LCU-level video bit allocation algorithm based on two-layer game in low-altitude communication environment

This paper addresses the issues of low video coding efficiency and insufficient bit rate utilization in low-altitude communication scenarios by proposing an largest coding unit (LCU)-level bit allocation (BA) optimization based on two-layer hybrid game model (HGLA) algorithm. Using the LCU as the basic unit, the algorithm performs region partitioning according to texture complexity, motion intensity, and edge information, and establishes a differentiated BA mechanism for high- and low-complexity regions. In particular, a combination of cooperative and non-cooperative game models is used for high-complexity regions to achieve coordinated BA; for low-complexity regions, a global quantization parameter (QP) smoothing strategy and a spatial weighting mechanism are introduced to improve bit rate utilization efficiency and visual continuity. Finally, experimental validation under four low-bit rate scenarios demonstrates that the proposed method achieves significant improvements in peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM), and subjective quality. Specifically, at the target bit rate of 16 Kbit/s, compared with four baseline methods including the high efficiency video coding (HEVC) rate control (RC) algorithm HM-RC and the frame-level multilayer perceptron (MLP)-based BA algorithm, the intra-frame rate control algorithm based on a simplified cubic rate-distortion model, and the variable-resolution rate control algorithm based on versatile video coding (VVC), the proposed method achieves average performance gains of 3.34%, 2.16%, and 9.8% in PSNR, SSIM, and mean opinion score (MOS), respectively, demonstrating its excellent practicality and adaptability in improving bit rate utilization efficiency and preserving image quality.