The progressive needs of video streaming for different applications in varied domains have created a new set of heterogeneous environments especially in Virtual Collaborative Environments. In order to get the best performance of such environments, video streaming has to be adapted to the different parameters that characterize these environments, namely: bandwidth, CPU, GPU, screen resolution, etc. In this paper, we define a new Web Service, named Wava (Web Service for Automatic Video Data Flows Adaptation). Wava allows multimedia platforms and collaborative application servers to adjust the adaptation at two levels: at the static level during initialization and at the dynamic level according to the variation of the environment.