HEVC rate control model parameter updating algorithm based on distortion measurement

Abstract

The invention discloses an HEVC rate control model parameter updating algorithm based on distortion measurement. According to the algorithm, iterative computation is conducted on the parameter alpha and the parameter beta of a code rate control model through a minimum mean square error LMS method; D is set to represent distortion of a video subjected to compressed encoding; R represents the compressed code rate, and C and K represent model parameters related to video sequence characters; the lengths of the iterative steps used by the parameter C and the parameter K during one iteration are delta C and delta K respectively, and the target code rate is R; an R-D code rate distortion model is described through the formula: D(R)=CR-K; during code rate control, the relational expression between the code rate R and the lagrangian multiplier lambda is shown in the specification, and the iterative formula is shown in the specification. According to the HEVC rate control model parameter updating algorithm based on distortion measurement, iteration is conducted according to the video features before and after encoding, HEVC rate control model parameters are accurately updated by accurately measuring the distortion amount, and therefore the more accurate code rate control effect is obtained.

Description

technical field [0001] The present invention relates to the technical field of video coding rate control, in particular to an HEVC rate control model parameter update algorithm based on distortion measurement, which conforms to the H.265 / MPEG-H HEVC (High Efficiency Video Coding) video coding standard. Background technique [0002] In video coding and transmission applications, the new generation of high-performance video coding standard H.265 / MPEG-HHEVC (High Efficiency Video Coding) is a video coding joint venture established by two international standardization organizations, ISO-IEC / MPEG and ITU-T / VCEG. Developed by the development team (JCT-VC), HEVC can reduce the bit rate by half compared with H.264 / AVC at the same visual quality. [0003] As a new-generation video coding standard, HEVC still belongs to the hybrid coding framework of prediction and transformation. It also includes coding modules such as intra prediction, inter prediction, orthogonal transformation, qu...

AI Technical Summary

Problems solved by technology

[0025] However, it can be known from formula (5) that λ comp The parameter α of the original model was used in the calculation old and beta old , and its parameters have changed after the video is encoded, so the parameter α of the original video model old and beta old It cannot fully reflect the parameter characteristics of the encoded video, so λ real with lambda comp Between the square error to adjust the α and β values, the resulting update model is only approximately close to the characteristics of the current video sequence

Images