Efficient and Reliable MPEG-4 Multicast MAC Protocol for Wireless Networks Multicasting is the transmission of data to a group of nodes identified by a single destination address. Furthermore, multicasting is considered as an appropriate transmission method for multimedia services. Multimedia applications are expected to become more prevalent over mobile ad hoc networks in the near future. Therefore, achieving reliability in multimedia communications is an important task. Video compression technologies are about reducing and removing redundant video data so that a digital video file can be effectively sent over a network. With modern compression standards, such as Moving Picture Expert Group 2 (MPEG-2), MPEG-4, and H.264, which is also known as advanced video coding MPEG-4 part 10, losses of different frames have different impacts on video quality. In this paper, we propose a leader-based reliable multicast medium-access control layer protocol for multimedia applications to enhance video quality. We present a Markov chain model and numerical formulation of our proposed protocol. Simulation results show that our proposed method is better than other protocolsin terms of the number of decodable frames, peak signal-to-noise ratio (PSNR), and video quality.