[LAD] LV2 Pitch bend control port (and function)

Harry van Haaren harryhaaren at gmail.com
Thu Oct 2 13:13:17 UTC 2014

On Thu, Oct 2, 2014 at 1:14 PM, Phil CM <philcm at gnu.org> wrote:
> I need a synth with a pitch control. A synth that can be controlled to
> produce all tones between one note and another, say from a2 to c3 in an
> anti-aliased way, like what you would get in pd by altering the pitch of a
> sine wave.

Hi Phil,

To start, welcome to LV2 programming: audio plugins are fun and complex area!

If you haven't already, I suggest you checkout the "plugins" directory
in the lv2 repository. It provides the best example code you'll find,
and accompanying http://lv2plug.in/book/  provides detailed
explainations and best-practices.

I don't personally use the "lv2-c++-tools" library, so cannot comment
on how it fares currently, but the large warning at the top of the
page you linked ( http://www.nongnu.org/ll-plugins/lv2pftci/ and
http://www.nongnu.org/ll-plugins/hacking.html ) makes me doubtful..
There was a fork of the library, which was somewhat updated to the new
spec: https://github.com/lvtk/lvtk  Last commit 4 months ago.

In answer to your question, the pitch bend signal actually arrives as
MIDI notes: they're a special case (unlike the standard 3-byte note-on
/ note off) event, and must be handles specially too. I don't know how
the lv2-c++-tools handles situations like pitch bend, as I don't use
it: sorry.

I do strongly advise to checkout the plugins: they are a brilliant
reference to make LV2 plugins.

Ok, that's quite a lot of info already I think!

LV2 specific development:
#lv2 on irc.freenode.net  (I'm "HarryHaaren", say Hi if/when you're on)
Mailing list (low-traffic):

Cheers, -Harry



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