Opus

opus	This is an audio codec. The name to use at the command line is opus. This codec can be used inside the ogg containers.

Opus is a general-purpose high-quality low-latency lossy audio codec created by the Xiph.org Foundation. The Opus developers claim it makes other lossy audio codecs obsolete (including Vorbis and MP3) and recommend it over Speex as a speech codec.

Source code

• modules/codec/opus.c