Curlew is an easy to use, Free and Open-Source Multimedia converter for Linux.
Darktable
Easy to use and elegant Multimedia converter.
ตัวแปลงเสียง
soundKonverter is a frontend to various audio converters.
DeaDBeeF
DeaDBeeF lets you play variety of audio formats, convert between them, customize the UI almost any way you want, and use many additional plugins which can extend it even more.
สีฟ้า
The ciano is a multimedia converter for all the format you need.