Code rate control method based on space-time domain context and motion complexity

Abstract

The invention relates to a code rate control method based on space-time domain context and motion complexity. The method comprises the following steps of: based on a R-lambda model, performing the first-step updating on model parameters alpha and Beta of a current basic unit C0 before coding of the C0; coding the current basic unit C0; waiting for completion of coding all the basic units of a frame where the C0 is, and performing the second-step updating on the current basic unit; guiding target bits allocation of a basic unit layer with the model parameters subjected to the two steps of parameter updating; defining a relative motion complexity coefficient of the current basic unit C0 to represent motion intensity of different basic units; regulating a lambda value of the current basic unit with Wi, j of the current basic unit C0 to make the lambda value adaptive to the motion intensity of different basic units, thereby realizing the aim of allocating more bits to the basic units with higher motion intensity. The code rate control method based on space-time domain context and motion complexity can guarantee that the basic units with higher motion intensity can get more target bits, thereby facilitating improvement of quality of video.

Description

technical field [0001] The invention belongs to the field of video coding, and in particular relates to a code rate control method for improving the accuracy of code rate control. Background technique [0002] With the development of computer network, communication technology and multimedia technology, video-related applications become more and more extensive. However, the video data is often very huge, and the storage and transmission of video brings great challenges to the existing storage and communication systems. Video compression technology must be used to reduce the storage capacity and transmission bandwidth of video. The code rate control technology is an important link in the video compression technology. Through the code rate control, under the constraints of the code rate and the buffer zone, the coding parameters can be adaptively adjusted to make the code stream adapt to the channel transmission bandwidth, and Minimize video distortion. [0003] Since the rel...

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Problems solved by technology

However, the rate control method based on the R-λ model also has certain limitations. In terms of parameter update, only the time correlation is used and the spatial correlation is ignored, so that the updated parameters are not accurate; the target bit allocation at the basic unit layer On the one hand, it is based on the following assumption: basic units at the same level and at the same position may have the same model parameters, but if the current basic unit moves violently, the difference between it and the basic unit at the corresponding position of the reference picture is usually large, so the two use the same Model parameters are not accurate

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