Avidemux is a free video editor designed for simple cutting, filtering and 
encoding tasks. It supports many file types, including AVI, DVD compatible 
MPEG files, MP4 and ASF, using a variety of codecs. Tasks can be automated 
using projects, job queue and powerful scripting capabilities.

If you use qt4 run the script as 'QT4=yes ./avidemux.SlackBuild' 
It will put the qt4 version in the desktop entry.

Requirements (all available at SlackBuilds.org):
  lame, faad2, faac, a52dec, libdca, xvidcore, and x264

Optional Dependencies (also available at SlackBuilds.org):
  qt4, aften, amrnb, jack-audio-connection-kit, libsamplerate