Self-adaption bit distribution method based on code rate control of hierarchical B frame structure

Abstract

The invention discloses a self-adaption bit distribution method based on code rate control of a hierarchical B frame structure. The self-adaption bit distribution method comprises the steps of: 1, figuring out a target bit number distributed to each GOP (Ground Observation Post) on the basis of the length requirement of a video sequence and the GOP in a configuration file attached by the video sequence and the speed requirement of the target bit; 2, figuring a target bit number distributed to each time layer in the hierarchical B frame structure on the basis of the target bit number of each GOP, obtained in the step 1; 3, figuring out a target bit number distributed to each image frame in the same time layer on the basis of the target bit number of each time layer, obtained in the step 2; and 4, updating a weight value of each time layer through iteration calculation according to coding information of a coding image. On the premise of no increase of the bit numbers consumed by the video coding actually, the coding complexity of each image frame in the video sequence is accurately predicted, each time layer bit distribution weight value in the hierarchical B frame structure is updated through iteration calculation, and the target bit numbers are distributed for each frame of image reasonably, thus coding efficiency of the video sequence and decoding quality of each frame of image are increased.

Description

technical field [0001] The invention relates to the technical field of code rate control in video coding, in particular to an adaptive bit allocation method for code rate control based on layered B frame structure. Background technique [0002] In recent years, with the development of multimedia technology, people have higher and higher requirements for the clarity and fluency of network video. However, the size of network bandwidth determines the number of transmitted bits per unit time. Different network terminals have different requirements for video quality, The demand for network bandwidth is not the same. It is precisely because of this demand that SVC (SVC is the abbreviation of English Scalable Video Coding, and its Chinese translation is Scalable Video Coding) technology has become one of the key technologies to solve video adaptation. SVC On the basis of maintaining the high-efficiency coding of H.264, the predictive coding structure based on hierarchical B frames ...

AI Technical Summary

Problems solved by technology

Although this fixed weight value bit allocation method takes into account the temporal prediction dependence between the base layer and each enhancement layer, it ignores two major differences in the video coding process: 1. Some video sequences have smooth motion between frames, Some video sequences have intense motion between frames, and different video sequences have different encoding complexities; 2. In the same video sequence, some parts of the frame motion are smooth, and some parts of the frame motion are intense, even in the same time layer The coding complexity is different between each image frame on

Using the fixed weight value bit allocation method, the fixed bit-allocated weight value is used for each time layer of different video sequences, and the same bit-allocated weight value is used for each image frame in the same time layer, which does not take into account at all. These two major differences in video coding, which will reduce the coding efficiency of the entire video sequence, thereby reducing the quality of the final decoded image

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