using filter under conditional argument ( if <condition> then use this_filter

[esby]

I am wondering if this kind of scripting is possible in avs.
I have seen there is an ? identifier that can do the if
but i am wondering if there can be 'filters' (or dll)
that could return a boolean depending of the condition on the frame parsed.

eg : we know that picfix can have a problem with scene change,
introducing color ghosting ( in the best case) and bad macro blocks (in the common case).

if we could have something like that...

!IsSceneChange(clip) ? source = source.antiblink(...)

this function could desactivate the antiblink when it will create trash...


esby

[Richard Berg]

This sort of thing will require a major overhaul of the scripting language, but believe me such ideas are very much on my mind for the future (v3.0+, I should say, before I scare sh0dan too much ). Heck, just reading Ben's website the other day, I was reminded that even the nonlinear scripting we take for granted was a new (and incompatible) thing not too long ago.

AVISource "video.avi"
dup
Trim 2000,2500
swap
dup
Trim 3000,3500
swap
Trim 1000,1500
AlignedSplice
AlignedSplice

-- vs. --

AVISource("video.avi")
Trim(2000,2500) ++ Trim(3000,3500) ++ Trim(1000,1500)

[esby]

I suppose the "Dup - Swap" code is quite old
(at least i hope to have figured out the example correctly),
Cause as far i remember using avisynth i never used these function.
One reason that make me thinking that too is the missing parenthesis.

To be serious, i don't think this kind of structure could be a big problem to code, i have been thinking about it.

What we need is :

Filters that returns a new structure( array of boolean ) made of boolean values for the clip(true=use the filter, false=dont use)

A new kind of function acting like a macro trim() ,
attached to this new structure,
applying or not the filter(clip) passed in parameter,
depending of the boolean value of the frame.

This could give something like that as syntax:

macroTrim( condition(source) , filter(source) ) 

condition(source) returning the array of boolean.
filter(source) being any filter you might want to use or not on the source.

Of course we could use optionnal syntax like :

 
condition(source).macroTrim( filter(source) )

but maybe i'm going to far in the future ...

esby

[dividee]

It might already be possible, as a function can already return an array, with this amended syntax (and renaming macroTrim to If )

If(condition(source),filter(source),source)

But there is one big problem: the whole array would need to be evaluated before frameserving can start and it might take a while...

Maybe better:

If("condition",source,filter(source))

In a way similar to Animate, the If filter would evaluate the condition for each frame. The condition function would return a single bool, and take as argument the source clip (second argument of If) and the frame number. The syntax could be extended to allow for condition functions with more parameters.

[WarpEnterprises]

Is this functionally more than playing with Layer to switch between two clips?
(Of course it would not calc both layers)

The way dividee described it would indeed be a big jump forward...