What excites me about Kdenlive is that it gives me a non-linear video editor (KDE NLVE, see?) without the licensing or platform hassles of commercial software.
The only catch is that you need the video codec (coder/decoder) libraries to be able to import and export video and audio formats of various types, and these are often encumbered by software patents that make them awkward to legally distribute across political borders. (Sigh.)
Upon attempting to render (Project > Render) a video to the "standard" MPEG-4 encoding (MP4-H264/AAC), Kdenlive shows me the following message:
Unsupported video codec: libx264
Thankfully, longtime Slackware contributer Eric Hameleers (slackware.com), aka "Alien Bob", has us covered with a pre-made build of FFmpeg (wikipedia.org), the all-in-one video library and CLI tool originally written by the programming beast, Fabrice Bellard (bellard.org).
Here is Alien’s FFmpeg package collection:
Just select the build that is right for you (e.g. 64-bit, Slackware 15.0) and download the *.txz file.
Install as root:
$ sudo -i # installpkg ffmpeg...txz
Restart Kdenlive and now H.264 video is available for rendering. Yahoo!