apt - ffmpeg installation, kubuntu utopic unicorn

I haven't found any utopic unicorn ffmeg repositories, so I am trying to install it from https://launchpad.net/~jon-severinsson/+archive/ffmpeg by changing version from utopic to trusty in /etc/apt/sources.list.
However, when I do that, I get the following error

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:

ffmpeg :

Depends: libavcodec54 (>= 7:1.2.5~) but 6:9.11-2ubuntu3 is to be installed or

               libavcodec-extra-54 (>= 7:1.2.5~) but it is not going to be 

installed

      Depends: libavdevice53 (>= 7:1.2.5~) but it is not going to be installed

      Depends: libavfilter3 (>= 7:1.2.5~) but it is not going to be installed


      Depends: libavformat54 (>= 7:1.2.5~) but 6:9.11-2ubuntu3 is to be installed

E: Unable to correct problems, you have held broken packages.

I suppose that's because of version difference and not sure, what to do.

Do I have to search for those libraries and add more repositories, or is there are some simple way to do this?

I think the Problem is, that Ubuntu is changing/changed from ffmpeg to avconv. One possible solution is that you install ffmpeg from their homepage