avisynth denoise filter applied only from frame x to frame y

[codemaster]

I want to know if it is possible, in avisynth, to apply a denoise filter for minimal noise, only from frame 650 to 1610, and to apply another denoise filter for medium noise, skipping all frames between 650 and 1610.

Also, a short avisynth script example would be excelent.

[poisondeathray]

Several ways to do it, but one of the easiest is to use trim()

a=whateversource("video.ext")

a
someminimalfilter()
minimal=last

a
mediumfilter()
medium=last

medium.trim(0,649) ++ minimal.trim(650,1610) ++ medium.trim(1611,0)

Other ways include remapframes() (so you remap frames from a heavy filtered version into light filtered) , clipclop, ApplyRange() - apply filter to range of frames