according to the changelog for opus 1.1.3 on http://www.opus-codec.org/downloads/ this version supports ambisonics encoding. Could we add an ambisonics keyword and enable that switch? Ambisonics is a popular, royalty free surround sound format in the linux audio world.
commit 525f7c18f51bb809d7dc01bebcb041d13c66cc02 Author: Alexis Ballier <aballier@gentoo.org> Date: Thu Sep 22 11:52:24 2016 +0200 media-libs/opus: add (experimental) ambisonics support (bug #594030) please note that, as i understood, since the format is not finalized you have no guarantee that ambisonics streams produced by 1.1.3 will be compatible with future versions.