A computing system creates and stores semantic metadata on content, such as videos, that enables efficient searching of the content. The existing metadata of a video file, for example, is examined and a keyword list is created. The processes used to derive the keyword list may depend on the type and format of the existing metadata. The keywords from the list are compared against external structured knowledge data sources that are topic oriented. Based on these comparisons and the matches found, semantic data, including topic, topic type, and attribute data are inserted into a topic table. This uniform and structured table is stored on the computing system and is efficiently searchable for finding relevant videos and for finding relationships between videos.