[MPlayer-dev-eng] [BUG?][PATCH] af_equalizer too quiet

[Rich Felker]

On Tue, Nov 22, 2005 at 09:35:01PM -0800, Corey Hickey wrote:
> Rich Felker wrote:
> > On Tue, Nov 22, 2005 at 08:08:13PM -0800, Corey Hickey wrote:
> > 
> >>I noticed that mplayer -af equalizer reduces the volume significantly.
> >>Consider this command:
> >>
> >>$ mplayer file.mp3 -af equalizer
> >>
> >>(this corresponds to -af equalizer=0:0:0:0:0:0:0:0:0:0)
> >>
> >>Since the suboptions accept a range from -12 to 12 and 0 is the default,
> >>I would expect 0 to be the neutral position and to have no effect on the
> >>audio. Instead, the volume is reduced by a factor of 40 by line 193 of
> >>af_equalizer.c:
> >>
> >>*out=yt/(4.0*10.0);
> >>
> >>Is that a bug? If so, the attached patch fixes it.
> > 
> > 
> > Yes, there are bugs like this all over libaf. If you could find and
> > fix them it would be most appreciated.
> 
> If and when I encounter them I'll see what I can do. At the moment I'm
> not aware of other bugs. Do you have any in mind?

-af volume is supposed to work in decibels but iirc it uses some sort
of broken scaling that makes it so volume=0 is not equivalent to no
filter. maybe this was already fixed tho? and -af resample halves the
volume in some modes but not others. fortunately lavcresample has made
resample obsolete, but it still should be fixed..

rich