Title :
Adaptive Quantization-Parameter Clip Scheme for Smooth Quality in H.264/AVC
Author :
Hu, Sudeng ; Wang, Hanli ; Kwong, Sam
Author_Institution :
Dept. of Comput. Sci., City Univ. of Hong Kong, Kowloon, China
fDate :
4/1/2012 12:00:00 AM
Abstract :
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 (Qp) 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 Qp clip range is developed to reduce the quality fluctuation. Experimental results demonstrate that the proposed Qp clip scheme can achieve excellent performance in quality smoothness and buffer regulation.
Keywords :
data compression; quantisation (signal); video coding; H.264/AVC; adaptive quantization-parameter clip scheme; encoder buffer; frame complexity variation; quality fluctuation; rate control; smooth bit rate; smooth quality; Bit rate; Complexity theory; Encoding; Prediction algorithms; Quantization; Streaming media; Video sequences; Encoder buffer; H.264/AVC; quantization-parameter clip; rate control (RC); smooth quality; Algorithms; Data Compression; Image Enhancement; Image Interpretation, Computer-Assisted; Photography; Reproducibility of Results; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Video Recording;
Journal_Title :
Image Processing, IEEE Transactions on
DOI :
10.1109/TIP.2011.2176347