Patent ID: 11902533
Assignee: ZHEJIANG UNIVIEW TECHNOLOGIES CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 18:
19. The bit rate control apparatus according to claim 11, wherein a method of performing prediction on a macroblock of the image to be encoded to obtain an optimal macroblock prediction mode by the prediction module comprises:
performing traversal of modes of prediction of the macroblock;
comparing rate distortion cost values corresponding to the respective prediction modes, and selecting the optimal prediction mode; and
wherein the macroblock is predicted using following formula:

D1=D0−(X*MyD+Y)

where D1 is an updated distortion value, D0 is a distortion value which has not been updated, X and Y are preset constants, and MyD represents a distortion tolerance of each macroblock;
calculated distortion value D1 is substituted into a current standard rate distortion function:

J=D1+λ*R 

where J is a rate distortion cost, λ is a Lagrangian parameter, and R is an encoding bit rate.