flv video file format :
FLV (Flash Video) is a proprietary file format used to deliver video over the Internet using Adobe Flash Player (formerly known as Macromedia Flash Player) version 6, 7, 8, or 9. FLV content may also be embedded within SWF files. Notable users of the FLV format include YouTube, Google Video, Reuters.com Yahoo! Video and MySpace.
Best way to cut/trim/split flv file :
GiliSoft Video Editor — Cut/trim/split flv file.
1) Launch GiliSoft Video Editor
Once installed GiliSoft Video Editor, Launch GiliSoft Video Editor.
2) Select one way to cut flv file
There are 3 ways to cut flv file in the easy video editing software:
a) Easy Video/Audio Cutter - Cut one flv file to several small flv clips.
b) Batch
Video/Audio Cutter - Cut wanted flv clips from a lot of flv files.
c) Advanced Video/Audio Cutter - Cut wanted flv clip after video editing(added watermark,subtile...)
3) Load File
Click 'Add File(s)' button, Select "FLV - Flash Video(.flv)" in its "Files of type" combo box.
Add your flv file, GiliSoft Video Editor will preview your flv file directly.
4) Select Start time, and End time.
5) Click 'Start' button to start to cut your flv file.
GiliSoft Video Editor is very powerful flv Splitter and flv Cutter, split flv, cut flv without re-encode, So It is very fast and without any quality loss.