[Haskell-cafe] Ideas

[Derek Elkins]

On Sat, 2007-08-25 at 23:36 +0200, jerzy.karczmarczuk at info.unicaen.fr
wrote:
> Evan Laforge writes: 
> 
> >> Indeed, you can write certain DSP algorithms beautifully in Haskell.
> >> Now, if only it could talk to the audio hardware... (Or just use common
> >> file formats even.)
> > 
> > Oh, that's easy.  I wrote an FFI interface to portaudio a while back
> > to write a delay-looping type utility in haskell.  It was pretty
> > trivial.  You could do the same for libsndfile or whatever. 
> > 
> > The only thing I'm uncertain about is whether it would have good
> > enough time and space performance.  All the real work is writing yet
> > another set of basic envelope, oscillator, and fft primitives.  You
> > *should* be able to go all the way down to the samples in pure haskell
> > though, which would be more elegant than those other languages :)
> 
> == 
> 
> Well, if you want to see what you can do with a lazy functional language,
> not necessarily Haskell, but Clean (sorry for advertizing a competitor
> on this list...), perhaps have a look on my PADL paper 
> 
> http://users.info.unicaen.fr/~karczma/arpap/cleasyn.pdf 
> 
> I generated .wav files as output, from lazy streams, so the sound was 
> off-line.
> My ambition was to code in a very, very compact way some musical
> instruments, with looping replaced by co-recursion. It cannot be extremely
> efficient, but it seems quite elegant and powerful. 

Last week I did exactly that.  Using lazy streams and a quickly hacked
up .wav file output, I played with some of the extended Karplus-Strong
plucked string/drum synthesis algorithms.