One thing you can do with video in Lightroom is to create a page frame from the video and process that .jpg file in the Develop module as you would any other, then select the page frame AND the video (with the frame as the 'most' selected) and use the 'Sync' button. This gives you access to Develop settings in LR that wouldn't otherwise be available for videos. Trimming, etc. is easily done in the Library module.
Mike.