Determining the path that a yum package installed to

Not in Linux at the moment, so can't double check, but I think it's:

rpm -ql ffmpeg

That should list all the files installed as part of the ffmpeg package.

yum uses RPM, so the following command will list the contents of the installed package:

$ rpm -ql package-name

I don't know about yum, but rpm -ql will list the files in a particular .rpm file. If you can find the package file on your system you should be good to go.