Adaptive search range control in H.265/HEVC with error propagation resilience and hierarchical adjustment

In the state-of-the-art video coding standards H.264/AVC and H.265/HEVC, adaptive search range (ASR) control has achieved a significant performance in reducing the computational complexity of motion estimation. Nevertheless, the application of ASR in adjacent coding units may bring error propagation, and the ASR values may vary subject to different layers in hierarchical prediction structure. Here we propose two separate algorithms for ASR in H.265/HEVC: an error propagation resilience algorithm that eliminates the rate-distortion (RD) loss due to error propagation, and a hierarchical range adjustment algorithm that adjusts the ASR values between hierarchical layers. Simulation results show that our methods greatly improve the RD performances of traditional ASR works whilst keeping almost intact complexity reductions.