I share my slackbuilds to install kdenlive 0.7.7.1 on slackware 13.1
here -> http://thewhitebird.org/pub/
-First copy the text and paste in lame.slackbuild new file.
-Then execute the slackbuil
-Install the package
-Idem to xvid, ffmpeg, mlt then kdenlive. the order is very important !