[MPlayer-dev-eng] [PATCH] patch for af_hrtf to relieve noises

[Vladimir Mosgalin]

Hi Xidorn Quan!

 On 2012.10.21 at 10:45:19 +0800, Xidorn Quan wrote next:

> > On Sat, Oct 20, 2012 at 11:21:32PM +0800, Xidorn Quan wrote:
> > > Hi,
> > >
> > > A simple patch is attached which is intend to relieve noises for
> > > af_hrtf by using clamp instead of casting directly.
> >
> > Not sure if overflows are supposed to be possible, it might just hide
> > an issue somewhere else.
> >
> 
> Well, I think it is true that it hides an issue somewhere else since
> there are still some noises after clamping when remixing stereo. This
> patch only relieve some of the noises.

Clamp will produce distortion just as well..

Maybe hrtf filter doesn't use correct (properly downscaled) coefficients
or something when downmixing?

It's quite common problem for hrtf filter to cause crackling noise when
there is loud sound in original multichannel track. For many tracks it's
a must to use something like -af volume=-5,hrtf and for some very loud
tracks in action movies sometimes even volume=-10 is required. In
neither case original tracks have overflows in any channel, they are
produced in hrtf filter itself.


-- 

Vladimir