SlackBuildsOrg/multimedia/FFaudioConverter

FFaudioConverter (Graphical audio converter)

is a GUI for converting music or videos to audio files with FFmpeg.

Features:
 * DnD support
 * Multithreading (use the full power of your cpu)
 * Convert many files or whole directories very fast
 * Audio filters possible (bass boost your music or do fade-ins/outs...)
 * Change of samplerate possible
 * High quality resampling with SoX possible
 * Quick mode for copying files in same format and skip already
   converted files

Currently supported output formats are:
 * mp3
 * aac
 * ogg
 * opus
 * flac
 * wav