Nowadays multimedia applications surround our life. The relevant technologies of multimedia have been widely used anywhere, e.g. education, medicine, research, transportation and recreation, as long as people who has a mobile device. The computing ability of mobile device is growing rapidly, but it still has its limitations. One of significant influence on most mobile devices is the active time of them depend on the capacity of battery. Multimedia may make battery runs out quickly because it usually carries a large amount of information and data so that it leads to a great quantity of calculation and bandwidth requirement. In order to alleviate the computation amount of mobile devices, we propose an adaptive cloud-based multimedia conversion system to eliminate energy consumption and unnecessary occupancy on bandwidth in accordance with the capability and network state of users’ mobile devices. Then we propose a Simulated Annealing-based algorithm to solve the optimization problem of scheduling for a multi-user environment.