VBR code rate control method for video real-time coding

Abstract

The invention provides a VBR code rate control method for video real-time coding, which is applied to an IPPP structure for video real-time coding and comprises the following steps of: sequentially distributing target code rates for different coding units by adopting a grading strategy; the grading strategy is divided into a GOPs level, a GOP level and an image level; setting the upper and lower limits of allowable fluctuation for the current GOP target code rate according to the tolerance of the user to the code rate fluctuation, and comparing the instantaneous estimated code rate with the upper and lower limits of the allowable fluctuation of the target code rate to decide how to adjust the QP so as to reduce unnecessary fluctuation of the QP; according to the influence degree of the scene change on the code rate and the scene change position, a new code rate fluctuation upper limit and a new code rate fluctuation lower limit are calculated, and QP adjustment is guided; when scene change occurs in a video image, weighted summation is carried out through the estimated instantaneous code rate and the distributed target code rate fluctuation upper and lower limits to obtain a new code rate control upper and lower limits, the weight proportion is related to the position of the current frame in the GOP, the control intensity is higher when the current frame is closer to the I frame, and the control intensity is weaker when the current frame is farther from the I frame.

Description

technical field [0001] The invention relates to the technical field of image recognition, in particular to a VBR code rate control method for video real-time coding. Background technique [0002] At present, the VBR methods applied to real-time video coding all use a relatively small target bit rate in simple scenes, and a larger target bit rate in complex scenes, so as to maintain stable video image coding quality. The existing VBR optimization methods are all based on the image content and motion state. By analyzing the image complexity information over a period of time, it is used as an influencing factor for calculating the target code rate, and different target codes can be allocated under different complexity. Rate. [0003] The deficiencies of the prior art include: [0004] In the existing VBR control technology, an accurate target bit rate is still used for control. When the instantaneous bit rate fluctuates up and down the target bit rate, it is easy to cause QP ...

AI Technical Summary

Problems solved by technology

[0004] Existing VBR control technology still adopts precise target bit rate for control, when the instantaneous bit rate fluctuates above and below the target bit rate, it will easily cause QP oscillation, which is not conducive to maintaining the stability of image quality

However, there is no suitable allocation strategy for scenes with different complexity and motion intensity. When the scene changes in the video image, the actual bit rate is prone to be too large or too small.

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