Re: [LAD] Has anyone ever played a plugin in realtime ... [related to:] hard realtime performance synth

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To: <linux-audio-dev@...>
Date: Thursday, February 11, 2010 - 9:15 am

On Wednesday 10 February 2010, at 22.45.40, Emanuel Rumpf

Any polyphonic synth will have to check for voices as part of the "allocate
voice" action for any noise started, so the question seems somewhat odd to me.

Are you thinking of voice stealing logic?

I would think most softsynths have this. The alternative would be to
dynamically allocate voices as needed, and I think some actually do this - but
this will be troublesome in a realtime implementation, unless you're on a full
realtime OS using physical RAM only. You may pre-allocate and lock a "huge"
block of memory for the synth, but then you still have a limited voice count
of sorts...

> That would require an extensive deterministic behavior, I think.

There are various solutions, such as stealing the "least audible" note, or
just grabbing the oldest playing note. Figuring out which note is *actually*
the least audible is a lot trickier than it might seem at first, so any real
implementation would be an approximation at best.

Anyway, I don't think there's much of a difference between "hardware" and
software synths in this regard. (They all do an equally bad job of it! ;-)
After all, most "hardware" synths are actually one or more DSPs and
(sometimes) MCUs running some sort of software, and even "real" hardware
synths will have an MCU or logic circuitry to implement this.

//David Olofson - Developer, Artist, Open Source Advocate

.--- Games, examples, libraries, scripting, sound, music, graphics ---.
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Messages in current thread:
Re: [LAD] Has anyone ever played a plugin in realtime ... [r..., Pedro Lopez-Cabanillas, (Fri Feb 5, 10:57 pm)
Re: [LAD] Has anyone ever played a plugin in realtime ... [r..., David Olofson, (Thu Feb 11, 9:15 am)
Re: [LAD] Has anyone ever played a plugin in realtime ... [r..., Fernando Lopez-Lezcano, (Wed Feb 10, 6:33 pm)