In order control manner and device null each one of the rate deformation trade-off due to the mode

摘要

PROBLEM TO BE SOLVED: To provide a method for control of code amount and distortion tradeoff.;SOLUTION: A method and an apparatus for control of rate-distortion tradeoff by mode selection in video encoders are disclosed. The system of the present invention first selects a distortion value D near a desired distortion value. Next, the system determines a quantizer value Q using the selected distortion value D. The system then calculates a Lagrange multiplier λ using the quantizer value Q. Using the selected Lagrange multiplier λ and quantizer value Q, the system begins encoding pixel blocks. If the system detects a potential buffer overflow, then the system will increase the Lagrange multiplier λ. If the Lagrange multiplier λ exceeds a maximum λ threshold, then the system will increase the quantizer value Q. If the system detects a potential buffer under-flow, then the system will decrease the Lagrange multiplier λ. If the Lagrange multiplier λ falls below a minimum λ threshold, then the system will decrease the quantizer value Q.;COPYRIGHT: (C)2008,JPO&INPIT