WO2017099371A1

WO2017099371A1 - Method and device for encoding and decoding intra-frame skip mode information

Info

Publication number: WO2017099371A1
Application number: PCT/KR2016/012977
Authority: WO
Inventors: 첸지에; 이진영
Original assignee: 삼성전자 주식회사
Priority date: 2015-12-11
Filing date: 2016-11-11
Publication date: 2017-06-15

Abstract

Disclosed are a method and a device for encoding and decoding a video. A method for decoding a video, according to an embodiment, comprises the steps of: determining the types of data units in an upper layer comprising a current encoding unit in a hierarchical structure of data units; and obtaining information about an intra-frame skip mode of the current encoding unit from a bitstream on the basis of the determined types of the data units in the upper layer, wherein, with respect to varied types of the data units in the upper layer, the information related to the intra-frame skip mode is shown as codewords having varied lengths in the bitstream.

Description

Method and apparatus for encoding intra frame skip mode information, method and apparatus for decoding

The present disclosure relates to encoding and decoding of video, and more particularly, to encoding and decoding of information related to an intra frame skip mode of a current coding unit.

In the recent international three-dimensional video coding standard, that is, three-dimensional high efficiency video coding (3D-HEVC), an intra frame skip mode is used for depth image coding as a coding technique. This technique adopts the intra frame prediction method. That is, the pixels in the current pixel block are predicted using the reconstructed values of other pixels at spatial locations adjacent to the current pixel block. This method is called intra frame prediction or intra prediction because the current pixel to be predicted and adjacent pixels used for prediction are in the same frame. After intra frame prediction is performed, according to the general intra frame prediction encoding mode, the difference between the predicted value of the pixel and the original value of the pixel is calculated, and the difference information and the prediction method information are encoded in the video bit stream and transmitted to the decoder. do. Accordingly, the decoder may perform intra frame prediction to obtain the predicted value of the pixel using the same prediction method, and then add the difference to the predicted value, resulting in a reconstructed value of the pixel. However, in the intra frame skip mode, the difference information is not transmitted after intra frame prediction is performed. In other words, the predicted value of the pixel is considered to be the finally reconstructed value of the pixel. Since there is no differential compensation, the reconstructed value may have a certain distortion compared to the original value before encoding, but the coding compression efficiency is still improved because other information is no longer transmitted. Indeed, there are many flat regions in the depth image. Within this flat area, the difference between the predicted value of the pixel obtained by intra prediction and the original value of the pixel is quite small. Therefore, the difference information is not transmitted, but the distortion of the reconstructed value is not large. Thus, this technique is adopted in 3D-HEVC for depth image coding.

In 3D-HEVC, inter prediction mode and other intra prediction modes are still maintained for depth image coding. Thus, in 3D-HEVC, the flag is fixedly transmitted into the bit stream to indicate whether the intra frame skip mode is used to encode the current pixel block, where the flag is transmitted before other information. Thus, if the flag indicates that intra frame skip mode is used for the current pixel block, only information about the intra frame prediction method used for prediction is transmitted after that, and other information is not transmitted. If the flag indicates that intra frame skip mode is not used for the current pixel block, other information, such as the prediction mode, block partition method, motion information, prediction direction and difference information, etc. It will continue to be sent later.

In 3D-HEVC, the method of indicating the intra frame skip mode is simple but the efficiency is low. This is because the flag is fixedly transmitted in this method irrespective of the type and additional information of the data unit containing the current pixel block. Indeed, in the video coding standard, for encoding of a pixel block included in different types of data units, the supported encoding modes are different. For example, for an intra predictive encoded frame, the encoder can select only the intra frame prediction mode, and therefore has a high probability of selecting the intra frame skip mode. For an inter prediction encoded frame, the encoder can choose either an intra frame prediction mode or an inter frame prediction mode, thus reducing the probability of selecting an intra frame skip mode. Therefore, the efficiency when fixedly transmitting the 1 bit flag is low. For example, when the probability of occurrence of intra frame skip mode is quite low, in order to indicate whether intra frame skip mode is used, the 1 bit flag should still be transmitted.

The present disclosure provides a method and apparatus for encoding / decoding information related to an intra frame skip mode of a current coding unit according to a type of a data unit of a higher layer including the current coding unit.

Through a method and apparatus for encoding / decoding video according to an embodiment, overhead may be saved and video coding compression efficiency may be improved.

1 is a flowchart of a method of encoding a video, according to an exemplary embodiment.

2 is a flowchart of a method of decoding a video, according to an exemplary embodiment.

3 is a block diagram of a video encoding apparatus, according to an embodiment.

4 is a block diagram of a video decoding apparatus, according to an embodiment.

According to an embodiment, a method of decoding a video may include: determining a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit; And obtaining, from the bit stream, information relating to an intra frame skip mode of the current coding unit, according to the determined type of the data unit of the higher layer, for different types of data units of the higher layer, Information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

According to an embodiment, the data unit of the higher layer may be any one of a sequence, a frame, a slice, a maximum coding unit, a maximum coding block, and a coding unit.

According to an embodiment, the obtaining of the information related to the intra frame skip mode of the current coding unit may include obtaining a first syntax element when the determined type of the data unit of the higher layer is the first type, and the higher layer. Obtaining a second syntax element when the determined type of the data unit of the layer is the second type, wherein the first syntax element is 1 indicating whether the intra frame skip mode is used in the current coding unit; May be a bit flag, and the second syntax element may have an integer value ranging from 0 to N to indicate use of the intra frame skip mode and additional coding information of the current coding unit, and N may be 3 or more. have.

According to an embodiment, the additional coding information is used in the current coding unit in addition to the intra prediction method of the intra frame skip mode and the intra frame skip mode when the intra frame skip mode is used in the current coding unit. It may include at least one of a prediction mode, a partition mode of the current coding unit, and an inter frame prediction direction.

According to an embodiment, the data unit of the higher layer may be a frame, and the data unit of the higher layer corresponding to the first type may be an intra prediction coded frame and the higher layer corresponding to the second type. The data unit of the layer may be an inter prediction coded frame.

According to an embodiment, the obtaining of the information related to the intra frame skip mode of the current coding unit may include obtaining a first syntax element when the determined type of the data unit of the higher layer is the first type, and the higher layer. Acquiring a second syntax element when the determined type of the data unit of the layer is the second type, wherein the first syntax element further comprises: using the intra frame skip mode and additional coding of the current coding unit. May have an integer value in the range of 0 to N1 for indicating information, and the second syntax element is an integer in the range of 0 to N2 for indicating use of the intra frame skip mode of the current coding unit and additional coding information. It may have a value, and both N1 and N2 may be three or more.

According to an embodiment, a value of the first syntax element indicating that the intra frame skip mode is used in the current coding unit and a value of the second syntax element indicating that the intra frame skip mode is used in the current coding unit are May differ from one another.

According to an embodiment, a video decoding apparatus includes: a data unit type determiner configured to determine a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of a data unit; And an intra frame skip mode information obtaining unit configured to obtain information related to an intra frame skip mode of the current coding unit from a bit stream according to the determined type of the data unit of the higher layer. For different types, the information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

According to an embodiment, a method of encoding a video may include determining a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit; And encoding the information related to the intra frame skip mode of the current coding unit and outputting a bit stream according to the determined type of the data unit of the higher layer, and outputting a bit stream to different types of data units of the higher layer. For the information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

In various embodiments described herein, the term 'image' may refer to a generic image including a still image as well as a video such as a video. In addition, the image may be a single view image or a multiview image, a 3D image including a texture image and a depth image, and may be a multi-layer image and a scalable image.

When various operations are performed on data related to an image, the data related to the image may be divided into data groups, and the same operation may be performed on data included in the same data group. Hereinafter, in the present specification, a data group formed according to a predetermined criterion is referred to as a 'data unit'. Hereinafter, the operation performed for each 'data unit' may mean that a corresponding operation is performed using data included in the data unit.

The hierarchical structure of the video data unit may include a sequence, a frame, a slice, a largest coding unit (LCU), a maximum coding block, a coding unit, a coding block, a prediction unit, and a prediction block from an upper layer to a lower layer. Can be. The data unit of the upper layer may include one or more data units of the lower layer. For example, the sequence may include one or more frames, the frame may include one or more slices, and the slice may include one or more maximum coding units arranged in a raster scan order. However, the hierarchical structure is not limited to the above example and may have a different form.

According to the type of the data unit of the higher layer to which the current coding unit belongs, a constraint may exist in the prediction mode of the current coding unit. For example, only an intra prediction mode may be selected as a prediction mode of a current coding unit for a current coding unit included in an intra prediction coding frame, and an intra frame prediction mode or inter as a prediction mode for an inter prediction coding frame. The frame prediction mode may be selected.

When the intra frame skip mode is used for the current coding unit, intra prediction is performed, but residual information is not encoded for the current coding unit, and thus the residual information is not included in the output bit stream. Instead, information indicating whether intra frame skip mode was used and information indicating which intra prediction method was used in intra frame skip mode may be encoded, and a single syntax element may be used to determine whether intra frame skip mode is used and It may indicate which intra prediction method was used in the intra frame skip mode.

In this disclosure, a method of encoding video is provided.

According to an embodiment, a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of data units is determined, and an intra frame skip mode of the current coding unit is determined according to the determined type of the data unit of the higher layer. The information associated with is encoded and a bit stream is output. For different types of data units of higher layers, the information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

According to an embodiment, the data unit of the upper layer may be any one of a sequence, a frame, a slice, a maximum coding unit, a maximum coding block, and a coding unit. In the current coding unit, the coding unit may be replaced with a maximum coding unit, a maximum coding block, a coding block, a prediction unit, or a prediction block.

If the data unit of the higher layer is a frame, for example, the frame may be an intra prediction coded frame or an inter prediction coded frame, a uni-prediction coded frame, or a bi-prediction coded frame, depending on the type thereof. Or a dual-hypothesis encoded frame, temporal predictive encoded frame or inter-view predictive encoded frame, base view frame or dependent view frame, texture Frame or depth frame or the like.

If the data of the higher layer is a slice, for example, the slice may be an intra prediction coded slice or an inter prediction coded slice, a uni-prediction coded slice, a bi-prediction coded slice or Dual-hypothesis coded slices, temporal predictive coded slices or inter-view predictive coded slices, base view slices or dependent view slices, texture slices Or a depth slice or the like.

According to an embodiment, when a determined type of a data unit of a higher layer including a current coding unit is different, information for indicating an intra frame skip mode may also be different for the current coding unit. According to the type of the data unit of the higher layer, information represented by codewords of different lengths in the bit stream may be encoded as information related to an intra frame skip mode of the current coding unit.

According to an embodiment, the first syntax element is encoded when the determined type of the data unit of the upper layer is the first type, and the second syntax element is the case where the determined type of the data unit of the upper layer is the second type. Can be encoded. The first syntax element and the second syntax element may be represented by codewords of different lengths in the bit stream. For example, when a data unit of a higher layer including the current coding unit has a high probability of using an intra frame skip mode, the first syntax element may be represented by a short length codeword in a bit stream, such as a 1-bit flag. When the data unit of the upper layer including the current coding unit has a low probability of using the intra frame skip mode, the second syntax element may be represented by a long length code word in the bit stream.

According to an embodiment, the data unit of the higher layer is a frame, and the data unit of the higher layer corresponding to the first type is an intra prediction coded frame, and the data unit of the higher layer corresponding to the second type. May be an inter prediction coded frame.

According to an embodiment, the first syntax element is a 1-bit flag indicating whether the intra frame skip mode is used in the current coding unit, and the second syntax element is the intra frame skipping of the current coding unit. It may have an integer value in the range of 0 to N to indicate the use of mode and additional coding information, and N may be 3 or more.

According to another embodiment, the first syntax element has an integer value in a range of 0 to N1 for indicating use of the intra frame skip mode and additional coding information of the current coding unit, and the second syntax element may include: It may have an integer value in the range of 0 to N2 to indicate the use of the intra frame skip mode and additional coding information of the current coding unit, and both N1 and N2 may be 3 or more.

According to an embodiment, a value of the first syntax element indicating that the intra frame skip mode is used in the current coding unit and a value of the second syntax element indicating that the intra frame skip mode is used in the current coding unit are It may be different from each other.

According to an embodiment, other information may be further encoded according to whether an intra frame skip mode is used for the current coding unit. When the intra frame skip mode is used for the current coding unit, information indicating the intra prediction method used for the intra frame skip mode may be encoded to output a bit stream. However, prediction residual information may not be encoded.

In the present disclosure, a method of decoding a video is provided.

According to an embodiment, a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of data units is determined, and an intra frame skip mode of the current coding unit is determined according to the determined type of the data unit of the higher layer. Information associated with is obtained from the bit stream. For different types of data units of higher layers, the information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

According to an embodiment, when a determined type of a data unit of a higher layer including a current coding unit is different, information for indicating an intra frame skip mode may also be different for the current coding unit. According to the type of the data unit of the higher layer, information represented by codewords of different lengths in the bit stream may be obtained as information related to an intra frame skip mode of the current coding unit.

According to an embodiment, a first syntax element is obtained from the bit stream when the determined type of the data unit of the upper layer is the first type, and the bit stream when the determined type of the data unit of the upper layer is the second type. A second syntax element can be obtained from. The first syntax element and the second syntax element may be represented by codewords of different lengths in the bit stream. For example, when a data unit of a higher layer including the current coding unit has a high probability of using an intra frame skip mode, the first syntax element may be represented by a short length codeword in a bit stream, such as a 1-bit flag. When the data unit of the upper layer including the current coding unit has a low probability of using the intra frame skip mode, the second syntax element may be represented by a long length code word in the bit stream.

According to an embodiment, other information may be further obtained from the bit stream according to whether the intra frame skip mode is used for the current coding unit. When the intra frame skip mode is used for the current coding unit, information indicating the intra prediction method used for the intra frame skip mode may be obtained from the bit stream. However, prediction residual information may not be obtained. A predicted pixel value may be obtained by performing prediction on the current coding unit according to the determined prediction method, and the predicted pixel value may be regarded as a reconstructed pixel value.

In the present disclosure, a video encoding apparatus is provided corresponding to a method of encoding a video.

According to an embodiment, the video encoding apparatus according to the data unit type determiner for determining the type of the data unit of the upper layer including the current coding unit in the hierarchical structure of the data unit and the determined type of the data unit of the higher layer, And an information encoder for encoding information related to an intra frame skip mode of the current coding unit and outputting a bit stream. For different types of data units of higher layers, the information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

According to an embodiment, when a determined type of a data unit of a higher layer including a current coding unit is different, information for indicating an intra frame skip mode may also be different for the current coding unit. According to the type of the data unit of the higher layer, the information encoder may encode information represented by codewords having different lengths in the bit stream as information related to an intra frame skip mode of the current coding unit.

According to an embodiment, the information encoder encodes a first syntax element when the determined type of the data unit of the upper layer is the first type, and if the determined type of the data unit of the higher layer is the second type, Two syntax elements can be encoded. The first syntax element and the second syntax element may be represented by codewords of different lengths in the bit stream. For example, when a data unit of a higher layer including the current coding unit has a high probability of using an intra frame skip mode, the first syntax element may be represented by a short length codeword in a bit stream, such as a 1-bit flag. When the data unit of the upper layer including the current coding unit has a low probability of using the intra frame skip mode, the second syntax element may be represented by a long length code word in the bit stream.

According to an embodiment, the information encoder may further encode other information according to whether an intra frame skip mode is used for the current coding unit. When the intra frame skip mode is used for the current coding unit, the information encoder may encode information indicating the intra prediction method used for the intra frame skip mode and output a bit stream. However, prediction residual information may not be encoded.

In the present disclosure, corresponding to a method of decoding a video, a video decoding apparatus is provided.

According to an embodiment, the video decoding apparatus may further include a data unit type determiner that determines a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit, and the determined type of the data unit of the higher layer. And an information obtaining unit obtaining information related to an intra frame skipping mode of the current coding unit from a bit stream. For different types of data units of higher layers, the information related to the intra frame skip mode may be represented by codewords of different lengths in the bit stream.

According to an embodiment, when a determined type of a data unit of a higher layer including a current coding unit is different, information for indicating an intra frame skip mode may also be different for the current coding unit. According to the type of the data unit of the higher layer, the information acquirer may acquire information represented by codewords of different lengths in the bit stream as information related to the intra frame skip mode of the current coding unit.

According to an embodiment, the information obtaining unit obtains a first syntax element when the determined type of the data unit of the upper layer is the first type, and if the determined type of the data unit of the upper layer is the second type, 2 Syntax element can be obtained. The first syntax element and the second syntax element may be represented by codewords of different lengths in the bit stream. For example, when a data unit of a higher layer including the current coding unit has a high probability of using an intra frame skip mode, the first syntax element may be represented by a short length codeword in a bit stream, such as a 1-bit flag. When the data unit of the upper layer including the current coding unit has a low probability of using the intra frame skip mode, the second syntax element may be represented by a long length code word in the bit stream.

According to an embodiment, the information acquisition unit may further encode other information according to whether the intra frame skip mode is used for the current coding unit. When the intra frame skip mode is used for the current coding unit, the information acquirer may obtain information indicating the intra prediction method used for the intra frame skip mode. However, prediction residual information may not be obtained.

Hereinafter, various embodiments will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, the method of encoding a video may include determining a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit, and determining the type of the data unit of the higher layer. And encoding information related to an intra frame skip mode of the current coding unit to output a bit stream.

Hereinafter, the encoding method of the first to fourth embodiments will be described with reference to FIG. 1.

According to the first embodiment, in step 110, a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit is determined.

In the present embodiment, the data unit of the upper layer is a frame, and the type of the frame including the current coding unit is determined in step 110. The frame may be an intra prediction coded frame or an inter prediction coded frame, a uni-prediction coded frame, a bi-prediction coded frame, or a dual-hypothesis coded frame, or temporal. ) May be a predictive encoded frame or an inter-view predictive encoded frame, a base view frame or a dependent view frame, a texture frame, or a depth frame.

In step 120, according to the determined type of the data unit of the higher layer, information related to an intra frame skip mode of the current coding unit is encoded and a bit stream is output.

According to the type of the frame including the current coding unit determined in step 110, information about the intra frame skip mode is encoded and included in the output bit stream.

If the frame including the current coding unit is an intra prediction coded frame, a flag may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit. For example, a flag value 1 is generated when the intra frame skip mode is used for the current coding unit, a flag value 0 is generated when the intra frame skip mode is not used for the current coding unit, and the generated value is a bit. Can be written to the stream.

If the frame including the current coding unit is an inter prediction coding frame, a syntax element may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. For example, the value 0 of the syntax element is generated when the inter frame skip mode is used for the current coding unit, the value 1 of the syntax element is generated when the inter frame direct mode is used for the current coding unit, and the intra frame skip mode The value 2 of the syntax element is generated when is used for the current coding unit, and the value 3, 4 or 5 of the syntax element is generated according to the partition method of the current coding unit when another inter frame prediction mode is used for the current coding unit. When the intra frame prediction mode (except the intra frame skip mode) is used for the current coding unit, the value 6 of the syntax element may be generated, and the generated value may be recorded in the bit stream.

When the intra frame skip mode is used for the current coding unit, information on the prediction method used for the intra frame skip mode may be further signaled into the bit stream. For example, a value 0 is generated when the first prediction method is used as the prediction method for the intra frame skip mode, and a value 1 is generated when the second prediction method is used as the prediction method for the intra frame skip mode, and an intra frame A value 2 is generated when the third prediction method is used as the prediction method for the skip mode, and a value 3 is generated when the fourth prediction method is used as the prediction method for the intra frame skip mode, and the generated value is assigned to the bit stream. Can be recorded.

When the intra frame skip mode is used for the current coding unit, prediction residual information may not be included in the bit stream.

In the present embodiment, a frame may be replaced with a sequence, a slice, a maximum coding unit, a maximum coding block, and a coding unit. In addition, in the current coding unit, a coding unit may be replaced with a maximum coding unit, a maximum coding block, a coding block, a prediction unit, or a prediction block.

According to the second embodiment, in step 110, a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit is determined.

In the present embodiment, the data unit of the upper layer is a slice, and the type of slice including the current coding unit is determined in step 110. A slice may be an intra prediction coded slice or an inter prediction coded slice, a uni-prediction coded slice, a bi-prediction coded slice, or a dual-hypothesis coded slice, or temporal, depending on its type. ) May be a predictive encoded slice or an inter-view predictive encoded slice, a base view slice or a dependent view slice, a texture slice, or a depth slice.

According to the type of the slice including the current coding unit determined in operation 110, information about an intra frame skip mode is encoded and included in the bit stream.

If the slice containing the current coding unit is a category A slice, a flag may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit. For example, flag value 1 is generated when intra frame skip mode is used for the current coding unit, flag value 0 is generated when intra frame skip mode is not used for the current coding unit, and the generated value is a bit. Can be written to the stream.

If the slice including the current coding unit is a category B slice or a category C slice, a syntax element may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information.

For example, for category B slices, when mode x is used for the current coding unit, the value 0 of the syntax element is generated, and when intra frame skip mode is used for the current coding unit, the value 1 of the syntax element is generated. When the mode y is used for the current coding unit, the value 2 of the syntax element is generated, and when the mode z is used for the current coding unit, the value 3 of the syntax element is generated, or depending on other conditions When a value 3, 4 or 5 is generated and another prediction mode is used for the current coding unit, another value of the syntax element may be generated, and the generated value of the syntax element may be recorded in the bit stream.

For category C slices, when intra frame skip mode is used for the current coding unit, the value 0 of the syntax element is generated and when mode x is used for the current coding unit, the value 1 of the syntax element is generated or the syntax element Value of 1,2. Or when k-1 is generated according to different conditions and mode y is used for the current coding unit, value 2 of the syntax element (if value 1 has been generated for mode x) or k (value 1 for mode x) , 2... Or k-1 has been generated), and when a different prediction mode is used for the current coding unit, another value of the syntax element may be generated. The generated value of the syntax element may be written to the bit stream.

Modes x, y, and z may be other prediction modes except intra frame skip mode.

When the intra frame skip mode is used for the current coding unit, information on the prediction method used for the intra frame skip mode may be further signaled into the bit stream. For example, a value 0 is generated when the first prediction method is used as the prediction method for the intra frame skip mode, and a value 1 is generated when the second prediction method is used as the prediction method for the intra frame skip mode, and an intra frame A value 2 is generated when the third prediction method is used as the prediction method for the skip mode, and a value 3 is generated when the fourth prediction method is used as the prediction method for the intra frame skip mode, and the generated value of the syntax element is Can be written to the bit stream.

In the present embodiment, a slice may be replaced with a sequence, a frame, a maximum coding unit, a maximum coding block, and a coding unit. In addition, in the current coding unit, a coding unit may be replaced with a maximum coding unit, a maximum coding block, a coding block, a prediction unit, or a prediction block.

According to the third embodiment, in step 110, a type of a data unit of a higher layer including a current coding unit in a hierarchy of data units is determined.

If the frame including the current coding unit is a Category A frame, a syntax element may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. When intra frame skip mode is used for the current coding unit, the value x of the syntax element is generated, otherwise, another value of the syntax element is generated according to the additional information, and the generated value of the syntax element is written to the bit stream. Can be. If the frame including the current coding unit is a category B frame, a syntax element may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. When intra frame skip mode is used for the current coding unit, the value y of the syntax element is generated, otherwise, another value of the syntax element is generated according to the additional information, and the generated value of the syntax element is written to the bit stream. Can be. At this time, the values x and y may be different from each other.

According to the fourth embodiment, in step 110, a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit is determined.

If the frame including the current coding unit is a Category A frame, a syntax element may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. When the intra frame skip mode is used for the current coding unit, a value of a syntax element dependent on the prediction method used for the intra frame skip mode may be generated. For example, the value x _a of the syntax element is generated when the first prediction method is used, the value x _b of the syntax element is generated when the second prediction method is used, and the value x of the syntax element when the third prediction method is used. _c may be generated, and the generated value of the syntax element may be recorded in the bit stream. If the intra frame skip mode is not used for the current coding unit, another value of the syntax element may be generated according to additional information.

If the frame including the current coding unit is a category B frame, a syntax element may be signaled into the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. If the intra frame skip mode is used for the current coding unit, a value of a syntax element dependent on the prediction method used for the intra frame skip mode may be generated. For example, the value y _a is generated when the first prediction method is used, the value y _b is generated when the second prediction method is used, and the value y _c is generated when the third prediction method is used, The generated value may be written to the bit stream. If the intra frame skip mode is not used for the current coding unit, another value may be recorded in the bit stream according to additional information.

In this case, the values x _a and y _a may be different from each other, the values x _b and y _b may be different from each other, and the values x _c and y _c may be different from each other.

According to FIG. 2, the method of decoding a video may include determining a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit and according to the determined type of the data unit of the higher layer. In step 220, information related to an intra frame skip mode of a current coding unit is obtained.

Hereinafter, the decoding method of Embodiments 5 to 8 will be described with reference to FIG.

According to the fifth embodiment, in step 210, a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of data units is determined.

In the present embodiment, the data unit of the upper layer is a frame, and the type of the frame including the current coding unit is determined in step 210. The frame may be an intra prediction coded frame or an inter prediction coded frame, a uni-prediction coded frame, a bi-prediction coded frame, or a dual-hypothesis coded frame, or temporal. ) May be a predictive encoded frame or an inter-view predictive encoded frame, a base view frame or a dependent view frame, a texture frame, or a depth frame.

In step 220, information related to an intra frame skip mode of the current coding unit is obtained from the bit stream according to the determined type of the data unit of the higher layer.

According to the type of the frame determined in step 210, information about an intra frame skip mode of the current coding unit is obtained from the bit stream.

If the frame containing the current coding unit is an intra prediction coding frame, a flag indicating whether the intra frame skip mode is used for the current coding unit is parsed from the bit stream. For example, if the value of the parsed flag is 1, it is determined that the intra frame skip mode is used for the current coding unit, and if the value of the parsed flag is 0, the intra frame skip mode is used for the current coding unit. It is decided not to.

If the frame that includes the current coding unit is an inter prediction coded frame, a syntax element that indicates whether an intra frame skip mode is used for the current coding unit and indicates additional coding information is parsed from the bit stream. For example, if the value of the parsed syntax element is 0, it is determined that the inter frame skip mode is used for the current coding unit. If the value of the parsed syntax element is 1, the inter frame direct mode is used for the current coding unit. If the value of the parsed syntax element is 2, it is determined that the intra frame skip mode is used for the current coding unit, and if the value of the parsed syntax element is 3, 4, or 5 another inter frame prediction mode is It is determined to be used for the current coding unit, the partitioning method for the current coding unit according to the parsed value is determined, and if the value of the parsed syntax element is 6, the intra frame prediction mode (except the intra frame skip mode) is What is used for the coding unit is determined.

If it is determined that the intra frame skip mode is used for the current coding unit, information about a prediction method used for the intra frame skip mode may be further parsed from the bit stream. For example, if the value parsed from the bit stream is 0, the first prediction method is used as the prediction method of the intra frame skip mode for the current coding unit, and if the value parsed from the bit stream is 1, the second prediction method is the current method. If the value used as the prediction method of the intra frame skip mode for the coding unit and the value parsed from the bit stream is 2, the third prediction method is used as the prediction method of the intra frame skip mode for the current coding unit and is parsed from the bit stream. If it is 3, the fourth prediction method is used as the prediction method of the intra frame skip mode with respect to the current coding unit.

When the intra frame skip mode is used for the current coding unit, prediction residual information may not be parsed from the bit stream. Prediction on the current coding unit may be performed according to the prediction method determined to obtain a predicted pixel value, and the predicted pixel value may be regarded as a reconstructed pixel value.

According to the sixth embodiment, in step 210, a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit is determined.

In the present embodiment, the data unit of the upper layer is a slice, and the type of the slice including the current coding unit is determined in step 210. A slice may be an intra prediction coded slice or an inter prediction coded slice, a uni-prediction coded slice, a bi-prediction coded slice, or a dual-hypothesis coded slice, or temporal, depending on its type. ) May be a predictive encoded slice or an inter-view predictive encoded slice, a base view slice or a dependent view slice, a texture slice, or a depth slice.

According to the type of slice determined in operation 210, information about an intra frame skip mode of the current coding unit is parsed from the bit stream.

If the slice containing the current coding unit is a category A slice, a flag indicating whether an intra frame skip mode is used for the current coding unit is parsed from the bit stream. For example, if the value of the parsed flag is 1, it is determined that the intra frame skip mode is used for the current coding unit. If the value of the parsed flag is 0, the intra frame skip mode is not used for the current coding unit. Is determined.

If the slice containing the current coding unit is a category B slice or a category C slice, a syntax element indicating whether an intra frame skip mode is used for the current coding unit and indicating additional coding information is parsed from the bit stream.

For example, for a category B slice, if the value of the parsed syntax element is 0, it is determined that mode x is used for the current coding unit, and if the value of the parsed syntax element is 1, it is intra for the current coding unit. If it is determined that the frame skip mode is used, and if the value of the parsed syntax element is 2, it is determined that mode y is used for the current coding unit, and if the value of the parsed syntax element is 3, the mode for the current coding unit It is determined that z is used, or if the value of the parsed syntax element is 3, 4 or 5, it is determined that mode z is used for the current coding unit, and additional coding information according to the value of the syntax element is also determined. .

For a category C slice, if the value of the parsed syntax element is 0, it is determined that the intra frame skip mode is used for the current coding unit. If the value of the parsed syntax element is 1, mode x is determined for the current coding unit. Is used, or the value of the parsed syntax element is 1, 2... Or k-1, it is determined that mode x is used for the current coding unit, at the same time additional coding information is determined, and if the value of the parsed syntax element is 2 (only value 1 of the parsed syntax element represents mode x). ) Or k (if the value 1, 2… or k of the parsed syntax element represents mode x), it is determined that mode y is used for the current coding unit, and if the value of the parsed syntax element is any other value, It is determined that another prediction mode is used for the coding unit.

Modes x, y, and z may be other prediction modes except intra frame skip mode.

According to the seventh embodiment, in step 210, a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit is determined.

If the frame containing the current coding unit is a Category A frame, a syntax element is parsed from the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. If the value of the parsed syntax element is x, it is determined that the intra frame skip mode is used for the current coding unit. Otherwise, it is determined that the intra frame skip mode is not used for the current coding unit, and at the same time additional information is determined according to the value of the syntax element.

If the frame including the current coding unit is a category B frame, a syntax element is parsed from the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. If the value of the parsed syntax element is y, it is determined that the intra frame skip mode is used for the current coding unit. Otherwise, it is determined that the intra frame skip mode is not used for the current coding unit, and at the same time additional information is determined according to the value of the syntax element. In this case, the values x and y may be different from each other.

According to the eighth embodiment, in step 210, a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit is determined.

If the frame containing the current coding unit is a Category A frame, a syntax element indicating whether an intra frame skip mode is used for the current coding unit and indicating additional coding information is parsed from the bit stream. If the value of the parsed syntax element is x _a , x _b or x _c , it is determined that the intra frame skip mode is used for the current coding unit. Otherwise, it is determined that intra frame skip mode is not used for the current coding unit, and additional information is also determined according to the value of the syntax element. When the intra frame skip mode is used for the current coding unit, the prediction method used for the intra frame skip mode is also determined. For example, if the value of the syntax element is x _a , it is determined that the first prediction method is used for the intra frame skip mode, and if the value of the syntax element is x _b, then the second prediction method is for the intra frame skip mode. It is determined that it is used, and if the syntax element value is x _c , it is determined that the third prediction method is used for the intra frame skip mode.

If the frame including the current coding unit is a category B frame, a syntax element is parsed from the bit stream to indicate whether an intra frame skip mode is used for the current coding unit and to indicate additional coding information. If the value of the parsed syntax element is y _a , y _b or y _c , it is determined that the intra frame skip mode is used for the current coding unit. Otherwise, it is determined that the intra frame skip mode is not used for the current coding unit, and additional information is also determined according to the value of the syntax element. When the intra frame skip mode is used for the current coding unit, the prediction method used for the intra frame skip mode is also determined. In particular, if the value of the syntax element is y _a, it is determined that the first prediction method is used for the intra frame skip mode, and if the value of the syntax element is y _b, it is determined that the second prediction method is used for the intra frame skip mode. If the value of the syntax element is y _c, it is determined that the third prediction method is used for the intra frame skip mode. In this case, the values x _a and y _a may be different from each other, the values x _b and y _b may be different from each other, and the values x _c and y _c may be different from each other.

3 is a block diagram of a video encoding apparatus, according to an embodiment.

As illustrated in FIG. 3, the video encoding apparatus 300 includes a data unit type determiner 310 and the higher layer that determine a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit. And an information encoder 320 for encoding the information related to the intra frame skipping mode of the current coding unit and outputting a bit stream according to the determined type of the data unit of.

Hereinafter, the video encoding apparatus of Embodiment 9 will be described with reference to FIG. 3.

In a ninth embodiment, the video encoding apparatus 300 includes a data unit type determiner 310 and an information encoder 320.

The data unit type determiner 310 determines a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit, wherein the data unit of the higher layer is a sequence, a frame, a slice, a maximum. It may be one of a coding unit, a maximum coding block, and a coding unit.

The information encoder 320 encodes information related to an intra frame skip mode of the current coding unit according to a type of a data unit of a higher layer including the current coding unit determined by the data unit type determiner 310, thereby bit Output the stream. In particular, the information encoder 320 may perform the processes of step 120 of the first to fourth embodiments, but is not limited thereto.

4 is a block diagram of a video decoding apparatus, according to an embodiment.

As shown in FIG. 4, the video decoding apparatus 400 may include a data unit type determiner 410 and a type of a data unit type determiner 410 for determining a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit. According to the determined type of the data unit, the information obtaining unit 420 for obtaining information associated with the intra frame skipping mode of the current coding unit from the bit stream.

Hereinafter, the video decoding apparatus of the tenth embodiment will be described with reference to FIG. 4.

In the tenth embodiment, the video decoding apparatus 400 includes a data unit type determiner 410 and an information acquirer 420.

The data unit type determiner 410 determines the type of the data unit of the upper layer including the current coding unit in the hierarchical structure of the data unit, wherein the data unit of the upper layer is sequence, frame, slice, maximum coding It may be one of a unit, a maximum coding block, and a coding unit.

The information acquisition unit 420 may bit stream the information related to the intra frame skip mode of the current coding unit according to the type of the data unit of the higher layer including the current coding unit provided by the data unit type determination unit 410. Parse from In particular, the information acquisition unit 420 may perform the processes of step 220 of the fifth embodiment, but is not limited thereto.

The foregoing is merely a preferred embodiment and does not limit the protection scope of the present invention. All changes, equivalent substitutions or improvements without departing from the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

In the method for decoding a video,

Determining a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit; And

Acquiring information related to an intra frame skip mode of the current coding unit from a bit stream according to the determined type of the data unit of the higher layer;

Wherein, for different types of data units of the higher layer, information associated with the intra frame skip mode is represented by codewords of different lengths in the bit stream.
The method of claim 1,

The data unit of the higher layer is any one of a sequence, a frame, a slice, a maximum coding unit, a maximum coding block, and a coding unit.
The method of claim 1,

Acquiring information related to an intra frame skip mode of the current coding unit may include:

Acquiring a first syntax element when the determined type of the data unit of the upper layer is the first type, and obtaining a second syntax element when the determined type of the data unit of the upper layer is the second type. and,

The first syntax element is a 1-bit flag indicating whether the intra frame skip mode is used in the current coding unit, and the second syntax element is an additional coding and use of the intra frame skip mode of the current coding unit. And an integer value ranging from 0 to N for representing information, wherein N is 3 or more.
The method of claim 3, wherein

The additional coding information may include an intra prediction method of the intra frame skip mode when the intra frame skip mode is used in the current coding unit, a prediction mode used in the current coding unit in addition to the intra frame skip mode, and the current coding. And at least one of a partition mode of a unit, and an inter frame prediction direction.
The method of claim 3, wherein

The data unit of the upper layer is a frame,

The data unit of the higher layer corresponding to the first type is an intra prediction coded frame,

The data unit of the higher layer corresponding to the second type is an inter prediction coded frame.
The method of claim 1,

Acquiring information related to an intra frame skip mode of the current coding unit may include:

Acquiring a first syntax element when the determined type of the data unit of the upper layer is the first type, and obtaining a second syntax element when the determined type of the data unit of the upper layer is the second type. and,

The first syntax element has an integer value in a range of 0 to N1 for indicating use of the intra frame skip mode of the current coding unit and additional coding information, and the second syntax element is configured to determine the value of the current coding unit. And an integer value in the range of 0 to N2 to indicate the use of intra frame skip mode and additional coding information, wherein N1 and N2 are both 3 or greater.
The method of claim 6,

The additional coding information may include an intra prediction method of the intra frame skip mode when the intra frame skip mode is used in the current coding unit, a prediction mode used in the current coding unit in addition to the intra frame skip mode, and the current coding. And at least one of a partition mode of a unit, and an inter frame prediction direction.
The method of claim 6,

Wherein the value of the first syntax element indicating that the intra frame skip mode is used in the current coding unit and the value of the second syntax element indicating the intra frame skip mode are used in the current coding unit are different from each other. How to decrypt.
The method of claim 6,

The data unit of the upper layer is a frame,

The data unit of the higher layer corresponding to the first type is an intra prediction coded frame,

The data unit of the higher layer corresponding to the second type is an inter prediction coded frame.
In the video decoding apparatus,

A data unit type determination unit that determines a type of a data unit of a higher layer including a current coding unit in a hierarchical structure of the data unit; And

An intra frame skip mode information obtaining unit obtaining information related to an intra frame skip mode of the current coding unit from a bit stream according to the determined type of a data unit of the higher layer;

Wherein, for different types of data units of the upper layer, the information related to the intra frame skip mode is represented by codewords of different lengths in the bit stream.
The method of claim 10,

The data unit of the higher layer is any one of a sequence, a frame, a slice, a maximum coding unit, a maximum coding block, and a coding unit.
The method of claim 10,

Acquiring information related to an intra frame skip mode of the current coding unit,

Acquiring a first syntax element when the determined type of the data unit of the higher layer is the first type, and obtaining a second syntax element when the determined type of the data unit of the upper layer is the second type; ,

The first syntax element is a 1-bit flag indicating whether the intra frame skip mode is used in the current coding unit, and the second syntax element is an additional coding and use of the intra frame skip mode of the current coding unit. And an integer value ranging from 0 to N for indicating information, wherein N is 3 or more.
The method of claim 12,

The additional coding information may include an intra prediction method of the intra frame skip mode when the intra frame skip mode is used in the current coding unit, a prediction mode used in the current coding unit in addition to the intra frame skip mode, and the current coding. And at least one of a partition mode of a unit and an inter frame prediction direction.
The method of claim 10,

Acquiring information related to an intra frame skip mode of the current coding unit,

Acquiring a first syntax element when the determined type of the data unit of the higher layer is the first type, and obtaining a second syntax element when the determined type of the data unit of the upper layer is the second type; ,

The first syntax element has an integer value in a range of 0 to N1 for indicating use of the intra frame skip mode of the current coding unit and additional coding information, and the second syntax element is configured to determine the value of the current coding unit. And an integer value in the range of 0 to N2 for indicating the use of intra frame skip mode and additional coding information, wherein N1 and N2 are both 3 or more.
In the method of encoding video,

Determining a type of a data unit of a higher layer including a current coding unit in the hierarchical structure of the data unit; And

Encoding information related to an intra frame skip mode of the current coding unit according to the determined type of the data unit of the higher layer, and outputting a bit stream;

Wherein, for different types of data units of the higher layer, the information related to the intra frame skip mode is represented by codewords of different lengths in the bit stream.