[LAD] Devs needed for opensource virtual analog softsynth idea

[Jeremy]

Hi Malte,

So I've been working on converting it some more.  If you could give me some
pointers as to the meaning of variables, that would be useful.


What are the EG... variables, like "EG", "EGFaktor","EGtrigger", and
"EGState"?

Also if you're looking for a channel stealing algorithm, try this:

the type of a synth engine is "synth"

typedef struct _synthblock {
 _synthblock* next;
_synthblock* previous;
synth item;
} synthblock;

Initially, you start out using the synthblock as an element of a singly
linked list of free synths.  You only need to use the "next", pointer, and
can ignore the "previous" pointer.  You can either only keep track of the
head, and use it as a stack, or you can keep track of the head and the tail
and use it as a queue.  Either way, adding is a constant time operation, and
taking the most recently or least recently used one is also a constant time
operation.

Then, you have an array which keeps track of which notes are on.

synthblock* currentnotes[NUM_MIDINOTES];

When you get a note-on signal, you pop the first synth block off of the
"free synth" list, and then you add a pointer to it in this array, indexed
according to what note it is playing.  However, you also add it to the *
doubly* linked list of which synths are playing, again, a constant time
operation, because you are just twiddling with the next and previous
pointers of two blocks.  Now, the array contains a pointer to a block which
is in the doubly linked list.

Now, when you want all the synths to process, you can iterate through the
doubly linked list, and thus you only need to process the ones that are
playing notes.

 When you receive a note off signal, you look up the note in the array, and
then remove that item from the doubly linked list, and add it to the singly
linked one.

In the end, you can do everything in constant time (or O(number of notes
being played))

Anyway, I don't know if it's pointless for me to put my ideas here, but I'll
probably implement it too, if this doesn't make sense now.

Jeremy

On Thu, Jan 6, 2011 at 3:36 PM, Malte Steiner <steiner at block4.com> wrote:

> On 06.01.2011 12:48, Jeremy wrote:
>
>> Yes.  Except it seems that you can select different settings for each of
>> your voices.  This doesn't really make sense if you are automatically
>> assigning the notes to synth engines.  I think perhaps the best way
>> would be to have one set of settings for *all* copies of the synth
>> engine, and if you want different settings, then you'd have to create
>> another copy of the plugin.
>>
>
> Yes, each voice has a different sound and response to a fixed midichannel,
> 1 for the first, 2 for the second voice and so on...
>
> Actually I find it rather interesting to have different settings between
> automatically assigned notes. For instance with slightly different sounds it
> even would become more alive.
> But yes, for the average usage it would be great to just copy the settings
> across the voices.
> The channel stealing algorhythm kept me from implementing polyphony so far,
> got to study that...
>
> A while ago I was against the idea of plugins but actually find it now
> usefull for recalling sessions. It would be great to stuff PD, Csound or
> AlsaModularSynth into a sequencer. So far I know that you can create LADSPA
> plugs with Faust and Csound but instruments??
>
>
> Cheers,
>
> Malte
>
> --
> ----
> media art + development
> http://www.block4.com
>
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> http://itunes.apple.com/us/album/automatenmusik/id383400418
>
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