Using FFmpegKit in Commercial Applications - tanersener/ffmpeg-kit GitHub Wiki

In order to use FFmpegKit in commercial applications, there are two things that must be considered.

The following conditions must be met based on the platform and the version you're using in your application.

	Android	Apple (iOS, macOS, tvOS)
v4.5.1 >=	dynamic/shared library	dynamic/shared library
< v4.5.1	dynamic/shared library	static library

Dynamic LGPL libraries of FFmpegKit can be used in a commercial applications. In this using scheme, commercial application will have its own license and FFmpegKit will be licensed under LGPL v3.0. The most important part of this scheme is, users of commercial application should be able to and allowed to replace FFmpegKit library with another version. It can be hard to achieve that in Apple App Store and Google Play Store, so be aware of this situation.
When static LGPL libraries are used there are two options. Either publishing commercial application source code under LGPL v3.0 or providing commercial application in an object (not necessarily source) format, so that a user has the opportunity to modify the LGPL library and relink the commercial application. Most developers find it hard to provide an application in an object format to allow relinking, so they prefer providing source code of their application.
When GPL libraries are used, either dynamic or static, commercial application will be licensed under GPL, all conditions defined by GPL v3.0 must be met. This means you must make the source code available to the users of your commercial application as described in the GPL, and they must be allowed to redistribute and modify it as described in the GPL.

Refer to Patents wiki page.