Code rate control method for AVS secondary encode based on scene

Abstract

The invention relates to a control method for AVS secondary encoding bit rate based on scene. The invention discloses a control method for AVS secondary encoding bit rate based on scene to ensure the stability of the video image reconstructed by coding and avoid mosaic appearance during violent movement and scene changes. The main points of the technical plan of the control method are that: a. a first coding is performed to a video sequence to complete scene detection and relevant statistics; b. a second coding is performed, and if the scene is changed, c step is carried out, otherwise d step is carried out; c. target bit allocation is performed to the newly divided image group layer, the average bit rate of the scene is estimated and the initial QP of each image group is calculated; d. target bit allocation is performed according to the characteristics of each frame and the bit rate of the frame is estimated; e. the occupation value and the underflow value of a buffer are updated. The control method has the advantages that, according to the relevant statistics of the video sequence, coding bits are dynamically allocated to different frames, and mosaic appearance is avoided; the control method is suitable for the coding of video signals.

Description

technical field [0001] The invention relates to video signal processing technology, in particular to a scene-based AVS secondary encoding code rate control method. Background technique [0002] Digital audio and video coding technology standard AVS is the first second-generation digital audio and video coding and decoding standard with independent intellectual property rights in my country. Its coding efficiency and competitiveness are equivalent to the international standard H.264 / AVC and twice that of MPEG-2 above. AVS is a common basic standard of the digital audio and video industry, which represents the current international advanced level. [0003] Rate control is one of the important technologies of video coding, and its ultimate goal is to transmit high-quality video sequences with limited buffer capacity and channel bandwidth. At present, the AVS coding standard adopts the rate control technology of H.264 / AVC, which is the JVT-G012 rate control method proposed by L...

AI Technical Summary

Problems solved by technology

However, when this method processes images with severe motion or scene switching, the MAD value of the current frame and the QP (quantization parameter) prediction are inaccurate because the MAD value of the basic unit at the same position in the previous frame is used to linearly predict the MAD value of the current basic unit. Defects, and because the code rate is evenly allocated to the entire sequence during the encoding process, the image quality of severe motion or scene switching drops sharply, resulting in large fluctuations in the reconstructed image quality of video encoding

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