High-definition video code rate control algorithm based on Sobel operator and linear regression

Abstract

Aiming at an HEVC video coding standard, the invention provides a high-definition video code rate control algorithm based on the Sobel operator and linear regression. The method mainly comprises the steps: finding an optimal initial QP (quantization parameter) for a coded first frame through a learned linear regression model, thereby enabling a coding process to quickly adapt to a set bandwidth; generating the intra-frame and inter-frame first-order gradient information through employing the Sobel operator, and then adaptively selecting optimal gradient information to replace coding complexity to serve as the weight of LCU layer bit distribution. The method enables the bit rate error to be lower, enables the output code rate to be more stable, and is better in subjective and objective quality of a video. An experiment result indicates that the method, compared with an HEVC standard code rate control scheme K0103, reduces the bit rate error by about 0.67%, and improves the peak SNR by about 0.44dB.

Description

technical field [0001] The invention relates to the problem of video coding code rate control in the field of image communication, in particular to an inter-frame code rate control algorithm of the new generation of high-definition video coding standard HEVC. Background technique [0002] In recent years, with the continuous emergence of high-definition and ultra-high-definition videos, the original video coding standard H.264 / AVC has gradually failed to meet people's requirements for video quality. In order to solve this problem, VCEG and MPEG formed the Joint Video Coding Team (JCT-VC) to jointly formulate a new generation of video coding standard - HEVC. Due to the addition of new coding technologies in many modules, HEVC doubles the compression efficiency compared to H.264 while ensuring the same video quality. [0003] Although the compression efficiency of HEVC has been greatly improved, the channel bandwidth is still difficult to meet in the existing real-time video ...

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Problems solved by technology

[0006] Aiming at the problem that the HEVC code rate control process of the new generation video compression coding standard cannot quickly adapt to the set bandwidth and the coding complexity is inconsistent with HVS (Human Visual System), the present invention proposes a Sobel operator and linear regression based High-definition video coding rate control algorithm, which greatly reduces the bit rate error, effectively reduces the delay, and improves the subjective and objective quality of the video. It has a good application prospect in the real-time coding transmission process with limited bandwidth.

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