phonon-backend-gstreamer1.0-co software package provides transitional package, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install phonon-backend-gstreamer1.0-co
phonon-backend-gstreamer1.0-co is installed in your system.
Make ensure the phonon-backend-gstreamer1.0-co package were installed using the commands given below,
$ sudo dpkg-query -l | grep phonon-backend-gstreamer1.0-co*
You will get with phonon-backend-gstreamer1.0-co package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Sound |
| Package | phonon-backend-gstreamer1.0-co |
| Version | 4:4.7.1+git20140403-0ubuntu1 |
| Description | transitional package |
| Sub Section | Sound |