Efficient realization of parallel HEVC intra encoding

The Adaptive Loop Filter (ALF) is a subjective and objective image quality improving filter in the High Efficiency Video Coding standard (HEVC). The ALF has shown to be compu-tationally complex and its complexity has been reduced dur-ing the HEVC development process. In the HEVC Test Model HM-7.0 ALF is a 9×7 cross + 3×3 square shaped filter. This paper presents a programmable application specific instruction processor for the ALF. The proposed processor processes 1920×1080p luminance frames at 30 frames per second, when operated at a clock frequency of 311 MHz. Low power consumption and a low gate count make the proposed processor suitable for embedded devices. The processor pro-gram code is written in pure C-language, which allows ver-satile use of the circuit and updates to the filter functionality without modifying the processor design. To the authors ’ best knowledge this is the first programmable solution for ALF on embedded devices.