11 Dec
2002
11 Dec
'02
8:19 a.m.
First, I
don't understand why you want to design a "synth API". If
you want to play a note, why not instantiate a DSP network that
does the job, connect it to the main network (where system audio
outs reside), run it for a while and then destroy it? That is what
events are in my system - timed modifications to the DSP network.
99% of the synths people use these days are hardcoded, highly
optimized monoliths that are easy to use and relatively easy to host.
We'd like to support that kind of stuff on Linux as well, preferably
with an API that works equally well for effects, mixers and even
basic modular synthesis.
Besides, real time instantiation is something that most of us want to
avoid at nearly any cost. It is a *very* complex thing to get right
(ie RT safe) in any but the simplest designs. However, if
you want, you can define functions like C x =
exp((x - 9/12) * log(2)) * middleA, where middleA is another
function that takes no parameters. Then you can give pitch as "C 4"
(i.e. C in octave 4), for instance. The expression is evaluated and
when the event (= modification to DSP network) is instantiated it
becomes an input to it, constant if it is constant, linearly
interpolated at a specified rate otherwise. I should explain more
about MONKEY for this to make much sense but maybe later.
This sounds interesting and very flexible - but what's the cost? How
many voices of "real" sounds can you play at once on your average PC?
(Say, a 2 GHz P4 or someting.) Is it possible to start a sound with
sample accurate timing? How many voices would this average PC cope
with starting at the exact same time? You could think of our API as...
It seems to be a solid design so far. I will definitely comment on it when
you have a first draft for a proposal.
--
Sami Perttu "Flower chase the sunshine"
Sami.Perttu(a)hiit.fi http://www.cs.helsinki.fi/u/perttu