24 Nov
2011
24 Nov
'11
10:03 p.m.
From: fons(a)linuxaudio.org
To: linux-audio-dev(a)lists.linuxaudio.org
Subject: Re: [LAD] sliders/fans
On Thu, Nov 24, 2011 at 02:21:25PM -0500, David Robillard wrote:
Suppose the minimum value of the widget would correspond to say
-100 dB if not handled specially. If you just have a single fader
per channel, you could arrange for the model or the DSP code to
translate that to 'off'. That is no longer the case if you have
'VCA' faders.
There are two thing you'd expect from such a system:
* If either the channel or the group fader is at minimum, then
the channel must be off (zero gain).
* If the channel fader is at -50 dB, and the group at -60 dB
you don't want zero gain, but -110 dB. Becaus either fader is
still in a position where you'd expect that moving it makes a
difference.
Wow. Isn't this a far bigger topic?
For example, having a user interface definition that says UpArrow
means the controller moves up is separate from saying:
a. UpArrow and gain implies dB values
b. UpArros and Frequency control implies lin/log/exp Hz values
If we want to impose semantics on the controllers that are under motion
then that is going to be one _big_ specification. Again, perhaps I need to
look at the HID definition we are referring too, I was actually anticipating
just the syntax of what the diverse key/mouse combinations cause rather
than what they effect.
There are some interfaces that expect fixed pixel steps for their controls,
the interfaces are not 'resizable'. Others are. I think it might be difficult
to impose semantic meaning of any given chance in the interface guide
for that and probably a few other reasons.
Comments?
nick