US Patent 7961783 Methods and systems for rate control in video encoder

A method of rate control in a video encoder includes performing a first encoding step to encode macroblocks of a current frame by utilizing a first quantization parameter to thereby generate a residual signal for the current frame; estimating a number of header bits for each macroblock mode to thereby estimate a total number of header bits for the current frame; estimating an available number of texture bits according to the total number of header bits for the current frame; determining a second quantization parameter according to the estimated available number of texture bits; and performing a second encoding step to encode the residual signal for the current frame by utilizing the second quantization parameter.