A multi-level error protection technique for H.264/AVC video bitstreams structured by Group of Pictures (GOP) is proposed. Protection levels are determined by motion energy, which considers displacements of all macroblocks between consecutive frames. Lagrange polynomial is applied in predicting motion energy of a GOP, which is derived from previous GOPs having a high correlation with each other. The optimum number of previous GOPs is selected in order to obtain a good motion energy estimation of the current one. Conducted analyses and simulation results show that video performance obtained by the proposed technique outperforms other motion activity-based Unequal Error Protection (UEP) techniques, while a similar channel code rate is applied.