Here you can download DirectShow codecs which can be used for RADIO Player Pro to play MP3 and other files.

Collection of DirectShow filters, and tools. Codecs are needed for encoding audio and video formats.
Homepage: http://sourceforge.net/projects/ffdshow-tryout/

Download: ffdshow_rev4533_20140929_clsid.exe

DirectShow filters for OGG, FLAC.
Homepage: https://xiph.org/dshow/downloads/

Download: opencodecs_0.85.17777.exe

Collection of DirectShow filters, and tools. Codecs are needed for encoding audio and video formats.
Homepage: http://www.codecguide.com/download_k-lite_codec_pack_mega.htm

Download: K-Lite_Codec_Pack_1085_Mega.exe

DirectShow codecs for various file types.
Homepage: http://www.free-codecs.com/