基于标准化量化步长θ的数据率模型

Rate Model Based on Standard Quantization Step Size

为了更精确地进行视频实时流控,通过分析视频编码的数据率特征,提出了一个新颖的基于标准化量化步长θ的数据率模型。在对离线实验获得的θ数据率曲线进行平滑处理后,即可创建一个数据率查找表,然后再基于查找表设计出简单高效的实时θ模型流控算法。因为θ模型估计精确,且无任何自适应参数,所以θ模型流控受视频场景切换影响很小。实验结果显示,θ模型流控的性能明显优于TMN8流控。与同样是基于精确数据率模型的ρ域流控相比,虽性能相当,但是θ模型流控不仅计算复杂度更低、更灵活,且更易于在硬件中实现。

A novel rate model of standard quantization step size （θ） for real-time rate control is proposed based on the analysis of rate characteristic in video coding. By smoothing the θ rate curve obtained offline, a look-up table of coding rate is created first. A simple and effective rate control algorithm for real-time video is developed based on the look-up table. Because the θ rate model is an accurate model without any adaptive parameter, the θ model rate control will not suffer from the impact of scene change. Our experiments show that the performance of θ model rate control is much better than the TMN8 rate control. Comparing with the p domain rate control which also adopts an accurate coding rate model, the θ model rate control has lower computational complexity and offers significant advantages in hardware implementation.