Recently there has been a compelling need to support real-time video multicast from a single source to multiple receivers in wireless ad hoc networks. The existing work uses tree-based schemes to perform video multicast. The optimization of those schemes typically requires a centralized computation, which is not suitable for wireless ad hoc networks. In this paper, we propose an optimized video multicast scheme over wireless ad hoc networks. First, we apply a prioritized coding scheme to enable the heterogeneous receivers to reconstruct the video at different quality levels. Then we formulate the video multicasting problem using the network model, the packet loss model, and the video distortion model. To solve the optimization problem, we propose a distributed algorithm to jointly optimize the source rate, the routing scheme, and the power allocation using hierarchical dual decompositions. The distributed nature of the proposed algorithm makes it very appropriate for wireless ad hoc networks. Through extensive simulations, we demonstrate that the proposed video multicast scheme can achieve much higher video quality compared to the uniform-power scheme or the tree-based routing schemes.