Combined rate control and mode decision optimization for MPEG-2 transcoding with spatial resolution reduction

This paper presents a new algorithm for MPEG-2 transcoding with spatial resolution reduction. The proposed method combines rate control and mode decision to achieve optimal transcoding performance using Lagrange multiplier algorithm. Since the proposed method incorporates motion vector mapping and mode decision into a single Lagrange multiplier formula, by minimizing the Lagrangian cost function, the optimal solution for mode decision can be obtained. The proposed transcoding scheme has demonstrated better subjective and objective results compared with other methods.