KR101677276B1 - Method and apparatus for video encoding by motion prediction using arbitrary partition, and method and apparatus for video decoding by motion compensation using arbitrary partition - Google Patents

Abstract

The video coding method according to claim 1, further comprising the steps of: dividing the video data into at least one maximum coding unit which is a coding unit of a maximum size; and inter prediction using a partition in which coding units are divided at an arbitrary ratio, The coding depth is determined to be the depth at which the coding result is to be outputted, and the coding depth of the coded video data corresponding to the coding depth of each divided area, coding A video encoding method and apparatus for outputting a bit stream including information on a depth and an encoding mode are disclosed.

Description

[0001] The present invention relates to a method and apparatus for video coding according to motion prediction using arbitrary partitions, and a video decoding method and apparatus using motion compensation using arbitrary partitions. by motion compensation using arbitrary partition}

The present invention relates to encoding and decoding of video.

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 existing video codec, video is encoded according to a limited encoding method based on a macroblock of a predetermined size.

Inter prediction of an existing video codec estimates motion of a macroblock by estimating a motion vector using 2Nx2N, 2NxN, Nx2N, and NxN sized partitions of 2Nx2N macroblocks.

The present invention relates to video coding and video decoding in accordance with inter prediction using an arbitrary type of partition.

A video encoding method according to an embodiment of the present invention includes dividing video data into at least one maximum encoding unit which is a maximum-size encoding unit, And inter prediction using the partition in which the coding unit is divided at an arbitrary ratio so that the depth coding of the hierarchical structure in which the coding unit of the higher depth is divided according to at least one of the divided regions of the maximum coding unit Encoding the video data of the maximum encoding unit on the basis of a unit and determining an encoding depth which is a depth at which the encoding result is output; And outputting a bitstream including information on the encoded video data, the coding depth and the coding mode corresponding to the coding depth for each of the divided areas, for each of the maximum coding units.

An encoding unit according to an embodiment may be characterized by a maximum size and a depth.

Depth indicates a stage in which coding units are hierarchically divided. As the depth increases, the depth coding units can be divided from the maximum coding unit to the minimum coding unit. In the present specification, it is defined that the depth is deepened from a high depth or a high depth toward a low depth or a bottom depth. As the depth increases, the number of division of the maximum encoding unit increases and the total number of divisions of the maximum encoding unit corresponds to 'maximum depth'. The maximum size and the maximum depth of the encoding unit may be preset.

The coding depth determination step may include selectively determining whether or not to perform inter prediction using the partition in which the coding unit is divided at an arbitrary ratio.

The output step may include information indicating whether the partition type for inter prediction includes a partition for dividing the coding unit at an arbitrary ratio in the bitstream.

According to an exemplary embodiment, at least one of the height and the width of the coding unit may be divided into one to three or three to one.

The maximum encoding unit according to an exemplary embodiment may be selectively set to at least one of 16x16, 32x32, 64x64, 128x128, and 256x256 blocks.

The coding depth according to an exemplary embodiment is determined by the depth of a coding unit for each depth of coding efficiency among coding results based on depth coding units according to the hierarchical structure of the corresponding divided area, The coding depth can be independently determined for each of at least one divided area within the area.

According to an embodiment of the present invention, there is provided a video decoding method including: receiving and parsing a bitstream of encoded video; Extracting, from the bitstream, video data encoded for each maximum encoding unit and information on a coding depth and a coding mode for each maximum encoding unit; And motion compensation using a partition in which the coding unit is partitioned at an arbitrary rate for each coding unit of at least one coding depth for each maximum coding unit based on information on the coding depth and coding mode for the maximum coding unit Wherein the coding unit for each coding depth is determined as one of the depths of the coding units of each layer of the hierarchical structure for each of at least one of the divided areas of the maximum coding unit.

The extracting step may further extract information indicating whether a partition type for inter prediction from the bitstream includes a partition for dividing the coding unit at an arbitrary ratio.

The decoding step according to an exemplary embodiment may further include a step of performing, on the basis of information indicating whether the partition type for inter prediction from the bit stream includes a partition for dividing the coding unit at an arbitrary ratio, It is possible to selectively determine whether to perform motion compensation using the partition.

A video encoding apparatus according to an embodiment of the present invention includes: a maximum encoding unit division unit that divides video data into at least one maximum encoding unit that is a maximum-size encoding unit; And inter prediction using the partition in which the coding unit is divided at an arbitrary ratio so that the depth coding of the hierarchical structure in which the coding unit of the higher depth is divided according to at least one of the divided regions of the maximum coding unit An encoding unit that encodes the video data of the maximum encoding unit based on a unit and determines a depth of encoding at which a result of encoding is output; And an output unit for outputting a bitstream including information on the encoded video data, the encoding depth, and the encoding mode corresponding to the encoding depth for each of the divided areas, for each maximum encoding unit

According to an aspect of the present invention, there is provided a video decoding apparatus including: a parser for receiving and parsing a bitstream of encoded video; An extraction unit for extracting, from the bitstream, video data encoded for each maximum encoding unit and information on a coding depth and an encoding mode for each maximum encoding unit; And motion compensation using a partition in which the coding unit is partitioned at an arbitrary rate for each coding unit of at least one coding depth for each maximum coding unit based on information on the coding depth and coding mode for the maximum coding unit Wherein the coding unit for each coding depth is determined as one of the depths of the coding units of each layer in the hierarchical structure for each of at least one of the divided areas of the maximum coding unit.

The present invention includes a computer-readable recording medium on which a program for implementing a video encoding method according to an embodiment is recorded. The present invention also includes a computer-readable recording medium on which a program for implementing a video decoding method according to an embodiment is recorded.

1 shows a block diagram of a video encoding apparatus according to an embodiment of the present invention.
2 shows a block diagram of a video decoding apparatus according to an embodiment of the present invention.
FIG. 3 illustrates a concept of an encoding unit according to an embodiment of the present invention.
4 is a block diagram of an image encoding unit based on an encoding unit according to an embodiment of the present invention.
5 is a block diagram of an image decoding unit based on an encoding unit according to an embodiment of the present invention.
FIG. 6 illustrates a depth-based coding unit and a prediction unit according to an embodiment of the present invention.
FIG. 7 shows a relationship between an encoding unit and a conversion unit according to an embodiment of the present invention.
FIG. 8 illustrates depth-specific encoding information, in accordance with an embodiment of the present invention.
FIG. 9 shows a depth encoding unit according to an embodiment of the present invention.
FIGS. 10A, 10B, and 10C illustrate the relationship between an encoding unit, a prediction unit, and a frequency conversion unit according to an embodiment of the present invention.
FIG. 11 shows encoding information for each encoding unit according to an embodiment of the present invention.
12 shows a flowchart of a video coding method according to an embodiment of the present invention.
13 shows a flowchart of a video decoding method according to an embodiment of the present invention.
FIG. 14 shows a block diagram of a video encoding apparatus according to inter prediction using a partition divided at an arbitrary ratio according to an embodiment.
FIG. 15 shows a block diagram of a video decoding apparatus by inter prediction using a partition divided at an arbitrary ratio according to an embodiment.
Figure 16 illustrates exemplary partitions in which an encoding unit is partitioned at an arbitrary rate, according to one embodiment.
17 shows a syntax of a sequence parameter set including information indicating whether or not to include a partition dividing an encoding unit at an arbitrary ratio, according to an embodiment.
FIG. 18 shows a flowchart of a video coding method according to inter prediction using a partition divided at an arbitrary ratio according to an embodiment.
19 shows a flowchart of a video decoding method by inter prediction using a partition divided at an arbitrary ratio according to an embodiment.

Hereinafter, a video encoding apparatus and a video decoding apparatus, a video encoding method, and a video decoding method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 27. Coding of video and decoding of video based on spatially hierarchical data units according to an embodiment of the present invention will be described below with reference to FIGS. 1 through 13, and with reference to FIGS. 14 through 19, Video coding and video decoding according to inter prediction using a partitioned partition will be described below.

Hereinafter, a video encoding apparatus, a video encoding apparatus, a video encoding method, and a video decoding method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 13.

1 shows a block diagram of a video encoding apparatus according to an embodiment of the present invention.

The video coding apparatus 100 according to an embodiment includes a maximum coding unit division unit 110, a coding depth determination unit 120, and an output unit 130.

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 image data may be output to the coding depth determination unit 120 for each of at least one maximum coding unit.

An encoding unit according to an embodiment may be characterized by a maximum size and a depth. Depth indicates a stage in which coding units are hierarchically divided. As the depth increases, the depth coding units can be divided from the maximum coding unit to the minimum coding unit. The depth of the maximum encoding unit is the highest depth and the minimum encoding unit can be defined as the least significant encoding unit. As the depth of the maximum encoding unit increases, the size of the depth-dependent encoding unit decreases, so that the encoding unit of the higher depth may include a plurality of lower-depth encoding units.

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

The maximum depth for limiting the total number of times the height and width of the maximum encoding unit can be hierarchically divided and the maximum size of the encoding unit may be preset.

The coding depth determiner 120 encodes at least one divided area in which the area of the maximum coding unit is divided for each depth, and determines the depth at which the final coding result is output for each of at least one of the divided areas. That is, the coding depth 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 depth coding for each maximum coding unit of the current picture. The determined coding depth and the image data of each coding unit are output to the output unit 130.

The image data in the maximum encoding unit is encoded based on the depth encoding unit according to at least one depth below the maximum depth, and the encoding results based on the respective depth encoding units are compared. As a result of the comparison of the encoding error of the depth-dependent encoding unit, the depth with the smallest encoding error can be selected. At least one coding depth may be determined for each maximum coding unit.

As the depth of the maximum encoding unit increases, the encoding unit is hierarchically divided and divided, and the number of encoding units increases. In addition, even if encoding units of the same depth included in one maximum encoding unit, the encoding error of each data is measured and it is determined whether or not the encoding unit is divided into lower depths. Therefore, even if the data included in one maximum coding unit has a different coding error according to the position, the coding depth can be determined depending on 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 divided according to one or more coding depth encoding units.

The predictive encoding and frequency conversion of the maximum encoding unit can be performed. Likewise, predictive coding and frequency conversion are performed on the basis of the depth coding unit for each maximum coding unit and for each depth below the maximum depth.

Since the number of coding units per depth is increased every time the maximum coding unit is divided by the depth, the coding including the predictive coding and the frequency conversion should be performed for every depth coding unit as the depth increases. For convenience of explanation, predictive coding and frequency conversion will be described based on a coding unit 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. To encode the image data, a step such as predictive encoding, frequency conversion, and entropy encoding is performed. The same data unit may be used for all steps, and the data unit may be changed step by step.

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

For predictive coding of the maximum coding unit, predictive coding may be performed based on the partial data unit of the coding unit for each depth of the maximum coding unit. The partial data unit of the encoding unit may include a data unit in which at least one of the height and the width of the encoding unit and the depth encoding unit is divided.

For example, when the size of the encoding unit is 2Nx2N (where N is a positive integer), the size of the partial data unit may be 2Nx2N, 2NxN, Nx2N, NxN, and the like. Prediction coding may be performed based on data units of various types, in addition to data units of a type in which at least one of the height and the width of an encoding unit is divided by half. Hereinafter, a data unit on which prediction encoding is based may be referred to as a 'prediction unit'.

The prediction mode of the encoding 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 can be performed for prediction units of 2Nx2N, 2NxN, Nx2N, and NxN sizes. In addition, the skip mode can be performed only for a prediction unit of 2Nx2N size. Encoding is performed independently for each prediction unit within an encoding unit, and a prediction mode having the smallest encoding error can be selected.

In addition, the video encoding apparatus 100 according to an exemplary embodiment may perform frequency 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 frequency conversion of a coding unit, frequency conversion may be performed based on a data unit having a size smaller than or equal to the coding unit. For example, a data unit for frequency conversion may include a data unit for intra mode and a data unit for inter mode. Hereinafter, the data unit on which the frequency conversion is based may be referred to as a 'conversion unit'.

The coding information according to the coding depth needs not only the coding depth but also prediction related information and frequency conversion related information. Therefore, the coding depth determiner 120 not only determines the coding depth at which the minimum coding error is generated, but also the partition type in which the coding unit of the coding depth is divided into prediction units, the prediction unit-specific prediction mode, Can be determined.

The coding depth determination unit 120 may measure the coding error of the depth-dependent coding 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 depth determination unit 120 and information on the depth encoding mode.

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

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

The coding depth information can be defined using depth division information indicating whether or not coding is performed at the lower depth coding unit without coding at the current depth. If the current depth of the current encoding unit is the encoding depth, the current encoding unit is encoded in the current depth encoding unit, so that the division information of the current depth can be defined so as not to be further divided into lower depths. On the other hand, if the current depth of the current encoding unit is not the encoding depth, the encoding using the lower depth encoding unit should be tried. Therefore, the division information of the current depth may be defined to be divided into the lower depth encoding units.

If the current depth is not the encoding depth, encoding is performed on the encoding unit divided into lower-depth encoding units. Since there are one or more lower-level coding units in the current-depth coding unit, the coding is repeatedly performed for each lower-level coding unit so that recursive coding can be performed for each coding unit of the same depth.

At least one coding depth is determined in one maximum coding unit and at least one coding mode information is determined for each coding depth so that information on at least one coding mode can be 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 set the corresponding encoding information for each minimum encoding unit included in the maximum encoding unit. That is, the coding unit of the coding depth includes at least one minimum coding unit that holds the same coding information. By using this, if the neighboring minimum encoding units have the same depth encoding information, it can be the minimum encoding unit included in the same maximum encoding 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 under-coding-by-depth coding unit information 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 the header of the bitstream.

According to the simplest embodiment of the video coding apparatus 100, the coding unit for depth is a coding unit which is half the height and width of the coding unit of one layer higher depth. That is, if the size of the current depth encoding unit is 2Nx2N, the size of the lower depth encoding unit is NxN. In addition, the current encoding unit of 2Nx2N size can include a maximum of 4 sub-depth encoding units of NxN size.

Therefore, the video decoding apparatus 100 according to an embodiment determines an encoding unit of an 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 . In addition, since each encoding unit can be encoded by various prediction modes, frequency 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.

2 shows a block diagram of a video decoding apparatus according to an embodiment of the present invention.

The video decoding apparatus 200 includes a receiving unit 210, an image data and encoding information extracting unit 220, and an image data decoding unit 230. The definition of various terms such as coding unit, depth, prediction unit, conversion unit, and information on various coding modes for various processing of the video decoding apparatus 200 according to an embodiment is the same as that of FIG. 1 and the video coding apparatus 100 Are the same as described above.

The receiving unit 205 receives and parses the bitstream of the encoded video. The image data and encoding information extracting unit 220 extracts image data for each 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 extracting unit 220 can extract information on the maximum size of the encoding unit of the current picture from the header of the current picture.

Also, the image data and encoding information extracting unit 220 extracts information on the encoding depth and the encoding mode for each maximum encoding unit from the parsed bitstream. The information on the extracted coding depth and coding mode is output to the image data decoding unit 230. That is, the video data of the bit stream can be divided into the maximum encoding units, and the video data decoding unit 230 can decode the video data per maximum encoding unit.

Information on the coding depth and the 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 includes information on partition type information, prediction mode information, Size information of the conversion unit, and the like. In addition, as the encoding depth information, depth-based segmentation information may be extracted.

The encoding depth and encoding mode information extracted by the image data and encoding information extracting unit 220 may be encoded in the encoding unit such as the video encoding apparatus 100 according to one embodiment, And information on the coding depth and coding mode determined to repeatedly perform coding for each unit to generate the minimum coding error. Therefore, the video decoding apparatus 200 can decode the data according to the coding scheme that generates the minimum coding error to recover the video.

The image data and encoding information extracting unit 220 can extract information on the encoding depth and the encoding mode for each minimum encoding unit. If information on the coding depth and the coding mode of the corresponding maximum coding unit is recorded for each minimum coding unit, the minimum coding units having the same coding depth and information on the coding mode are estimated as data units included in the same maximum coding unit . That is, if the minimum coding units of the same information are collected and decoded, it is possible to decode based on the coding units of the coding depth with the smallest coding error.

The image data decoding unit 230 decodes the image data of each maximum encoding unit based on the information on the encoding depth and the encoding mode for each maximum encoding unit to reconstruct the current picture. The image data decoding unit 230 can decode the image data for each coding unit of at least one coding depth based on the coding depth information for each coding unit. The decoding process may include a prediction process including intra prediction and motion compensation, and an inverse frequency conversion process.

The image data decoding unit 230 decodes each of the prediction units and prediction modes for each coding unit on the basis of the partition type information and the prediction mode information of the prediction unit of the coding unit for each coding depth for each coding unit, Or motion compensation.

In addition, the image data decoding unit 230 may perform frequency inverse transform for each encoding unit on the basis of the size information of the conversion unit of each encoding depth-based encoding unit for frequency inverse conversion for each maximum encoding unit .

The image data decoding unit 230 can determine the coding depth of the current maximum encoding unit using the division information by depth. If the partition information indicates that the current depth is to be decoded, the current depth is the depth of the encoding. Therefore, the image data decoding unit 230 can decode the current depth encoding unit for the image data of the current maximum encoding unit using the partition type, the prediction mode, and the conversion unit size information of the prediction unit.

That is, it is possible to observe the encoding information set for the minimum encoding unit and to decode the minimum encoding units that hold the encoding information including the same division information, into one data unit.

The video decoding apparatus 200 according to an exemplary embodiment recursively performs encoding for each maximum encoding unit in the encoding process to obtain information on an encoding unit that has generated the minimum encoding error and can use the encoded information for decoding the current picture have. That is, it is possible to decode video data in the optimal encoding unit for each maximum encoding unit.

Accordingly, even if an image with a high resolution or an excessively large amount of data is used, the information on the optimal encoding mode transmitted from the encoding end is used, and the image data is efficiently encoded according to the encoding unit size and encoding mode, Can be decoded and restored.

FIG. 3 shows the concept of a hierarchical coding unit.

An example of an encoding unit may include 32x32, 16x16, 8x8, and 4x4 from an encoding unit with a width x height of 64x64. In addition to the square-shaped encoding units, there may be encoding units whose width x height is 64x32, 32x64, 32x16, 16x32, 16x8, 8x16, 8x4, 4x8.

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. With respect to the video data 320, 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 4. 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 2.

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. Therefore, the maximum size of the video data 310 and 320 having the higher resolution than the video data 330 can be selected to be 64. FIG.

The maximum depth indicates the total number of layers in the hierarchical encoding unit. Therefore, since the maximum depth of the video data 310 is 2, the encoding unit 315 of the video data 310 is encoded from a maximum encoding unit having a major axis size of 64, Units. On the other hand, since the maximum depth of the video data 330 is 2, the encoding unit 335 of the video data 330 has a depth of two layers from the encoding units having the major axis size of 16, Units.

Since the maximum depth of the video data 320 is 4, the encoding unit 325 of the video data 320 has a depth of four layers from 32 to 16, 8, and 4 Encoding units. The deeper the depth, the better the ability to express detail.

4 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 depth determination unit 120 of the video encoding apparatus 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. The inter-frame estimation and the motion compensation are performed using the reference frame and the reference frame.

The data output from the intraprediction unit 410, the motion estimation unit 420 and the motion compensation unit 425 is output as a quantized transform coefficient through the frequency transform unit 430 and the quantization unit 440. The quantized transform coefficients are reconstructed into spatial domain data through the inverse quantization unit 460 and the frequency inverse transform unit 470 and the data of the reconstructed spatial domain is passed through the deblocking unit 480 and the loop filtering unit 490 Processed and output to the reference frame 495. [ The quantized transform coefficient may be output to the bitstream 455 via the entropy encoding unit 450.

The motion estimation unit 420, the motion compensation unit 425, and the frequency transformation unit 420, which are components of the image encoding unit 400, are applied to the video encoding apparatus 100 according to an embodiment of the present invention. The quantization unit 440, the entropy encoding unit 450, the inverse quantization unit 460, the frequency inverse transform unit 470, the deblocking unit 480, and the loop filtering unit 490, The work should be performed based on the depth encoding unit considering the maximum depth.

In particular, the intra prediction unit 410, the motion estimation unit 420, and the motion compensation unit 425 determine the prediction unit and the prediction mode in the coding unit in consideration of the maximum size and depth of the coding unit, and the frequency conversion unit 430 ) Should consider the size of the conversion unit considering the maximum size and depth of the encoding unit.

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

The bit stream 505 passes through the parsing unit 510 and the encoded video data to be decoded and the encoding-related information necessary for decoding are parsed. The encoded video 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 through the frequency inverse transform unit 540.

The intra-prediction unit 550 performs intraprediction on the intra-mode encoding unit for the video data in the spatial domain, and the motion compensating unit 560 performs intra-prediction on the intra-mode encoding unit using the reference frame 585 And performs motion compensation for the motion compensation.

The data in the spatial domain that has passed through the intra prediction unit 550 and the motion compensation unit 560 may be post-processed through the deblocking unit 570 and the loop filtering unit 580 and output to the reconstruction 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 decoding unit 230 of the video decoding apparatus 200, operations after the parsing unit 510 of the image decoding unit 500 according to the embodiment may be performed.

The entropy decoding unit 520, the inverse quantization unit 530, and the frequency inverse transforming unit 520, which are the components of the video decoding unit 500, in order to be applied to the video decoding apparatus 200 according to one embodiment. The intraprediction unit 550, the motion compensation unit 560, the deblocking unit 570 and the loop filtering unit 580 all have to perform an operation based on the encoding unit of the encoding depth for each maximum encoding unit .

In particular, the intra prediction unit 550 and the motion compensation unit 560 determine a coding unit and a prediction mode in consideration of the maximum size and depth of a coding unit, and the frequency inverse transform unit 540 sets the maximum size and depth of the coding unit The size of the conversion unit should be considered.

FIG. 6 illustrates a depth-based coding unit and a prediction unit according to an embodiment of the present invention.

The video encoding apparatus 100 and the video decoding apparatus 200 according to an exemplary embodiment use a hierarchical encoding unit to consider an image characteristic. The maximum height, width, and maximum depth of the encoding unit may be adaptively determined according to the characteristics of the image, or may be variously set according to the demand of the user. The size of each coding unit may be determined according to the maximum size of a predetermined coding unit.

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. Since the depth is deeper along the vertical axis of the hierarchical structure 600 of the encoding unit according to the embodiment, the height and width of the encoding unit for each depth are divided. In addition, along the horizontal axis of the hierarchical structure 600 of the coding unit, a prediction unit which is a partial data unit on which prediction coding of each depth coding unit is based is shown.

That is, the coding unit 610 is the largest coding unit among the hierarchical structures 600 of the coding units and has a depth of 0, and the size of the coding units, that is, the height and the width, 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.

The partial data units are arranged as a prediction unit of the encoding unit along the horizontal axis for each depth. That is, the prediction unit of the encoding unit 610 having a size of 64x64 with a depth of 0 is a partial data unit 610 having a size of 64x64, partial data units 612 having a size of 64x32 included in the encoding unit 610 of size 64x64, Partial data units 614 of size 32x64, and partial data units 616 of size 32x32. Conversely, the encoding unit may be a minimum-sized square data unit including the conversion units 610, 612, 614, and 616.

Likewise, the prediction unit of the encoding unit 620 of the size 32x32 of the depth 1 is the partial data unit 620 of the size 32x32, the partial data units 622 of the size 32x16, and the partial data unit 620 of the size 32x32 included in the encoding unit 620 of the size 32x32, Partial data units 624 of size 16x32, partial data units 626 of size 16x16.

Likewise, the prediction unit of a 16x16 size 16x16 encoding unit is a 16x16 partial data unit 630, a 16x8 partial data unit 632, and a 16x16 partial data unit 630 included in the 16x16 encoding unit 630, Partial data units 634 of size 8x16, and partial data units 636 of size 8x8.

Likewise, the prediction unit of the encoding unit 640 of the size 8x8 of the depth 3 includes the partial data unit 640 of the size 8x8, the partial data units 642 of the size 8x4, and the partial data units 640 of the size 8x8 included in the encoding unit 640 of the size 8x8, Partial data units 644 of size 4x8, and partial data units 646 of size 4x4.

Finally, a coding unit 650 of size 4x4 is the minimum coding unit and the coding unit of the lowest depth, and the prediction unit is a data unit 650 of size 4x4.

The coding depth determiner 120 of the video coding apparatus 100 according to an exemplary embodiment of the present invention determines the coding depth of the maximum coding unit 610 by multiplying the coding unit of each depth included in the maximum coding unit 610 Encoding is performed.

The number of coding units per depth to include data of the same range and size increases as the depth of the coding unit increases. For example, for data containing one coding unit at depth 1, four coding units at depth 2 are required. Therefore, in order to compare the encoding results of the same data by depth, they should be encoded using a single depth 1 encoding unit and four depth 2 encoding units, respectively.

For each depth-of-field coding, encoding is performed for each prediction unit of the depth-dependent coding unit along the horizontal axis of the hierarchical structure 600 of the coding unit, and a representative coding error, which is the smallest coding error at the corresponding depth, is selected . In addition, depths are deepened along the vertical axis of the hierarchical structure 600 of encoding units, and the minimum encoding errors can be retrieved by comparing the representative encoding errors per depth by performing encoding for each depth. The depth 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. [

FIG. 7 shows a relationship between an encoding unit and a conversion unit according to an embodiment of the present invention.

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

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 frequency conversion can be performed.

In addition, the data of the encoding unit 710 of 64x64 size is encoded by performing the frequency conversion with the conversion units of 32x32, 16x16, 8x8, and 4x4 size of 64x64 or smaller, respectively, and then the conversion unit having the smallest error with the original Can be selected.

FIG. 8 illustrates depth-specific encoding information, in accordance with an embodiment of the present invention.

The encoding information encoding unit of the video encoding apparatus 100 according to the embodiment is information on an encoding mode, and includes information on a partition type 800, information on a prediction mode 810, Information 820 on the unit size can be encoded and transmitted.

The partition type information 800 indicates information on a type in which the current encoding unit is divided as a prediction unit for predictive encoding of the current encoding unit. For example, the current encoding unit CU_0 of depth 0 and size 2Nx2N includes a prediction unit 802 of size 2Nx2N, a prediction unit 804 of size 2NxN, a prediction unit 806 of size Nx2N, a prediction unit 808 of size NxN ) And can be used as a prediction unit. In this case, information 800 regarding the partition type of the current encoding unit includes a prediction unit 802 of size 2Nx2N, a prediction unit 804 of size 2NxN, a prediction unit 806 of size Nx2N, and a prediction unit 808 of size NxN. Lt; / RTI >

The information 810 on the prediction mode indicates the prediction mode of each prediction unit. The prediction unit indicated by the information 800 relating to the partition type is predicted to be one of the intra mode 812, the inter mode 814 and the skip mode 816 through the prediction mode information 810, for example. Can be set.

In addition, the information 820 on the conversion unit size indicates whether to perform frequency conversion on the basis of which conversion unit the current encoding unit is performed. For example, the conversion unit may be one of a first intra-conversion unit size 822, a second intra-conversion unit size 824, a first inter-conversion unit size 826, have.

The encoding information extracting unit of the video decoding apparatus 200 according to the embodiment extracts the information 800 about the partition type, the information 810 about the prediction mode, the information 820 about the conversion unit size ) Can be extracted and used for decoding.

FIG. 9 shows a depth encoding unit 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 the prediction encoding of the coding units of depth 0 and 2N_0x2N_0 has a partition type 912 of 2N_0x2N_0 size, a partition type 914 of 2N_0xN_0 size, a partition type 916 of N_0x2N_0 size, a partition of size N_0xN_0 Type < / RTI >

For each partition type, predictive encoding should be repeatedly performed for each prediction unit of 2N_0x2N_0 size, two 2N_0xN_0 size prediction units, two N_0x2N_0 size prediction units, and four N_0xN_0 size prediction units. For a prediction unit of size 2N_0x2N_0, size N_0x2N_0, size 2N_0xN_0 and size N_0xN_0, predictive coding can be performed in intra mode and inter mode. The skip mode can be performed only for predictive encoding in a prediction unit of size 2N_0x2N_0.

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 (920), and the coding units 922, 924, 926 and 928 of the partition type of the depth 2 and the size N_0xN_0 are changed The minimum coding error can be repeatedly searched for.

Since encoding is repeatedly performed on the encoding units 922, 924, 926, and 928 of the same depth, encoding of only one of the encoding units of depth 1, for example, will be described. The prediction unit 930 for predicting the coding unit of the depth 1 and the size 2N_1x2N_1 (= N_0xN_0) includes a partition type 932 of size 2N_1x2N_1, a partition type 934 of size 2N_1xN_1, a partition type 936 of size N_1x2N_1, , And a partition type 938 of size N_1xN_1. For each partition type, predictive coding should be repeatedly performed for each prediction unit of a size 2N_1x2N_1, a prediction unit of two sizes 2N_1xN_1, a prediction unit of two sizes N_1x2N_1, and a prediction unit of four sizes N_1xN_1.

If the coding error by the partition type 938 of the size N_1xN_1 is the smallest, the coding units 942, 944, 946 and 948 of the depth 2 and the size N_2xN_2 are changed while changing the depth 1 to the depth 2 (940) The minimum coding error can be repeatedly searched for.

If the maximum depth is d, the depth-based segmentation information can be set until the depth d-1. That is, the prediction unit 950 for predictive coding of the coding unit of the depth d-1 and the size 2N_ (d-1) x2N_ (d-1) A partition type 954 of size 2N_ (d-1) xN_ (d-1), a partition type 956 of size N_ (d-1) x2N_ 1) xN_ (d-1) < / RTI >

(D-1) x2N_ (d-1), two predicted units of two sizes 2N_ (d-1) (d-1) x2N_ (d-1), four sizes N_ (d-1) xN_ (d-1). Since the maximum depth is d, the coding unit 952 of depth d-1 no longer undergoes the division process.

The video coding apparatus 100 according to an exemplary embodiment compares depth-based coding errors to determine the depth of coding for the coding unit 912, and selects the depth at which the smallest coding error occurs.

For example, a coding error for a coding unit of depth 0 is predicted for each partition type 912, 914, 916, and 918, and a prediction unit in which the smallest coding error occurs is determined. Similarly, a prediction unit having the smallest coding error can be searched for every depth 0, 1, ..., d-1. At the depth d, the coding error can be determined through predictive coding based on the prediction unit 960, which is a coding unit of size 2N_dx2N_d.

In this way, the minimum coding error of each of the depths 0, 1, ..., d-1, and d is compared and the depth with the smallest error is selected to be determined as the coding depth. The coding depth and the prediction unit of the corresponding depth can be encoded and transmitted as information on the coding mode. In addition, since the coding unit must be divided from the depth 0 to the coding depth, only the division information of the coding depth is set to '0', and the division information by depth is set to '1' except for the coding depth.

The encoding information extracting unit 220 of the video decoding apparatus 200 according to an exemplary embodiment may extract information on the encoding depth and prediction unit of the encoding unit 912 and decode the encoding unit 912. [ The video decoding apparatus 200 according to an exemplary embodiment of the present invention uses division information by depth to grasp the depth with the division information of '0' as a coding depth and can use it for decoding using information on the coding mode for the corresponding depth have.

FIGS. 10A, 10B, and 10C illustrate the relationship between an encoding unit, a prediction unit, and a frequency conversion unit according to an embodiment of the present invention.

The coding unit 1010 is coding units for coding depth determined by the video coding apparatus 100 according to the embodiment with respect to the maximum coding unit. The prediction unit 1060 is a prediction unit of each coding depth unit among the coding units 1010 and the conversion unit 1070 is a conversion unit of each coding depth unit.

When the depth of the maximum encoding unit is 0, the depth of the encoding units 1012 and 1054 is 1 and the depth of the encoding units 1014, 1016, 1018, 1028, 1050, The coding units 1020, 1022, 1024, 1026, 1030, 1032 and 1048 have a depth of 3 and the coding units 1040, 1042, 1044 and 1046 have a depth of 4.

A portion (1014, 1016, 1022, 1032, 1048, 1050, 1052, 1054) of the prediction units 1060 is a type in which the coding unit is divided. That is, the prediction units 1014, 1022, 1050 and 1054 are partition types of 2NxN, the prediction units 1016, 1048 and 1052 are partition types of Nx2N, and the prediction units 1032 are partition types of NxN. That is, the prediction unit of the depth-dependent coding units 1010 is smaller than or equal to each coding unit.

The image data of a part 1052 of the conversion units 1070 is subjected to frequency conversion or frequency inverse conversion in units of data 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 of the prediction units 1060. That is, the video encoding apparatus 100 according to the embodiment and the video decoding apparatus 200 according to an embodiment can perform the intra prediction / motion estimation / motion compensation operation for the same encoding unit and the frequency conversion / , Each based on a separate data unit.

FIG. 11 shows encoding information for each encoding unit according to an embodiment of the present invention.

The output unit 130 of the video encoding apparatus 100 according to an exemplary embodiment outputs encoding information for each encoding unit and the encoding information extracting unit 220 of the video decoding apparatus 200 according to an exemplary embodiment extracts encoding information for each encoding unit It is possible to extract the encoding information.

The encoding information may include division information for the encoding unit, partition type information, prediction mode information, and conversion unit size information. The encoding information shown in FIG. 11 is an example that can be set in the video encoding apparatus 100 according to the embodiment and the video encoding apparatus 200 according to an embodiment.

The division information may indicate the coding depth of the corresponding encoding unit. That is, since depths that are no longer divided according to the division information are coding depths, partition type information, prediction mode, and conversion unit size information can be defined with respect to the coding depth. When it is necessary to further divide by one division according to the division information, encoding should be performed independently for each of four divided sub-depth coding units.

As the partition type information, the partition type of the conversion unit of the coding unit of the coding depth can be represented by 2Nx2N, 2NxN, Nx2N and NxN. The prediction mode may be represented by one of an intra mode, an inter mode, and a skip mode. The intra mode and the inter mode can be defined in the partition types 2Nx2N, 2NxN, Nx2N and NxN, and the skip mode can be defined only in the partition type 2Nx2N. The conversion unit size can be set to two kinds of sizes in the intra mode and two kinds of sizes in the inter mode.

The encoding unit-specific encoding information of the belonging encoding depth may be stored for each minimum encoding unit in the encoding unit. Therefore, if encoding information held in each of the adjacent minimum encoding units is checked, it can be confirmed whether or not the encoding information is included in the encoding unit of the same encoding depth. In addition, since the encoding unit of the encoding depth can be identified by using the encoding information held in the minimum encoding unit, the distribution of encoding depths in the maximum encoding unit can be inferred.

In this case, when the current encoding unit is predicted with reference to the neighboring data unit, the encoding information of the minimum encoding unit in the depth encoding unit adjacent to the current encoding unit is directly used, so that the data of the minimum encoding unit can be referred to.

In yet another embodiment, the encoding information of the depth encoding unit may be stored only for the minimum encoding unit represented in the depth encoding unit. In this case, when the current encoding unit is predicted by referring to the surrounding encoding unit, the data adjacent to the current encoding unit in the depth encoding unit may be retrieved using the encoding information of the adjacent depth encoding unit.

12 shows a flowchart of a video coding method according to an embodiment of the present invention.

In step 1210, the current picture is divided into at least one maximum encoding unit. In addition, the maximum depth indicating the possible total number of divisions may be set in advance.

In step 1220, the area of the maximum coding unit is coded at least in one divided area for each depth, and the depth at which the final coding result is output for each of at least one of the divided areas is determined. The maximum encoding unit is divided into stages, and each time the depth is deepened, it is necessary to repeatedly perform encoding for each lower-depth encoding unit.

For each depth-based coding unit, the conversion unit for each partition type having the smallest coding error should be determined. In order to determine the coding depth that causes the minimum coding error of the coding unit, the coding error should be measured and compared for each coding unit of each depth.

In step 1230, video data as a final encoding result for each of at least one divided area and information on the coding depth and coding mode are output for each maximum coding unit. The information on the encoding mode may include information on the encoding depth or division information, partition type information of the encoding depth, prediction mode information, and conversion unit size information. Information on the encoded encoding mode can be transmitted to the decoding end together with the encoded video data.

13 shows a flowchart of a video decoding method according to an embodiment of the present invention.

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

In step 1320, the image data of the current picture allocated to the largest coding unit of the maximum size from the parsed bitstream, and information on the coding depth and coding mode of each coding unit are extracted. The coding depth for each maximum coding unit is the depth selected with the smallest coding error for each maximum coding unit in the process of coding the current picture. The encoding of the maximum encoding unit is the image data encoded based on at least one data unit obtained by dividing the maximum encoding unit hierarchically by depth. Therefore, the decoding efficiency of the image can be improved by decoding the respective image data after grasping the coding depth for each coding unit.

In step 1330, the image data of each maximum encoding unit is decoded based on the information on the encoding depth and the encoding mode for each maximum encoding unit. The decoded image data can be reproduced by a reproducing apparatus, stored in a storage medium, or transmitted via a network.

Referring to FIGS. 14 to 19, video encoding and video decoding according to inter prediction using an arbitrarily partitioned partition according to an embodiment will be described in detail below.

FIG. 14 shows a block diagram of a video encoding apparatus according to inter prediction using a partition divided at an arbitrary ratio according to an embodiment.

The video encoding apparatus 1400 according to one embodiment includes a maximum encoding unit division unit 1410, an encoding unit 1420, and an output unit 1430.

The maximum encoding unit division unit 1410 divides the video data into at least one maximum encoding unit which is a maximum-size encoding unit. The video data divided into the maximum coding units is output to the coding unit 1420. The maximum encoding unit may be set in advance for each data unit such as a frame sequence, a frame, a slice, and a coding unit.

The maximum encoding unit according to an embodiment may be selectively set to at least one of 16x16, 32x32, 64x64, 128x128, and 256x256 blocks.

The encoding unit 1420 encodes the video data of the largest encoding unit divided by the maximum encoding unit division unit 1410. The encoding unit 1420 encodes each of the at least one sub-region of the maximum encoding unit based on the depth-dependent encoding units of the hierarchical structure. Inter prediction is performed by estimating the motion information of a partition by searching a similar area using a partition included in the depth encoding unit during the encoding process of the depth encoding unit.

The inter prediction according to an embodiment may use a partition in which coding units are divided at an arbitrary ratio. Examples of prediction units and partition types shown in FIGS. 3 to 11 include 2Nx2N, 2NxN, Nx2N, and NxN sized partitions in which a 2Nx2N coding unit is divided. In this manner, in addition to the partition in which at least one of the width and height of the encoding unit is divided at a ratio of 1: 1, the encoding unit 1420 according to an embodiment may include a partition including a partition partitioned at an arbitrary ratio or an asymmetric ratio Inter prediction can be performed according to the type.

For example, a partition partitioned by an arbitrary ratio of coding units according to an exemplary embodiment may be a partition in which at least one of the height and the width of the coding unit is divided into 1 to 3 or 3 to 1. In addition, the arbitrary ratio to be divided into partitions may be various ratios such as one to two, two to one, one to three, three to one, two to three, three to two, one to four, four to one,

The partition type according to an exemplary embodiment may include not only a partition where an encoding unit is divided at an arbitrary ratio but also a partition where an encoding unit is divided asymmetrically. In addition, the partition type for inter prediction of an encoding unit according to an embodiment is not limited to a partition divided in a predetermined direction according to an arbitrary ratio, and may include an arbitrary type partition.

The encoding unit 1420 according to an exemplary embodiment can selectively determine whether or not to perform inter prediction using a partition in which an encoding unit is divided at an arbitrary ratio. Information indicating whether to perform inter prediction using a partition in which coding units are divided at an arbitrary ratio may be separately encoded and included in the bit stream.

The encoding unit 1420 according to an exemplary embodiment encodes the video data of the maximum encoding unit on the basis of the depth-dependent encoding units according to the hierarchical structure for each of the divided regions, compares the depth-based encoding results, Select depth. The selected depth is a coding depth for the divided area of the maximum coding unit, and information on the coding depth is encoded as a coding result of the coding unit. At least one coding depth for one maximum coding unit can be determined since the coding depth is independently determined for each of at least one divided area within the maximum coding unit.

The output unit 1430 according to an exemplary embodiment outputs a bitstream including encoded video data, coding depth, and coding mode information corresponding to the coding depth for each partition, for each maximum coding unit. The output unit 1430 according to the embodiment may include information indicating whether the partition type for inter prediction includes a partition for dividing an encoding unit at an arbitrary ratio into a bitstream. Information indicating whether or not a partition type for inter prediction includes a partition for dividing an encoding unit at an arbitrary ratio is set for each data unit such as a frame sequence, a slice, and a coding unit, and is used as a sequence parameter set of a bit stream, Unit encoding information or the like.

Since the coding unit according to an exemplary embodiment stores a much larger amount of data than conventional macroblocks, regions having different image characteristics may be included in one coding unit. In order to predict-encode the encoding units, it is advantageous that the regions having the same image characteristics are divided among the encoding units to generate a partition for predictive encoding.

However, the larger the size of an encoding unit, the higher the possibility that the boundary between the regions that are distinguished from each other is likely to be shifted toward one of the upper, lower, left, and right sides. In the case where only a partition which divides the width and height of a coding unit by one-to-one is used, in order to precisely predict and encode an encoding unit where the boundary between the regions distinguished from each other is precisely encoded, a small partition including only one independent region The current encoding unit can not but be divided into low-depth encoding units.

However, when inter prediction using a partition that is divided at an arbitrary rate as in the video encoding apparatus 1400 according to an embodiment is possible, the current depth-dependent coding unit is shifted to one side from the current depth, It is sufficient to perform the inter prediction using the partition to be used. Therefore, when a partition of an encoding unit includes not only a partition which halves the height or width of a coding unit in one-to-one, but also a partition which divides by an arbitrary ratio or an arbitrary type partition, a more efficient and accurate prediction encoding Is possible.

In addition, the predictive encoding by a partition or an arbitrary type partition where an encoding unit is divided at an arbitrary ratio is performed by hardware performance of a video decoder, a user request to be provided with a video decoding service, Can be selectively performed.

FIG. 15 shows a block diagram of a video decoding apparatus by inter prediction using a partition divided at an arbitrary ratio according to an embodiment.

The video decoding apparatus 1500 according to an exemplary embodiment includes a parsing unit 1510, an extracting unit 1520, and a decoding unit 1530. The parsing unit 1510 receives the bitstream of the encoded video and parses the symbols of the bitstream. The extracting unit 1520 extracts, from the parsed bitstream, the video data encoded for each maximum encoding unit, and information on the encoding depth and encoding mode for each maximum encoding unit.

The extracting unit 1520 according to an embodiment may further extract information indicating whether the partition type for inter prediction from the bitstream includes a partition for dividing an encoding unit at an arbitrary ratio. Whether or not the partition type for inter prediction includes a partition for dividing an encoding unit at an arbitrary ratio can be extracted from a sequence parameter set of a bit stream, a slice header, encoding information for each encoding unit, and the like.

The decoding unit 1520 receives the video data and the encoding information extracted by the extracting unit 1520, and decodes the video data based on the encoding information. Specifically, the decoding unit 1520 according to an exemplary embodiment decodes video data for each coding unit of at least one coding depth for each maximum coding unit, based on the coding depth for each coding unit and the coding mode information.

In particular, the decoding unit 1520 according to an exemplary embodiment may selectively perform encoding (decoding) according to information indicating whether a partition type for inter prediction that is extracted by the extracting unit 1520 includes a partition for dividing an encoding unit at an arbitrary ratio It is possible to perform motion compensation using a partition in which units are divided at an arbitrary ratio.

In other words, the decoding unit 1520 according to an embodiment may be configured to have one to two, two to one, one to three, three to one, two to three, three to two, one Motion compensation can be performed using a predicted motion vector according to a partition type including an asymmetrically partitioned partition at an arbitrary rate such as 4, 4, or 1. In addition, motion compensation may be performed using not only a partition in which a coding unit is divided in a certain direction but also an arbitrary type partition.

The decoding unit 1520 according to an embodiment determines whether or not encoding is performed by performing inter prediction using a partition in which an encoding unit is divided at an arbitrary ratio, and selectively determines whether motion is performed according to a partition having an arbitrary ratio of width and height It is possible to accurately reconstruct an encoding unit divided into regions having various image characteristics.

The video decoding apparatus 1500 according to the embodiment can reconstruct and reproduce video data decoded for each maximum encoding unit.

Therefore, when it is possible to perform predictive decoding using a partition that is divided at an arbitrary rate, such as the video encoding apparatus 1400 according to the embodiment and the video decoding apparatus 1500 according to an embodiment, It is possible to perform inter prediction using a partition that is shifted to one side from the current depth without needing to divide it further. By using the partitions that are partitioned at the arbitrary ratio, it is possible to predict or encode or decode the large coding unit more accurately and efficiently.

Figure 16 illustrates exemplary partitions in which an encoding unit is partitioned at an arbitrary rate, according to one embodiment.

The partition type for predictive encoding of an encoding unit according to an embodiment may include a partition in which the height and width of an encoding unit are divided at an arbitrary ratio. For example, a partition of a 64x64-sized encoding unit 1600 is divided into 64x32, 32x64, and 32x32 partitions in which at least one of the height and the width of the encoding unit is divided one by one, as well as 1 to 3 or 3 to 1 You can include one partition.

That is, the partition type of the 64x64-sized encoding unit 1600 may include 64x16, 64x48 sized partitions generated by dividing the height by 1 to 3 or 3 to 1 like 1610 or 1620. [ The partition type of the 64x64 encoding unit 1600 may include 16x64 or 48x64 size partitions generated by dividing the width by 1 to 3 or 3 to 1 like 1630 or 1640. [

17 shows a syntax of a sequence parameter set including information indicating whether or not to include a partition dividing an encoding unit at an arbitrary ratio, according to an embodiment.

sequence_parameter_set indicates the syntax of the sequence parameter set 1700 for the current video slice. An example in which information indicating whether or not a partition type for inter prediction according to an embodiment includes a partition for dividing an encoding unit at an arbitrary ratio is inserted in a syntax of a sequence parameter set 1700 for a video slice will be described in detail.

picture_width is the width of the input image, picture_height is the syntax indicating the height of the input image, max_coding_unit_size is the size of the maximum encoding unit, and max_coding_unit_depth is the syntax indicating the maximum depth.

(Use_independent_cu_decode_flag) indicating whether the coding unit level is independently decoded, use_independent_cu_decode_flag indicating whether to independently parse the coding unit level (use_independent_cu_parse_flag), availability (motion_mv_accuracy_control_flag) of the motion vector accuracy control operation, Availability of an arbitrary directional intra prediction operation (use_arbitrary_direction_intra_flag), availability of a prediction unit decoding operation on frequency conversion (use_frequency_domain_prediction_flag), availability of rotation conversion operation (use_rotational_transform_flag), availability of subdecryption using a tri- use_tree_significant_map_flag), the availability of the intra prediction encoding operation using the multi-parameter (use_multi_parameter_intra_prediction_flag), the availability of the enhanced motion vector prediction encoding operation (use_advanced_motion_vector_prediction_flag) The availability of the adaptive loop filtering operation (use_adaptive_loop_filter_flag), the availability of the quad tree structure adaptive loop filtering operation (use_quadtree_adaptive_loop_filter_flag), the availability of the quantization operation using the delta value of the quantization parameter (use_delta_qp_flag) Information indicating the possibility (use_random_noise_generation_flag), whether or not an arbitrary type partition for inter prediction of an encoding unit is allowed (use_arbitrary_motion_partition_flag) can be defined. Syntaxes indicating the availability of the above-described various operations enable efficient decryption by defining whether the corresponding operations are used in the current decoding process of the slice.

In particular, the filter length (alf_filter_length) of the adaptive loop filter, the adaptive loop filter type (alf_filter_type) and the adaptive loop filter type (alf_filter_type) are determined according to the availability of the adaptive loop filtering operation (use_adaptive_loop_filter_flag) and the availability of the quadtree structure adaptive loop filtering operation (use_quadtree_adaptive_loop_filter_flag) A reference value (alf_qbits) for quantization of the adaptive loop filter coefficient, and a number of color components (alf_num_color) in the adaptive loop filtering may be defined in the sequence parameter set 1700.

The information on the correspondence between the depth of the coding unit, the coding tool, and the operation mode used in the video coding apparatus 1400 and the video decoding apparatus 1500 according to the embodiment is determined by the depth of the coding unit uiDepth (Mvp_mode [uiDepth]) corresponding to the inter prediction in accordance with the inter-prediction prediction mode (mvp_mode [uiDepth]) and the operation mode (significant_map_mode [uiDepth]) indicating the type of the signify map among the tri- That is, the correspondence relation between the inter prediction and the corresponding operation mode corresponding to the depth of the encoding unit according to the embodiment, or the correspondence between the operation mode and the sub-decryption using the tri-sign information, is set in the sequence parameter set 1700 .

The bit depth of the input sample (input_sample_bit_depth) and the bit depth of the inner sample (internal_sample_bit_depth) may also be set in the sequence parameter set 1700.

The video decoding apparatus 1500 according to the embodiment extracts information indicating whether or not to permit arbitrary type partitioning for inter prediction of an encoding unit (use_arbitrary_motion_partition_flag) by reading the sequence parameter, and if the encoding unit is arbitrary It may be determined whether to perform inter prediction using a partitioned partition.

Information indicating whether or not an arbitrary type partition for inter prediction of an encoding unit is allowed (use_arbitrary_motion_partition_flag), which is used by the video encoding apparatus 1400 according to the embodiment and the video decoding apparatus 1500 according to the embodiment, The present invention is not limited to the embodiment inserted in the sequence parameter set 1700 shown in FIG. 22, but may be set in units of a maximum encoding unit, a slice, a frame, a picture, a GOP,

If the information indicating whether or not arbitrary type partition for inter prediction of the coding unit is allowed in the slice header (use_arbitrary_motion_partition_flag) is 'true', inter prediction is performed using the partition where the coding unit is divided at an arbitrary ratio in the corresponding slice And if it has a value of 'false', inter prediction is performed using only the partitions in which at least one of the width and the height of the coding unit in the corresponding slice is divided into one to one.

FIG. 18 shows a flowchart of a video coding method according to inter prediction using a partition divided at an arbitrary ratio according to an embodiment.

In step 1810, the video data is divided into at least one maximum encoding unit which is a maximum-size encoding unit.

In step 1820, the video data of the maximum coding unit is coded on the basis of the coding unit for each depth of the hierarchical structure for each of at least one divided region of the maximum coding unit, and the coding depth, which is the depth at which the coding result is outputted, is determined. According to an embodiment, inter prediction can selectively use a partition in which an encoding unit is divided at an arbitrary ratio. Whether or not to perform inter prediction using a partition in which coding units are divided at an arbitrary ratio can be set for each data unit such as a frame sequence, a frame, a slice, and a coding unit.

In step 1830, a bitstream including encoded video data, coding depth, and coding mode information corresponding to the coding depth for each partition may be output for each maximum coding unit. According to an embodiment, information indicating whether to perform inter prediction using a partition in which coding units are divided at an arbitrary ratio may be encoded and inserted into a bitstream and output.

19 shows a flowchart of a video decoding method by inter prediction using a partition divided at an arbitrary ratio according to an embodiment.

In step 1910, a bitstream for the encoded video is received and the symbols are parsed.

In step 1920, video data encoded for each maximum coding unit and information on coding depth and coding mode for each maximum coding unit are extracted from the bitstream. According to an embodiment, information indicating whether to perform inter prediction using a partition in which coding units are divided at an arbitrary ratio may be extracted from the bit stream. Information indicating whether to perform inter-prediction using a partition in which coding units are divided at an arbitrary ratio can be extracted from a sequence parameter set, a slice header, coding information for each coding unit, and the like.

In step 1930, based on the information on the encoding depth and the encoding mode for each maximum encoding unit, for each encoding unit of at least one encoding depth for each maximum encoding unit, motion compensation using a partition in which encoding units are divided at an arbitrary ratio is included Decryption can be performed. Whether decoding including motion compensation using a partition in which coding units are divided at an arbitrary ratio is performed may be performed by using information indicating whether to perform inter prediction using a partition in which the coding unit extracted from the bit stream is partitioned at an arbitrary ratio As shown in FIG.

In a case where inter prediction using a partition divided at an arbitrary ratio as in the video coding method and the video decoding method according to the embodiment is possible, the current depth coding unit is divided into one side at the current depth without further division into lower depths Partition can be used to perform inter prediction.

In addition, since it is possible to select whether or not the partition of the coding unit includes a partition dividing the height or width of the coding unit into one to one, as well as a partition to be divided at an arbitrary ratio or an arbitrary type partition, A video coding method and a video decoding method according to an embodiment can be used in a secondary decoding system that does not support partitions. Therefore, if necessary, accurate and efficient predictive coding according to the video decoding method of the embodiment can be selectively performed.

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 includes a storage medium such as a magnetic storage medium (e.g., ROM, floppy disk, hard disk, etc.) and an optical reading medium (e.g., CD-ROM, DVD, etc.).

The present invention has been described with reference to the preferred embodiments. 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 (3)

Obtaining asymmetric partition permitting information from the bitstream indicating whether the partition type for inter prediction comprises an asymmetric partition type representing an asymmetric prediction unit;
Obtaining division information of a current encoding unit from a bitstream;
Determining encoding units of lower depth generated by dividing the height and width of the current encoding unit by half when the division information of the current encoding unit indicates division;
Obtaining partition type information of the current depth encoding unit from the bitstream when the division information of the current depth encoding unit indicates non-division;
If the asymmetric partition type is allowed according to the asymmetric partition permitting information, the partition type information is used to determine whether to perform inter prediction on the current depth coding unit, a symmetric prediction unit, Determining a prediction unit;
Wherein if the asymmetric partition type is not allowed according to the asymmetric partition permitting information, the partitioning type information is used to determine whether the non-partitioning prediction unit or the symmetry prediction unit ;
Performing inter-prediction on the current depth encoding unit using the determined prediction unit;
Determining one or more conversion units from the current depth coding unit when the division information of the current depth coding unit indicates non-division; And
Performing an inverse conversion on the current depth encoding unit using the conversion unit,
The symmetric prediction unit is a prediction unit generated by halving one of the height and the width of the coding unit and the asymmetric prediction unit is a prediction unit generated by dividing one of the height and the width of the coding unit, Wherein the prediction unit is a prediction unit generated by dividing one of a height and a width of the coding unit by an asymmetric ratio. 2. The method of claim 1, wherein performing the inter-
Determining a predicted value of the prediction unit from reference blocks determined through motion compensation; And
And combining the predictive value with residual information obtained from the bitstream to determine a reconstructed image of the encoded unit. A video decoding apparatus comprising:
Obtaining asymmetric partition permitting information indicating whether or not the partition type for inter prediction includes an asymmetric partition type indicating an asymmetric prediction unit from the bit stream, obtaining division information of the current depth encoding unit from the bit stream, A processor for determining lower-depth encoding units generated by halving the height and width of the current-depth encoding unit when the division information of the current-depth encoding unit indicates division;
Wherein when the partition information of the current depth coding unit indicates non-partitioning, partition type information of the current depth coding unit is obtained from the bitstream, and the prediction unit determined based on the partition type information is used to determine the current depth A decoding unit for performing inter prediction on an encoding unit; And
Determining one or more conversion units from the current depth coding unit when the division information of the current depth coding unit indicates non-division, and performing an inverse conversion to the current depth coding unit using the conversion unit ≪ / RTI >
Wherein the decoding unit is configured to determine whether or not an asymmetric partition type is allowed for inter prediction based on the asymmetric partition permitting information, , A symmetric prediction unit or an asymmetric prediction unit is determined,
Wherein if the asymmetric partition type is not allowed for inter prediction according to the asymmetric partition permitting information, the decoding unit may perform the inter prediction using the partition type information to perform inter prediction on the current depth coding unit Determining a prediction unit or the symmetric prediction unit,
The symmetric prediction unit is a prediction unit generated by halving one of the height and the width of the coding unit and the asymmetric prediction unit is a prediction unit generated by dividing one of the height and the width of the coding unit, Wherein the prediction unit is a prediction unit generated by dividing one of a height and a width of the coding unit by an asymmetric ratio.

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