H.264 code rate control method

Abstract

The present invention discloses an H.264 code rate control method, for in sequence performing code rate control to each current macro block in the current P-frame, which includes: if the current macro block is the first macro block of the current P-frame, taking the average quantization parameter QP of the former frame as the QP of the current macro block; otherwise, calculating the edge direction of the current macro block, and using the edge direction to predict the mean absolute error MAD of the current macro block, updating the quadratic code rate- quantitative step length R-Q model coefficient based on the historical information of the coded macro block, determining the head information bit number predicted value and pre-allocation code rate of the current macro block; an then based on the MAD predicted value, head information bit number predicted value and pre-allocation code rate of the current macro block, using the quadratic R-Q model with update coefficient to determine the QP of the current macro block. Using the method of the invention can more efficiently use correlativity of time-domain and space-domain, overcome the defect of JVT-G012 code rate control algorithm andits improved algorithm existing in the performance or computational complexity, to achieve the most effective code rate control.

Description

A H.264 code rate control method technical field The invention relates to video compression technology, in particular to an H.264 code rate control method in the video compression technology. Background technique Bit rate control plays a vital role in video compression technology. Its ultimate goal is to effectively suppress the quality fluctuation of the video sequence and reduce the number of frame skipping under the given target bit rate and buffer capacity. Thus, the transmitted video quality is optimized. H.264 is the latest international standard for video compression developed by the Joint Video Team (JVT) in recent years. When using the H.264 video compression standard for bit rate control, due to the quantization parameter (QP) It is used in both the rate control process and the rate-distortion optimization process, so there will be a problem of "laying hen paradox": in order to calculate the rate-distortion optimization (RDO) of the current macroblock, it is ne...

AI Technical Summary

Problems solved by technology

In view of this, the main purpose of the present invention is to provide a H.264 code rate control method, which can overcome the defects in performance or computational complexity of the JVT-G012 code rate control algorithm and its improved algorithm, and realize the most effective code rate control method. rate control

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