Exploring Operation Sharing in Directional Intra Frame Prediction of AV1 Video Coding

摘要

AOMedia Video 1 (AV1) is a new bitstream format for royalty-free open source video coding, developed with the goal of providing competitive compression rates to state-of-the-art standards with high image quality. Due to the high computational cost of some tools included in AV1, the development of hardware solutions is required for real-time compression. This work presents a hardware solution for the directional intra-frame prediction of AV1 that explores operation sharing. An analysis over all bilinear filters that compose the 56 directional intra prediction modes was performed and allowed identifying that 37% of all prediction operations could be shared. The resulting proposed architecture was synthesized for the TSMC 40nm technology with a target frequency of 1,296 MHz, necessary for real-time processing of 4K video sequences at 60fps. The architecture achieved a power dissipation of 4,110 mW and a circuit area of 584.845 Kgates. The operation sharing strategy led to a decrease of 1.08% in power dissipation and 1.17% in circuit area when compared to a solution without sharing, on top of the automatic optimizations achieved by the RTL Compiler tool.