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 statistics 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 distortion of the frames of the video sequence.