[MPlayer-dev-eng] [PATCH] forceable software volume control

[D Richard Felker III]

On Sat, Nov 06, 2004 at 05:45:25PM +0100, Reimar Döffinger wrote:
> Hi,
> > > > This is incredibly stupid and broken. It's only a few dB, hardly
> > > > sufficient!
> > > > If you're going to work on fixing mplayer volume code, make EVERYTHING
> > > > work in dB and make the range essentially unlimited. (e.g. -100 dB to
> > > > 100 dB or something)
> > > 
> > > I can't claim to know much about audio and dB, but this thing works on 
> > > multiplication...
> > > its certainly got unlimited range in reducing volume, can go all the way to 
> > > 0%. and being able to multiply to 2 times greater is usually more than 
> > > enough... 10 times greater can already be considered unlimited.
> > > 
> > > Isn't this sufficient? Or am I misunderstanding your point?...
> > 
> > no, not at all. 2x greater is barely any change at all. it's the same
> > as a couple clicks on a soundsystem that goes by a decibel scale. 10x
> > is the very minimum cap that would be acceptible. but again it should
> > all be done in decibels since linear scales don't make sense to use
> > for signals.
> 
> This just does not work as easy as that in the digital case. Amplifying
> 2x means you need one extra bit, for 8x amplification you need 3 extra
> bits. So without changing the format (hard to do as often both source
> and soundcard want 16 bit), this will only work when whoever created the
> file wasted at least 3 bits out of 16 by not adjusting the volume
> correctly. I am not convinced that adjusting to such crap is a good
> idea.

usually studios mastering dvd wasted 5-6 out of 16 bits... :(

rich