This week in video search

Google has launched a Web-based video search service that allows people to view content from the company's indexed database of video from Unicef, Greenpeace, CNET Networks (publisher of News.com) and others that have uploaded material since April.

The search engine complements Google's existing site, which lets people search the closed-caption text of, but not yet play back, television shows from PBS, CNN and others that Google has hosted.

The new content is marked by a triangle icon. To use the service, people must download Google Video Viewer. Once they have, they can watch an entire video piece or start viewing at the section that includes their search keywords.

Google's new video search tool is turning out to be a little more expansive than the company had planned, with users uploading copyrighted content ranging from the last "Matrix" movie to the "Family Guy" cartoons. Consumers browsing the service have uncovered links to full versions of feature-length movies, TV shows and other content.

A day after Google released its Video Viewer, a Norwegian programmer tweaked the application to make it play clips that are not on Google's servers. The search giant had restricted the Video Viewer, which is based on the open-source VLC player, to only play back files that are stored on its servers. Jon Johansen, also known as DVD Jon, posted code on his Web site that he said removes that restriction.

A few days later, America Online quietly launched a new video-on-demand search service, opening the doors for millions of Internet users to view music videos, news segments and other content from parent company Time Warner, whose mountain of media holdings give AOL an advantage over rivals Google and Yahoo.

The beta service, called AOL Video, offers free access to search and play more than 15,000 licensed and originally produced video assets from Time Warner, including movies trailers from Warner Brothers, television programs, music videos and news clips from CNN, MSNBC and others.