slackbuilds/audio/soundconverter/README

SoundConverter is the leading audio file converter for the GNOME
Desktop.  It reads anything GStreamer can read (Ogg Vorbis, AAC, MP3,
FLAC, WAV, AVI, MPEG, MOV, M4A, AC3, DTS, ALAC, MPC, Shorten, APE, SID,
MOD, XM, S3M, etc...), and writes to Opus, Ogg Vorbis, FLAC, WAV, AAC,
and MP3 files, or use any GNOME Audio Profile. SoundConverter aims to
be simple to use and very fast. Thanks to its multithreaded design, it
will use as many cores as possible to speed up the conversion. It can
also extract the audio from videos.

Optional dependencies for more audio support are gst0-plugins-ugly 
and gst0-ffmpeg.