Patent ID: 8451891

Claim:
A rate control method per block for a video encoder, the method comprising: estimating an average bit rate of a block; and determining a variation of a quantization coefficient such that an objective function based on the difference between an objective bit rate and the estimated average bit rate is minimized, wherein, in said estimating the average bit rate of the block, the average bit rate is estimated by a long term prediction, wherein, in said estimating the average bit rate of the block, the long term prediction is performed by using a Kalman filter, wherein, in said estimating the average bit rate of the block, the Kalman filter is acquired by the following Equation: x ^ ⁡ ( t + 1 ) = x ^ ⁡ ( t ) + 1 t + 1 ⁢ ( y ⁡ ( t ) - x ^ ⁡ ( t ) ) x ^ ⁡ ( 0 ) = 0 where {circumflex over (x)}(t) is an estimated average bit rate of t th block by the long term prediction, and y(t) is a measured generation bit rate of t th block.