VirtualDub is a fast, flexible video capture and processing tool.
The program first helps you get video into your PC, from a capture card, video camera, any Video for Windows-compatible device. You get complete control over frame rates, video formats, video and audio compression methods, and more. Real-time noise reduction then ensures the best possible picture quality, while an integrated volume meter and histogram makes it easy to monitor your input levels,
And if you already have a video clip to hand (AVI format, preferably) then VirtualDub will allow you to process it many useful ways. You're able to remove segments of a video, for instance, then save the rest, without re-encoding. The program can save the soundtrack from a clip, or replace it without affecting the video. And VirtualDub comes with 39 powerful filters for processing some or all of your movie in various ways: resizing, tweaking brightness or contrast, deinterlacing, rotating, sharpening or smoothing are just a few of the options on offer.
Alternatively, you can simply re-encode a clip, perhaps to reduce its size for internet downloads, tweaking frame size, frame rate, colour depth, compression algorithm, and more. This can take a while with large movies, but then all video processing tools place a heavy demand on your system resources, and on balance VirtualDub probably works quicker than most.
The sheer weight of features is a little intimidating at first, but it's worth persevering - VirtualDub is probably the best free video processing tool around