Flexible band offset mode in sample adaptive offset in HEVC

摘要

A Flexible Band Offset (FBO) apparatus and method of performing Sample Adaptive Offset (SAO) filtering within encoders and decoders, such as according to the High Efficiency Video Coding (HEVC) standard, and similarly configured coding devices. The number of Band Offset (BO) modes and the number of necessary offsets is reduced. The invention beneficially provides simpler coding, reduces temporary buffer size requirements, and can yield a small performance gain over existing SAO techniques of HEVC test model HM 5.

主权项

1. An apparatus for sample adaptive offset (SAO) signaling during entropy encoding and decoding of video, comprising:
(a) a video encoder having a computer processor and memory storing programming; (b) programming executable on said video encoder computer processor for:
(i) receiving a decoded video signal from a deblocking filter;(ii) setting a fixed length code within an encoder, for transmission to a decoder, in response to steps comprising:
(A) selecting four consecutive bands for which an SAO offset for each will be transmitted;(B) assuming remaining bands have zero SAO offsets;(C) encoding a fixed length code indicating extent of offset for a first non-zero band offset (BO) of said four consecutive bands; and(D) generating positioning for said four consecutive bands by adding an offset to said first non-zero band offset (BO) and using the modulo remainder based on number of BO bands and encoding SAO offset for each; (c) a video decoder having a computer processor and memory storing programming; (d) programming executable on said video decoder computer processor for:
(i) sample adaptive offset filtering of an encoded video signal based on receiving said fixed length code within said video decoder, in response to steps comprising:
(A) determining position of said first band based on decoding said fixed length code;(B) decoding four SAO offsets for four consecutive bands determined during encoding;(C) determining position of remaining bands in response to adding an offset to said first band and taking a modulo remainder based on number of BO bands and adding decoded SAO offsets to them; and(D) adding zero SAO offsets to all remaining bands.