this is related to porn isn't it
Say you have a UFC fight or maybe a interview on a new show and you just want to take out part of the vid to post or watch? Like when you just post a youtube vid of part of Brock's fight where he is break dancing after getting whacked by Cain.
What format is the video?
Say wmv or something off youtube.
It really can vary depending on which format you are using. You could try something like avidemux: http://www.afterdawn.com/software/audio_video/video_tools/avidemux.cfm