YTD Video Downloader is a great little piece of freeware for downloading and converting video...if you can ignore the aggressive upselling and multiple browser add-on bundling offers. It quickly downloads video from YouTube, Vimeo, Blip.tv, Vevo, and more than 60 other supported video sites, converts video to the standard formats for iPad, iPhone and PSP (MP4); iPod (MOV); cell phone (3GP); Windows Media Video (WMV); Xvid MPEG-4 (AVI) and MPEG Audio Layer 3 (MP3), and also plays back videos in a very basic player.
YTD Video Downloader automatically loads whatever URL you've got saved to your primary clipboard, saving you the trouble of hitting Ctrl-V (and also possibly embarrassing yourself with an accidentally exposed URL). Hitting Download starts automatically transferring the MP4 file to the customizable "Save to" location, but the entire bottom half of the interface is dedicated to promoting the Pro version (along with a large, red Upgrade Now button at the top of the interface).
Multiple files in the Activity tab can be sorted by any of the columns -- Size, Progress, Speed, Status, and ETA -- and the columns can be resized, but the columns can't be reordered or removed, and it's odd that the entire interface doesn't resize or go full-screen. Thus, if a video fails, it's difficult to read what comes after "Failure (6) ..." in the space allotted.
The player works by loading a specific directory on your machine, then listing all of the supported videos it can show. Double-clicking loads the video with a very basic set of player controls -- play/pause, full-screen, volume -- that are familiar to anyone who's ever used any online video service. It's about as bare-bones as a video player can get, but it works fine.
There's no built-in program help for YTD Video Downloader, but the app links to the helpful Web site. One nice addition for power users is support for the open-source FFmpeg media framework for converting files using a large range of customizable parameters. The Web site also provides command-line examples for less experienced users who want to dip their toes into manual conversion.
YTD Video Downloader does what it says on the tin, and does it quickly. It's also regularly updated to account for changes in the various video service platforms. If you don't mind the additional software bundling and aggressive promotion for the Pro version, it's a powerful, lightweight, and free tool for saving streaming video for later viewing.