Patent ID: 8483272

Claim:
A method, comprising: in a video compression process, performing bit rate control by determining an initial quantization parameter QP init for a frame based on the type of frame and a quantization parameter QP previous of frame a previous frame of the same type; adapting QP init to form an adapted quantization parameter QP adapt based on fullness of a hypothetical reference decoder (HRD) buffer, and on a local rate ratio of an instant bit rate to a target bit rate; controlling QP adapt to form a final quantization parameter OP final based on the type of frame; and compressing the frame using QP final , wherein the frame is encoded according to the MPEG2 standard, and said determining of QP init comprises: calculating ⁢ ⁢ QP init = alpha * QP previous_I ⁢ _frame + beta * QP previous_P ⁢ _frame + gamma * QP previous_B ⁢ _frame where alpha+beta+gamma=1, where each ≧0, QP previous — I — frame is the quantization parameter of most recent I frame, QP previous — P — frame is the quantization parameter of the most recent P frame, and QP previous — B — frame is the quantization parameter of the most recent B frame.