[Libre-soc-dev] [RFC] REMAP, SHAPE, complex (full) FFT

[Jacob Lifshay]

On Tue, Jul 20, 2021, 08:01 Luke Kenneth Casson Leighton <lkcl at lkcl.net>
wrote:

> currently i have a reordering phase in the middle of the butterflies,
> however i *believe* it will be possible to *pre-load* the data in just the
> right inversed-order, and also set the "swapping" indices up in an
> inversed-order...
>

Do note that DCT isn't just a single thing, there are at least 8 different
kinds of 1D DCT (named DCT I through DCT VIII), and more combinations of 2D
and 3D DCT:

https://en.wikipedia.org/wiki/Discrete_cosine_transform#Formal_definition

Jacob

>