aften software package provides audio AC3 encoder, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install aften
aften is installed in your system.
Make ensure the aften package were installed using the commands given below,
$ sudo dpkg-query -l | grep aften *
You will get with aften package name, version, architecture and description in a table
| Distro | Ubuntu 12 04 lts precise pangolin |
| Section | Sound |
| Package | aften |
| Version | 0.0.8+git20100105-0ubuntu2 |
| Description | audio AC3 encoder |
| Sub Section | Sound |