 reference list, the reference picture may be changed to another reference picture or the reference order of the reference picture may be changed. have.

Accordingly, in the case of FIG. 10, change related information of a reference picture with respect to the L0 / L1 / LC reference list may be set for each slice. In addition, in the embodiment described in FIG. 5, the LC change related information 57, 58, 59 is transmitted / read per slice separately from the information related to the reference image change for the L0 / L1 reference list. In the embodiments of FIG. 10, the LC reference list along with information 153, 155, 157, 159, 161, 163, 165, and 167 related to the reference image change for the L0 / L1 reference list in the slice header 150 Information (169, 171, 173) related to the change of the reference image with respect to can be transmitted / read.

In addition, various embodiments in which the active header related information and the change related information of the L0 / L1 / LC reference list are described in the slice headers 80, 90, and 150 with reference to FIGS. Features of the present invention should not be interpreted as being limited thereto. For example, the active number related information and the change related information for the L0 / L1 / LC reference list according to another embodiment may be included in the adaptation parameter set (APS) information or any parameter set, sequence header, and the like. have.

Accordingly, the active number related information and the change related information for the L0 / L1 / LC reference list according to another embodiment may be transmitted / read along with the adaptation parameters or any parameters. Active number related information and change related information for the L0 / L1 / LC reference list according to another embodiment may be set for each sequence and transmitted / read together with various parameters for each sequence.

11 is a flowchart of a video prediction encoding method, according to an embodiment.

In step 111, LC default number information may be set for each picture for an LC reference list for predictive encoding of an image having a B slice type. In addition, for each picture, the LC default number information may be set together with at least one of the L0 default number information and the L1 default number information.

In operation 112, an LC reference list including one or more reference images among the reference pictures included in the LO reference list and the L1 reference list may be determined based on the LC default number information.

In operation 113, the B slice type image may be predictively encoded using the LC reference list determined in operation 112.

According to an embodiment, the video predictive encoding method may omit setting of the LC combination confirmation information indicating whether the LC reference list is configured using one or more reference images of the L0 reference list and the L1 reference list.

In addition to the LC default number information for each picture set in step 111, LC active number related information may be set for each slice.

According to one embodiment, for each slice, based on the reference list active number change confirmation information, the LC active number change confirmation information and the LC active number information may be set. Further, for each slice, LC active number information may be set together with at least one of L0 active number information and L1 active number information based on the reference list active number change confirmation information.

According to an embodiment, LC change related information may be set for each slice. In addition, for each slice, along with at least one of the L0 change related information and the L1 change related information, the LC change related information may be set for each slice.

According to an embodiment, the LC default number information set for the current picture may be transmitted together with the parameters for the current picture. In addition, according to an embodiment, the LC active number information set for the current slice may be transmitted together with the parameters for the current slice. According to an embodiment, the LC change related information set for the current picture may be transmitted together with the parameters for the current slice.

12 is a flowchart of a video predictive decoding method according to an embodiment.

In operation 121, LC default number information indicating a basic valid number of reference pictures allocated to the LC reference list for each picture may be read for the LC reference list for predictive encoding of the B slice. When the video prediction decoding method according to an embodiment receives the video stream, the LC default number information together with the parameters for the current picture may be extracted and read from the video stream. According to an embodiment, the LC default number information may be read for each picture together with at least one of the L0 default number information and the L1 default number information.

In operation 122, an LC reference list including one or more reference images among the reference pictures included in the LO reference list and the L1 reference list may be determined based on the LC default number information.

In step 123, the B slice may be predictively decoded using the LC reference list determined in step 122.

According to an embodiment, the video predictive decoding method may determine an LC reference list without reading LC combination confirmation information indicating whether to construct an LC reference list using one or more reference images of the L0 reference list and the L1 reference list. have.

In addition to the LC default number information read in step 121, LC active change related information can be read for each slice. From the received videostream, LC active count information along with parameters for the current slice can be extracted and read. Further, according to an embodiment, the LC active number change confirmation information may be read based on the reference list active number change confirmation information. Further, based on the LC active number change confirming information, LC active number information can be read.

According to one embodiment, for each slice, the reference list active number change confirmation information is read, and based on the reference list active number change confirmation information, the LC active number information is combined with at least one of the L0 active number information and the L1 active number information. Can be read.

In addition to the LC default number information read in step 121, LC change related information may be read for each slice. According to an embodiment, LC change related information together with parameters for the current slice may be extracted and read from the received videostream. According to one embodiment, LC change related information may be read per slice, with at least one of L0 change related information and L1 change related information.

Hereinafter, a video encoding method and apparatus for performing prediction encoding on a prediction unit and a partition based on coding units having a tree structure, and a video decoding method and apparatus for performing prediction decoding will be described with reference to FIGS. 13 to 27.

13 is a block diagram of a video encoding apparatus involving video prediction based on coding units having a tree structure, according to an embodiment of the present invention.

According to an embodiment, the video encoding apparatus 100 including video prediction based on coding units having a tree structure may include a maximum coding unit splitter 110, a coding unit determiner 120, and an outputter 130. . For convenience of description below, the video encoding apparatus 100 that includes video prediction based on coding units having a tree structure, according to an embodiment, is abbreviated as “video encoding apparatus 100”.

The maximum coding unit division unit 110 may divide a current picture based on a maximum coding unit which is a coding unit of a maximum size for a current picture of an image. If the current picture is larger than the maximum encoding unit, the image data of the current picture may be divided into at least one maximum encoding unit. The maximum encoding unit according to an exemplary embodiment may be a data unit of size 32x32, 64x64, 128x128, 256x256, or the like, and a data unit of a character approval square whose width and height are two. The image data may be output to the coding unit determiner 120 for at least one maximum coding unit.

The coding unit according to an embodiment may be characterized by a maximum size and depth. The depth indicates the number of times the coding unit is spatially divided from the maximum coding unit. As the depth increases, the depth coding unit can be divided from the maximum coding unit to the minimum coding unit. The depth of the largest coding unit is the highest depth and the minimum coding unit may be defined as the lowest coding unit. As the maximum coding unit decreases as the depth increases, the size of the coding unit for each depth decreases, and thus, the coding unit of the higher depth may include coding units of a plurality of lower depths.

As described above, the image data of the current picture may be divided into maximum coding units according to the maximum size of the coding unit, and each maximum coding unit may include coding units divided by depths. Since the maximum coding unit is divided according to depths, image data of a spatial domain included in the maximum coding unit may be hierarchically classified according to depths.

The maximum depth and the maximum size of the coding unit that limit the total number of times of hierarchically dividing the height and the width of the maximum coding unit may be preset.

The encoding unit determination unit 120 encodes at least one divided area in which the area of the maximum encoding unit is divided for each depth, and determines the depth at which the final encoding result is output for each of at least one of the divided areas. That is, the coding unit determination unit 120 selects the depth at which the smallest coding error occurs, and determines the coding depth as the coding depth by coding the image data in units of coding per depth for each maximum coding unit of the current picture. The determined coded depth and the image data for each maximum coding unit are output to the outputter 130.

Image data in the largest coding unit is encoded based on coding units according to depths according to at least one depth less than or equal to the maximum depth, and encoding results based on the coding units for each depth are compared. As a result of comparing the encoding error of the coding units according to depths, a depth having the smallest encoding error may be selected. At least one coding depth may be determined for each maximum coding unit.

As the depth of the maximum coding unit increases, the coding unit is divided into hierarchically and the number of coding units increases. In addition, even in the case of coding units having the same depth included in one largest coding unit, a coding error of each data is measured, and whether or not division into a lower depth is determined. Therefore, even in the data included in one largest coding unit, since the encoding error for each depth is different according to the position, the coding depth may be differently determined according to the position. Accordingly, one or more coding depths may be set for one maximum coding unit, and data of the maximum coding unit may be partitioned according to coding units of one or more coding depths.

Therefore, the encoding unit determiner 120 according to the embodiment can determine encoding units according to the tree structure included in the current maximum encoding unit. The 'encoding units according to the tree structure' according to an exemplary embodiment includes encoding units of depth determined by the encoding depth, among all depth encoding units included in the current maximum encoding unit. The coding unit of coding depth can be hierarchically determined in depth in the same coding area within the maximum coding unit, and independently determined in other areas. Similarly, the coding depth for the current area can be determined independently of the coding depth for the other area.

The maximum depth according to one embodiment is an index related to the number of divisions from the maximum encoding unit to the minimum encoding unit. The first maximum depth according to an exemplary embodiment may indicate the total number of division from the maximum encoding unit to the minimum encoding unit. The second maximum depth according to an exemplary embodiment may represent the total number of depth levels from the maximum encoding unit to the minimum encoding unit. For example, when the depth of the maximum encoding unit is 0, the depth of the encoding unit in which the maximum encoding unit is divided once may be set to 1, and the depth of the encoding unit that is divided twice may be set to 2. In this case, if the coding unit divided four times from the maximum coding unit is the minimum coding unit, since the depth levels of depth 0, 1, 2, 3 and 4 exist, the first maximum depth is set to 4 and the second maximum depth is set to 5 .

Prediction encoding and transformation of the largest coding unit may be performed. Similarly, prediction encoding and transformation are performed based on depth-wise coding units for each maximum coding unit and for each depth below the maximum depth.

Since the number of coding units for each depth increases each time the maximum coding unit is divided for each depth, encoding including prediction encoding and transformation should be performed on all the coding units for each depth generated as the depth deepens. For convenience of explanation, prediction encoding and transformation will be described based on coding units of a current depth among at least one maximum coding unit.

The video encoding apparatus 100 according to an exemplary embodiment may select various sizes or types of data units for encoding image data. Precoding encoding, transformation, and entropy encoding are performed to encode the image data. The same data unit may be used in all stages, or the data unit may be changed in stages.

For example, the video encoding apparatus 100 may select not only a coding unit for encoding the image data but also a data unit different from the coding unit in order to perform prediction encoding on the image data of the coding unit.

For prediction encoding of the largest coding unit, prediction encoding may be performed based on a coding unit of a coding depth, that is, a more strange undivided coding unit, according to an embodiment. Hereinafter, a more strange undivided coding unit on which prediction encoding is based is referred to as a 'prediction unit'. The partition in which the prediction unit is divided may include a data unit in which at least one of the height and the width of the prediction unit and the prediction unit is divided. A partition is a data unit in which a prediction unit of a coding unit is divided, and a prediction unit may be a partition having the same size as a coding unit.

For example, if the encoding unit of size 2Nx2N (where N is a positive integer) is not further divided, it is a prediction unit of size 2Nx2N, and the size of the partition may be 2Nx2N, 2NxN, Nx2N, NxN, and the like. According to an embodiment, the partition type includes not only symmetric partitions in which the height or width of the prediction unit is divided by a symmetrical ratio, but also partitions divided in an asymmetrical ratio, such as 1: n or n: 1, by a geometric form. It may optionally include partitioned partitions, arbitrary types of partitions, and the like.

The prediction mode of the prediction unit may be at least one of an intra mode, an inter mode, and a skip mode. For example, the intra mode and the inter mode may be performed for partitions having sizes of 2N × 2N, 2N × N, N × 2N, and N × N. In addition, the skip mode can be performed only for a partition of 2Nx2N size. The encoding may be performed independently for each prediction unit within the coding unit to select a prediction mode having the smallest encoding error.

In addition, the video encoding apparatus 100 according to an exemplary embodiment may perform conversion of image data of an encoding unit based on not only an encoding unit for encoding image data but also a data unit different from the encoding unit. For conversion of a coding unit, the conversion may be performed based on a conversion unit having a size smaller than or equal to the coding unit. For example, the conversion unit may include a data unit for the intra mode and a conversion unit for the inter mode.

The conversion unit in the encoding unit is also recursively divided into smaller conversion units in a similar manner to the encoding unit according to the tree structure according to the embodiment, And can be partitioned according to the conversion unit.

For a conversion unit according to one embodiment, a conversion depth indicating the number of times of division until the conversion unit is divided by the height and width of the encoding unit can be set. For example, if the size of the conversion unit of the current encoding unit of size 2Nx2N is 2Nx2N, the conversion depth is set to 0 if the conversion depth is 0, if the conversion unit size is NxN, and if the conversion unit size is N / 2xN / 2, . That is, a conversion unit according to the tree structure can be set for the conversion unit according to the conversion depth.

The coding information according to the coding depth needs not only the coding depth but also prediction related information and conversion related information. Therefore, the coding unit determination unit 120 can determine not only the coding depth at which the minimum coding error is generated, but also the partition type in which the prediction unit is divided into partitions, the prediction mode for each prediction unit, and the size of the conversion unit for conversion.

A method of determining a coding unit, a prediction unit / partition, and a transformation unit according to a tree structure of a maximum coding unit according to an embodiment will be described in detail with reference to FIGS. 9 to 19.

The encoding unit determination unit 120 may measure the encoding error of the depth-dependent encoding unit using a Lagrangian Multiplier-based rate-distortion optimization technique.

The output unit 130 outputs, in the form of a bit stream, video data of the maximum encoding unit encoded based on at least one encoding depth determined by the encoding unit determination unit 120 and information on the depth encoding mode.

The encoded image data may be a result of encoding residual data of the image.

The information on the depth-dependent coding mode may include coding depth information, partition type information of a prediction unit, prediction mode information, size information of a conversion unit, and the like.

The coded depth information may be defined using depth-specific segmentation information indicating whether to encode to a coding unit of a lower depth without encoding to the current depth. If the current depth of the current coding unit is a coding depth, since the current coding unit is encoded in a coding unit of the current depth, split information of the current depth may be defined so that it is no longer divided into lower depths. On the contrary, if the current depth of the current coding unit is not the coding depth, encoding should be attempted using the coding unit of the lower depth, and thus split information of the current depth may be defined to be divided into coding units of the lower depth.

If the current depth is not the coded depth, encoding is performed on the coding unit divided into the coding units of the lower depth. Since at least one coding unit of a lower depth exists in the coding unit of the current depth, encoding may be repeatedly performed for each coding unit of each lower depth, and recursive coding may be performed for each coding unit of the same depth.

Since the coding units of the tree structure are determined in one maximum coding unit and information on at least one coding mode is determined for each coding unit of coding depth, information on at least one coding mode is determined for one maximum coding unit . Since the data of the maximum encoding unit is hierarchically divided according to the depth and the depth of encoding may be different for each position, information on the encoding depth and the encoding mode may be set for the data.

Accordingly, the output unit 130 according to the embodiment can allocate encoding depths and encoding information for the encoding mode to at least one of the encoding unit, the prediction unit, and the minimum unit included in the maximum encoding unit .

The minimum unit according to an exemplary embodiment is a square data unit having a minimum coding unit having the lowest coding depth divided into quadrants. The minimum unit according to an exemplary embodiment may be a maximum size square data unit that can be included in all coding units, prediction units, partition units, and conversion units included in the maximum coding unit.

For example, the encoding information output through the output unit 130 may be classified into encoding information per depth unit and encoding information per prediction unit. The encoding information for each depth coding unit may include prediction mode information and partition size information. The encoding information to be transmitted for each prediction unit includes information about the estimation direction of the inter mode, information about the reference picture index of the inter mode, information on the motion vector, information on the chroma component of the intra mode, information on the interpolation mode of the intra mode And the like.

Information on the maximum size of a coding unit defined for each picture, slice or GOP, and information on the maximum depth can be inserted into a header, a sequence parameter set, or a picture parameter set of a bitstream.

Information on the maximum size of the conversion unit allowed for the current video and information on the minimum size of the conversion unit can also be output through a header, a sequence parameter set, or a picture parameter set or the like of the bit stream. The output unit 130 may encode and output reference information, prediction information, unidirectional prediction information, slice type information including a fourth slice type, etc. related to the prediction described above with reference to FIGS. 1 to 6.

According to an embodiment of the simplest form of the video encoding apparatus 100, a coding unit according to depths is a coding unit having a size in which a height and a width of a coding unit of one layer higher depth are divided by half. That is, if the size of the coding unit of the current depth is 2Nx2N, the size of the coding unit of the lower depth is NxN. In addition, the current coding unit having a size of 2N × 2N may include up to four lower depth coding units having a size of N × N.

Therefore, the video encoding apparatus 100 determines the encoding unit of the optimal shape and size for each maximum encoding unit based on the size and the maximum depth of the maximum encoding unit determined in consideration of the characteristics of the current picture, Encoding units can be configured. In addition, since each encoding unit can be encoded by various prediction modes, conversion methods, and the like, an optimal encoding mode can be determined in consideration of image characteristics of encoding units of various image sizes.

Therefore, if an image having a very high image resolution or a very large data amount is encoded in units of existing macroblocks, the number of macroblocks per picture becomes excessively large. This increases the amount of compression information generated for each macroblock, so that the burden of transmission of compressed information increases and the data compression efficiency tends to decrease. Therefore, the video encoding apparatus according to an embodiment can increase the maximum size of the encoding unit in consideration of the image size, and adjust the encoding unit in consideration of the image characteristic, so that the image compression efficiency can be increased.

The video encoding apparatus 100 of FIG. 13 may perform the prediction encoding operation of the video prediction encoding apparatus 10 described above with reference to FIGS. 1A and 1A.

The coding unit determiner 120 may perform an operation of the prediction encoder 14 of the video predictor encoding apparatus 10. That is, the prediction and compensation operation of the prediction encoder 14 may be performed based on the prediction unit and the partition included in each coding unit among the coding units of the hierarchical structure in which the current image is divided. In particular, for pair prediction of a partition of a B slice type, a reference picture may be determined using a L0 / L1 / LC reference list. As described above, unidirectional prediction of the B-slice type pair prediction according to an embodiment is performed using a reference image according to a reference order of one of the L0 / L1 / LC reference lists.

The coding unit determiner 120 may determine the prediction error of the current partition by performing prediction encoding on the current partition by referring to the reference image indicated by the L0 / L1 / LC reference list according to the corresponding reference order. In addition, the coding unit determiner 120 may reconstruct the prediction region by referring to the reference image for pair prediction indicated by the L0 / L1 / LC reference list according to the corresponding reference order for motion compensation of the prediction error of the current partition. have. Coding units of the coded depth determined in this manner may constitute a coding unit having a tree structure according to an embodiment.

The output unit 130 of the video encoding apparatus 100 may perform an output operation of the video prediction encoding apparatus 10. That is, the output unit 130 may output the quantized transform coefficients of the prediction error generated by the bi-prediction and the unidirectional prediction according to one embodiment, for each coding unit having a tree structure, for each maximum coding unit. .

The output unit 130 may encode and output information about a coded depth and a coding mode of coding units having a tree structure. The information about the encoding mode may include reference information and prediction mode information determined by prediction encoding according to an embodiment. The reference information may include an index indicating a reference picture, motion information indicating a reference block, and the like.

The output unit 130 may encode reference list related information as prediction mode information about pair prediction of a B slice type, according to an exemplary embodiment. For example, the L0 / L1 / LC default number information, L0 / L1 / LC active number information, L0 / L1 / LC change related information, etc. set by the LC related information setting unit 12 are encoded as prediction mode information. Can be output.

Reference list related information for pair prediction according to an embodiment may be encoded for each slice including the current partition, for each sequence, or for each picture.

14 is a block diagram of a video decoding apparatus involving video prediction based on coding units having a tree structure, according to an embodiment of the present invention.

A video decoding apparatus 200 including video prediction based on a coding unit according to an exemplary embodiment includes a receiving unit 210, a video data and coding information extracting unit 220, and a video data decoding unit 230 do. For convenience of explanation, a video decoding apparatus 200 that accompanies video prediction based on a coding unit according to an exemplary embodiment is referred to as a 'video decoding apparatus 200' in short.

Definition of various terms such as a coding unit, a depth, a prediction unit, a transformation unit, and information about various encoding modes for a decoding operation of the video decoding apparatus 200 according to an embodiment may be described with reference to FIG. 13 and the video encoding apparatus 100. Same as described above with reference.

The receiving unit 210 receives and parses the bitstream of the encoded video. The image data and encoding information extracting unit 220 extracts image data encoded for each encoding unit according to the encoding units according to the tree structure according to the maximum encoding unit from the parsed bit stream and outputs the extracted image data to the image data decoding unit 230. The image data and encoding information extraction unit 220 can extract information on the maximum size of the encoding unit of the current picture from the header, sequence parameter set, or picture parameter set for the current picture.

Also, the image data and encoding information extracting unit 220 extracts information on the encoding depth and the encoding mode for the encoding units according to the tree structure for each maximum encoding unit from the parsed bit stream. The extracted information about the coded depth and the coding mode is output to the image data decoder 230. That is, the image data of the bit string may be divided into maximum coding units so that the image data decoder 230 may decode the image data for each maximum coding unit.

Information on the coding depth and coding mode per coding unit can be set for one or more coding depth information, and the information on the coding mode for each coding depth is divided into partition type information of the coding unit, prediction mode information, The size information of the image data, and the like. In addition, as the encoding depth information, depth-based segmentation information may be extracted.

The information about the coded depth and the encoding mode according to the maximum coding units extracted by the image data and the encoding information extractor 220 may be encoded according to the depth according to the maximum coding unit, as in the video encoding apparatus 100 according to an embodiment. Information about a coded depth and an encoding mode determined to repeatedly perform encoding for each unit to generate a minimum encoding error. Therefore, the video decoding apparatus 200 may reconstruct an image by decoding data according to an encoding method that generates a minimum encoding error.

The encoding information for the encoding depth and the encoding mode according to the embodiment may be allocated for a predetermined data unit among the encoding unit, the prediction unit and the minimum unit. Therefore, the image data and the encoding information extracting unit 220 may extract predetermined data Information on the coding depth and coding mode can be extracted for each unit. If the information about the coded depth and the coding mode of the maximum coding unit is recorded for each of the predetermined data units, the predetermined data units having the information about the same coded depth and the coding mode are inferred as data units included in the same maximum coding unit. Can be.

The image data decoder 230 reconstructs the current picture by decoding image data of each maximum coding unit based on the information about the coded depth and the encoding mode for each maximum coding unit. That is, the image data decoding unit 230 decodes the image data encoded based on the read partition type, the prediction mode, and the conversion unit for each coding unit among the coding units according to the tree structure included in the maximum coding unit . The decoding process may include a prediction process including intra prediction and motion compensation, and an inverse process.

The image data decoding unit 230 may perform intra prediction or motion compensation according to each partition and prediction mode for each coding unit based on partition type information and prediction mode information of a prediction unit of each coding depth .

In addition, the image data decoding unit 230 may read the conversion unit information according to the tree structure for each encoding unit for inverse conversion according to the maximum encoding unit, and perform inverse conversion based on the conversion unit for each encoding unit. Through the inverse transformation, the pixel value of the spatial domain of the encoding unit can be restored.

The image data decoding unit 230 can determine the coding depth of the current maximum coding unit using the division information by depth. If the division information indicates that it is no longer divided at the current depth, then the current depth is the depth of the encoding. Therefore, the image data decoder 230 may decode the coding unit of the current depth using the partition type, the prediction mode, and the transformation unit size information of the prediction unit with respect to the image data of the current maximum coding unit.

In other words, the encoding information set for the predetermined unit of data among the encoding unit, the prediction unit and the minimum unit is observed, and the data units holding the encoding information including the same division information are collected, and the image data decoding unit 230 It can be regarded as one data unit to be decoded in the same encoding mode. Information on the encoding mode can be obtained for each encoding unit determined in this manner, and decoding of the current encoding unit can be performed.

In addition, the video decoding apparatus 200 of FIG. 14 may perform the prediction decoding operation of the video prediction decoding apparatus 20 described above with reference to FIG. 2.

The image data and encoding information extractor 220 according to an embodiment may include a quantized transform coefficient of a prediction error generated by prediction according to an embodiment, for each coding unit having a tree structure, from the parsed bitstream. Can be extracted.

Also, the image data and encoding information extractor 220 extracts prediction mode information according to an embodiment while extracting information about a coded depth and an encoding mode for the coding units having a tree structure, from the parsed bitstream. can do. The image data and encoding information extractor 220 may extract reference information and prediction mode information determined by prediction encoding according to an embodiment of the encoding mode information. From the reference information, an index indicating a reference picture, motion information indicating a reference block, and the like may be extracted.

The image data and encoding information extractor 220 may extract reference list related information from prediction mode information regarding pair prediction of a B slice type, according to an exemplary embodiment. For example, the L0 / L1 / LC default number information, the L0 / L1 / LC active number information, the L0 / L1 / LC change information, and the like, which are read by the LC-related information reading unit 12, are the video data and the encoding information. The extraction unit 220 may extract the prediction mode information. Prediction mode information determined by bi-prediction and unidirectional prediction according to an embodiment is for each slice or per sequence including the current partition. Or it may be extracted separately for each picture.

The image data decoder 230 of the video decoding apparatus 200 may perform an operation of the prediction decoder 24 of the video predictive decoding apparatus 20.

The image data decoder 230 may determine coding units having a tree structure and determine partitions for each coding unit by using information about a coded depth and an encoding mode. The image data decoder 230 may reconstruct the prediction error of the coding unit by performing a decoding process including inverse quantization and inverse transformation on the encoded image data for each coding unit of the tree structure of the current image.

The image data decoder 230 may perform prediction decoding on the prediction error based on partitions included for each coding unit of the tree structure. In particular, prediction decoding on a partition of a B slice type capable of pair prediction may be performed using a reference image indicated by the L0 / L1 / LC reference list. The image data decoder 230 may reconstruct the prediction region of the current partition by referring to the reference image indicated by the L0 / L1 / LC reference list in a corresponding reference order.

Accordingly, the image data decoder 230 may generate a reconstructed image of the current image by performing prediction decoding on each partition of the coding unit having a tree structure for each maximum coding unit.

As a result, the video decoding apparatus 200 can recursively perform encoding for each maximum encoding unit in the encoding process, obtain information on the encoding unit that has generated the minimum encoding error, and use the encoded information for decoding the current picture. That is, it is possible to decode the encoded image data of the encoding units according to the tree structure determined as the optimal encoding unit for each maximum encoding unit.

Therefore, even if a high resolution image or an excessively large amount of data is used, the image data can be efficiently used according to the coding unit size and the encoding mode that are adaptively determined according to the characteristics of the image by using the information about the optimum encoding mode transmitted from the encoding end. Can be decoded and restored.

15 illustrates a concept of coding units, according to an embodiment of the present invention.

An example of an encoding unit is that the size of an encoding unit is represented by a width x height, and may include 32x32, 16x16, and 8x8 from an encoding unit having a size of 64x64. The encoding unit of size 64x64 can be divided into the partitions of size 64x64, 64x32, 32x64, 32x32, and the encoding unit of size 32x32 is the partitions of size 32x32, 32x16, 16x32, 16x16 and the encoding unit of size 16x16 is the size of 16x16 , 16x8, 8x16, and 8x8, and a size 8x8 encoding unit can be divided into partitions of size 8x8, 8x4, 4x8, and 4x4.

With respect to the video data 310, the resolution is set to 1920 x 1080, the maximum size of the encoding unit is set to 64, and the maximum depth is set to 2. For the video data 320, the resolution is set to 1920x1080, the maximum size of the coding unit is 64, and the maximum depth is 3. With respect to the video data 330, the resolution is set to 352 x 288, the maximum size of the encoding unit is set to 16, and the maximum depth is set to 1. The maximum depth illustrated in FIG. 9 represents the total number of divisions from the maximum coding unit to the minimum coding unit.

It is preferable that the maximum size of the coding size is relatively large in order to improve the coding efficiency as well as to accurately characterize the image characteristics when the resolution or the data amount is large. Accordingly, the video data 310 or 320 having a higher resolution than the video data 330 may be selected to have a maximum size of 64.

Since the maximum depth of the video data 310 is 2, the encoding unit 315 of the video data 310 is divided into two from the maximum encoding unit having the major axis size of 64, and the depths are deepened by two layers, Encoding units. On the other hand, since the maximum depth of the video data 330 is 1, the encoding unit 335 of the video data 330 divides the encoding unit 335 having a long axis size of 16 by one time, Encoding units.

Since the maximum depth of the video data 320 is 3, the encoding unit 325 of the video data 320 divides the encoding unit 325 from the maximum encoding unit having the major axis size of 64 to 3 times, , 8 encoding units can be included. As the depth increases, the expressive power of the detailed information may be improved.

16 is a block diagram of an image encoding unit based on an encoding unit according to an embodiment of the present invention.

The image encoding unit 400 according to an exemplary embodiment includes operations to encode image data in the encoding unit determination unit 120 of the video encoding device 100. [ That is, the intraprediction unit 410 performs intraprediction on the intra-mode encoding unit of the current frame 405, and the motion estimation unit 420 and the motion compensation unit 425 perform intraprediction on the current frame 405 of the inter- And a reference frame 495, as shown in FIG.

The data output from the intraprediction unit 410, the motion estimation unit 420 and the motion compensation unit 425 are output as quantized transform coefficients through the transform unit 430 and the quantization unit 440. The quantized transform coefficients are restored to the data of the spatial domain through the inverse quantizer 460 and the inverse transformer 470, and the recovered data of the spatial domain is passed through the deblocking block 480 and the loop filtering unit 490. Processed and output to the reference frame 495. The quantized transform coefficients may be output to the bitstream 455 via the entropy encoder 450.

In order to be applied to the video encoding apparatus 100 according to an exemplary embodiment, the intra predictor 410, the motion estimator 420, the motion compensator 425, and the transform unit may be components of the image encoder 400. 430, quantizer 440, entropy encoder 450, inverse quantizer 460, inverse transform unit 470, deblocking unit 480, and loop filtering unit 490 are all maximum for each largest coding unit. In consideration of the depth, a task based on each coding unit among the coding units having a tree structure should be performed.

In particular, the intra prediction unit 410, the motion estimation unit 420, and the motion compensation unit 425 compute the maximum size and the maximum depth of the current maximum encoding unit, And the prediction mode, and the conversion unit 430 determines the size of the conversion unit in each coding unit among the coding units according to the tree structure.

The motion estimator 420 and the motion compensator 425 may determine a L0 / L1 / LC reference list in order to determine a B slice type reference image capable of pair prediction. The LC reference list may be constructed using the reference pictures of the L0 reference list and the L1 reference list by using the basic validity number of the LC reference list set for each picture. In addition, the effective number of reference pictures of the L0 / L1 / LC reference list may be arbitrarily changed for each slice or picture, or the reference picture or reference order of the L0 / L1 / LC reference list may be changed. In this case, the motion estimator 420 may determine the prediction error by performing prediction on the current image using the reference image according to the changed L0 / L1 / LC reference list in the corresponding reference order. Similarly, the motion compensator 425 may generate a reconstructed image by compensating for a prediction error of the current image by using the reference image according to the changed L0 / L1 / LC reference list in the corresponding reference order.

17 is a block diagram of an image decoder based on coding units, according to an embodiment of the present invention.

The bitstream 505 passes through the parsing unit 510 and the encoded image data to be decoded and the encoding-related information necessary for decoding are parsed. The encoded image data is output as inverse quantized data through the entropy decoding unit 520 and the inverse quantization unit 530, and the image data in the spatial domain is restored via the inverse transform unit 540.

For the image data of the spatial domain, the intra prediction unit 550 performs intra prediction on the coding unit of the intra mode, and the motion compensator 560 uses the reference frame 585 together to apply the coding unit of the inter mode. Perform motion compensation for the

Data in the spatial domain that has passed through the intra predictor 550 and the motion compensator 560 may be post-processed through the deblocking unit 570 and the loop filtering unit 580 to be output to the reconstructed frame 595. Further, the post-processed data via deblocking unit 570 and loop filtering unit 580 may be output as reference frame 585.

In order to decode the image data in the image data decoder 230 of the video decoding apparatus 200, step-by-step operations after the parser 510 of the image decoder 500 according to an embodiment may be performed.

In order to be applied to the video decoding apparatus 200 according to an embodiment, the parser 510, the entropy decoder 520, the inverse quantizer 530, and the inverse transform unit 540, which are components of the image decoder 500, may be used. ), The intra predictor 550, the motion compensator 560, the deblocking unit 570, and the loop filtering unit 580 must all perform operations based on coding units having a tree structure for each maximum coding unit. do.

In particular, the intraprediction unit 550 and the motion compensation unit 560 determine the partition and prediction mode for each coding unit according to the tree structure, and the inverse transform unit 540 determines the size of the conversion unit for each coding unit .

The motion compensator 560 may determine a L0 / L1 / LC reference list to determine a reference image of a B slice type capable of pair prediction. The LC reference list may be constructed using the reference pictures of the L0 reference list and the L1 reference list by using the basic validity number of the LC reference list set for each picture. In addition, the effective number of reference pictures of the L0 / L1 / LC reference list may be arbitrarily changed for each slice or picture, or the reference picture or reference order of the L0 / L1 / LC reference list may be changed. In this case, the motion compensator 560 may generate a reconstructed image by compensating for the prediction error of the current image by using the reference image according to the changed L0 / L1 / LC reference list in the corresponding reference order.

18 is a diagram of deeper coding units according to depths, and partitions, according to an embodiment of the present invention.

The video encoding apparatus 100 according to an embodiment and the video decoding apparatus 200 according to an embodiment use hierarchical coding units to consider image characteristics. The maximum height, width, and maximum depth of the coding unit may be adaptively determined according to the characteristics of the image, and may be variously set according to a user's request. According to the maximum size of the preset coding unit, the size of the coding unit for each depth may be determined.

The hierarchical structure 600 of the encoding unit according to an embodiment shows a case where the maximum height and width of the encoding unit is 64 and the maximum depth is 4. In this case, the maximum depth indicates the total number of division from the maximum encoding unit to the minimum encoding unit. Since the depth deepens along the vertical axis of the hierarchical structure 600 of the coding unit according to an embodiment, the height and the width of the coding unit for each depth are divided. Also, a prediction unit and a partition on which the prediction encoding of each deeper coding unit is based on the horizontal axis of the hierarchical structure 600 of the coding unit are shown.

That is, the coding unit 610 has a depth of 0 as the largest coding unit of the hierarchical structure 600 of the coding unit, and the size, ie, the height and width, of the coding unit is 64x64. A depth-1 encoding unit 620 having a size of 32x32, a depth-2 encoding unit 620 having a size 16x16, a depth-3 encoding unit 640 having a size 8x8, a depth 4x4 having a size 4x4, There is an encoding unit 650. An encoding unit 650 of depth 4 of size 4x4 is the minimum encoding unit.

Prediction units and partitions of coding units are arranged along the horizontal axis for each depth. That is, if the encoding unit 610 having a depth 0 size of 64x64 is a prediction unit, the prediction unit is a partition 610 having a size of 64x64, a partition 612 having a size 64x32, 32x64 partitions 614, and size 32x32 partitions 616. [

Likewise, the prediction unit of the 32x32 coding unit 620 having the depth 1 is the partition 620 of the size 32x32, the partitions 622 of the size 32x16, the partition 622 of the size 16x32 included in the coding unit 620 of the size 32x32, And a partition 626 of size 16x16.

Similarly, the prediction unit of the coding unit 630 of size 16x16 having a depth of 2 includes a partition 630 of size 16x16, partitions 632 of size 16x8, and a partition of size 8x16 included in the coding unit 630 of size 16x16. 634, partitions 636 of size 8x8.

Likewise, the prediction unit of the 8x8 encoding unit 640 of depth 3 is a partition 640 of size 8x8, partitions 642 of size 8x4, partitions 642 of size 4x8 included in the encoding unit 640 of size 8x8, 644, and a partition 646 of size 4x4.

Finally, the coding unit 650 of size 4x4 having a depth of 4 is the minimum coding unit and the coding unit of the lowest depth, and the corresponding prediction unit may also be set only as the partition 650 having a size of 4x4.

The coding unit determiner 120 of the video encoding apparatus 100 according to an exemplary embodiment may determine a coding depth of the maximum coding unit 610. The coding unit of each depth included in the maximum coding unit 610. Encoding must be performed every time.

The number of deeper coding units according to depths for including data having the same range and size increases as the depth increases. For example, four coding units of depth 2 are required for data included in one coding unit of depth 1. Therefore, in order to compare the encoding results of the same data for each depth, each of the coding units having one depth 1 and four coding units having four depths 2 should be encoded.

For each depth coding, encoding may be performed for each prediction unit of a coding unit according to depths along a horizontal axis of the hierarchical structure 600 of the coding unit, and a representative coding error, which is the smallest coding error at a corresponding depth, may be selected. . In addition, a depth deeper along the vertical axis of the hierarchical structure 600 of the coding unit, the encoding may be performed for each depth, and the minimum coding error may be searched by comparing the representative coding error for each depth. The depth and partition at which the minimum coding error occurs among the maximum coding units 610 can be selected as the coding depth and the partition type of the maximum coding unit 610. [

19 illustrates a relationship between a coding unit and transformation units, according to an embodiment of the present invention.

The video encoding apparatus 100 according to an embodiment or the video decoding apparatus 200 according to an embodiment encodes or decodes an image in coding units having a size smaller than or equal to the maximum coding unit for each maximum coding unit. The size of the conversion unit for conversion during the encoding process can be selected based on a data unit that is not larger than each encoding unit.

For example, in the video encoding apparatus 100 or the video encoding apparatus 200 according to an embodiment, when the current encoding unit 710 is 64x64 size, the 32x32 conversion unit 720 The conversion can be performed.

In addition, the data of the 64x64 encoding unit 710 is converted into 32x32, 16x16, 8x8, and 4x4 conversion units each having a size of 64x64 or smaller, and then a conversion unit having the smallest error with the original is selected .

20 illustrates encoding information according to depths, according to an embodiment of the present invention.

The output unit 130 of the video encoding apparatus 100 according to one embodiment includes information on the encoding mode, information 800 relating to the partition type, information 810 relating to the prediction mode for each encoding unit of each encoding depth, , And information 820 on the conversion unit size may be encoded and transmitted.

The information about the partition type 800 is a data unit for prediction encoding of the current coding unit and indicates information about a partition type in which the prediction unit of the current coding unit is divided. For example, the current encoding unit CU_0 of size 2Nx2N may be any one of a partition 802 of size 2Nx2N, a partition 804 of size 2NxN, a partition 806 of size Nx2N, and a partition 808 of size NxN And can be divided and used. In this case, the information 800 regarding the partition type of the current encoding unit indicates one of a partition 802 of size 2Nx2N, a partition 804 of size 2NxN, a partition 806 of size Nx2N, and a partition 808 of size NxN .

The prediction mode information 810 indicates a prediction mode of each partition. For example, through the information 810 about the prediction mode, whether the partition indicated by the information 800 about the partition type is predictive encoding is performed in one of the intra mode 812, the inter mode 814, and the skip mode 816. Whether or not can be set.

In addition, the information 820 on the conversion unit size indicates whether to perform conversion based on which conversion unit the current encoding unit is to be converted. For example, the transform unit may be one of a first intra transform unit size 822, a second intra transform unit size 824, a first inter transform unit size 826, and a second intra transform unit size 828. have.

The video data and encoding information extracting unit 210 of the video decoding apparatus 200 according to one embodiment is configured to extract the information 800 about the partition type, the information 810 about the prediction mode, Information 820 on the unit size can be extracted and used for decoding.

21 is a diagram of deeper coding units according to depths, according to an embodiment of the present invention.

Partition information may be used to indicate changes in depth. The division information indicates whether the current-depth encoding unit is divided into lower-depth encoding units.

The prediction unit 910 for predictive encoding of the coding unit 900 having depth 0 and 2N_0x2N_0 size includes a partition type 912 having a size of 2N_0x2N_0, a partition type 914 having a size of 2N_0xN_0, a partition type 916 having a size of N_0x2N_0, and a N_0xN_0. It may include a partition type 918 of size. Only the partitions 912, 914, 916 and 918 in which the prediction unit is divided at the symmetric ratio are exemplified. However, as described above, the partition type is not limited to this and may be an asymmetric partition, an arbitrary type partition, . &Lt; / RTI >

For each partition type, predictive coding must be performed repeatedly for one 2N_0x2N_0 partition, two 2N_0xN_0 partitions, two N_0x2N_0 partitions, and four N_0xN_0 partitions. Prediction encoding may be performed in intra mode and inter mode on partitions having a size 2N_0x2N_0, a size N_0x2N_0 and a size 2N_0xN_0, and a size N_0xN_0. The skip mode may be performed only for predictive encoding on partitions having a size of 2N_0x2N_0.

If the encoding error caused by one of the partition types 912, 914, and 916 of the sizes 2N_0x2N_0, 2N_0xN_0 and N_0x2N_0 is the smallest, there is no need to further divide into lower depths.

If the coding error by the partition type 918 of the size N_0xN_0 is the smallest, the depth 0 is changed to 1 and divided (920), and the coding unit 930 of the partition type of the depth 2 and the size N_0xN_0 is repeatedly encoded The minimum coding error can be retrieved.

The prediction unit 940 for prediction encoding of the coding unit 930 having a depth of 1 and a size of 2N_1x2N_1 (= N_0xN_0) includes a partition type 942 having a size of 2N_1x2N_1, a partition type 944 having a size of 2N_1xN_1, and a partition type having a size of N_1x2N_1. 946, a partition type 948 of size N_1 × N_1 may be included.

If the coding error by the partition type 948 having the size N_1xN_1 size is the smallest, the depth 1 is changed to the depth 2 and divided (950), and repeatedly performed on the coding units 960 of the depth 2 and the size N_2xN_2 Encoding can be performed to search for the minimum coding error.

If the maximum depth is d, the depth-based coding unit is set up to the depth d-1, and the division information can be set up to the depth d-2. That is, when encoding is performed from the depth d-2 to the depth d-1 to the depth d-1, the prediction encoding of the coding unit 980 of the depth d-1 and the size 2N_ (d-1) x2N_ (d-1) The prediction unit for 990 is a partition type 992 of size 2N_ (d-1) x2N_ (d-1), partition type 994 of size 2N_ (d-1) xN_ (d-1), size A partition type 996 of N_ (d-1) x2N_ (d-1) and a partition type 998 of size N_ (d-1) xN_ (d-1) may be included.

Among the partition types, one partition 2N_ (d-1) x2N_ (d-1), two partitions 2N_ (d-1) xN_ (d-1), two sizes N_ (d-1) x2N_ By encoding through prediction encoding repeatedly for each partition of (d-1) and four partitions of size N_ (d-1) xN_ (d-1), a partition type for generating a minimum encoding error may be searched. .

Even if the encoding error of the partition type 998 of size N_ (d-1) xN_ (d-1) is the smallest, the maximum depth is d, so the coding unit CU_ (d-1) of the depth d-1 is no longer The encoding depth of the current maximum coding unit 900 may be determined as the depth d-1, and the partition type may be determined as N_ (d-1) xN_ (d-1) without going through a division process into lower depths. Also, since the maximum depth is d, the division information is not set for the encoding unit 952 of the depth d-1.

The data unit 999 may be referred to as a 'minimum unit' for the current maximum coding unit. The minimum unit according to an exemplary embodiment may be a quadrangle data unit having a minimum coding unit having the lowest coding depth divided into quadrants. Through the iterative coding process, the video coding apparatus 100 according to an embodiment compares the coding errors of the coding units 900 to determine the coding depth, selects the depth at which the smallest coding error occurs, determines the coding depth, The corresponding partition type and the prediction mode can be set to the coding mode of the coding depth.

In this way, the depth with the smallest error can be determined by comparing the minimum coding errors for all depths of depths 0, 1, ..., d-1, d, and can be determined as the coding depth. The coding depth, and the partition type and prediction mode of the prediction unit can be encoded and transmitted as information on the encoding mode. In addition, since the coding unit must be split from the depth 0 to the coded depth, only the split information of the coded depth is set to '0', and the split information for each depth except the coded depth should be set to '1'.

The video data and encoding information extracting unit 220 of the video decoding apparatus 200 according to an exemplary embodiment extracts information on the encoding depth and the prediction unit for the encoding unit 900 and uses the information to extract the encoding unit 912 . The video decoding apparatus 200 according to an embodiment may identify a depth having split information of '0' as a coding depth using split information for each depth, and may use the decoding depth by using information about an encoding mode for a corresponding depth. have.

22, 23, and 24 illustrate a relationship between a coding unit, a prediction unit, and a transformation unit, according to an embodiment of the present invention.

The coding units 1010 are coding units according to coding depths determined by the video encoding apparatus 100 according to an embodiment with respect to the maximum coding unit. The prediction unit 1060 is a partition of prediction units of each coding depth unit in the coding unit 1010, and the conversion unit 1070 is a conversion unit of each coding depth unit.

If the depth-based coding units 1010 have a depth of 0, the coding units 1012 and 1054 have a depth of 1, and the coding units 1014, 1016, 1018, 1028, 1050, and 1052 have depths. 2, coding units 1020, 1022, 1024, 1026, 1030, 1032, and 1048 have a depth of three, and coding units 1040, 1042, 1044, and 1046 have a depth of four.

Some partitions 1014, 1016, 1022, 1032, 1048, 1050, 1052, and 1054 among the prediction units 1060 are in the form of a segment of a coding unit. That is, the partitions 1014, 1022, 1050 and 1054 are 2NxN partition types, the partitions 1016, 1048 and 1052 are Nx2N partition type, and the partition 1032 is NxN partition type. The prediction units and the partitions of the depth-dependent coding units 1010 are smaller than or equal to the respective coding units.

The image data of a part 1052 of the conversion units 1070 is converted or inversely converted into a data unit smaller in size than the encoding unit. The conversion units 1014, 1016, 1022, 1032, 1048, 1050, 1052, and 1054 are data units of different sizes or types when compared with the prediction units and the partitions of the prediction units 1060. In other words, the video coding apparatus 100 according to the embodiment and the video decoding apparatus 200 according to the embodiment can perform the intra prediction / motion estimation / motion compensation operation for the same coding unit and the conversion / Each can be performed on a separate data unit basis.

Thus, for each maximum encoding unit, the encoding units are recursively performed for each encoding unit hierarchically structured in each region, and the optimal encoding unit is determined, so that encoding units according to the recursive tree structure can be constructed. The encoding information may include split information about a coding unit, partition type information, prediction mode information, and transformation unit size information. Table 1 below shows an example that can be set in the video encoding apparatus 100 according to the embodiment and the video decoding apparatus 200 according to an embodiment.

Partition information 0 (encoding for the encoding unit of size 2Nx2N of current depth d) Partition information 1 Prediction mode Partition type Conversion unit size For each sub-depth d + 1 encoding units, Intra
Inter

Skip (2Nx2N only) Symmetrical partition type Asymmetric partition type Conversion unit partition information 0 Conversion unit
Partition information 1 2Nx2N
2NxN
Nx2N
NxN 2NxnU
2NxnD
nLx2N
nRx2N 2Nx2N NxN
(Symmetrical partition type)

N / 2xN / 2
(Asymmetric partition type)

The output unit 130 of the video encoding apparatus 100 according to an embodiment outputs encoding information about coding units having a tree structure, and the encoding information extraction unit of the video decoding apparatus 200 according to an embodiment ( 220 may extract encoding information about coding units having a tree structure from the received bitstream.

The split information indicates whether the current coding unit is split into coding units of a lower depth. If the division information of the current depth d is 0, since the depth at which the current encoding unit is not further divided into the current encoding unit is the encoding depth, the partition type information, prediction mode, and conversion unit size information are defined . If it is to be further split by the split information, encoding should be performed independently for each coding unit of the divided four lower depths.

The prediction mode may be represented by one of an intra mode, an inter mode, and a skip mode. Intra mode and inter mode can be defined in all partition types, and skip mode can be defined only in partition type 2Nx2N.

The partition type information indicates symmetrical partition types 2Nx2N, 2NxN, Nx2N and NxN in which the height or width of the predicted unit is divided into symmetrical proportions and asymmetric partition types 2NxnU, 2NxnD, nLx2N, nRx2N divided by the asymmetric ratio . Asymmetric partition types 2NxnU and 2NxnD are respectively divided into heights 1: 3 and 3: 1, and asymmetric partition types nLx2N and nRx2N are respectively divided into 1: 3 and 3: 1 widths.

The conversion unit size may be set to two kinds of sizes in the intra mode and two kinds of sizes in the inter mode. That is, if the conversion unit division information is 0, the size of the conversion unit is set to the size 2Nx2N of the current encoding unit. If the conversion unit division information is 1, a conversion unit of the size where the current encoding unit is divided can be set. Also, if the partition type for the current encoding unit of size 2Nx2N is a symmetric partition type, the size of the conversion unit may be set to NxN, or N / 2xN / 2 if it is an asymmetric partition type.

Encoding information of coding units having a tree structure according to an embodiment may be allocated to at least one of a coding unit, a prediction unit, and a minimum unit unit of a coding depth. The coding unit of the coding depth may include one or more prediction units and minimum units having the same coding information.

Therefore, if the encoding information held by each adjacent data unit is checked, it may be determined whether the adjacent data units are included in the coding unit having the same coding depth. In addition, since the encoding unit of the encoding depth can be identified by using the encoding information held by the data unit, the distribution of encoding depths within the maximum encoding unit can be inferred.

Therefore, in this case, when the current encoding unit is predicted with reference to the neighboring data unit, the encoding information of the data unit in the depth encoding unit adjacent to the current encoding unit can be directly referenced and used.

In another embodiment, when prediction encoding is performed by referring to a neighboring coding unit, data adjacent to the current coding unit in a depth-specific coding unit is encoded by using encoding information of adjacent coding units. The neighboring coding unit may be referred to by searching.

FIG. 25 illustrates a relationship between coding units, prediction units, and transformation units, according to encoding mode information of Table 1. FIG.

The maximum coding unit 1300 includes coding units 1302, 1304, 1306, 1312, 1314, 1316, and 1318 of the coding depth. Since one of the encoding units 1318 is a coding unit of the encoding depth, the division information may be set to zero. The partition type information of the encoding unit 1318 of the size 2Nx2N is the partition type information of the partition type 2Nx2N 1322, 2NxN 1324, Nx2N 1326, NxN 1328, 2NxnU 1332, 2NxnD 1334, nLx2N 1336, And < RTI ID = 0.0 > nRx2N 1338 < / RTI >

The TU size flag is a kind of conversion index, and the size of the conversion unit corresponding to the conversion index can be changed according to the prediction unit type or partition type of the coding unit.

For example, when the partition type information is set to one of the symmetric partition types 2Nx2N 1322, 2NxN 1324, Nx2N 1326 and NxN 1328, if the conversion unit division information is 0, the conversion unit of size 2Nx2N 1342) is set, and if the conversion unit division information is 1, the conversion unit 1344 of size NxN can be set.

When the partition type information is set to one of the asymmetric partition types 2NxnU 1332, 2NxnD 1334, nLx2N 1336 and nRx2N 1338, if the TU size flag is 0, the conversion unit of size 2Nx2N 1352) is set, and if the conversion unit division information is 1, a conversion unit 1354 of size N / 2xN / 2 can be set.

26 is a flowchart of a video encoding method based on coding units having a tree structure, according to an embodiment of the present invention.

In operation 1210, the current image is split into at least one maximum coding unit. In addition, a maximum depth indicating the total number of possible divisions may be set in advance.

In operation 1220, the depth of the at least one partitioned region in which the region of the largest coding unit is divided for each depth is encoded. The depth at which the final encoding result is output for each of the at least one divided region is determined, and the coding unit according to the tree structure is determined.

The maximum coding unit is spatially divided whenever the depth is deep, and is divided into coding units of a lower depth. Each coding unit may be divided into coding units having a lower depth while being spatially divided independently of other adjacent coding units. Encoding must be repeatedly performed for each coding unit for each depth.

Among coding units having a hierarchical structure obtained by dividing a current image, prediction and compensation operations may be performed on prediction units and partitions included in each coding unit. For pair prediction of a B slice type partition, a L0 / L1 / LC reference list may be used to determine a reference picture.

The prediction error of the current partition may be determined by performing prediction encoding on the current partition by referring to the reference image for unidirectional prediction indicated by the L0 / L1 / LC reference list according to the reference order. In addition, in order to compensate for the motion of the prediction error of the current partition, the prediction region of the current partition may be restored as the reference image indicated by the L0 / L1 / LC reference list is referenced according to the reference order. Coding units having a coding depth determined in this manner may be determined as a coding unit having a tree structure.

In operation 1230, image data, which is a final encoding result of at least one divided region, for each maximum coding unit, and information about an encoding depth and an encoding mode are output. The information about the encoding mode may include information about the coded depth or split information, partition type information of a prediction unit, prediction mode information, and the like.

That is, for each largest coding unit, a quantized transform coefficient of a prediction error generated by bi-prediction and unidirectional prediction may be output for each coding unit having a tree structure.

Information about a coded depth and an encoding mode constituting coding units having a tree structure according to an embodiment may be encoded and output. Reference information including an index indicating a reference image determined by bi-prediction and unidirectional prediction, motion information indicating a reference block, and the like may be output together with a quantized transform coefficient of a prediction error and prediction mode information. have.

As prediction mode information about pair prediction of a B slice type according to an embodiment, reference list related information may be encoded and output. For example, L0 / L1 / LC default number information, L0 / L1 / LC active number related information, L0 / L1 / LC change related information, etc. may be encoded and output as prediction mode information. Reference list related information for pair prediction according to an embodiment may be encoded for each slice including the current partition, for each sequence, or for each picture.

The information about the encoded encoding mode may be transmitted to the decoding end together with the encoded image data.

27 is a flowchart of a video decoding method based on coding units, according to a tree structure, according to an embodiment of the present invention.

In step 1310, the bitstream for the encoded video is received and parsed.

In operation 1320, image data of the current picture allocated to the largest coding unit having the maximum size, and information about a coded depth and an encoding mode for each largest coding unit are extracted from the parsed bitstream. The coded depth of each largest coding unit is a depth selected to have the smallest coding error for each largest coding unit in the encoding process of the current picture. In encoding by the largest coding unit, image data is encoded based on at least one data unit obtained by hierarchically dividing the maximum coding unit by depth.

According to the information about the coding depth and the encoding mode according to an embodiment, the maximum coding unit may be split into coding units having a tree structure. Coding units according to coding units having a tree structure are coding units of coding depths, respectively. Accordingly, the efficiency of encoding and decoding of an image can be improved by decoding the respective image data after determining the coding depth of each coding unit.

As information about an encoding mode in an embodiment, reference information and prediction mode information for prediction decoding according to an embodiment may be extracted. As reference information for prediction decoding according to an embodiment, an index indicating a reference image, motion information, and the like may be extracted.

As prediction mode information for bi-prediction and unidirectional prediction of a B slice type image, L0 / L1 / LC default number information, L0 / L1 / LC active number related information, and L0 / L1 / LC change Reference list related information including related information may be extracted. According to an exemplary embodiment, the L0 / L1 / LC default number information may be read for each picture. According to an exemplary embodiment, the L0 / L1 / LC active number related information and the L0 / L1 / LC change related information may be read per slice, per picture, or per sequence.

In operation 1330, image data of each maximum coding unit is decoded based on the information about the coded depth and the encoding mode for each maximum coding unit. While decoding is performed on the current coding unit based on the information about the coded depth and the encoding mode, a prediction unit or a partition is determined based on the partition type information, and a prediction mode is determined for each partition based on the prediction mode information. Predictive decoding may be performed for each.

For motion compensation on a partition of a B slice type capable of pair prediction, a reference list including a reference picture and a reference order may be determined. By referring to the reference images indicated by the L0 / L1 / LC reference list and the corresponding reference order, a restoration region may be generated by performing motion compensation on a prediction error of a partition.

For each coding unit, image data of a spatial region may be reconstructed while decoding is performed for each maximum coding unit, and a picture and a video, which is a picture sequence, may be reconstructed. The restored video can be played back by the playback apparatus, stored in a storage medium, or transmitted over a network.

The above-described embodiments of the present invention can be embodied in a general-purpose digital computer that can be embodied as a program that can be executed by a computer and operates the program using a computer-readable recording medium. The computer-readable recording medium may include a storage medium such as a magnetic storage medium (eg, a ROM, a floppy disk, a hard disk, etc.) and an optical reading medium (eg, a CD-ROM, a DVD, etc.).

So far I looked at the center of the preferred embodiment for the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims

In the video predictive encoding method,
A base of a reference picture assigned to the LC reference list for an LC reference list including L0 reference list, which is list information of a reference picture for predictive encoding of an image having a B slice type, and at least one reference picture included in the L1 reference list. Setting LC default number information indicating the effective number for each picture;
Determining the LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information; And
Predicting encoding the B slice type image using the determined LC reference list.

The method of claim 1, wherein the setting of the LC default number information for each picture comprises:
LC active indicating whether the effective number of reference images allocated to the LC reference list is arbitrarily changed based on the reference list active number change confirmation information indicating whether or not the effective number of reference images of any reference list is changed for each slice. And setting the number change confirmation information and the LC active number information indicating the current valid number of the reference image after the random change for each slice.

The method of claim 1, wherein the setting of the LC default number information for each picture comprises:
And setting, for each slice, LC change related information including information on a method of changing a reference picture or a reference order of the LC reference list.

The method of claim 1, wherein the video predictive encoding method comprises:
And transmitting the LC combination acknowledgment information indicating whether to construct the LC reference list using one or more reference images of the L0 reference list and the L1 reference list.

The method of claim 1, wherein the setting of the LC default number information for each picture comprises:
The LC default number information together with at least one of L0 default number information indicating a basic valid number of reference pictures allocated to the L0 reference list and L1 default number information indicating a basic valid number of reference pictures allocated to the L1 reference list And setting the picture for each picture.

The method of claim 1, wherein the setting of the LC active number information for each slice comprises:
For each slice, based on the reference list active number change confirmation information indicating whether the effective number of the reference image is randomly changed, L0 active number information indicating the current valid number of reference images of the L0 reference list after the random change and the random number Setting LC active number information indicating a current valid number of reference images of the LC reference list after the random change together with at least one of L1 active number information indicating a current valid number of reference images in the L1 reference list after the change; Video prediction encoding method comprising a.

The method of claim 3, wherein the setting of the LC change related information for each slice comprises:
At least one of L0 change related information including information about a reference image or a reference order of the L0 reference list and information about a method of changing the reference image or reference order of the L1 reference list; And setting the LC change related information for each slice.

The method of claim 1, wherein the video predictive encoding method comprises:
And transmitting the LC default number information together with the parameters for the current picture.

The video prediction encoding method of claim 2,
And transmitting the LC active number information together with parameters for a current slice.

The method of claim 3, wherein the video predictive encoding method comprises:
And transmitting the LC change related information together with parameters for a current slice.

In the video predictive decoding method,
A reference picture allocated to the LC reference list for each picture for an LC reference list including L0 reference list, which is list information of a reference picture for predictive decoding of an image having a B slice type, and at least one reference picture included in the L1 reference list. Reading LC default number information indicating the basic effective number of;
Determining the LC reference list including at least one reference picture among the reference pictures included in the LO reference list and the L1 reference list based on the LC default number information; And
Predicting and decoding the B slice type image using the determined LC reference list.

The method of claim 11, wherein the reading of the LC default number information for each picture comprises:
LC active indicating whether the effective number of reference images allocated to the LC reference list is arbitrarily changed based on the reference list active number change confirmation information indicating whether or not the effective number of reference images of any reference list is changed for each slice. Reading the number change confirmation information; And
And reading LC active number information indicating a current valid number of reference images of the LC reference list after the random change, based on the read LC active number change confirming information.

The method of claim 11, wherein the reading of the LC default number information for each picture comprises:
And reading LC change related information including information on a reference image of the LC reference list or a method of changing the reference order for each slice.

12. The method of claim 11, wherein determining the LC reference list comprises:
Video prediction decoding, characterized in that the LC reference list can be determined without reading LC combination confirmation information indicating whether to construct the LC reference list using one or more reference images of the L0 reference list and the L1 reference list. Way.

The method of claim 11, wherein the reading of the LC default number information for each picture comprises:
The LC default number information together with at least one of L0 default number information indicating a basic valid number of reference pictures allocated to the L0 reference list and L1 default number information indicating a basic valid number of reference pictures allocated to the L1 reference list And decoding the pictures for each of the pictures.

The method of claim 11, wherein the reading of the LC default number information for each picture comprises:
Reading reference list active number change confirmation information indicating whether the effective number of the reference image is randomly changed for each slice;
L0 active number information indicating the current valid number of reference images of the L0 reference list after the random change based on the read reference list active number change confirming information, and the current validity of the reference image of the L1 reference list after the random change. And reading LC active number information indicating a current valid number of reference images of the LC reference list after at least one of the L1 active number information indicating the number.

14. The method of claim 13, wherein reading LC change related information for each slice comprises:
At least one of L0 change related information including information about a reference image or a reference order of the L0 reference list and information about a method of changing the reference image or reference order of the L1 reference list; And reading the LC change related information for each slice.

The method of claim 11, wherein the reading of the LC default number information for each picture comprises:
Extracting, from the received video stream, the LC default number information along with parameters for a current picture; And
And reading out the extracted LC default number information.

The method of claim 12, wherein reading LC active number information for each slice comprises:
Extracting, from the received video stream, the LC active number information along with parameters for the current slice; And
And decoding the extracted LC active number information.

14. The method of claim 13, wherein reading LC active number information for each slice comprises:
Extracting, from the received videostream, the LC change related information along with parameters for the current slice; And
And reading out the extracted LC change related information.

In the video predictive encoding apparatus,
A base of a reference picture assigned to the LC reference list for an LC reference list including L0 reference list, which is list information of a reference picture for predictive encoding of an image having a B slice type, and at least one reference picture included in the L1 reference list. An LC-related information setting unit for setting LC default number information indicating the effective number for each picture; And
Based on the LC default number information, the LC reference list including one or more reference images among the reference pictures included in the LO reference list and the L1 reference list is determined, and the B slice is determined using the determined LC reference list. And a predictive encoding unit configured to predictively encode an image of a type.

In the video predictive decoding apparatus,
A reference picture allocated to the LC reference list for each picture for an LC reference list including L0 reference list, which is list information of a reference picture for predictive decoding of an image having a B slice type, and at least one reference picture included in the L1 reference list. An LC-related information reading section for reading LC default number information indicating a basic valid number of; And
Based on the LC default number information, the LC reference list including one or more reference images among the reference pictures included in the LO reference list and the L1 reference list is determined, and the B slice is determined using the determined LC reference list. And a predictive decoding unit configured to predict and decode an image of a type.

A computer-readable recording medium having recorded thereon a program for implementing the video predictive encoding method according to any one of claims 1 to 10.

21. A computer-readable recording medium having recorded thereon a program for computerically implementing the video predictive decoding method according to any one of claims 11 to 20.