I guess I have to find a way to implement it and test it.
By the way, I'm testing max's hilbert~ with olli's - find picture attached.
is this a good way to test it by the way? Seems Max's is more accurate
2016-06-23 22:40 GMT-03:00 Matt Barber brbrofsvl@gmail.com:
Not sure. I've used csound's a lot in ambisonic decoding and it's always worked well.
On Thu, Jun 23, 2016 at 6:06 PM, Alexandre Torres Porres <porres@gmail.com
wrote:
olli's seems easier for me to code, and better than csound's huh?
thanks
2016-06-23 11:27 GMT-03:00 Matt Barber brbrofsvl@gmail.com:
csound's hilbert transform is also 6th-order. Code here:
https://github.com/csound/csound/blob/2ec0073f4bb55253018689a19dd88a432ea6da...
On Thu, Jun 23, 2016 at 9:16 AM, katja katjavetter@gmail.com wrote:
Attached is a zip with test patch for [olli~] and [hilbert~] so you can compare and also check with different sample rates. It seems that Olli's coefficients are optimized to work well from 20 Hz up at 44K1 sample rate, and Pd's built-in from 80 Hz up. They both work at other samples rates too, but with different range.
Since the coefficients for x[n-2] and y[n-2] are non-zero in the biquads, the maximum phase shift is as large as in any 2nd order section, therefore I think the four sections together are 8 order equivalent indeed.
By the way, the abstraction in my first response wasn't completely vanilla-compatible, this is fixed in current attachment (for anyone else interested).
Katja
On Thu, Jun 23, 2016 at 6:24 AM, Alexandre Torres Porres porres@gmail.com wrote:
Awesome, I can code it based on that :) but which order is it?
I see it has 4 biquads, but it doesnt look like an 8th order because
some
coefficients are zeroed out, so I'm confused.
Another question, does it work at any sample rate? This question is
also
aimed to pd's hilbert~ abstraction by the way.
cheers
2016-06-22 17:27 GMT-03:00 katja katjavetter@gmail.com:
Hi, Olli Niemitalou has coefficients published for a higher order 'hilbert transformer' on http://yehar.com/blog/, attached is [olli~] abstraction based on it.
Katja
On Wed, Jun 22, 2016 at 4:37 AM, Alexandre Torres Porres porres@gmail.com wrote: > Howdy, I'm working on a frequency shifter object (via single
sideband
> modulation / complex modulation). > > In Max they have a so called "6th order hilbert transformer with a > minimum > of error". In Pd, the hilbert~ abstraction is 4th order. I'm
copying the
> pd > abstraction for now, but I was hoping to use such a higher order
filter
> and > also use- but I can't find a source for such a formula. Any help
finding
> it? > > thanks > > _______________________________________________ > Pd-list@lists.iem.at mailing list > UNSUBSCRIBE and account-management -> > https://lists.puredata.info/listinfo/pd-list >
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