TECHNICAL FIELD

An embodiment of the disclosure relates to a method and apparatus for processing a video signal using inter prediction and, more particularly, to a method and apparatus for performing inter prediction using a history-based motion vector prediction.

BACKGROUND ART

Compression encoding means a series of signal processing techniques for transmitting digitized information through a communication line or techniques for storing information in a form suitable for a storage medium. The medium including a picture, an image, audio, etc. may be a target for compression encoding, and particularly, a technique for performing compression encoding on a picture is referred to as video image compression.

Next-generation video contents are supposed to have the characteristics of high spatial resolution, a high frame rate and high dimensionality of scene representation. In order to process such contents, a drastic increase in the memory storage, memory access rate and processing power will result.

Accordingly, it is required to design a coding tool for processing next-generation video contents efficiently.

DISCLOSURE

Technical Problem

An embodiment of the disclosure proposes constraints on redundancy check for adding an HMVP candidate to a merge list (or AMVP list).

Technical objects to be achieved in an embodiment of the disclosure are not limited to the aforementioned technical objects, and other technical objects not described above may be evidently understood by a person having ordinary skill in the art to which the disclosure pertains from the following description.

Technical Solution

In an aspect of an embodiment of the disclosure, a method of processing a video signal based on inter prediction includes constructing a first merge candidate list of a current block using a spatial merge candidate and temporal merge candidate of the current block, constructing a second merge candidate list by adding a history-based merge candidate indicating motion information of a block coded prior to the current block to the first merge candidate list, obtaining a merge index indicating a merge candidate applied to the current block within the second merge candidate list, and generating a prediction block of the current block using motion information of a merge candidate indicated by the merge index. The history-based merge candidate may be added to the first merge candidate list if the history-based merge candidate has motion information not overlapping motion information of a pre-defined merge candidate among merge candidates included in the first merge candidate list.

Preferably, the history-based merge candidate may be added to the first merge candidate list if the history-based merge candidate has motion information not overlapping motion information of a pre-defined specific number of merge candidates among the merge candidates included in the first merge candidate list.

Preferably, the history-based merge candidate may be added to the first merge candidate list if the history-based merge candidate has motion information not overlapping motion information of a specific spatial merge candidate included in the first merge candidate list.

Preferably, the history-based merge candidate is derived from a pre-defined number of candidates within a history-based buffer storing the history-based merge candidates.

Preferably, constructing the second merge candidate list may further include adding a history-based spatial temporal merge candidate. The history-based spatial temporal candidate may be derived using the two history-based merge candidates and the temporal merge candidate.

Preferably, a motion vector of the history-based spatial temporal candidate may be derived as an average value of motion vectors of the two history-based merge candidates and an average value of motion vectors of the temporal merge candidates.

In an aspect of an embodiment, an apparatus for processing a video signal based on inter prediction includes a memory storing a video signal and a processor coupled to the memory. The processor may be configured to construct a first merge candidate list of a current block using a spatial merge candidate and temporal merge candidate of the current block, construct a second merge candidate list by adding a history-based merge candidate indicating motion information of a block coded prior to the current block to the first merge candidate list, obtain a merge index indicating a merge candidate applied to the current block within the second merge candidate list, and generate a prediction block of the current block using motion information of a merge candidate indicated by the merge index. The history-based merge candidate may be added to the first merge candidate list if the history-based merge candidate has motion information not overlapping motion information of a pre-defined merge candidate among merge candidates included in the first merge candidate list.

Advantageous Effects

According to an embodiment of the disclosure, complexity according to redundancy check can be improved and efficiency can be enhanced by limiting redundancy check for addition to a merge list (or AMVP list).

Effects which may be obtained in the disclosure are not limited to the aforementioned effects, and other technical effects not described above may be evidently understood by a person having ordinary skill in the art to which the disclosure pertains from the following description.

