This paper presents a novel scheme for video transmission over error-prone networks. The proposed scheme exploits the error resilient features of H.264/AVC and employs an unequal error protection (UEP) approach to protect effectively the streams. A novel algorithm is proposed to classify macroblocks into slice groups using the explicit mode of Flexible Macroblock Ordering (FMO). A rate distortion optimized algorithm is used to assign unequal amounts of FEC protection to the resulting slice groups according to their importance. In addition, a Converged Motion Estimation (CME) is proposed to further improve the proposed UEP scheme. The idea behind the CME is to make the macroblocks be referenced in a skewed manner, such that highly important macroblocks are converged on only a few and the use of redundancy for error protection is efficient. Simulation results show the superiority of the proposed method over other approaches for transmission of H.264/AVC streams.