Here you go.
Cnr_v261
Got bored and needed something to do
. It should work fine now, and I changed the scene change detection to a more straight forward approach. It works how scene change detection works in temporalsoften, (i.e. percentage of total change). Even added the option to consider luma only or both chroma and luma in the decision (previous versions considered both, though both v2.51 and v2.4 were slightly broken in different ways). If there are any problems let me know.
Note: I didn't get permission from the original author, but hopefully it is ok as I doubt this thread would have started if he was still active and able to fix it. Though, if anyone wants me to take the link down I gladly will.