This paper introduces a novel on-line video browsing and retrieval platform, so-called OVIDIUS (On-line VIDeo Indexing Universal System). In contrast with traditional and commercial main stream video retrieval platforms, where video content is treated in a more or less monolithic manner (i.e., with global descriptions associated with the whole document), the proposed approach makes it possible to browse and access video content in a finer, per-segment basis. The hierarchical metadata structure exploits the MPEG-7 approach for structural description of video content. The MPEG-7 description schemes have been here enriched with both semantic and content-based metadata. The developed approach shows all its pertinence within a multi-terminal context and in particular for video access from mobile devices. The platform has been recently (February, 2010) validated within the framework of the Médi@TIC French national project