I use this one.
http://www.dbpoweramp.com/dmc.htm
Release 10 is free, but Release 11 is a 30-day trial.
You can get Release 10 from here.
http://www.dbpoweramp.com/bin/dMC-r10.exe
And you also need ogg codec.
http://www.dbpoweramp.com/codec-central-ogg.htm