KR20130045784A - Method and apparatus for scalable video coding using inter prediction mode - Google Patents

Abstract

PURPOSE: A scalable coding method of an inter-prediction mode and a device thereof are provided to selectively use motion information of surrounding blocks and motion information for a block of a basic layer for predicting motion information of an enhancement layer in scalable video coding based on a plurality of layers, thereby reducing the number of bits necessary for encoding and decoding. CONSTITUTION: When a determined motion information prediction mode is a first mode, an image decoding device predicts motion information for a decoding object block of an enhancement layer through motion information for a surrounding block of the enhancement layer(S310,S330). When the determined motion information prediction mode is a second mode, the image decoding device predicts the motion information for the decoding object block of the enhancement layer through motion information for a block corresponding to a reference layer(S320). [Reference numerals] (BB) Yes; (CC) No; (S300) Inter-layer motion predicted?; (S310) Obtain motion information on surrounding blocks of an enhancement layer; (S320) Obtain motion information on a corresponding block of a reference layer; (S330) Predict motion information on a target decoding block of the enhancement layer using the obtained motion information

Description

Inter prediction mode scalable coding method and apparatus {METHOD AND APPARATUS FOR SCALABLE VIDEO CODING USING INTER PREDICTION MODE}

The present invention relates to an image processing technique, and more particularly, to a scalable video coding method and apparatus for encoding / decoding an image.

Recently, as the broadcasting service having high definition (HD) resolution (1280x1024 or 1920x1080) has been expanded not only in Korea but also in the world, many users are getting used to high resolution and high quality video. Is adding. In addition, as HDTV and UHD (Ultra High Definition), which has four times the resolution of HDTV, have increased interest, video standardization organizations have recognized the need for compression technology for higher resolution and higher quality images. It also provides higher compression efficiency than H.264 / AVC (Advanced Video Coding), the video compression coding standard currently used in HDTVs, mobile phones, etc., which provides the same image quality as the existing coding method, but provides a lot of gain in terms of frequency band and storage. New standards are needed to do this. Currently, the Moving Picture Experts Group (MPEG) and the Video Coding Experts Group (VCEG) are working together to standardize the next-generation video codec, High Efficiency Video Coding (HEVC). The general goal of HEVC is to encode a video including UHD video with twice the compression efficiency compared to H.264 / AVC. HEVC can provide high-definition video at lower frequencies than current HD, UHD video as well as 3D broadcasting and mobile communication networks.

In HEVC, a prediction image may be generated by performing a prediction on an image spatially or temporally, and a difference between an original image and a prediction image may be encoded. Such predictive encoding may increase the efficiency of image encoding.

An object of the present invention is to provide a scalable video coding method and apparatus capable of improving encoding / decoding efficiency.

According to an aspect of the present invention, there is provided a scalable video decoding method comprising: determining a motion information prediction mode for a decoding target block of an enhancement layer; When the determined motion information prediction mode is a first mode, predicting motion information on a decoding target block of the enhancement layer by using motion information on a neighboring block of the enhancement layer; And when the determined motion information prediction mode is the second mode, predicting motion information on a decoding target block of the enhancement layer by using motion information on a corresponding block of a reference layer. .

A scalable video decoding apparatus according to an embodiment of the present invention includes a first motion predictor for predicting motion information of a decoding target block of an enhancement layer using motion information of a neighboring block; And a second motion predictor for predicting motion information on a decoding target block of an enhancement layer by using motion information on a corresponding block of a reference layer, wherein the first motion predictor includes: a first motion predictor according to the motion information prediction mode signaled by the encoding apparatus; , One of two motion predictors is used to predict motion information for the decoding object block of the enhancement layer.

According to an embodiment of the present invention, in order to predict motion information of an enhancement layer in multi-layer scalable video coding, encoding and decoding are performed by selectively using among motion information of neighboring blocks and motion information for a corresponding block of a base layer. Coding efficiency can be increased by reducing the number of bits required for the C2, thereby providing better image quality at the same bit rate.

1 is a block diagram illustrating a configuration of an image encoding apparatus according to an embodiment of the present invention.
2 is a block diagram illustrating a configuration of an image decoding apparatus according to an embodiment of the present invention.
3 is a conceptual diagram illustrating the concept of an image and a block used in an embodiment of the present invention.
4 is a conceptual diagram schematically illustrating an embodiment of a multi-layer based scalable video coding structure.
FIG. 5 is a block diagram illustrating an embodiment of a configuration of a motion compensation unit illustrated in FIG. 2.
FIG. 6 is a block diagram illustrating an embodiment of a configuration of the second motion predictor illustrated in FIG. 5.
7 is a flowchart illustrating a scalable video coding method according to a first embodiment of the present invention.
8 is a diagram for describing an embodiment of an inter-layer motion prediction method.
9 is a flowchart illustrating a scalable video coding method according to a second embodiment of the present invention.
10 is a flowchart illustrating a scalable video coding method according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . In addition, the content described as "include" a specific configuration in the present invention does not exclude a configuration other than the configuration, it means that additional configuration may be included in the scope of the technical idea of the present invention or the present invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

In addition, the components shown in the embodiments of the present invention are shown independently to represent different characteristic functions, which does not mean that each component is composed of separate hardware or software constituent units. That is, each constituent unit is included in each constituent unit for convenience of explanation, and at least two constituent units of the constituent units may be combined to form one constituent unit, or one constituent unit may be divided into a plurality of constituent units to perform a function. The integrated embodiments and separate embodiments of the components are also included within the scope of the present invention, unless they depart from the essence of the present invention.

In addition, some of the components are not essential components to perform essential functions in the present invention, but may be optional components only to improve performance. The present invention can be implemented only with components essential for realizing the essence of the present invention, except for the components used for the performance improvement, and can be implemented by only including the essential components except the optional components used for performance improvement Are also included in the scope of the present invention.

1 is a block diagram illustrating a configuration of an image encoding apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the image encoding apparatus 100 may include a motion predictor 111, a motion compensator 112, an intra predictor 120, a switch 115, a subtractor 125, and a converter 130. And a quantization unit 140, an entropy encoding unit 150, an inverse quantization unit 160, an inverse transform unit 170, an adder 175, a filter unit 180, and a reference image buffer 190.

The image encoding apparatus 100 performs encoding in an intra mode or an inter mode with respect to an input image and outputs a bit stream. Intra prediction means intra prediction and inter prediction means inter prediction. In the intra mode, the switch 115 is switched to intra, and in the inter mode, the switch 115 is switched to inter. The image encoding apparatus 100 generates a prediction block for an input block of an input image and then encodes a difference between the input block and the prediction block.

In the intra mode, the intra predictor 120 generates a prediction block by performing spatial prediction using pixel values of blocks that are already encoded around the current block.

In the inter mode, the motion predictor 111 finds a motion vector in the reference picture stored in the reference picture buffer 190 that best matches the input block in the motion prediction process. The motion compensation unit 112 generates a prediction block by performing motion compensation using a motion vector.

The subtracter 125 generates a residual block by a difference between the input block and the generated prediction block. The transforming unit 130 performs a transform on the residual block to output a transform coefficient. The quantization unit 140 quantizes the input transform coefficient according to the quantization parameter and outputs a quantized coefficient. The entropy encoding unit 150 entropy-codes the input quantized coefficients according to a probability distribution to output a bit stream.

Since the HEVC performs inter prediction coding, i.e., inter prediction coding, the currently encoded image needs to be decoded and stored for use as a reference image. Accordingly, the quantized coefficients are inversely quantized in the inverse quantization unit 160 and inversely transformed in the inverse transformation unit 170. The inverse quantized and inverse transformed coefficients are added to the prediction block through the adder 175 and a reconstruction block is generated.

The restoration block passes through the filter unit 180 and the filter unit 180 applies at least one of a deblocking filter, a sample adaptive offset (SAO), and an adaptive loop filter (ALF) can do. The filter unit 180 may be referred to as an adaptive in-loop filter. The deblocking filter can remove block distortion occurring at the boundary between the blocks. SAO may add an appropriate offset value to pixel values to compensate for coding errors. The ALF may perform filtering based on a comparison between the reconstructed image and the original image, and may be performed only when high efficiency is applied. The restoration block having passed through the filter unit 180 is stored in the reference image buffer 190.

2 is a block diagram illustrating a configuration of an image decoding apparatus according to an embodiment of the present invention.

2, the image decoding apparatus 200 includes an entropy decoding unit 210, an inverse quantization unit 220, an inverse transform unit 230, an intra prediction unit 240, a motion compensation unit 250, (260) and a reference image buffer (270).

The video decoding apparatus 200 receives the bit stream output from the encoder and decodes the video stream into an intra mode or an inter mode, and outputs a reconstructed video, i.e., a reconstructed video. In the intra mode, the switch is switched to the intra mode, and in the inter mode, the switch is switched to the inter mode. The image decoding apparatus 200 obtains a residual block from the input bitstream, generates a prediction block, adds the residual block and the prediction block, and generates a reconstructed block, that is, a reconstruction block.

The entropy decoding unit 210 entropy-decodes the input bitstream according to a probability distribution and outputs a quantized coefficient. The quantized coefficients are inversely quantized in the inverse quantization unit 220 and inversely transformed in the inverse transformation unit 230. As a result of inverse quantization / inverse transformation of the quantized coefficients, a residual block is generated.

In the intra mode, the intra predictor 240 generates a predictive block by performing spatial prediction using pixel values of already encoded blocks around the current block.

In the inter mode, the motion compensator 250 generates a prediction block by performing motion compensation using the motion vector and the reference image stored in the reference image buffer 270.

The residual block and the prediction block are added through the adder 255, and the added block is passed through the filter unit 260. [ The filter unit 260 may apply at least one or more of the deblocking filter, SAO, and ALF to the reconstructed block or the reconstructed picture. The filter unit 260 outputs a reconstructed image, that is, a reconstructed image. The reconstructed picture may be stored in the reference picture buffer 270 to be used for inter prediction.

Methods for improving the prediction performance of the encoding / decoding apparatus include a method of increasing the accuracy of the interpolation image and a method of predicting the difference signal. Here, the difference signal is a signal indicating the difference between the original image and the predicted image. In the present invention, the "difference signal" may be replaced with "difference signal", "residual block" or "difference block" according to the context, and those skilled in the art may affect the spirit and the essence of the invention. This can be distinguished to the extent that it does not give.

Even if the interpolated image is more accurate, a difference signal can only be generated. Therefore, it is necessary to improve encoding performance by improving the performance of difference signal prediction and reducing the difference signal to be encoded as much as possible.

As a difference signal prediction method, a filtering method using fixed filter coefficients may be used. However, such a filtering method has a limitation in prediction performance because filter coefficients cannot be used adaptively according to image characteristics. Therefore, it is necessary to improve the accuracy of prediction by filtering according to the characteristics of each prediction block.

3 is a conceptual diagram illustrating the concept of an image and a block used in an embodiment of the present invention.

Referring to FIG. 3, an encoding target block is a set of spatially connected pixels in a current encoding target image. The encoding target block is a unit in which encoding and decoding are performed, and may be a quadrangle or an arbitrary shape. The neighbor reconstruction block is a block in which encoding and decoding are completed before the current encoding target block is encoded in the current encoding target image.

The predictive image is an image obtained by collecting predictive blocks used for encoding each block, from the first encoding target block of the image to the current encoding target block in the current encoding target image. Here, the prediction block refers to a block having a prediction signal used for encoding the respective encoding target blocks in the current encoding target video. That is, the prediction block refers to each block in the prediction image.

The neighboring block means a neighboring reconstruction block of the current encoding target block and a neighboring prediction block that is a prediction block of each neighboring reconstruction block. That is, the neighbor block refers to the neighbor reconstruction block and the neighbor prediction block together.

The prediction block of the current encoding target block may be a prediction block generated by the motion compensator 112 or the intra predictor 120 according to the embodiment of FIG. 1. In this case, after the prediction block filtering process is performed on the prediction block generated by the motion compensator 112 or the intra prediction unit 120, the subtractor 125 may perform a difference between the filtered final prediction block and the original block. Can be.

The neighboring block may be a block stored in the reference image buffer 190 or a separate memory in the embodiment of FIG. 1. In addition, the neighbor reconstruction block or the neighbor prediction block generated in the image encoding process may be used as the neighbor block.

4 is a conceptual diagram schematically illustrating an embodiment of a scalable video coding structure using multiple layers to which the present invention can be applied. In FIG. 4, a group of pictures (GOP) represents a picture group, that is, a group of pictures.

In order to transmit video data, a transmission medium is required, and the performance of the transmission medium varies depending on various network environments. A scalable video coding method may be provided for application to these various transmission media or network environments.

The scalable video coding method is a coding method for enhancing the coding / decoding performance by eliminating inter-layer redundancy by utilizing texture information, motion information, residual signal, etc. between layers. The scalable video coding method can provide various scalabilities in terms of spatial, temporal, and image quality according to surrounding conditions such as a transmission bit rate, a transmission error rate, and a system resource.

Scalable video coding can be performed using multiple layers structure to provide a bitstream applicable to various network situations. For example, the scalable video coding structure may include a base layer that compresses and processes image data using a general image encoding method, and compresses the image data using both the encoding information of the base layer and a general image encoding method. May include an enhancement layer for processing.

Here, the layer may be a set of images and bitstreams classified based on space (eg, image size), time (eg, encoding order, image output order), image quality, complexity, and the like. it means. The plurality of layers may also have dependencies between each other.

Referring to FIG. 4, for example, a base layer may be defined as a QCIF (Quarter Common Intermediate Format), a frame rate of 15 Hz, and a 3 Mbps bit rate, and the first enhanced layer is a CIF (Common Intermediate). Format), a frame rate of 30 Hz, and a 0.7 Mbps bit rate, and the second enhancement layer may be defined as a standard definition (SD), a frame rate of 60 Hz, and a 0.19 Mbps bit rate. The format, the frame rate, the bit rate, and the like are one example, and can be determined as needed. Also, the number of layers to be used is not limited to the present embodiment, but can be otherwise determined depending on the situation.

At this time, if a CIF 0.5 Mbps bit stream is needed, the bit stream may be truncated and transmitted so that the bit rate is 0.5 Mbp in the first enhancement layer. The scalable video coding method can provide temporal, spatial, and image quality scalability by the method described in the embodiment of FIG.

Hereinafter, the target layer, the target image, the target slice, the target unit, the target block, the target symbol, and the target bin mean a layer, an image, a slice, a unit, a block, a symbol, and a bin currently encoded or decoded, respectively. Thus, for example, the target layer may be a layer to which the target symbol belongs. In addition, the other layer is a layer excluding the target layer, and means a layer available in the target layer. That is, another layer may be used to perform decoding in the target layer. Layers available in the target layer may include, for example, temporal, spatial and image quality sublayers.

In addition, hereinafter, the corresponding layer, the corresponding image, the corresponding slice, the corresponding unit, the corresponding block, the corresponding symbol, and the corresponding bin correspond to the target layer, the target image, the target slice, the target unit, the target block, the target symbol, and the target bin, respectively. Means image, slice, unit, block, symbol, and bin. The corresponding image refers to an image of another layer existing on the same time axis as the target image. When the display order of an image in another layer and an image in another layer are the same, it may be said that an image in the target layer and an image in another layer exist on the same time axis. Whether the pictures exist on the same time axis may be identified using an encoding parameter such as a picture order count (POC). The corresponding slice refers to a slice existing in a position corresponding to the same or similar to the target slice of the target image in the corresponding image. The corresponding unit refers to a unit existing in a corresponding position in the corresponding image that is spatially identical to or similar to the target unit of the target image. The corresponding block refers to a block existing at a position corresponding to the same as or similar to the target block of the target image in the corresponding image.

In addition, hereinafter, a slice indicating a unit in which an image is divided is used to mean a division unit such as a tile or an entropy slice. Independent image encoding and decoding are possible between the divided units.

In addition, hereinafter, a block means a unit of image encoding and decoding. When encoding or decoding an image, a coding or decoding unit refers to a divided unit when a single image is divided into subdivided units to be encoded or decoded, and thus, a macroblock, a coding unit (CU), and a prediction unit (PU). It may be called a Prediction Unit, a Transform Unit, a transform block, or the like. One block may be further divided into smaller sub-blocks.

In consideration of the characteristics of scalable video coding as described above, inter-layer intra prediction, inter-layer inter prediction, or inter-layer differential signal prediction may be performed to remove inter-layer redundancy.

The inter-layer inter prediction is a method of using motion information on a corresponding block of a reference layer in an enhancement layer. A detailed description thereof will be described below.

Hereinafter, a scalable video coding method according to an embodiment of the present invention will be described in detail with reference to FIGS. 5 to 10. In the following description, a method of coding an enhancement layer as described with reference to FIG. 4 will be described.

FIG. 5 is a block diagram schematically illustrating a configuration of a decoding apparatus according to an embodiment of the present invention, and illustrates a specific configuration of the motion compensator 250 illustrated in FIG. 2.

Referring to FIG. 5, the motion compensator 250 predicts motion information (eg, a motion vector) by using a plurality of motion prediction methods, and predicts a decoding target block of an enhancement layer in different ways. The first motion predictor 251 and the second motion predictor 255 may be configured to be included.

The first motion predictor 251 may use the motion information of the neighboring block in the enhancement layer to predict the motion information of the decoding target block of the enhancement layer.

For example, the motion merger 252 included in the first motion predictor 251 uses motion information of neighboring candidate blocks as motion information for the decoding target block, for example, motion merge defined in HEVC. By using a merge method, motion information about a decoding target block of the enhancement layer may be predicted.

More specifically, in the motion merging method, the encoding apparatus selects any one of a merge candidate list in which motion information about neighboring blocks are combined as a candidate to merge, and selects the selected motion merging candidate. It can signal the index to.

Meanwhile, the decoding apparatus may select any one of the motion merge candidate lists previously created using the motion merge candidate index signaled by the encoding apparatus as a motion vector for the decoding target block.

The motion vector predictor 253 uses one candidate block having optimal performance in terms of rate-distortion among the motion information of each neighboring candidate block. For example, the motion vector prediction unit defined in HEVC may be improved. The motion information of the decoding target block of the enhancement layer may be predicted by using an Advanced Motion Vector Prediction (AMVP) method.

Specifically, in the improved motion vector prediction method, the encoding apparatus compares a rate-distortion cost value among an AMVP candidate list including motion information of neighboring blocks. A motion prediction candidate may be selected and an index for the selected motion prediction candidate may be signaled.

Meanwhile, the decoding apparatus selects any one of the motion prediction candidate lists previously prepared using the motion prediction candidate index signaled by the encoding apparatus, synthesizes a motion vector difference value (MVD) with the selected motion prediction candidate, and improves the improvement. A motion vector for the decoding target block of the layer may be generated.

 Meanwhile, the second motion predictor 255 may predict the motion information of the decoding target block of the enhancement layer by using the motion information of the corresponding block of the reference layer.

Referring to FIG. 6, the second motion predictor 255 may include a scaler 256 and a motion vector generator 257.

The scaling unit 256 adaptively scales the motion information of the corresponding block of the reference layer according to the inter-layer resolution difference, and the motion vector generator 257 adjusts the motion vector difference value (MVD) to the scaled motion information. ) May be synthesized to generate a motion vector for the decoding target block of the enhancement layer.

For example, the reference layer may be a base layer.

In the decoding apparatus according to the embodiment of the present invention, a module selected according to the motion prediction mode among the motion merger 252, the motion vector predictor 253, and the second motion predictor 255 as described above may be entropy. The motion vector for the decoding target block of the enhancement layer to be used in the motion compensation unit 250 may be configured by using the motion information transmitted from the unit 101 or the motion information deduced from the reference layer.

7 is a flowchart illustrating a scalable video coding method according to a first embodiment of the present invention. The decoding method according to an embodiment of the present invention shown in FIGS. It will be described in conjunction with the block diagrams that represent.

Referring to FIG. 7, it is determined whether the motion information prediction mode for the current decoding target block of the enhancement layer performs inter-layer motion prediction (step S300).

For example, the motion information prediction mode is determined according to the information signaled by the encoding apparatus, and specifically, the signaling information may include a flag indicating whether to perform inter-layer inter coding. Can be.

In addition, the step S400 of determining the motion information prediction mode and a series of subsequent steps may be performed in units of a coding unit (CU).

When the determined motion information prediction mode is a first mode in which inter-layer motion prediction is not performed, the first motion predictor 251 obtains motion information on neighboring blocks of the enhancement layer (step S310). The motion information of the decoding object block of the enhancement layer is predicted using the obtained motion information of the neighboring block (step S320).

On the other hand, when the determined motion information prediction mode is the second mode for performing inter-layer motion prediction, the second motion predictor 255 obtains motion information on the corresponding block of the reference layer (step S320). In operation S320, the motion information of the decoding target block of the enhancement layer is predicted using the motion information of the block of the corresponding block of the reference layer.

Referring to FIG. 8, the scaling unit 256 of the second motion predicting unit 255 may perform an operation on the corresponding block B2 of the base layer in order to predict motion information of the decoding target block B1 of the enhancement layer. The motion vector for the decoding target block B1 may be generated by scaling the motion vector with respect to the resolution difference between the enhancement layer and the base layer.

For example, the corresponding block B2 of the base layer is a block that best matches the decoding target block B1 of the enhancement layer among the blocks existing in the base layer, or the decoding target of the enhancement layer. The block may be a co-located block having a position corresponding to the block B1.

In addition, when the current decoding target block is a block included in the base layer instead of the enhancement layer, the first motion predictor 251 uses the motion information on the neighboring block to obtain motion information about the decoding target block of the base layer. It can be predicted.

On the other hand, with respect to generation of a predictive image in video coding, in the skip mode, motion information is derived from a neighboring block, and then a predictive image (or block) is generated using the derived motion information, and motion information or residual image information is generated. It may not be encoded or decoded.

The video coding method according to the embodiment of the present invention may be performed differently depending on whether the skip mode is applied.

9 is a flowchart illustrating a scalable video coding method according to a second embodiment of the present invention, which shows an example of a video decoding method performed when not in a skip mode.

Referring to FIG. 9, it is first determined whether inter-layer motion prediction is performed on the current decoding target block of the enhancement layer (S400).

If the inter-layer motion prediction is not performed, the motion merging unit 252 decodes the motion merge candidate index signaled by the encoding apparatus (step S410) and then uses the decoded motion merge candidate index. In operation S420, any one of a previously created merge candidate list is selected as a motion vector for the decoding target block of the enhancement layer.

On the other hand, when the inter-layer motion prediction is performed, the second motion predictor 255 deduces the motion vector of the corresponding block of the reference layer (step S430) and then resolutions the deduced motion vector. Scale according to (S440 step).

For example, the scaling unit 256 included in the second motion predictor 255 scales a motion vector obtained from a corresponding block of the reference layer according to inter-layer resolution, and resolutions of the enhancement layer and the reference layer. If S is the same, step S440 is omitted and a motion vector for a corresponding block of the reference layer may be used as a motion vector for a decoding block of the enhancement layer.

10 is a flowchart illustrating a scalable video coding method according to a third embodiment of the present invention, which shows an example of a video decoding method performed in a skip mode.

Referring to FIG. 10, it is first determined whether inter-layer motion prediction is performed on a current decoding target block of an enhancement layer (S500).

When the inter-layer motion prediction is not performed, the motion vector predictor 253 decodes the motion prediction candidate index signaled by the encoding apparatus (step S510), and then decodes the decoded motion prediction candidate index. In operation S520, a motion vector is selected from a prediction candidate list.

Thereafter, the motion vector predictor 253 decodes a motion vector difference value (MVD, Motion Vector Difference) signaled by the encoding apparatus (step S530), and then decodes the motion vector difference to the motion vector selected in step S520. A value MVD is synthesized to generate a motion vector for the decoding object block of the enhancement layer (S540).

On the other hand, when the inter-layer motion prediction is performed, the second motion predictor 255 deduces the motion vector of the corresponding block of the reference layer (step S430) and then, through the scaling unit 256. The inferred motion vector is scaled according to the inter-layer resolution difference (S440).

Thereafter, the motion vector generator 257 decodes the motion vector difference value MVD signaled by the encoding apparatus (step 570), and then decodes the motion vector difference value (MVD) to the scaled motion vector in step S440. ) Is synthesized to generate a motion vector for the decoding target block of the enhancement layer (step S580).

The scalable video coding method and apparatus according to an embodiment of the present invention have been described above with reference to the video decoding method and apparatus. However, the scalable video coding method according to an embodiment of the present invention is illustrated in FIGS. It may be implemented by performing a series of steps according to the decoding method as described with reference.

In detail, the scalable video encoding method and apparatus according to the embodiment of the present invention perform inter prediction having the same configuration as the decoding method and apparatus described with reference to FIGS. The motion information may be predicted, and a prediction signal may be generated according to the predicted motion information.

In the above-described embodiments, methods are described based on a flowchart as a series of steps or blocks, but the present invention is not limited to the order of the steps, and some steps may occur in different orders or in a different order than the steps described above have. It will also be understood by those skilled in the art that the steps depicted in the flowchart illustrations are not exclusive, that other steps may be included, or that one or more steps in the flowchart may be deleted without affecting the scope of the present invention. You will understand.

The above-described embodiments include examples of various aspects. While it is not possible to describe every possible combination for expressing various aspects, one of ordinary skill in the art will recognize that other combinations are possible. Accordingly, it is intended that the invention include all alternatives, modifications and variations that fall within the scope of the following claims.

Claims (12)

A multi-layer scalable video decoding method,
Determining a motion information prediction mode for a decoding target block of an enhancement layer;
When the determined motion information prediction mode is a first mode, predicting motion information on a decoding target block of the enhancement layer by using motion information on a neighboring block of the enhancement layer; And
If the determined motion information prediction mode is the second mode, estimating motion information of a decoding target block of the enhancement layer by using motion information of a corresponding block of a reference layer; Flexible video decoding method. The method of claim 1, wherein the motion information prediction mode is
It is determined according to the information signaled by the encoding apparatus, the signaling information includes a flag indicating whether to perform inter-layer motion prediction (flag). The method of claim 1, wherein the determining of the motion information prediction mode comprises:
A scalable video decoding method performed in units of coding units (CUs). The method of claim 1, wherein predicting the motion information in the first mode comprises:
If it is not a skip mode, decoding a motion merge candidate index; And selecting one of a motion merge candidate list in which motion information about neighboring blocks is combined using the decoded motion merge candidate index as a motion vector for a decoding target block of the enhancement layer. Scalable video decoding method comprising. The method of claim 1, wherein predicting the motion information in the first mode comprises:
When in the skip mode, decoding a motion prediction candidate index; Selecting one of a motion prediction candidate list including motion information on neighboring blocks by using the decoded motion prediction candidate index; And generating a motion vector for a decoding object block of the enhancement layer by synthesizing a motion vector difference (MVD) to the selected motion prediction candidate. The method of claim 1, wherein predicting the motion information in the second mode comprises:
Scaling motion information on a corresponding block of the reference layer according to a resolution difference between layers. The method of claim 6, wherein predicting the motion information in the second mode comprises:
And in the skip mode, generating a motion vector for a decoding target block of the enhancement layer by synthesizing a motion vector difference value (MVD) with the scaled motion information. The method of claim 1, wherein the reference layer is
A scalable video decoding method which is a base layer. A multi-layer scalable video decoding apparatus,
A first motion predictor for predicting motion information on a decoding target block of an enhancement layer using motion information on a neighboring block; And
A second motion predictor for predicting motion information on a decoding target block of the enhancement layer by using motion information on a corresponding block of the reference layer,
According to the motion information prediction mode signaled by the encoding device, one of the first and second motion predictors is used to predict motion information for the decoding target block of the enhancement layer. 10. The method of claim 9, wherein the first motion predictor
In the non-skip mode, a motion merging unit for selecting one of the motion merge candidate lists including motion information about neighboring blocks using a motion merge candidate index as a motion vector for the decoding target block of the enhancement layer Scalable video decoding apparatus comprising a. 10. The method of claim 9, wherein the first motion predictor
In the skip mode, the motion prediction candidate index is used to select any one of the motion prediction candidate lists including the motion information for neighboring blocks, and the motion vector differential value (MVD) is synthesized by the selected motion prediction candidate. A scalable video decoding apparatus comprising a motion vector predictor constituting a motion vector for a decoding target block of an enhancement layer. 10. The method of claim 9, wherein the second motion predictor
A scaling unit for scaling motion information of a corresponding block of the reference layer according to a resolution difference between layers; And
And a motion vector generator for synthesizing a motion vector difference value (MVD) to the scaled motion information to generate a motion vector for a decoding target block of the enhancement layer.

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