ffmpeg is the only consumer of this libs that causes collisions with libs needed by other packages. Maybe its optional support could be dropped then :/
I think other packages should be ported to libilbc: http://www.ilbcfreeware.org/ states: iLBC is now part of the WebRTC project. Please go to webrtc.org for the latest information about iLBC. This site is kept for historical reference only. media-libs/libilbc's description is: Packaged version of iLBC codec from the WebRTC project
the collision is with dev-libs/ilbc-rfc3951
(In reply to Pacho Ramos from comment #2) > the collision is with dev-libs/ilbc-rfc3951 I understood that: * dev-libs/ilbc-rfc3951 Available versions: 0-r1 Homepage: http://www.ilbcfreeware.org/ Description: iLBC is a speech codec suitable for robust voice communication over IP