libmp3lame-dev software package provides MP3 encoding library (development), 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 libmp3lame-dev
libmp3lame-dev is installed in your system.
Make ensure the libmp3lame-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libmp3lame-dev *
You will get with libmp3lame-dev package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Library development |
| Package | libmp3lame-dev |
| Version | 3.99.5+repack1-3ubuntu1 |
| Description | MP3 encoding library (development) |
| Sub Section | libdevel |