A fast inter-frame encoding scheme using the edge information and the spatiotemporal encoding parameters for HEVC

High Efficiency Video Coding (HEVC), as a novel video coding standard, has shown a better coding efficiency than all existing standards, such as H.264/AVC. It adopts a lot of new efficient coding tools, the most important one is the new hierarchical structures which include the coding unit (CU), prediction unit (PU) and transform unit (TU). However, the rate-distortion (RD) optimization process for all CUs, PUs, and TUs cause large computational costs. In this paper, a fast Inter-frame encoding scheme using the edge information and the spatiotemporal encoding parameters is proposed to reduce the encoder complexity of HEVC, which consists of a fast all 2 N x 2 N modes decision method, a fast CU depth level decision method and a fast PU mode decision method. This scheme uses edge information to express the structure complexity and uses the difference of edge information between current CU and its spatiotemporal CUs to express the edge similarity (ES) in one frame and the edge movement (EM) between two adjacent frames. And then, utilizes ES and EM as assistant parameters cooperate with CU depth levels and PU mode RD costs of spatiotemporal CUs to accomplish the early termination of CU split and the PU mode selection. The experimental results show that the proposed fast inter-frame encoding method can significantly reduce the computational costs with negligible RD loss. There are 53.7 and 54.9% encoding time savings on average, but only with average 1.5 and 1.8% Bjontegaard difference bitrate (BDBR) losses for various test sequences under random access and low delay conditions, respectively.