> David Boothe wrote:
> > 
> > It does take a while for this to render. I tried this on my 180 mHz Pentium
> > Pro using Windows console version 3.51. It took about 80 seconds to render
> > the 5 second sound file. By comparison, commenting out the hrtfer line and
> > sending asrc directly out, takes about 2 seconds to render. Based on what
> > this opcode does, I suspect it has a lot of number crunching to do.
> 
> I think it does convolution, i.e. it convolves the input file with the
> HRTF impulse files.  Convolution is VERY processor intensive.  I'd
> explain it, but I'm horrible at explaining convolution (I've tried

That's strange... Motivated by the messages about hrtfer I yesterday
tried it too, on a 90MHz Pentium running Linux-2.2.1, with csound-3.511.
I didn't use soundin but a PWM signal generated with the 'vco' opcode,
and I controlled it via MIDI.

Well, it 'basically' ran in realtime ! That means, I had many breaks in the
audio output, but the fragmented audio, when listened to in the headphones,
really seemed to move in 3d space. So I wonder why David's PPro180 takes
80s for a 5s audio file, that's really strange. Is the Windows Version
that much slower than the Linux one ?