Re: [LAD] Fader mapping - was - Ardour MIDI tracer

On Fri, Aug 22, 2014 at 08:11:39AM -0700, Len Ovens wrote: You have two mappings: * Position (mm or degrees) to MIDI (0..127) by the control surface, * MIDI (0..127) to gain (dB), or to whatever is being controlled, by the DAW or instrument. Position to gain (or anything else), in other words what is experienced bu the user, results from the combination of those two. This also means that the controller can't have any calibration marks unless it knowns the mapping used by the receiver. This is always true, regardless of the actual mappings used. Having a linear mapping from postion or angle to 0..127 is in almost all cases the only sensible thing to do. The accuracy with which a user can set or move a fader or pot does not depend on its position. Hence the resolution should not depend on it. Such a linear mapping is very probably also what is assumed by the receiver, which will have its mapping defined such that in combination with the one from the controller you get the desired result, e.g. a good audio taper for a fader. For a fader you want small steps (0.5 dB or less) in the upper region. At low gains larger ones (1 dB or so down to -60 and even bigger ones below that) are perfectly OK, and allow to extend the range and/or to have smaller steps in the upper region. What would feel very strange to a user is to have bigger _physical_ (mm or degrees) steps in any part of the range. Hence the linear mapping to 0..127. There may be exceptions for some very specific controllers (e.g. thrust levers in an airplane), but an audio fader is not one of them. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)