Rate Control Method Based on Logarithmic r-q Model and Hierarchical Bit Allocation

Abstract

A code rate control method based on a logarithmic R-Q model and hierarchical bit allocation, comprising the following steps: calculating the content complexity of an image area to be encoded, and performing hierarchical bit allocation; using the logarithmic R-Q model, calculating The quantization step size of the area to be encoded in the image; complete the encoding process of one coding unit, update the model parameters, and then encode the next coding unit until the encoding of the entire video sequence is completed. The present invention makes full use of different hierarchical structures of video coding and R-Q statistical characteristics to accurately allocate and map channel bandwidth, and can obtain a more accurate output video bit rate under the condition of lower video quality and lower cost , effectively improve the bit rate control accuracy and better video quality fidelity, in the actual video business, can more effectively use the channel bandwidth resources, so that the source and the channel are more matched.

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 subject in video coding, and it 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 bit rate control is to ensure the maximum video coding quality, 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 response to the growing demand for video consumption, in 2010, ITU and ISO / IEC began to formulate a new generation of video coding standards - High Efficiency Video Coding (HEVC, High Efficiency Video Coding), which aims to be able to H.264 has bee...

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 ModelingRate Control in the Emerging HEVC Standard”, Picture Coding Symposium (PCS), 2012.IEEE, 2012, pp.401-404.) proposed a quadratic model for H.264 video Transplantation of coding standards, experimental test results show that the rate control accuracy is not ideal; Yeo-Jin Yoon et al. on.IEEE, 2012, pp.1-4.) proposes 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 precise enough

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