From Ben Bird:
BTV is an application for the Macintosh that allows you to easily view and capture video. It works with any Macintosh compatible video input source such as video input cards, TV cards, built-in video, USB, DV, and FireWire video sources. It works with any Macintosh compatible video input source. View video in a window or full-screen. Capture video to disk as a standard QuickTime movie using custom compression settings. Capture frames of video to disk in many different file formats (PICT, JPEG, TIFF and more). Save captured files to a pre-defined destination with an automatic name. Capture movies to several hard disks in sequence. Multiple monitor support: play video full screen on any monitor attached to your computer. Automatic monitor resolution switching. Channel changing on ixTV and TurboTV tuner cards. AppleScript support. Includes the macgix LiveCam AppleScript to turn BTV into a Webcam application.