i said that i won't do Opus port, so of course i did it.
this is preliminary release, it works on some Opus files i have (and some i made with ffmpeg). there will be some improvements, but the code is already usable. it decodes mono or stereo ogg/opus streams to interleaved 16-bit pcm.
the code itself was taken from ffmpeg and massaged until it works. no attempts to clean it up or something were made, sorry. ogg parser was written from scratch. you will need my iv.vfs too.
GNU LGPL. good luck, and happy hacking.  http://repo.or.cz/iv.d.git/tree/HEAD:/dopus