Debian packages

Debian packages are available in the official repositories. You can check the Kdenlive packages versions here:
Debian packages are available for the following architectures: [alpha] [amd64] [arm] [armel] [hppa] [hurd-i386] [i386] [ia64] [kfreebsd-i386] [kfreebsd-amd64] [m68k] [mips] [mipsel] [powerpc] [s390] [sparc]:

To install Kdenlive packages from Debian repositories.

As root, type:

apt-get install kdenlive frei0r-plugins dvgrab recordmydesktop dvdauthor mkisofs

Upgrade to Debian Unstable

The last released version of Kdenlive is usually available within 10 days in Debian testing, but if you really want to get Kdenlive's current development version, you might want to upgrade to Debian unstable. Be aware that this is for experienced users only and might break parts of your system that are currently working. In Debian terminology, the word unstable indicates that packages are not yet in a stable release. You may experience problems with some recent packages. Make sure you understand what you are doing.

Under root account, add the following lines to /etc/apt/sources.list:

deb-src unstable main contrib non-free
deb unstable main contrib non-free

You may select mirrors in your country for faster download. 

To upgrade to Debian unstable, as root type:

apt-get update;
apt-get dist-upgrade

Debian multimedia packages

Do NOT use the repository. The domain has now been bought by a untrusted source, please remove it from your apt list!