[vdr] Re: Linear volume response in VDR

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Reinhard Walter Buchner wrote:
> 
> Hi,
> 
> >An alternate proposal would be:
> >    Vol = Volume + (255*Volume - Volume*Volume)* q / 65025
> > Q is a free parameter in this quadratic variant. For q=0, this is the
> > linear identity as before, and for q=255 this has a gradient of 0 at
> > 255. All q=0..255 should work, and theres always 0->0 and 255->255.
> 
> Which is pretty much what I did in my nessy patch long ago ;o)) It was
> only a little more complex because I also added an adjustable balance
> control. The q value was user adjustable as a sensitivity control in my
> case.
> 
> > Of course, if anyone knows what kind of non-linearity is behind the
> > volume control, this would be even better.
> 
> Nope, I have NO idea. IIRC it only applied to the newer TT cards.
> The Rev 1.3 (it's been a LONG time) doesn't have the problem of
> non linear volume.

Well, I have a Siemens Rev. 1.3 (the very old ones) and this modification
does make the volume control more linear.

Klaus