WinFF is a graphical front end for the free video conversion tool, FFmpeg, which aims to help you convert movie clips from one format to another.
At its most basic, the program works much like most similar applications. You can add videos in just about every possible format. The program comes with a lengthy list of output profiles: Audio, AVI, Blackberry, Creative ZEN, DV, DVD, Google, Google-Android, iPod-iTunes, LG, Mobile Phones, MP4, Nokia, PS3, PSP, QuickTime, Websites, WMV and more. And each of these contains a further set of presets to help define the video's resolution, aspect ratio, codec and more.
Click the "Options" button, though, and further tabs appear where you can more specifically define exactly what you need. You're able to set your video bitrate, frame rate, resolution and aspect ratio; the audio bitrate, sample rate, channels and volume; and you can even crop the video, which can sometimes be a useful way to reduce file size.
But the real power here comes from WinFF's close linking to FFmpeg, so if you want to write a new preset, or include support for any other FFmpeg feature you like, then you can probably do so.
This isn't for beginners, of course. This preset, for example, is simpler than most:
-vcodec xvid -vtag dx50 -s 640x480 -aspect 4:3 -maxrate 3000k -b 1050k -qmin 3 -qmax 5 -bufsize 300000 -bf 1 -i_qoffset 150 -b_qoffset 150 -g 300 -acodec mp3 -ar 44100 -ab 320k -ac 2
If you're knowledgeable about video, though, you can probably look at that and already understand what some of it means. So if you need more flexibility than you currently get from the standard video conversion tools, a little time spent researching the possibilities of WinFF just might pay off.
While the core WinFF program isn't that powerful or easy to use, it is very customisable (though you might spend quite some time figuring out the fine details)