A 4-way parallel CAVLC design for H.264/AVC 4Kx2K 60fps encoder

Abstract

This paper presents a high performance design for Context-Based Adaptive Variable Length Coding (CAVLC) used in the H.264/AVC standard. A two-stage encoder is proposed to make the scan and encode stage work simultaneously. The scan engine scans four coefficients at each cycle. Parallel encoder for four “levels” and parallel encoder for four “Run_before” are adopted to accelerate the encode engine. Only 120 cycles at most are needed to process one MB. The proposed CAVLC encoder can support 4Kx2K@60fps (frame per second) real-time encoding at 250MHz and the gate count is about 32k.