ConvertFPS: Why is switch mode enforced?

[LigH]

I'd like to use ConvertFPS to make a very soft blended time lapse effect. Unfortunately I can't, because ConvertFPS forces me to use the "switch mode" above a certain relation between original and target framerate.

Why is it so much enforced? I am certain I want "blend mode", I know its side effects - they are just what I want to get. Why can't I override the threshold?

And if you will definitely never consider to change the behaviour of ConvertFPS again ... are there any alternative plugins resembling the behaviour of its blend mode also for frame rate relations larger than 2/3 (e.g. exactly 1/2 - like 50p to 25p)?

[GodofaGap]

Perhaps you could interlace the footage and then use a deinterlacer in blend mode?


SomeSource().Assumetff
Separatefields.Selectevery(4,0,3).Weave
Smoothdeinterlace(blend=true)

[Didée]

For exactly 1/2 rate like 50p > 25p, there are the obvious alternatives "Merge(SelectEven,SelectOdd)" , or TemporalSoften(1,255,255,255,2).Merge(last,0.25).SelectEven()". ;)

For arbitrary rate changes, BlendFPS() comes to the rescue. It's in motion.dll by mg262, does what ConvertFPS does (just without any limitations), and even has the optional "aperture" parameter in case that it's needed. :)

[Gavino]

I'd like to use ConvertFPS to make a very soft blended time lapse effect. Unfortunately I can't, because ConvertFPS forces me to use the "switch mode" above a certain relation between original and target framerate.
Why is it so much enforced?
According to the wiki (http://avisynth.org/mediawiki/ConvertFPS), this is to avoid frame skipping.

It makes sense to have a lower limit on the target fps, because ConvertFPS works by blending (at most) two source frames together.

However, it seems to me that the limit should be half the source rate, rather than two-thirds. Going below half-rate requires blending more than two frames to get the right effect. Between a half and two-thirds, it's true that some source frames will appear with less than 50% weight, but no frames will be entirely lost.

[LigH]

For arbitrary rate changes, BlendFPS() comes to the rescue. It's in motion.dll by mg262 ...

:thanks: Long live WarpEnterprises!
...

There is even a "BlendWeight"?! -- Ah, that's about the "opposite", a blending analyser.