In wireless multicast multimedia streaming, every data block (i.e., a group of packets) needs to be delivered within a hard deadline. On the other hand, to provide multilevel services, the widely adopted scalable video coding (SVC) prioritizes a video bit stream into a base layer and several enhancement layers. In this paper, we combine SVC with the transmission delay constraint and focus on multicasting hard deadline constrained prioritized (HDCP) data over wireless erasure channels. Specifically, we first define the performance metric and formulate the optimization problem. Then, we focus on a new adaptive RNC encoding and scheduling scheme to maximize the effective network throughput. Particularly, we propose simple and efficient greedy scheduling technique, which not only obtains near-optimal performance with low-time complexity but also suits time-varying fading channels. In addition, we extend our discussion to the more practical scenario with erroneous feedback and propose sampling-based feedback mechanism to reduce the system overhead. Both analytical and simulation results are provided to corroborate the effectiveness of the proposed techniques.