What do you mean? Both FLAC and WavPack claim to be patent-free.

ksec · on Sept 15, 2022

I am not aware of FLAC claims to be patent free ( when it started ), it may be royalty free and patent free now given it has been 20+ years since 1.0. They do however claims they dont hold any patent on it.

WavePack was specifically designed to be Patent Free, or using old and expired Patent techniques.