Method and apparatus for coding video and method and apparatus for decoding video accompanied with arithmetic coding

Patent metadata

Field	Value
Publication number	US-9258571-B2
Application number	US-201514603218-A
Country	US
Kind code	B2
Filing date	Jan 22, 2015
Priority date	Jun 28, 2011
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A method of decoding a video through symbol decoding includes parsing symbols of image blocks from a received bitstream; classifying a current symbol into a prefix bit string and a suffix bit string based on a threshold value determined according to a size of a current block; performing arithmetic decoding of the prefix bit string and the suffix bit string by using respective arithmetic decoding methods determined for each of the prefix bit string and the suffix bit string; performing inverse binarization of the prefix bit string and the suffix bit string by using respective binarization methods determined for each of the prefix bit string and the suffix bit string; and restoring the image blocks by performing an inverse transformation operation and a prediction operation on the current block by using the current symbol restored through the arithmetic decoding and the inverse binarization.

First claim

What is claimed is:

1. An apparatus for decoding a video, the apparatus comprising:
a receiver which is configured to receive a bitstream including information about a last coefficient location of a transformation block;
an arithmetic decoder which is configured to obtain a prefix bitstring of the last coefficient location among the information about the last coefficient location by performing context-based arithmetic decoding on the bitstream, and, when the prefix bitstring is greater than a predetermined value, obtain, from the bitstream, a suffix bitstring according to a bypass mode;
an inverse-binarizer which is configured to perform inverse binarization on the prefix bitstring according to a truncated binarization scheme to obtain an inverse-binarized prefix, and perform inverse binarization on the suffix bitstring according to a fixed-length binarization scheme to obtain an inverse-binarized suffix; and
a symbol reconstructor which is configured to reconstruct a symbol indicating the last coefficient location of the transformation block by using the inverse-binarized prefix and the inverse-binarized suffix,
wherein a range of a value of the inverse-binarized prefix is determined based on a size of the transformation block and a range of a value of the inverse-binarized suffix is determined based on the value of the inverse-binarized prefix, and
wherein a value of the symbol indicating the last coefficient location of the transformation block is reconstructed by using the value of the inverse-binarized prefix and the value of the inverse-binarized suffix.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Seregin Vadim
• Kim Il-Koo

Classifications

• H04N19/59

  involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution · CPC title

• H04N19/44

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title

• H04N19/91 Primary

  Entropy coding, e.g. variable length coding [VLC] or arithmetic coding · CPC title

• H04N19/157

  Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title