mp3 is (royalty) free now, patent expired.

[PoBoy]

https://www.iis.fraunhofer.de/en/ff/amm/prod/audiocodec/audiocodecs/mp3.html

On April 23, 2017, Technicolor's mp3 licensing program for certain mp3 related patents and software of Technicolor and Fraunhofer IIS has been terminated.

EDIT :
https://en.wikipedia.org/wiki/MP3#Licensing.2C_ownership_and_legislation

The basic MP3 decoding and encoding technology is patent-free in the European Union, all patents having expired there by 2012 at the latest. In the United States, the technology became substantially patent-free on 16 April 2017 (see below).

 

[mk76]

Where will it benefit ?

 

[6pack]

Where will it benefit ?

mobile phones (required license to distribute the plugin), linux distros, windows os (windows media player), android boxes, mp3 players etc.
Lot of the linux distros did not have the mp3 and other audio video plugins installed by default due to such patent laws.