DaVinci Resolve 14, or Beta 15 are free. You can get it here: https://www.blackmagicdesign.com/produc ... ciresolve/
I just downloaded and installed it myself but haven't tried doing anything with it. There's a learning curve as with any new software. However, for doing basic scene detection or splitting, it might be relatively easy to do. When you click on the download button, the two options on the left are the free versions.