[pulseaudio-discuss] On scaling the HRIR in module-virtual-surround-sink

[Niels Ole Salscheider]

Hello Alexander,

On Tuesday 11 March 2014, 15:00:31, Tanu Kaskinen wrote:
> On Sun, 2014-03-09 at 00:57 +0600, Alexander E. Patrakov wrote:
> > Hello.
> > 
> > [Do not blindly apply patches from this e-mail! They mutually exclusive,
> > and I don't have a firm opinion which one of them is correct.]
> > 
> > Today I tried to improve the existing module-virtual-surround-sink (but
> > the same issue also affects the IIR-based rewrite that is still sitting
> > on my laptop). The problem is: the current normalization code does not
> > do what it is designed to do. The module clips on some testcases. Let me
> > copy-paste the problematic code for easy discussion.
> 
> <snip>
> 
> > Thoughts?
> 
> My thoughts:
> 
> The scaling should be put in its own function with a comment that
> explains why the scaling is done, a high level description of how the
> scaling algorithm works, and a note that it's unclear whether the
> algorithm actually makes sense. Something like this could be included
> too: "This algorithm doesn't pretend to be perfect, it's just something
> that appears to work (not too quiet, no audible clipping) on the
> material that it has been tested on. If you find a real-world example
> where this algorithm results in audible clipping, please write a patch
> that adjusts the scaling factor constants or improves the algorithm (or
> if you can't write a patch, at least report the problem to the
> PulseAudio mailing list or bug tracker)."

Would you like to write such a patch or should I do it? Or do you have an idea 
for a better heuristic?

Regards,

Ole