How to have an RPM replace another in the SPEC file?

[uncholowapo]

Say that I just built an RPM for ffmpeg-mt (multithreaded version) along with the components like the -devel packages and would like them to replace the current ffmpeg on my system while still having the system recognize it as ffmpeg, how would I write that in the spec file? I know Arch Linux uses the variable "Provides" to make the system recognize a custom package from AUR as a regular one from the default repos.

Any help would be great.