[pulseaudio-discuss] [PATCH] add module-virtual-surround-sink

Tanu Kaskinen tanuk at iki.fi
Thu Mar 8 08:11:15 PST 2012

On Sun, 2012-01-22 at 14:32 +0100, Niels Ole Salscheider wrote:
> > As for the complexity - yes, it can be reduced substantially, because
> > you use the simplest possible implementation of convolution with a
> > rather long filter. Please try to use FFT-based convolution and
> > benchmark.
> > 
> > Or, even better, try to approximate one of the available HRIRs with a
> > combination of an IIR filter of some low (4-6) order and a
> > fixed-per-channel delay, and hard-code that. As there is no scientific
> > way of designing IIR filters with arbitrary impulse response yet, the
> > simplest possible way of doing such approximation is to autogenerate
> > random IIR filters of a given order, compare their response with the
> > desired one, and leave the whole thing running for a day or so until it
> > finds something suitable.
> Sure, my code is O(n^2) while FFT is O(n log n) but it is somewhat simpler and 
> has less overhead.
> I will try your proposed alternatives when I find the time to do so (exams are 
> coming up).

It seems that the performance really matters: my computer can't do the
processing in real time :(


More information about the pulseaudio-discuss mailing list