a simple .net wraper for https://github.com/AOMediaCodec/libavif
the native win-x64 libMiAvifJpgWraper.dll must be added manually to the project
using AvifLoaderNET;
ImageSource imgSrc = AvifLoader.AvifToImageSource("input.avif"); //uses the rgb pixels data
byte[] _ = AvifLoader.AvifToJpeg("input.avif"); //converts to jpeg
File.WriteAllBytes("output.jpg", _);