Rate Distortion Optimization (RDO) is employed in High-Efficiency Video Coding (HEVC) to enhance its coding efficiency. Owing to its coding complexity, RDO is traditionally performed within each frame with fixed quantization parameters (QPs), without fully considering the coding dependencies between the current frame and future frames within a temporal propagation chain. To improve the coding efficiency of HEVC, it is desirable to perform a global RDO among consecutive frames while maintaining a similar coding complexity. To address this problem, in this paper, temporal dependencies are first measured via a model for the energy of prediction residuals that enables the formulation of the global RDO in low-delay (LD) HEVC. Second, the notion of propagation length is introduced, which is defined as the impact length of the current frame on future frames. This length is estimated via offline experiments and used to propose two novel methods to predict the impact of the coding distortion of the current frame on future frames from previous frames of similar coding properties. Third, we apply these two methods to adaptively determine the Lagrangian multiplier and its corresponding QP for each frame in the LD configuration of HEVC. Experimental results show that, in comparison to the default LD HEVC, the first method can achieve, on average, BD-rate savings of 5.0% and 4.9% in low-delay-P (LDP) and low-delay-B (LDB) configurations, respectively, and the second can achieve, on average, BD-rate savings of 4.9% and 4.9% in the LDP and LDB configurations, respectively, all with insignificant increases in encoding time.

高效视频编码（HEVC）中采用了速率失真优化（RDO），以提高其编码效率。由于其编码复杂性，传统上在具有固定量化参数（QP）的每个帧内执行RDO，而无需完全考虑时间传播链中当前帧和未来帧之间的编码依赖性。为了提高HEVC的编码效率，期望在保持相似的编码复杂度的同时在连续帧之间执行全局RDO。为了解决这个问题，在本文中，首先通过预测残差能量模型对时间相关性进行测量，该模型能够在低延迟（LD）HEVC中制定全局RDO。其次，介绍传播长度的概念，定义为当前帧对未来帧的影响长度。该长度是通过离线实验估算的，并用于提出两种新颖的方法，以根据相似编码属性的先前帧预测当前帧的编码失真对未来帧的影响。第三，我们应用这两种方法为HEVC的LD配置中的每一帧自适应确定拉格朗日乘数及其对应的QP。实验结果表明，与默认的LD HEVC相比，第一种方法在低延迟P（LDP）和低延迟B（LDB）中平均可实现BD速率节省5.0％和4.9％。在LDP和LDB配置中，第二种配置分别可以平均节省4.9％和4.9％的BD速率，而所有这些都在编码时间上有可观的增加。该长度是通过离线实验估算的，并用于提出两种新颖的方法，以根据相似编码属性的先前帧预测当前帧的编码失真对未来帧的影响。第三，我们应用这两种方法为HEVC的LD配置中的每一帧自适应确定拉格朗日乘数及其对应的QP。实验结果表明，与默认的LD HEVC相比，第一种方法在低延迟P（LDP）和低延迟B（LDB）中平均可实现BD速率节省5.0％和4.9％。在LDP和LDB配置中，第二种配置分别可以平均节省4.9％和4.9％的BD速率，而所有这些都在编码时间上有可观的增加。该长度是通过离线实验估算的，并用于提出两种新颖的方法，以根据相似编码属性的先前帧预测当前帧的编码失真对未来帧的影响。第三，我们应用这两种方法为HEVC的LD配置中的每一帧自适应确定拉格朗日乘数及其对应的QP。实验结果表明，与默认的LD HEVC相比，第一种方法在低延迟P（LDP）和低延迟B（LDB）中平均可实现BD速率节省5.0％和4.9％。在LDP和LDB配置中，第二种配置分别可以平均节省4.9％和4.9％的BD速率，而所有这些都在编码时间上有可观的增加。