Google is testing an extension of AdSense for ad placement in online videos.

AdSense for Video builds on the foundation laid by the In-Stream Video Ads introduced over a year ago. This execution adds graphical ads and text overlays to advertiser options.

Graphical overlays will appear as semi-transparent layers over the bottom 20 percent of the video. Text overlays display a transparent logo over the video. Ads will be sold on a CPM and CPC basis, respectively.

As with other Google ad formats, ad placement will be determine by the context; in this case, the content of the video. Google Content Network sites, and select YouTube videos, will run them at outset.

20 video sites in the Content Network have partnered with Google to test the format, including Brightcove and Eyespot, which will allow customers to go use Google to sell excess video inventory.