Cine Encoder is an application that allow to convert media files while preserving HDR metadata.
Videomasse
It is a FLOSS, powerful, multitasking and cross-platform graphical user interface (GUI) for FFmpeg and yt-dlp.
MystiQ
Benutzerfreundlicher und eleganter Multimedia-Konverter.
HandBrake
HandBrake ist ein Open-Source-Videotranscoder.
Ciano
The ciano is a multimedia converter for all the format you need.