Computational complexity allocation and control for inter-coding of high efficiency video coding with fast coding unit split decision

• A computational complexity allocation and control method for the low-delay P-frame configuration of the HEVC encoder.
• The complexity allocation includes the group of pictures layer, the frame layer, and the CU layer in the HEVC encoder.
• Motion vector estimation information is applied for CU complexity allocation and depth split determination.

HEVC provides the quadtree structure of the coding unit (CU) with four coding-tree depths to facilitate high coding efficiency. However, compared with previous standards, the HEVC encoder increases computational complexity considerably, thus making it inappropriate for applications in power-constrained devices. This study therefore proposes a computational complexity allocation and control method for the low-delay P-frame configuration of the HEVC encoder. The complexity allocation includes the group of pictures (GOP) layer, the frame layer, and the CU layer in the HEVC encoder. Each layer involved uses individual method to distribute the complexity. In particular, motion vector estimation information is applied for CU complexity allocation and depth split determination. The total computational complexity can thus be reduced to 80% and 60% or even lower. Experiment results revealed that the average BD-PSNR exhibited a decrease of approximately 0.1 dB and a BD-bitrate increment of 2% when the target complexity was reduced to 60%.