This disclosure describes rate control techniques that can improve video coding based on a “two-pass” approach. The first pass codes a video sequence using a first set of quantization parameters (QPs) for the purpose of estimating rate-distortion characteristics of the video sequence based on the statistic of the first pass. A second set of QPs can then be defined for a second coding pass. The estimated rate-distortion characteristics of the first pass are used to select Qps for the second pass in a manner that minimizes quality fluctuation between the frames of the video sequence. Furthermore, selection of the second set of QPs may also substantially maximize quality of the frames at the substantially minimized quality flucuation in order to achieve low average frame distortion with the minimized quality fluctuation.