FFmpeg

FFmpeg is a cross platform, free, open source media encoder/decoder toolkit. It contains the programs and libraries necessary to convert audio and video into a wide range of formats. FFmpeg was written by Fabrice Bellard (creator of QEMU and BPG).

USE flags
Some packages know the  USE flag for enabling ffmpeg/libav-based audio/video codec support.

The above list is non-comprehensive. Use (part of ) to see all available flags:

Emerge
If not already pulled in as a dependency of other packages, and after setting appropriate USE flags, FFmpeg:

Configuration
This section needs some help.

Media player (ffplay)
If built with USE=, a command line media player called is available.

For more information consult the following commands:

External resources

 * https://gentoo.org/support/news-items/2015-04-16-ffmpeg-default.html
 * FFmpeg Wiki
 * [HOWTO using ffplay as your default player for audio/video]