KR101601017B1 - Method and apparatus for video decoding by individual parsing or decoding in data unit level, and method and apparatus for video encoding for individual parsing or decoding in data unit level - Google Patents

Abstract

Extracts at least one of information indicating whether the data unit is independently parsed and information indicating whether the data unit is to be independently decoded or not, A video decoding method for parsing a stream, extracting encoded video data and encoding information, and decoding encoded video data on a data unit basis, based on whether to independently decode data units and encoding information.

Description

[0001] The present invention relates to a video decoding method and apparatus for independently parsing or decoding data unit levels, and a video coding method and apparatus for independently parsing or decoding data unit levels, , and method and apparatus for video encoding for individual parsing or decoding in data unit level}

The present invention relates to video encoding and decoding.

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, the video is decoded according to a limited encoding method based on a macroblock of a predetermined size. The macroblocks are sequentially decoded and predictive coding or decoding that refers to surrounding information is widely used.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to video coding in accordance with independent coding of a predetermined data unit level, and video decoding in accordance with independent parsing or decoding of a predetermined data unit level.

A video decoding method according to an embodiment of the present invention includes receiving at least one of information indicating whether or not to independently parse a data unit and information indicating whether the data unit is independently decoded, Extracting; Parsing the bitstream based on information indicating whether the data unit is independently parsed to extract information on the encoded video data and the encoding depth and encoding mode for each maximum encoding unit; And decoding at least one coding unit for each coding depth in units of a maximum coding unit of the coded video data on the basis of information indicating whether the data unit is independently decoded and information on coding depth and coding mode for each 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. 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 information indicating whether or not the data unit is independently parsed includes information indicating whether or not to independently parse the encoding unit level indicating whether information independently encoded for each maximum encoding unit can be extracted from the bitstream And the information indicating whether the data unit is independently decoded may include information indicating whether or not the decoding unit independently decodes the data encoded independently for each maximum encoding unit.

Information indicating whether the encoding unit level is independently parsed and information indicating whether the encoding unit level is independently decoded may be set independently of each other.

According to an embodiment of the present invention, in accordance with the independent parsing of the data unit or the independent decoding of the data unit, predetermined peripheral information for predictive decoding of the coding unit is not decoded before the coding unit, And performing prediction decoding of the encoding unit by searching for and referring to surrounding information that can be referred to by the encoding unit when the encoding unit is not present.

According to an embodiment of the present invention, in the case where only a partial area of the video is a decoding target, the decoding step may include a decoding step of decoding at least one maximum value of the partial area of the coded video data Only the encoding unit can be decoded.

The video decoding method according to an embodiment includes a step of parallelly restoring and reproducing video data decoded in parallel at the coding unit level at the coding unit level on the basis of information indicating whether or not the coding unit level is independently encoded As shown in FIG.

The predictive decoding step according to an exemplary embodiment of the present invention may include a step of performing intra prediction, inter prediction, frequency domain prediction decoding, entropy decoding based on Context-Based Adaptive Binary Arithmetic Coding (CABAC) For decoding the predictive value using at least one of neighboring information currently available to the coding unit or information of the current coding unit when the current peripheral information of the coding unit can not be referred to for at least one operation of the prediction unit can do.

Information indicating whether the data unit is independently parsed or information indicating whether the data unit is independently decoded may be extracted from a slice header or a sequence parameter set of the bitstream according to an exemplary embodiment.

According to an aspect of the present invention, there is provided a video encoding method including: dividing a current picture into at least one maximum encoding unit that is a maximum-size encoding unit; Coding the video data of the maximum coding unit on the basis of the depth-dependent coding unit of the hierarchical structure in which the coding unit of the higher depth is divided for each of at least one divided region of the maximum coding unit, Determining an encoding depth to be output; And information indicating a coding depth and a coding mode for each of the coding units, the information indicating whether to independently parse the data units, and whether to independently decode the data units And outputting a bitstream including at least one of the information.

The step of outputting the bitstream according to an embodiment may include a step of setting information indicating whether the data unit is independently decoded according to whether encoding is independently performed for each data unit in the coding operation for determining the coding depth .

According to one embodiment, the bitstream outputting step may include a step of, based on whether the encoded video data and the information on the encoding depth and encoding mode for each maximum encoding unit are embedded in the bitstream independently for each data unit, And setting information indicating whether the data unit is to be independently parsed.

According to an embodiment of the present invention, when the reference information for predictive encoding of the encoding unit is independently encoded at the encoding unit level, if the reference information is not related to the encoding unit encoded before the encoding unit, And searching for and referring to peripheral information that can be referred to among the peripheral information encoded before the encoding unit to predict the unit.

According to an embodiment, in the case where the entropy encoding according to the intra prediction, the frequency domain prediction encoding, the inter prediction, the post-intra prediction, and the context based adaptive binary arithmetic coding of the coding unit is performed, And referring to the information of the current encoding unit or surrounding information encoded before the current encoding unit in the information.

The video encoding method and the video decoding method according to an embodiment may parallelly process the plurality of encoding units simultaneously by a plurality of independent processors.

A video decoding apparatus according to an embodiment of the present invention includes a parsing unit that receives a bitstream of encoded video and extracts at least one of information indicating whether the data unit is independently parsed or information indicating whether the data unit is independently decoded, part; An extracting unit for parsing the bitstream based on information indicating whether the data unit is independently parsed and extracting encoded video data and information on a coding depth and a coding mode for each maximum coding unit; And decoding at least one coding unit for each coding depth in units of a maximum coding unit of the coded video data on the basis of information indicating whether the data unit is independently decoded and information on coding depth and coding mode for each coding unit And a decoding unit.

A video encoding apparatus according to an exemplary embodiment includes: a maximum encoding unit division unit that divides a current picture into at least one maximum encoding unit, which is a maximum-size encoding unit; Coding the video data of the maximum coding unit on the basis of the depth-dependent coding unit of the hierarchical structure in which the coding unit of the higher depth is divided for each of at least one divided region of the maximum coding unit, An encoding depth determination unit for determining an encoding depth, which is a depth to be outputted; And information indicating a coding depth and a coding mode for each of the coding units, the information indicating whether to independently parse the data units, and whether to independently decode the data units And an output unit outputting a bitstream including at least one of the information.

The present invention includes a computer-readable recording medium on which a program for implementing a video decoding method according to an embodiment of the present invention is recorded. The present invention also includes a computer-readable recording medium on which a program for implementing a video coding method according to an embodiment of the present invention 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 for independent unit level independent parsing and decoding according to an embodiment of the present invention.
FIG. 15 is a block diagram of a video decoding apparatus according to an embodiment of the present invention. Referring to FIG.
16 shows a schematic diagram of parallel processing of slice levels by the H.264 standard part decoding method.
FIG. 17 shows a table for possible combinations of slice level parallel processing and encoding unit level parallel processing according to an embodiment of the present invention.
FIG. 18 shows a diagram of a parallel processing at an encoding unit level according to an embodiment of the present invention.
Figure 19 illustrates a diagram of hierarchical parallel processing of data units in accordance with one embodiment of the present invention.
FIG. 20 illustrates a partial decoding scheme that is possible by independent decoding of coding unit levels according to an embodiment of the present invention.
FIG. 21 is a diagram illustrating a parallel display of encoding units possible by parallel decoding at the encoding unit level according to an embodiment of the present invention.
FIG. 22 shows a syntax of a sequence parameter set into which information indicating whether to independently parse an encoding unit level and information indicating whether to independently decode an encoding unit level is inserted according to an embodiment.
FIG. 23 shows a diagram of intra prediction for independent decoding at an encoding unit level according to an embodiment of the present invention.
24A illustrates a post-processing scheme of intra prediction using a reconstructed sample according to an embodiment of the present invention.
FIG. 24B shows a diagram of post-processing of intra prediction for independent decoding at the coding unit level according to an embodiment of the present invention.
FIG. 25 illustrates a scheme of entropy decoding according to the CABAC scheme for independent coding of coding unit levels and independent decoding of coding unit levels according to an embodiment of the present invention.
26 shows a flowchart of a video encoding method for independent parsing or decoding according to an embodiment of the present invention.
FIG. 27 shows a flowchart of a video decoding method according to an independent parsing or decoding method according to an embodiment of the present invention.

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. Encoding 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 to 13, and with reference to FIGS. 14 to 27, The coding of the video and the decoding of the video in consideration of independent coding or independent decoding of the coding unit level will be described later.

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 may 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. Accordingly, the decoding efficiency of the image can be improved by decoding each 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.

14 to 27, video coding or decoding considering independent parsing or independent decoding of coding unit levels according to an embodiment will be described in detail below.

FIG. 14 shows a block diagram of a video encoding apparatus for independent unit level independent parsing and decoding according to an embodiment of the present invention.

The video coding apparatus 1400 for independent parsing and decoding of coding unit levels according to an embodiment includes a maximum coding unit division unit 1410, a coding depth determination unit 1420 and an output unit 1430.

The maximum encoding unit division unit 1410 divides the current picture into at least one maximum encoding unit, which is a maximum-size encoding unit. The pixel value data of the maximum coding unit is output to the coding depth determiner 1420.

The coding depth determination unit 1420 compresses and encodes the pixel value data of the maximum coding unit generated by the maximum coding unit division unit 1410. Specifically, the coding depth determiner 1420 encodes each area in units of depths in units of depth in a maximum coding unit. Encoding is performed for each divided area at the current depth within the maximum encoding unit, and when the depth is deeper, the divided area is divided again to create a new divided area. Therefore, Is performed recursively.

The coding results calculated according to the recursive coding process for coding each divided area of the maximum coding unit by depth coding units are compared and the depth of the highest coding efficiency is selected for each divided area to determine the coding depth of the corresponding divided area do. Since the depth with the highest coding efficiency for each divided area is determined independently of each other, one or more coding depths can be determined within one maximum coding unit.

The coding depth determiner 1420 may perform parallel coding of a predetermined number of coding units at a slice level. For example, B slices that refer to the same I slice or P slice are encoded in parallel.

The coding depth determiner 1420 according to an embodiment can perform independent coding at the coding unit level. Therefore, the information of the surrounding encoding unit may not be referred to in order to encode the current encoding unit.

In addition, since the coding depth determiner 1420 performs independent coding at the coding unit level, the coding depth determiner 1420 can perform parallel coding for a predetermined number of coding units. The coding units to be coded in the next cycle according to the coding unit level parallel coding can not be used as reference information for coding the coding units to be coded in the current cycle. In addition, the encoding units encoded in the same period according to the parallel encoding at the encoding unit level can not be used as reference information among each other.

A coding tool that assumes sequential coding performs predictive coding with reference to surrounding information that is encoded first in a sequential order.

Therefore, in the case of the independent encoding of the encoding unit level according to the embodiment, the coding tool that assumes the sequential encoding of the encoding unit can not be performed as it is. When the coding depth determiner 1420 performs intra prediction independently at the coding unit level and the reference information of the current coding unit is not the information about the coding unit encoded before the current coding unit, It is possible to search for and refer to peripheral information that can be referred to among peripheral information encoded before the encoding unit. A method of referring to peripheral information that can be referred to among the peripheral information encoded before the encoding unit for each coding tool will be described in detail below.

When the coding depth determiner 1420 performs intra prediction independently at the coding unit level and the reference information of the current coding unit is not the information about the coding unit encoded before the current coding unit, The DC value calculated using the information encoded before the current encoding unit among the peripheral information of the current encoding unit may be determined as the predicted value of the current encoding unit.

The intra prediction mode indicates the direction of the surrounding information to be referred to for intraprediction of the current encoding unit. Accordingly, a plurality of intra prediction modes can be set according to the number of directions that the current encoding unit can refer to. When the coding depth determiner 1420 performs intra prediction independently at the coding unit level and the reference information of the current coding unit is not the information about the coding unit encoded before the current coding unit, The type of the intra prediction mode can be compressed only in the intra prediction mode indicating the intra prediction direction of the information encoded before the current coding unit among the peripheral information of the current coding unit.

The coding depth determiner 1420 according to an exemplary embodiment may perform frequency domain prediction that predicts a transform coefficient of the current coding unit using the transform coefficients of the surrounding encoding units in the frequency domain. In performing the frequency domain prediction independently at the coding unit level, the coding depth determiner 1420 according to an embodiment uses the information encoded before the current coding unit among the peripheral information of the current coding unit, The conversion coefficient can be predicted.

The prediction mode by the frequency domain prediction according to an exemplary embodiment may indicate the direction of the surrounding information referred to by the current encoding unit. When the coding depth determiner 1420 performs frequency domain prediction independently at the coding unit level and the reference information of the current coding unit is not the information about the coding unit encoded before the current coding unit , The prediction mode for the frequency domain prediction of the current coding unit can be changed to the prediction mode indicating the direction of the information encoded before the current coding unit among the peripheral information of the current coding unit.

The coding depth determiner 1420 according to an exemplary embodiment may retrieve information about referenceability of a neighboring coding unit to retrieve reference information of a current coding unit for inter prediction. When the coding depth determiner 1420 according to the embodiment independently performs inter prediction at the coding unit level and the reference information of the current coding unit is not the information about the coding unit encoded before the current coding unit, The motion vector between the surrounding encoding unit and the current encoding unit can be predicted based on the changed reference possibility among the reference possibility for the surrounding information of the current encoding unit.

The coding depth determiner 1420 according to an exemplary embodiment may perform a predetermined post-process on the predicted value after the intra prediction for the current coding unit. The coding depth determiner 1420 according to an embodiment can modify the intra prediction values of the current coding unit using various parameters and peripheral information according to the purpose of the post-processing. The encoding depth determiner 1420 performs intra prediction and post-prediction operations independently at the encoding unit level. In this case, when the reference information of the current encoding unit is information about the encoding unit encoded before the current encoding unit Processed pixel value of the encoding unit can be calculated using the post-processed pixel value and the pixel value of the current encoding unit among the encoded peripheral information of the current encoding unit.

The coding depth determiner 1420 may perform entropy coding according to a context-based Adaptive Binary Arithmetic Coding (CABAC) using context information of surrounding information of a coding unit . In performing the entropy encoding independently at the encoding unit level, the encoding depth determination unit 1420 refers to the context information of the surrounding information encoded before the current encoding unit among the peripheral information of the current encoding unit It may happen that it can not be done.

The output unit 1430 of the embodiment outputs a bitstream including the encoded video data of the coding depth determined for each maximum coding unit in the coding depth determiner 1420 and information on the coding depth and coding mode for each maximum coding unit Output. In order to independently parse or decode the encoding unit level according to an embodiment, the output unit 1430 may output at least one of information indicating whether the data unit is independently parsed in the bitstream and information indicating whether the data unit is independently decoded And outputs it.

Information indicating whether data units are independently decoded can be set according to whether data units are independently encoded or not. Information indicating whether data units are independently parsed can be set according to whether data units are independently inserted into a bitstream.

Independent or independent decoding of data units according to an embodiment may include slicing-level independent parsing or independent decoding or coding unit level independent parsing or independent decoding. Accordingly, the information indicating whether or not the data unit is independently parsed may include at least one of information indicating whether the parsing is performed independently of the slice level, or information indicating whether the parsing unit independently parses the coding unit level, and information indicating whether the data unit is independently decoded May include at least one of information indicating whether the slice level is independently decoded and information indicating whether the decoding unit is to be decoded independently.

The information indicating whether the data unit is independently parsed and the information indicating whether or not the data unit is independently decoded may be independently set according to an embodiment. Accordingly, the combination of the information indicating whether the data unit is independently parsed and the information indicating whether or not the data unit is independently decoded is determined according to whether or not independent parsing or independent decoding is performed in the encoding process ('true' ('false'), ('false', 'true'), ('true', 'true') or ('false', 'false').

According to one embodiment, information indicating whether data units are independently parsed or information indicating whether data units are independently decoded can be stored in a slice header or a sequence parameter set.

The video encoding apparatus 1400 according to one embodiment can encode an encoding unit independently from the surrounding information. The video coding apparatus 1400 according to the embodiment encodes data of a coding unit (32x32, 64x64, 128x128, 256x256, etc.) of a large data unit larger than the existing macroblocks (8x8, 16x16) The present encoding unit can be predictively encoded using the included data. Therefore, it is possible to perform independent encoding at the encoding unit level for predictive encoding independently for each encoding unit.

In addition, a plurality of encoding units can be encoded in parallel if there are many operation processes that can be independently encoded for each encoding unit. Therefore, by independent coding at the coding unit level, decoding units can independently or independently parse or decode the coding units, and it is possible to parallelly parse and decode a plurality of coding units.

FIG. 15 is a block diagram of a video decoding apparatus according to an embodiment of the present invention. Referring to FIG.

The video decoding apparatus 1500 according to an exemplary embodiment includes a receiving unit 1510, a parsing unit 1520, and a decoding unit 1530. A receiving unit 1510 according to an exemplary embodiment receives a bitstream of encoded video. The receiving unit 1510 according to an exemplary embodiment extracts at least one of information indicating whether the data unit is independently parsed and information indicating whether the data unit is independently decoded from the received bitstream.

The information indicating whether the data unit is independently parsed and the information indicating whether the data unit is independently decoded are separately set and can be separately extracted. Information indicating whether data units are independently parsed or information indicating whether data units are independently decoded can be extracted from a slice header or a sequence parameter set of a bitstream according to an exemplary embodiment.

Whether to perform independent parsing or independent encoding according to one embodiment can be defined at a slice level or an encoding unit level. That is, the information indicating whether the data unit is independently parsed or the information indicating whether to independently decode the data unit according to one embodiment includes information indicating whether the parsing is independent parsing or independent decoding, whether the parsing is unitary level independent parsing or independent decoding Information.

The I slice is highly likely to refer to the surrounding information for intraprediction of the current encoding unit on the basis of the characteristics of the I slice, the P slice and the B slice, but relatively the P slice and the B slice depend on the surrounding information for intra prediction Is low. Thus, independent parsing or independent decoding of a slice level has higher performance when implemented in P slices and B slices than I slices.

The extracting unit 1520 extracts the encoded information by parsing the bit stream for each data unit based on the information indicating whether the data unit is independently parsed. For example, if a bitstream for the encoded video is received in consideration of parsing of the encoding unit level, the extracting unit 1520 according to an embodiment parses the encoded data for each maximum encoding unit, And information on the encoding depth and information on the encoding mode.

The decoding unit 1530 according to the embodiment may extract video data encoded per encoding unit extracted by the extracting unit 1520 based on information indicating whether the data unit extracted by the extracting unit 1520 is independently decoded, Can be independently decoded. And can be decoded according to the encoding mode for each encoding unit corresponding to at least one encoding depth in the maximum encoding unit, based on information on the encoding depth and encoding mode of the maximum encoding unit.

An independent parsing operation or independent decoding operation per data unit according to an embodiment can be performed in one operation processor. Accordingly, if there are a plurality of operation processors, independent parsing operations and independent decoding operations of different data units can be performed simultaneously for each operation processor. Therefore, parallel processing of a plurality of data units is possible by the independent parsing and independent decoding operation for each data unit according to the embodiment.

A decoding tool based on sequential decoding decodes the current encoding unit by referring to the information of the encoding unit to be decoded first in a sequential order. Therefore, the bit stream received by the video decoding apparatus 1500 according to the embodiment may include data independently encoded for each data unit. Therefore, if the decoding tool based on sequential decoding is used as it is, I can not.

Accordingly, in accordance with independent parsing of data units or independent decoding of data units, the decoding unit 1530 according to an embodiment decodes predetermined surrounding information for predictive decoding of an encoding unit before being decoded prior to the current encoding unit In the absence of the current coding unit, it is possible to perform predictive decoding of the current coding unit by referring to the surrounding information that can be referred to by the current coding unit.

In the case where the decoding unit 1530 according to an embodiment performs independent intra prediction of a coding unit level and the current surrounding information for intra prediction of the current coding unit can not be referred to, The DC value calculated using the surrounding information can be determined as the predicted value of the current encoding unit.

In the case where the decoding unit 1530 according to the embodiment performs independent intra prediction of a coding unit level, when the intra prediction of the current coding unit is in a state where the current peripheral information can not be referred to, The intra prediction can be performed according to the intra prediction direction mode compressed only in the intra prediction direction with respect to the surrounding information.

In the case where the decoding unit 1530 according to the embodiment performs the independent frequency-domain prediction of the coding unit level, if the current peripheral information for frequency-domain prediction of the current coding unit can not be referred to, The transform coefficients of the current encoding unit can be restored by using other referential surrounding encoding units.

In particular, the frequency-domain prediction mode of the coding unit in the coding information can indicate the direction of the current peripheral information to be referred to by the coding unit. Accordingly, if the current peripheral information of the coding unit can not be referred to, the decoding unit 1530 decodes the conversion coefficient according to the frequency-domain prediction mode changed so as to indicate the direction to the other neighboring coding units that the current coding unit can currently reference Can be restored.

Also, when the decoding unit 1530 according to an embodiment performs independent inter-prediction at the coding unit level, when the possibility of reference to the neighboring coding units for inter prediction of the current coding unit is changed, A motion vector for a neighboring encoding unit that can be accessed by using the motion vector can be used.

When the decoding unit 1530 according to the embodiment does not restore the current peripheral information of the current coding unit for the post-intra prediction processing performed independently at the coding unit level before the current coding unit, The intra prediction value of the current encoding unit can be post-processed using another reconstructed pixel value that can be referred to from among the reconstructed neighboring pixels of the current encoding unit.

In performing the independent entropy decoding according to the context-based adaptive binary arithmetic coding (CABAC) at the coding unit level, the decoding unit 1530 according to an embodiment determines whether the current surrounding information of the current coding unit is in a reference- , The current encoding unit can not be referred to the context information of the surrounding encoding unit.

Since the decoding unit 1530 according to the embodiment decodes independently for each coding unit, it can decode at least one maximum coding unit corresponding to a partial area of the coded video data. Therefore, only a part of the encoded video can be selectively decoded.

In addition, since the decoding unit 1530 according to the embodiment decodes the video data independently and in parallel in units of coding units, the video data decoded in parallel at the coding unit level can be restored and reproduced in parallel at the maximum coding unit level. A delay time may occur when a display device reproduces a pixel of a large encoding unit. If a display unit sequentially reproduces an encoding unit, a delay time that can not be ignored for one picture to be reproduced may occur. Therefore, if a display device processes and parallelly processes a plurality of encoded units decoded in parallel at the encoding unit level according to the video decoding apparatus 1500 according to an embodiment, can do.

Since the video decoding apparatus 1500 according to the embodiment decodes data in a large encoding unit, various video information can be included in one encoding unit. Accordingly, the video coding apparatus 1400 and the video decoding apparatus 1500 according to the embodiment may use the information of one coding unit as much as possible to reduce data temporally or spatially overlapping in the coding unit Decryption operation can be performed. Accordingly, in the video coding apparatus 1400 and the video decoding apparatus 1500 according to the embodiment, the sub-decoding at the coding unit level is performed independently for each coding unit.

16 shows a schematic diagram of parallel processing of slice levels by the H.264 standard part decoding method.

The H.264 standard decoding method supports concurrent processing of frames or slice levels. The I-slice 1610 is decoded in the first order without referring to another slice. The P slice 1620 is decoded to a second rank that is later than the I slice 1610 because it refers to the I slice 1610. [ The B slice 1630 refers to the I slice 1610 and the P slice 1620 and is therefore decoded into a third order that is later than the I slice 1610 and the P slice 1620. [

The B slice 1640 is decoded to a fourth order that is later than the I slice 1610 and the B slice 1630 because the I slice 1610 and the B slice 1630 refer to the B slice 1650, 1620 and the B slice 1630, it is decoded to a fourth rank, which is later than the P slice 1620 and the B slice 1630. Non-cross-referenced B slices 1640 and 1650 can be processed in parallel. The B slices processed in parallel can be handled irrespective of the processing order of the slices since there is no inter-slice dependency.

FIG. 17 shows a table for possible combinations of slice level parallel processing and encoding unit level parallel processing according to an embodiment of the present invention.

The video encoding apparatus 1400 and the video decoding apparatus 1500 according to the embodiment can perform hierarchical parallel processing up to data units of a level smaller than a slice. Independent parsing and independent decoding for parallel processing can also be set separately. Likewise, parallel parse and parallel decoding for each encoding unit can be set separately.

Referring to the table of FIG. 17, the hierarchical parallel processing according to an embodiment not only can adopt 'case 1' which can perform parallel processing only up to the slice level as in the H.264 standard part decoding method, As in case 3, parallel-parsing or parallel decoding of the coding unit level as well as parallel processing of the slice level can be selectively combined. Although not included in the diagram, the case where the parallel processing of the slice level and the parallel parsing and the parallel decoding of the encoding unit are all adopted can also be implemented in the video encoding apparatus 1400 and the video decoding apparatus 1500 according to the embodiment.

In addition, the video decoding apparatus 1500 according to the embodiment can selectively implement parallel parsing or parallel decoding of the encoding unit, although the slice level parallel processing is not adopted as in case 4 or case 5.

The parsing operation is an operation of reading a symbol in the bit stream, and the decryption operation is an operation of generating a reconstructed sample. Therefore, the operation of decoding operation is complicated and the amount of computation is larger than that of the encoding unit level parsing operation. Therefore, it is desirable that sequential parsing and parallel decoding (Case 3) be adopted if performance improvement in terms of the amount of computation is considered through parallel processing.

In addition, when image quality deterioration due to independent decoding at the coding unit level is a concern, it is preferable that parallel-parsing and sequential decoding (case 1 or case 2) at the coding unit level is adopted.

Accordingly, the video coding apparatus 1400 according to an exemplary embodiment can selectively implement independent coding and parallel coding of coding units in consideration of hardware performance, user requirements, transmission environment, and the like for negative coding. In addition, the video decoding apparatus 1500 according to an exemplary embodiment may perform independent parsing, independent decoding, parallel parsing, or parallel decoding on video data depending on whether the received encoded video data is independently encoded or parallel-encoded .

FIG. 18 shows a diagram of a parallel processing at an encoding unit level according to an embodiment of the present invention.

The video coding apparatus 1400 and the video decoding apparatus 1500 according to the embodiment can divide the picture 1800 into a maximum coding unit and process it independently for each coding unit. In detail, the video coding apparatus 1400 according to an embodiment can independently code at a coding unit level, and simultaneously code a predetermined number of maximum coding units at the same time. For example, according to the parallel encoding, the three maximum encoding units 1810, 1820, and 1830 can be simultaneously encoded in one period.

In addition, if the video decoding apparatus 1500 according to the embodiment receives the video bit stream independently encoded at the encoding unit level, it must be parsed or encoded independently for each encoding unit. For example, when decoding a video bitstream encoded according to the parallel coding, data for three maximum coding units 1810, 1820 and 1830 can be parallel-parsed or parallel-decoded.

Figure 19 illustrates a diagram of hierarchical parallel processing of data units in accordance with one embodiment of the present invention.

The video encoding apparatus 1400 according to an exemplary embodiment may separately set the encoding unit level parallel processing for each slice. For example, I-slice 1910, P-slice 1920, and B-slice 1930 can not be processed in parallel because they must be cross-referenced. But they can not be processed in parallel because they are not cross-referenced between B slices 1940 and 1950. Thus, I slice 1910 is ranked first, P slice 1920 is ranked second, B slice 1930 is ranked third, B slice 1640 and B slice 1650 are ranked fourth, .

Further, according to the hierarchical parallel processing according to the embodiment, even if parallel processing is adopted at the slice level, sequential processing or parallel processing can be selectively adopted at the coding unit level. For example, sequential parsing and sequential decoding of the coding unit level may be employed for the I-slice 1910 and the P-slice 1920, and for the B-slices 1930, 1940 and 1950, And parallel decoding may be employed.

Also, parallel parsing and parallel decoding at the encoding unit level may be set separately as described above. That is, a combination of parallel parse and sequential decode at the encoding unit level or a combination of sequential parse and parallel decode may be adopted for one slice.

FIG. 20 illustrates a partial decoding scheme that is possible by independent decoding of coding unit levels according to an embodiment of the present invention.

The video encoding apparatus 1400 according to the embodiment independently encodes the video data 2010 for each encoding unit level. The video decoding apparatus 1500 according to an exemplary embodiment receives a bitstream independently encoded in a coding unit, and independently parses or decodes the bitstream at a coding unit level to reconstruct the video data.

Therefore, when it is desired to decode only the partial region 2015 of the video data 2010, the video decoding apparatus 1500 according to the embodiment can independently decode and recover only the maximum coding units corresponding to the partial region 2015 have. Accordingly, the resulting image 2020 reconstructed by the video decoding apparatus 1500 according to an embodiment may include a partially reconstructed partial area 2025. [

FIG. 21 shows a diagram of a parallel display of coding units possible by decoding a coding unit level according to an embodiment of the present invention.

In addition, video data encoded at a coding unit level by the video coding apparatus 1400 according to an embodiment is decoded in parallel by a predetermined number of coding units according to the video decoding apparatus 1500 according to an embodiment . The display apparatus can receive the video signals of the decoding units decoded in parallel and reconstructed, and reproduce them in parallel for each coding unit.

For example, if a video coding apparatus 1400 according to an embodiment selects one picture 2100 including maximum coding units A1 to 4, B1 to 4, C1 to 4, D1 to 4, and E1 to 4 Decoded independently at the coding unit level and restored.

The video encoding apparatus 1400 according to the embodiment can decode and recover the maximum five consecutive encoding units in the horizontal direction in parallel. A set 2110 of the encoding units A1, B1, C1, D1 and E1 in the first processing cycle, a set 2120 of encoding units A2, B2, C2, D2 and E2 in the second processing cycle, A set 2130 of B3, C3, D3 and E3 and a set 2140 of coding units A4, B4, C4, D4 and E4 are decoded in the fourth processing cycle and restored for each processing cycle. In this case, in order to reproduce one picture 2100, the display unit reconstructs the reconstructed encoding units into a set of encoding units 2110, 2120, 2130, and 2140, which are reconstructed in parallel for every five encoding units, As shown in FIG.

Alternatively, the video encoding apparatus 1400 according to an exemplary embodiment may parallelly decode and reconstruct four consecutive maximum encoding units in the vertical direction. In this case, a set of coding units A1, A2, A3 and A4 is set in the first processing cycle, a set of the coding units B1, B2, B3 and B4 is set in the second processing cycle and a set of the coding units C1, A set of coding units D1, D2, D3 and D4 in the fourth processing cycle, and a set of coding units E1, E2, E3 and E4 in the fifth processing cycle are decoded and restored. In this case, in order to reproduce one picture 2100, the display apparatus reconstructs the reconstructed encoding units into a plurality of sets of encoding units (A1 to 4, B1 to 4, C1 to 4, D1 to 4, and E1 to 4) can be reproduced in the restored order.

FIG. 22 shows a syntax of a sequence parameter set into which information indicating whether to independently parse an encoding unit level and information indicating whether to independently decode an encoding unit level is inserted according to an embodiment.

The sequence_parameter_set indicates the syntax of the sequence parameter set 2200 for the current video slice. An example in which information indicating whether or not to independently parse an encoding unit level according to an embodiment and information indicating whether or not an encoding unit level is independently decoded is inserted into a syntax of a sequence parameter set 2200 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 improved 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) (Use_random_generation_flag), and information indicating the availability (use_arbitrary_motion_partition_flag) of a motion prediction operation according to a prediction unit that is divided into an arbitrary shape. 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 2200.

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 relationship between the inter prediction and the corresponding operation mode or the sub-decoding using the tri-sign information and the corresponding operation mode according to the depth of the encoding unit according to the embodiment is set in the sequence parameter set 2200 .

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 2200.

The video decoding apparatus 1500 according to the embodiment extracts the information (use_independent_cu_decode_flag) indicating whether the encoding unit level is independently decoded and the information (use_independent_cu_parse_flag) indicating whether or not the encoding unit level is independently parsed by reading the sequence parameter, It is possible to determine whether to perform independent parsing or decoding of the encoding unit level in the sequence.

(Use_independent_cu_decode_flag) indicating whether the coding unit level is independently decoded to be set and encoded by the video coding apparatus 1400 according to the embodiment and the video coding apparatus 1500 according to an embodiment, whether or not to independently parse the coding unit level (Use_independent_cu_parse_flag) is not limited to the embodiment inserted in the sequence parameter set 2200 shown in FIG. 22, but can be set in units of a maximum encoding unit, a slice, a frame, a picture, a GOP, .

If the information (use_independent_cu_parse_flag) indicating whether or not to independently parse the encoding unit level is included in the slice header, if the information indicating that the encoding unit level is independently parsed (use_independent_cu_parse_flag) is 'true' And if it has a 'false' value, it performs the existing sequential parsing on the slice.

If information indicating whether or not to independently decode the coding unit level (use_independent_cu_decode_flag) is included in the slice header, if the information indicating the independent decoding of the coding unit level (use_independent_cu_decode_flag) is 'true' Independent decoding is performed, and if it has a value of 'false', the existing sequential decoding is performed on the corresponding slice.

FIG. 23 shows a diagram of intra prediction for independent decoding at an encoding unit level according to an embodiment of the present invention.

The video decoding apparatus 1500 according to an exemplary embodiment may perform an arbitrary directional intra prediction of the current encoding unit 2310 in consideration of the directions of the current encoding units 2320, 2330, and 2340 of the encoding unit 2310 Can be performed. The random directional intra prediction is a prediction that calculates the intra prediction value of the current encoding unit 2310 according to extrapolation using restoration samples of the surrounding encoding units 2320, 2330, and 2340 of the current encoding unit 2310. [ Technique.

According to the independent decoding of the coding unit level according to the embodiment, it is not possible to refer to the reconstructed samples of the surrounding coding unit existing at the boundary of the current coding unit. If the pixel value on the boundary 2335 between the current encoding unit 2310 and the upper left surrounding encoding unit 2330 can not be referred to because the top surrounding encoding unit 2330 has not yet been decoded, Only the intra prediction mode in which only the pixel values on the boundary 2345 of the surrounding encoding unit 2340 are referred to can be performed. For example, the DC value of the pixel value on the boundary 2345 as the intra prediction value of the current encoding unit 2310 can be calculated.

Likewise, when the left surrounding encoding unit 2340 has not yet been decoded and the pixel value on the boundary 2345 between the current encoding unit 2310 and the left surrounding encoding unit 2340 can not be referred to, Only the intra prediction mode in which only the pixel values on the boundary 2335 of the top surrounding encoding unit 2330 are referred to can be performed. For example, the DC value of the pixel value on the boundary 2335 as the intra prediction value of the current encoding unit 2310 can be calculated.

If neither the upper peripheral encoding unit 2330 nor the left peripheral encoding unit 2340 has been decoded yet and can not be referred to, a predetermined DC value is selected as the intra prediction value of the current encoding unit 2310, 2310 may be set to a prediction mode in which intra prediction can not be performed.

In addition, the video encoding apparatus 1400 according to an exemplary embodiment may independently refer to the current encoding unit 2310 without referring to the surrounding encoding units 2320, 2330, and 2340 for the current encoding unit 2310, Intra prediction can be performed.

In addition, the video encoding apparatus 1400 according to an exemplary embodiment may perform frequency domain prediction. According to the frequency domain prediction, the predicted value of the transform coefficient of the current encoding unit in the frequency domain can be calculated using restoration samples of the surrounding encoding unit. Accordingly, the video decoding apparatus 1500 according to the embodiment can perform predictive decoding in the frequency domain. The transform coefficients of the current encoding unit in the frequency domain can be recovered using restoration samples of the surrounding encoding unit.

The frequency domain prediction mode is defined according to the direction of the surrounding information to be referred to. For example, when the vertical directional peripheral information is referred to, the frequency domain prediction mode FDP_mode is set to 0 (FDP_mode = 0) and the frequency domain prediction mode is set to 1 if the horizontal directional peripheral information is referred to (FDP_mode = One). The frequency domain prediction mode is set to 2 (FDP_mode = 2) for the coding unit conforming to the DC intra prediction mode, and the frequency domain prediction mode is set to 3 when all of the information in the vertical direction and the information in the horizontal direction are referred to (FDP_mode = 3).

In order for the video encoding apparatus 1400 according to the embodiment to recover the transform coefficient of the current encoding unit using the surrounding information, the reconstruction sample of the encoding unit decoded before the current encoding unit should be referred to. However, if the reference information for restoring the transform coefficients of the current encoding unit is a sample that can not be referred to in accordance with the independent encoding at the encoding unit level, the video encoding apparatus 1500 according to an exemplary embodiment You can refer to the restoration sample instead.

For example, if the transform coefficients of the independent upper-level coding unit can not be currently referenced in accordance with the independent coding of the coding unit level, the video coding apparatus 1400 according to the embodiment can adjust the frequency The area prediction mode is changed to the mode 'FDP_mode = 1' which refers to the peripheral information in the horizontal direction. If the transform coefficients of the left encoding unit can not be referred to in the similar manner, the video encoding device 1400 according to the embodiment can convert the frequency-domain prediction mode into the vertical surrounding information Quot; FDP_mode = 0 "

However, if the current encoding unit is the maximum encoding unit, the frequency domain prediction is not performed.

The video decoding apparatus 1500 according to the embodiment reads information (use_independent_cu_decode_flag) indicating whether the coding unit level is independently decoded or information (use_independent_cu_parse_flag) indicating whether or not the coding unit level is independently parsed has a value of 'true' If independent parse or independent decoding of the encoding unit level is adopted, it is necessary to perform decoding according to independent frequency domain prediction at the encoding unit level. However, there may occur a case where the current peripheral information can not be referred to by independent parsing or decoding of the encoding unit level according to the embodiment.

The encoded information inserted and transmitted by the video encoding apparatus 1400 according to the embodiment may include a frequency domain prediction that is adjusted to represent peripheral information that can be referred to for frequency domain prediction independently performed at the encoding unit level Mode FDP_mode. Accordingly, the video decoding apparatus 1500 may extract the encoding information from the received bitstream and perform frequency domain prediction decoding according to the frequency domain prediction mode of the encoded information.

24A illustrates a post-processing scheme of intra prediction using a reconstructed sample according to an embodiment of the present invention.

The video coding apparatus 1400 according to an embodiment of the present invention may use the reconstructed samples of the surrounding coding unit of the current coding unit as multi-parameters, It is possible to perform multi-parameter intra prediction that post-processes the predicted value.

Referring to FIG. 24A, the white circular pixels of the current coding unit 2400 are samples of the intra prediction value, and the black circular pixels of the area 2405 surrounding the current coding unit 2400 are peripheral reconstruction samples. In step 2411, the upper-left pixel is post-processed using the upper peripheral restoration sample and the left peripheral restoration sample. The post-processed reconstruction samples of the current encoding unit 2400 are shown as white square pixels.

As shown stepwise along steps 2412, 2413, 2414, 2415, and 2416, the upper sample or left sample of the current pixel is reconstructed from the reconstructed sample (black circular pixel) Intraprediction values of the current pixel are post-processed using reconstruction samples (white square pixels).

FIG. 24B shows a diagram of post-processing of intra prediction for independent decoding at the coding unit level according to an embodiment of the present invention.

Since the video encoding apparatus 1400 according to an embodiment of the present invention can not reference reconstructed samples of the surrounding encoding unit of the current encoding unit when performing independent encoding at the encoding unit level, It is desirable to change the parameter.

Referring to FIG. 24B, the white circular pixels of the current coding unit 2450 are samples of the intra prediction value, and the black circular pixels of the area 2455 surrounding the current coding unit 2450 are peripheral reconstruction samples. However, the surrounding reconstruction samples of the current area 2455 can not be referred to in accordance with the encoding unit level independent encoding.

In this case, in the video encoding apparatus 1400 according to the embodiment of the present invention, since the upper left pixel can not refer to the upper and lower surrounding reconstructed samples in step 2461, . Also, the right pixel and the bottom pixel of the post-processed upper left pixel may be post-processed using the post-processed upper left pixel and each lower pixel.

Similarly, using post-processed restoration samples among the upper, left, and lower pixels of the current pixel among the pixels of the current encoding unit 2450, as shown stepwise according to steps 2462, 2463, 2464, and 2465, Lt; / RTI > can be post-processed.

The video decoding apparatus 1500 according to an embodiment may perform independent parsing or decoding of an encoding unit level so that if a neighboring reconstructed sample of the current encoding unit can not be referred to, Processed post-reconstruction samples among the upper, left and lower pixels of the current pixel among the pixels of the encoding unit can be used.

FIG. 25 illustrates a scheme of entropy decoding according to the CABAC scheme for independent coding of coding unit levels and independent decoding of coding unit levels according to an embodiment of the present invention.

The video encoding apparatus 1400 according to an embodiment of the present invention can refer to pixels at the boundary between the current encoding unit and the upper encoding unit and the left encoding unit of the current encoding unit in order to perform entropy encoding according to the CABAC scheme .

However, when the encoding unit level independent encoding is performed, the video encoding device 1400 according to an embodiment of the present invention may convert the reconstructed samples of the surrounding encoding unit of the current encoding unit into the encoded samples of the current encoding unit in order to perform entropy encoding according to the CABAC scheme You can not refer to it.

For example, according to the sequential coding at the coding unit level, for entropy coding of the current coding unit CUcurrent 2510 according to the CABAC scheme, the boundary 2525 between the upper coding unit CUa 2520 and the CUcurrent 2510 and the left side The boundary 2535 between the encoding unit CUb 2530 and the CUcurrent 2510 can be referred to.

However, according to the encoding unit level independent encoding according to an embodiment, pixels of the boundary 2525 and the boundary 2535 can not be referred to for entropy encoding of CUcurrent 2510. [ Further, even though the entropy decoding of the encoding unit level according to an embodiment is performed, restoration samples on boundary 2525 and boundary 2535 can not be referenced for entropy decoding of CUcurrent 2510. [

26 shows a flowchart of a video encoding method for independent parsing or decoding according to an embodiment of the present invention.

In step 2610, the current picture is divided into at least one maximum encoding unit which is a maximum-size encoding unit. In step 2620, at least one coding depth is determined for each of the maximum coding units, for each of at least one divided area generated as the depth increases. It is possible to independently encode an encoding unit level that does not refer to surrounding information for encoding of the current encoding unit. In addition, if an operation environment supports a plurality of operation processors at the same time, independent encoding in which each encoding unit is encoded independently from peripheral information, and parallel encoding in which a plurality of encoding units are simultaneously encoded in parallel can be implemented.

In step 2630, for each maximum encoding unit, a bitstream including encoded video data and information on the encoding depth and encoding mode for each maximum encoding unit may be output. At least one of information indicating whether data units are independently parsed or information indicating whether data units are independently decoded is inserted into the bitstream according to an embodiment. In particular, information indicating whether to support independent coding or independent parsing of the coding unit level can be inserted into the bitstream and output.

FIG. 27 shows a flowchart of a video decoding method according to an independent parsing or decoding method according to an embodiment of the present invention.

In step 2710, a bitstream for the encoded video is received, and at least one of information indicating whether the data unit is independently parsed from the bitstream and information indicating whether the data unit is independently decoded is extracted. Information indicating whether data units are independently parsed or not and information indicating whether data units are independently decoded can be extracted from a slice header, a sequence parameter set, or encoding unit information.

Independent or independent decoding of data units according to one embodiment may be slice-level independent parsing or independent decoding, and may be independent unit-level parsing or independent decoding.

In step 2720, the bit stream is parsed based on the information indicating whether the data unit is independently parsed, and the video data and the encoding information encoded for each maximum encoding unit are extracted from the bit stream. The encoding information may include information on at least one encoding depth present in the maximum encoding unit and information on an encoding mode for each encoding unit of the encoding depth. If the information indicating whether the data unit is independently parsed is 'true', the symbol of the current encoding unit can be parsed without referring to the surrounding information.

At step 2730, at least one coding unit for each coding depth is decoded for each coding unit of the coded video data on the basis of the information indicating whether the data units are independently decoded and the coding depth for each coding unit and the coding mode, do. If the information indicating whether or not the data unit is independently decoded defines independent decoding at the coding unit level, the video data encoded for each maximum coding unit according to an embodiment may be decoded without referring to the information of the surrounding coding unit.

According to a decoding tool according to sequential decoding, peripheral information to be referred to for decoding a current encoding unit may not be accessible according to independent decoding. In this case, it is preferable that the reference information for the current encoding unit is changed so that predictive decoding of the current encoding unit can be performed while referring to information currently accessible.

According to the embodiment of the present invention, since the large coding unit can be adopted, prediction unit decoding of the current coding unit can be performed without referring to the surrounding information. As the hardware performance and the hardware cost are reduced, it is possible to implement a decoder using a plurality of operation processors. Therefore, parallel decoding at the encoding unit level is possible by simultaneously performing independent parsing and decoding of encoding unit levels for different encoding units for each of a plurality of operation processes.

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)

Dividing an image into a plurality of maximum encoding units using information on a size of a maximum encoding unit;
Acquiring, from a bitstream, information for parallel motion prediction of an encoding unit in one of the plurality of maximum encoding units;
When neighboring coding units of the current coding unit and the current coding unit are included in the current maximum coding unit when parallel motion prediction is possible for the coding units included in the current maximum coding unit according to the information, Determining a block that can not reference an encoding unit; And
And determining a motion vector of the current encoding unit using a motion vector of one block among the blocks excluding the non-referable block,
Wherein the neighboring encoding unit is decoded prior to the current encoding unit according to a decoding order,
Wherein the partition type for performing the inter prediction of the current coding unit indicates a prediction block having the same size as the size of the current coding unit,
Wherein the current maximum encoding unit is hierarchically divided into at least one depth encoding unit,
When the current depth coding unit is divided, the current depth coding unit is divided into four sub-depth coding units independent of neighboring coding units,
A prediction block for prediction is generated from the current-depth encoding unit when the current-depth encoding unit is not divided,
A maximum depth indicating a maximum dividable maximum number of times of the current maximum encoding unit is obtained from the bitstream, a minimum encoding unit that can be generated from among the encoding units that are hierarchically divided from the current maximum encoding unit, A prediction block for prediction is generated from the current-depth encoding unit when the size of the current-depth encoding unit is equal to the size of the minimum-size encoding unit when the size difference between the current depth and the current depth is determined based on the maximum depth. / RTI > delete A motion vector determination apparatus comprising:
And a processor for determining a motion vector of the current encoding unit using a motion vector of one of neighboring blocks of the current encoding unit,
Wherein the processor divides an image into a plurality of maximum encoding units using information on a size of a maximum encoding unit and encodes the parallel motion estimates of the encoding units in one of the plurality of maximum encoding units Wherein when the parallel encoding of the current encoding unit and the current encoding unit included in the current maximum encoding unit is possible according to the information, And determines a block to which the neighboring coding unit can not be referred if it is included in the maximum coding unit, and determines a motion vector of the current coding unit by using one of the neighboring blocks excluding the non- Lt; / RTI >
Wherein the neighboring encoding unit is decoded prior to the current encoding unit according to a decoding order,
Wherein the partition type for performing the inter prediction of the current coding unit indicates a prediction block having the same size as the size of the current coding unit,
Wherein the current maximum encoding unit is hierarchically divided into at least one depth encoding unit,
When the current depth coding unit is divided, the current depth coding unit is divided into four sub-depth coding units independent of neighboring coding units,
A prediction block for prediction is generated from the current-depth encoding unit when the current-depth encoding unit is not divided,
A maximum depth indicating a maximum dividable maximum number of times of the current maximum encoding unit is obtained from the bitstream, a minimum encoding unit that can be generated from among the encoding units that are hierarchically divided from the current maximum encoding unit, A prediction block for prediction is generated from the current-depth encoding unit when the size of the current-depth encoding unit is equal to the size of the minimum-size encoding unit when the size difference between the current depth and the current depth is determined based on the maximum depth. A motion vector decision unit.

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