The libavif command-line tools packaged for Windows x64 .NET applications.
dotnet add package Soenneker.Libavif.Windows
The package copies avifenc.exe, avifdec.exe, and avifgainmaputil.exe beneath the application output directory:
Resources/win-x64/libavif/
Resolve that directory from AppContext.BaseDirectory; do not depend on the process working directory. This package contains Windows x64 binaries only and does not select a binary for other operating systems or architectures.
Most applications should reference Soenneker.Libavif.Util, which selects and invokes the matching platform tool. Reference this package directly when you need the native assets without the managed wrapper.
The binaries come from AOMediaCodec/libavif. The upstream license and source information are included with the runtime.