Rate control method based on logarithm R-Q model and hierarchical bit allocation

Abstract

The invention provides a rate control method based on a logarithm R-Q model and hierarchical bit allocation. The rate control method includes the first step of computing content complexity of a region to be encoded in an image and carrying out hierarchical bit allocation, the second step of using the logarithm R-Q model to compute the quantifying step size of the region to be encoded in the image, the third step of completing the encoding process of one encoding unit, updating model parameters and then carrying out encoding on the next encoding unit until encoding of a whole video sequence is completed. According to the rate control method, the different hierarchical structure of video encoding and R-Q statistic characteristics are fully utilized, the bandwidth of a communication channel is accurately allocated and mapped, more accurate output video code rate can be obtained on the condition of lower cost of video quality, and rate control accuracy and better fidelity of video quality are effectively improved. Meanwhile, in actual video services, channel bandwidth resources can be more effectively utilized, so that information sources and the communication channels are more matched with each other.

Description

Technical field [0001] The invention belongs to the technical field of video image coding, in particular to a code rate control method based on a logarithmic R-Q model and hierarchical bit allocation. Background technique [0002] Rate control is a basic topic in video coding, which is of great significance to the application of video coding standards. In the process of video transmission and storage, network bandwidth and storage resources are limited. The function of rate control is to ensure that the video encoding quality is maximized, so that the output bit stream can meet the transmission and storage restrictions. Therefore, rate control plays an extremely important role in the application of video coding standards. [0003] In order to cope with the increasing demand for video consumption, in 2010, ITU and ISO / IEC started to formulate a new generation of video coding standards-High Efficiency Video Coding (HEVC), which aims to be able to compare with the current most popula...

AI Technical Summary

Problems solved by technology

Compared with the previous coding standards, the HEVC encoder introduces many new coding techniques, such as quadtree partitioning, asymmetric block partitioning, parallel coding techniques, etc., which have higher complexity and more challenging code rate control.

[0004] Among the existing HEVC rate control algorithms, most of them directly apply the rate control algorithms of previous video coding standards to the HEVC standard, without considering some new technologies and new features introduced by HEVC, and there is no well-targeted solution. performance, the accuracy of rate control is not high

Matteo Naccari and Fernando Pereira (“Quadratic Modeling Rate Control in the Emerging HEVC Standard”, Picture Coding Symposium (PCS), 2012.IEEE, 2012, pp.401-404.) proposed a quadratic model, which is the H.264 Transplantation of video coding standards, experimental test results show that the rate control accuracy is not ideal; Yeo-Jin Yoon et al. (“A New Rate Control Method for Hierarchical Video Coding in HEVC”, Broadband Multimedia Systems and Broadcasting (BMSB), 2012 IEEE International Symposium on.IEEE,2012,pp.1-4.) proposed a code rate control method based on an exponential model. The code rate allocation is only at the frame level, without finer division, and the code rate control is not accurate enough

Images