San Diego-based VMIX, a provider of software used by web sites to manage online video publishing, said Thursday that the firm has inked a deal with television broadcasting firm Post-Newsweek Stations. VMIX said that Post-Newsweek--a division of the Washington Post Company--will use the firm's video platform for its stations, WDIV Detroit, DPRC Houston, WPLG Miami, WKMG Orlando, KSAT San Antonio, WJXT Jacksonville, and a weather site www.justweather.com. Financial impact of the deal was not disclosed.