[PD] object name and anti aliasing technique : WAS : Re: better tabread4~

[cyrille henry]

Steffen Juul a écrit :
> 
> On 25/06/2008, at 22.33, cyrille henry wrote:
> 
>> so finally, what should be the name of this object?
>>
>> is it ok if i remove the other test i made and to use only this one?
> 
> I think you a free to name your code what you want.
yes, but i prefere a name that everybody is happy with.


> And also to delete 
> it.
well, deleting file is usually a bad idea, but the current implementation are only test. i dont think anyone is using them yet.
So i think there is no problem if i replace tabread4*~ with only the best of them.
 

> I however think people would find it interesting with a "lib"* of 
> tabread's with different interpolation schemes.
yes, i think we all agree that having a lib offering the choice is great, but how much do we need.
i don't see interest having 2 or 3 different object offering a 4 points interpolations.

then, it's possibile to have interpolation using more points, and also interpolation that offer antialiasing.

BTW : i just commited a tabosc4aa~ (aa is for anti aliasing).
this is also just a test.
it's far from perfect, but lot's better than the original tabread4~ when dealing with high pitch transposition.
for now, i did this with a classic 8x upsampling + biquad filter inside the tabread4aa~ (ok, this is more cpu intensive : about 1 to 1.5 % cpu)
before i'm doing more work on this, did anyone have experience with this?

how do other software deal with this?
(some use a Shanon interpolation, but this is hard to code in an efficient way + i don't have very good result in the test i made) 

> 
> At least i think it would be cool with a collection where also the 
> interpolation methods of the "others" are included (fx, the SC one).

i think we could have the standard tabread~ / tabread4~, a good (like the curent tabread4c~), and a very good (better than the curent tabread4aa~).
and maybe an extra for non realtime synthesis.
this should be made for tabread / tabosc / vd, and maybe some other i forget.

having only one object that offer many interpolation schematic is great, but need more work.
for now, i think it's simpler to use one interpolation schematic per object. (just like miller did with tabread~ and tabread4~).

so, i'm looking for a _prefix_ to use like this : 
tabread_prefix_~
tabosc_prefix_~ 
vd_prefix_~

one _prefix_ or the 4 points interpolation as describe by charles henry
and an other one for the best anti alliased interpolation i can possibly make.


cheers
cyrille


> 
> Thanks for publishing.
> 
> (* where ever its one-file-multi-class, one-class-per-file or 
> multi-method-per-class.)
> 
>