Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.
IEEE Trans Image Process. 2012 Apr;21(4):1911-9. doi: 10.1109/TIP.2011.2176347. Epub 2011 Dec 5.
In this paper, we investigate the issues over the smooth quality and the smooth bit rate during rate control (RC) in H.264/AVC. An adaptive quantization-parameter (Q(p)) clip scheme is proposed to optimize the quality smoothness while keeping the bit-rate fluctuation at an acceptable level. First, the frame complexity variation is studied by defining a complexity ratio between two nearby frames. Second, the range of the generated bits is analyzed to prevent the encoder buffer from overflow and underflow. Third, based on the safe range of the generated bits, an optimal Q(p) clip range is developed to reduce the quality fluctuation. Experimental results demonstrate that the proposed Q(p) clip scheme can achieve excellent performance in quality smoothness and buffer regulation.
在本文中，我们研究了 H.264/AVC 中率控制 (RC) 过程中平滑质量和平滑比特率的问题。提出了一种自适应量化参数 (Q(p)) 剪辑方案，以在保持可接受的比特率波动水平的同时优化质量平滑度。首先，通过定义两个相邻帧之间的复杂度比来研究帧复杂度的变化。其次，分析生成的比特数的范围，以防止编码器缓冲区溢出和下溢。第三，基于生成的比特的安全范围，开发了最佳的 Q(p)剪辑范围，以减少质量波动。实验结果表明，所提出的 Q(p)剪辑方案可以在质量平滑度和缓冲区调节方面实现优异的性能。
