How do I install Gstreamer 1.8.3 under Ubuntu 14.04?

[Pete Wassertal]

Hello,
 
I need the current stable Gstreamer release in my Ubuntu 14.04 system. Since I can't find a source to install pre-built packages via apt I try to build everything from source. Currently I have a working 1.6.3 installation.
 
Here is what I do:
 
I get:
gst-plugins-base-1.8.3.tar.xz, gst-libav-1.8.3.tar.xz, gstreamer-1.8.3.tar.xz, gst-plugins-good-1.8.3.tar.xz, gst-plugins-bad-1.8.3.tar.xz, gst-plugins-ugly-1.8.3.tar.xz
from https://gstreamer.freedesktop.org/src/
and unpack them.

I'm building the packages in the order gstreamer - plugins-base - libav - plugins-good - plugins-bad - plugins-ugly
with the following commands: 
./autogen.sh; make; sudo make install

Everything works without error messages.

When everything is done I try to verify the installed version:
$ gst-launch-1.0 --version
and I get the answer:
gst-launch-1.0 version 1.8.3
GStreamer 1.6.3
Unknown package origin

1.6.3 still seems to be active!

The next check:
dpkg -l | grep gstreamer
shows 1.6.3 versions of all relevant packages too.

I'm doing this because I need the nvenc element, which isn't available according to gst-inspect after doing this (logs seem to indicate that they were built correctly).


What am I doing wrong? Are pre-built packages available somewhere?


Thanks

Pete