Interesting. As a denoiser before upscaling, renoising is useless.
As a prefilter on HD content... I've encoded with x264 to see the difference in encoding and taken screenshots afterwards. FrameRateConverter is with preset=Normal... preset=Slower just wasn't working with this at all performance-wise.
- RemoveGrain(21) [1.43MB)
- MClean() [1.46MB]
- MClean(rn=5) [1.46MB]
- MClean(rn=10) [1.46MB]
- MClean(rn=10), 16-bit processing [1.57MB]
MClean gives a plastic effect as a prefilter, or perhaps it could work with lower settings, but with rn=10 it looks better than RemoveGrain. Note that there are considerable rounding errors in 8-bit. If I do the whole processing in 16-bit, quality is much better. I think MClean should internally work in 16-bit if the source is 8-bit, otherwise there are rounding differences on subtle details applied several times in a row.
For some reason, I'm unable to convert to 16-bit and back to 8-bit for the prefilter.
Code:
Pref=last.ConvertBits(16).MClean(rn=10).ConvertBits(8, dither=1)
FrameRateConverter(NewNum=60, NewDen=1, Prefilter=Pref)
MRecalculate: wrong pixel type in FrameRateConverter line 145
In terms of performance, this is using MvTools2 which has MT performance issues. With FRC Preset=Normal which uses DCT=0, the encoding won't start at all, it jams, even though MT normally works with DCT=0. With FRC Preset=Slower (non-MT), it drags extremely slowly.