A Lossless Intra Reference Block Recompression Scheme for Bandwidth Reduction in HEVC-IBC

TL;DR

This paper introduces a lossless recompression scheme for intra reference blocks in HEVC-IBC, significantly reducing memory bandwidth and power consumption by compressing reference data before storage.

Contribution

It proposes a novel pixel-wise texture analysis and edge-based adaptive prediction method that compresses intra reference blocks without additional signaling.

Findings

Achieves 72% average data reduction

Reduces DRAM bandwidth requirement

Lowers power consumption in HEVC-IBC

Abstract

The reference frame memory accesses in inter prediction result in high DRAM bandwidth requirement and power consumption. This problem is more intensive by the adoption of intra block copy (IBC), a new coding tool in the screen content coding (SCC) extension to High Efficiency Video Coding (HEVC). In this paper, we propose a lossless recompression scheme that compresses the reference blocks in intra prediction, i.e., intra block copy, before storing them into DRAM to alleviate this problem. The proposal performs pixel-wise texture analysis with an edge-based adaptive prediction method yet no signaling for direction in bitstreams, thus achieves a high gain for compression. Experimental results demonstrate that the proposed scheme shows a 72% data reduction rate on average, which solves the memory bandwidth problem.