Oracle Corp. said it is proposing a specification for broadcasting video over the Internet, a move to enter a market where Microsoft Corp. has made significant investments. The database software maker said the specification will help convert video and sound into a compressed digital form for delivery on personal computers. The specification establishes the Redwood Shores-based company's presence in the nascent online broadcasting market, in which Microsoft has made significant investments, including an acquisition last week of video-streaming start-up VXtreme Inc. and a 10% stake in closely held Progressive Networks Inc. Video streaming produces images that move smoothly rather than with the jerky motion typically seen on computers. Lawrence Mann, director of product management for Oracle video products, said its encoding standard is intended to simplify adding video to users' software. Oracle will release an updated version of its video server product, which incorporates this standard and allows users to access and store video, this fall. Oracle shares closed down 38 cents at $57 on Nasdaq.