Re: [Sursound] Ambisonic Decoder Design Resources

[/dav/random]

Hi Jörn,

well about the physics/maths of the technique there is a paper [1].
Let me just give you a small introduction/rough idea... the program
performs a numerical optimization of a cost function. The cost function
uses Rv and Re as building blocks. The nice feature of this kind of
numerical minimizations is that the constraints you put are not hard and
you can tune them. For example, if I remember well, I read that you are not
particularly interested in optimizing for localization error. then you can
tune the parameters of the cost function to care about other stuff (e.g.
the modulus of Re instead of its direction).

The program is not straightforward to use... you have to read the paper
first and know a bit of ambisonics (I know _you_ do). Anyway I am very
happy to generate decoders for any of you... just contact me.
The code is not well organized. Everything started as a test... not as a
structured project. I hope that little by little I'll be able to give it a
better shape. Be patient.

We tested the decoders produced by idhoa with Aaron Heller, Eric Benjamin
and Fernando Lopez-Lezcano in a wonderful afternoon at CCRMA (thanks again
guys!) against the decoders produced by allrad (if I remember well... Aaron
produced them). They sounded very very very similar... probably because the
CCRMA layout is fairly "regular" (not in SH sense). I think idhoa makes
more sense for weird layouts.

Ciao
d


[1] https://secure.aes.org/forum/pubs/conferences/?elib=17364
(if you don't have access drop me an email)
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Re: [Sursound] Ambisonic Decoder Design Resources

[Jörn Nettingsmeier]

On 02/24/2016 11:37 AM, /dav/random wrote:

Thanks Archontis for mentioning also my little project!
Since I moved out from Barcelona Media, I'm developing the project in my
freetime and the updated repository changed to:
https://github.com/davrandom/idhoa

I don't want to SPAM more... so if anyone is interested, just drop an email.


can't speak for anyone else here, but personally i would very much like 
to be informed about this project, and it seems perfectly on topic for 
sursound.



--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487

Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister VDT

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Re: [Sursound] Ambisonic Decoder Design Resources

[/dav/random]

Thanks Archontis for mentioning also my little project!
Since I moved out from Barcelona Media, I'm developing the project in my
freetime and the updated repository changed to:
https://github.com/davrandom/idhoa

I don't want to SPAM more... so if anyone is interested, just drop an email.

d

On Sat, Feb 20, 2016 at 8:58 PM, Politis Archontis <
archontis.poli...@aalto.fi> wrote:

> Hi Richard,
>
> In terms of literature for general HOA decoding, the parts are all around,
> I personally like the papers by Franz Zotter cause they present all the
> relevant information in a clear and usable manner. The All-round Ambisonic
> Panning and Decoding paper in JAES I think has most of the stuff you’ll
> need, and not only for the specific method.
>
> In terms of open code there are not so much stuff around. As the rest of
> the people mentioned, one is Aaron Heller’s ambisonic toolkit, in Matlab,
> which is very extensive!
> https://bitbucket.org/ambidecodertoolbox/adt.git
>
> I have also released a Matlab library in a more educational manner, not so
> much for efficiency as for readability, you can find it if you want to have
> a look in:
> http://research.spa.aalto.fi/projects/ambi-lib/ambi.html
> This implements some recent decoders too, including the ALLRAD method
> mentioned before, and another interesting one called CSAD (constant-angular
> spread), which has constant energy vector magnitude and zero angular error.
> You can also check energy/velocity vector plots for any decoder that you
> choose to implement. Could be a good starting point for making your own
> code.
>
> Additionally, a powerful but more complicated is the decoder generator of
> Davide Scaini, from University of Pompeau Fabra and Barcelona Media, which
> converges on an optimal decoder by iterative numerical optimization on the
> velocity/energy vectors, in Python. You can find the implementaiton in:
> https://github.com/BarcelonaMedia-Audio/idhoa
>
> Good luck with your project!
> Archontis Politis
>
>
> 
> From: Sursound [sursound-boun...@music.vt.edu] on behalf of Dave Malham [
> dave.mal...@york.ac.uk]
> Sent: 20 February 2016 20:56
> To: Surround Sound discussion group
> Subject: Re: [Sursound] Ambisonic Decoder Design Resources
>
> I would definitely recommend Aaron's decoder toolkit and, in fact, the
> whole oeuvre from the Benjamin-Lee-Heller group (BLaH). This can be found
> at http://www.ai.sri.com/ajh/ambisonics/
>
>  Dave
>
> On 20 February 2016 at 17:58, Jörn Nettingsmeier <
> netti...@stackingdwarves.net> wrote:
>
> > On 02/20/2016 06:22 PM, Richard Graham wrote:
> >
> >> Hi Archontis,
> >>
> >> I would like to design decoders for 2d and 3d arrays, 1st through
> >> 3rd order (at least), both regular and irregular arrays. C code
> >> examples would be incredibly helpful as I plan to develop decoders
> >> for Pd and Max.
> >>
> >
> > Fons' ambdec is GPL, and it comes with a nice set of example setups.
> > It's C++, but the way Fons uses it, it reads pretty much like plain C.
> > After all, a dsp loop is a dsp loop...
> >
> > Most importantly, I’d like to figure out how to calculate these
> >> coefficients myself and I am having trouble finding literature on
> >> how to do that. I have reached out to a few folks who used their own
> >> programs to calculate coefficients. Essentially, I’d like to build
> >> my own program in the C programming language.
> >>
> >
> > Aaron Heller has a Matlab/Octave toolkit out that will generate matrices
> > for you, and it's completely open. But it relies on quite complex
> > functions of the framework... His solutions are used at CCRMA, to
> > great effect. Probably your best starting point.
> >
> > Richard has one but keeps it proprietary, Fons has one but also doesn't
> > like to part with it (although he has been very generous about
> > generating custom Ambdec setups for people, me included).
> >
> > For the nitty-gritty, check out the papers from recent Ambisonics
> > symposia and the ICSA conferences. Talk to Thomas Musil from Graz for
> > the old-school, lovingly hand-optimized matrix approach, or to Zotter et
> > al. for the All-Rad approach that works for arbitrary setups but is
> > quite complex and kind of brute-forceish. I can dig them up for you if
> you
> > can't find them.
> >
> > Shortly, I will have access to a 16-channel ring on the horizontal
> >> plane and a b-format cube. This system will be modular and
> >> configurable into irregular setups, too.
&g

Re: [Sursound] Ambisonic Decoder Design Resources

[Fernando Lopez-Lezcano]

On 02/20/2016 09:58 AM, Jörn Nettingsmeier wrote:

On 02/20/2016 06:22 PM, Richard Graham wrote:

Hi Archontis,

...

Most importantly, I’d like to figure out how to calculate these
coefficients myself and I am having trouble finding literature on
how to do that. I have reached out to a few folks who used their own
programs to calculate coefficients. Essentially, I’d like to build
my own program in the C programming language.


Aaron Heller has a Matlab/Octave toolkit out that will generate matrices
for you, and it's completely open. But it relies on quite complex
functions of the framework... His solutions are used at CCRMA, to
great effect. Probably your best starting point.


ADT (Ambisonics Decoder Toolkit) can actually generate full proper 
decoders in Faust, which can then be compiled to pretty much anything - 
including straight C... I have been using Slepian style 3D decoders for 
our 12 + 8 + 4 + 1 setup compiled into SuperCollider UGens which are 
then incorporated into our custom diffusion system. Works very well, if 
I may say...


-- Fernando



Richard has one but keeps it proprietary, Fons has one but also doesn't
like to part with it (although he has been very generous about
generating custom Ambdec setups for people, me included).

For the nitty-gritty, check out the papers from recent Ambisonics
symposia and the ICSA conferences. Talk to Thomas Musil from Graz for
the old-school, lovingly hand-optimized matrix approach, or to Zotter et
al. for the All-Rad approach that works for arbitrary setups but is
quite complex and kind of brute-forceish. I can dig them up for you if
you can't find them.


Shortly, I will have access to a 16-channel ring on the horizontal
plane and a b-format cube. This system will be modular and
configurable into irregular setups, too.


nice! but unless you really need extremely high horizontal resolution
for research purposes or a truly humongous listening area, a better use
for all those speakers would be to make a more or less uniform 3D rig.
gets you a nice dodecahedron for full third-order all around.


best,


jörn





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Re: [Sursound] Ambisonic Decoder Design Resources

[Richard Graham]

Folks, many thanks for all these incredibly helpful resources.
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Re: [Sursound] Ambisonic Decoder Design Resources

[Jörn Nettingsmeier]

On 02/20/2016 08:31 PM, David Pickett wrote:

At 19:53 20-02-16, Bo-Erik Sandholm wrote:

 >It has been verified by listening test that for FOA it is optimal to not
 >have too many speakers in the horizontal ring. Look at old mails in the
 >list.

This is a tall order: could you specify approx dates, subject lines, or
keywords to search on?  Alternatively, please repeat the information
here, as it could be of interest.


IIRC, one of the BLaH papers also cites listening tests that have found 
the hexagon to be preferred over square or rectangular setups for first 
order.



--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487

Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister VDT

http://stackingdwarves.net

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Re: [Sursound] Ambisonic Decoder Design Resources

[David Pickett]

Many thanks!

David

At 08:55 21-02-16, Bo-Erik Sandholm wrote:
>http://search.gmane.org/?query=number+of+speakers+&author=Fons&group=g
>mane.comp.audio.sursound&sort=relevance&DEFAULTOP=and&xP=Znumber%09Zsp
>eaker&xFILTERS=Gcomp.audio.sursound-Asandholm---A
>
>The years was 2011 or 2012, hit 2 in this search link gives a indication of
>the subject of the discussion.
>BR Bosse
>On 20 Feb 2016 20:55, "David Pickett"  wrote:
>
>> At 19:53 20-02-16, Bo-Erik Sandholm wrote:
>>
>> >It has been verified by listening test that for FOA it is optimal to not
>> >have too many speakers in the horizontal ring. Look at old mails in the
>> >list.
>>
>> This is a tall order: could you specify approx dates, subject lines, or
>> keywords to search on?  Alternatively, please repeat the information here,
>> as it could be of interest.
>>
>> David

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Re: [Sursound] Ambisonic Decoder Design Resources

[Bo-Erik Sandholm]

http://thread.gmane.org/gmane.comp.audio.sursound/1969/focus=1972
This is a good mail from 2011 from our guru Fons, 6 speakers for horizontal
FOA.
Bosse
On 21 Feb 2016 08:55, "Bo-Erik Sandholm"  wrote:

>
> http://search.gmane.org/?query=number+of+speakers+&author=Fons&group=gmane.comp.audio.sursound&sort=relevance&DEFAULTOP=and&xP=Znumber%09Zspeaker&xFILTERS=Gcomp.audio.sursound-Asandholm---A
>
> The years was 2011 or 2012, hit 2 in this search link gives a indication
> of the subject of the discussion.
> BR Bosse
> On 20 Feb 2016 20:55, "David Pickett"  wrote:
>
>> At 19:53 20-02-16, Bo-Erik Sandholm wrote:
>>
>> >It has been verified by listening test that for FOA it is optimal to not
>> >have too many speakers in the horizontal ring. Look at old mails in the
>> >list.
>>
>> This is a tall order: could you specify approx dates, subject lines, or
>> keywords to search on?  Alternatively, please repeat the information here,
>> as it could be of interest.
>>
>> David
>>
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>>
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Re: [Sursound] Ambisonic Decoder Design Resources

[Bo-Erik Sandholm]

http://search.gmane.org/?query=number+of+speakers+&author=Fons&group=gmane.comp.audio.sursound&sort=relevance&DEFAULTOP=and&xP=Znumber%09Zspeaker&xFILTERS=Gcomp.audio.sursound-Asandholm---A

The years was 2011 or 2012, hit 2 in this search link gives a indication of
the subject of the discussion.
BR Bosse
On 20 Feb 2016 20:55, "David Pickett"  wrote:

> At 19:53 20-02-16, Bo-Erik Sandholm wrote:
>
> >It has been verified by listening test that for FOA it is optimal to not
> >have too many speakers in the horizontal ring. Look at old mails in the
> >list.
>
> This is a tall order: could you specify approx dates, subject lines, or
> keywords to search on?  Alternatively, please repeat the information here,
> as it could be of interest.
>
> David
>
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
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Re: [Sursound] Ambisonic Decoder Design Resources

[Politis Archontis]

(sorry for the double post, my mail manager is misbehaving..)
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Re: [Sursound] Ambisonic Decoder Design Resources

[Politis Archontis]

Hi Richard,

In terms of literature for general HOA decoding, the parts are all around, I 
personally like the papers by Franz Zotter cause they present all the relevant 
information in a clear and usable manner. The All-round Ambisonic Panning and 
Decoding paper in JAES I think has most of the stuff you’ll need, and not only 
for the specific method.

In terms of open code there are not so much stuff around. As the rest of the 
people mentioned, one is Aaron Heller’s ambisonic toolkit, in Matlab, which is 
very extensive! 
https://bitbucket.org/ambidecodertoolbox/adt.git

I have also released a Matlab library in a more educational manner, not so much 
for efficiency as for readability, you can find it if you want to have a look 
in:
http://research.spa.aalto.fi/projects/ambi-lib/ambi.html
This implements some recent decoders too, including the ALLRAD method mentioned 
before, and another interesting one called CSAD (constant-angular spread), 
which has constant energy vector magnitude and zero angular error. You can also 
check energy/velocity vector plots for any decoder that you choose to 
implement. Could be a good starting point for making your own code.

Additionally, a powerful but more complicated is the decoder generator of 
Davide Scaini, from University of Pompeau Fabra and Barcelona Media, which 
converges on an optimal decoder by iterative numerical optimization on the 
velocity/energy vectors, in Python. You can find the implementaiton in:
https://github.com/BarcelonaMedia-Audio/idhoa
 
Good luck with your project!
Archontis Politis



From: Sursound [sursound-boun...@music.vt.edu] on behalf of Dave Malham 
[dave.mal...@york.ac.uk]
Sent: 20 February 2016 20:56
To: Surround Sound discussion group
Subject: Re: [Sursound] Ambisonic Decoder Design Resources

I would definitely recommend Aaron's decoder toolkit and, in fact, the
whole oeuvre from the Benjamin-Lee-Heller group (BLaH). This can be found
at http://www.ai.sri.com/ajh/ambisonics/

 Dave

On 20 February 2016 at 17:58, Jörn Nettingsmeier <
netti...@stackingdwarves.net> wrote:

> On 02/20/2016 06:22 PM, Richard Graham wrote:
>
>> Hi Archontis,
>>
>> I would like to design decoders for 2d and 3d arrays, 1st through
>> 3rd order (at least), both regular and irregular arrays. C code
>> examples would be incredibly helpful as I plan to develop decoders
>> for Pd and Max.
>>
>
> Fons' ambdec is GPL, and it comes with a nice set of example setups.
> It's C++, but the way Fons uses it, it reads pretty much like plain C.
> After all, a dsp loop is a dsp loop...
>
> Most importantly, I’d like to figure out how to calculate these
>> coefficients myself and I am having trouble finding literature on
>> how to do that. I have reached out to a few folks who used their own
>> programs to calculate coefficients. Essentially, I’d like to build
>> my own program in the C programming language.
>>
>
> Aaron Heller has a Matlab/Octave toolkit out that will generate matrices
> for you, and it's completely open. But it relies on quite complex
> functions of the framework... His solutions are used at CCRMA, to
> great effect. Probably your best starting point.
>
> Richard has one but keeps it proprietary, Fons has one but also doesn't
> like to part with it (although he has been very generous about
> generating custom Ambdec setups for people, me included).
>
> For the nitty-gritty, check out the papers from recent Ambisonics
> symposia and the ICSA conferences. Talk to Thomas Musil from Graz for
> the old-school, lovingly hand-optimized matrix approach, or to Zotter et
> al. for the All-Rad approach that works for arbitrary setups but is
> quite complex and kind of brute-forceish. I can dig them up for you if you
> can't find them.
>
> Shortly, I will have access to a 16-channel ring on the horizontal
>> plane and a b-format cube. This system will be modular and
>> configurable into irregular setups, too.
>>
>
> nice! but unless you really need extremely high horizontal resolution for
> research purposes or a truly humongous listening area, a better use for all
> those speakers would be to make a more or less uniform 3D rig.
> gets you a nice dodecahedron for full third-order all around.
>
>
> best,
>
>
> jörn
>
>
>
> --
> Jörn Nettingsmeier
> Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487
>
> Meister für Veranstaltungstechnik (Bühne/Studio)
> Tonmeister VDT
>
> http://stackingdwarves.net
>
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>



--

Re: [Sursound] Ambisonic Decoder Design Resources

[David Pickett]

At 19:53 20-02-16, Bo-Erik Sandholm wrote:

>It has been verified by listening test that for FOA it is optimal to not
>have too many speakers in the horizontal ring. Look at old mails in the
>list.

This is a tall order: could you specify approx dates, subject lines, 
or keywords to search on?  Alternatively, please repeat the 
information here, as it could be of interest.


David

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Re: [Sursound] Ambisonic Decoder Design Resources

[Dave Malham]

I would definitely recommend Aaron's decoder toolkit and, in fact, the
whole oeuvre from the Benjamin-Lee-Heller group (BLaH). This can be found
at http://www.ai.sri.com/ajh/ambisonics/

 Dave

On 20 February 2016 at 17:58, Jörn Nettingsmeier <
netti...@stackingdwarves.net> wrote:

> On 02/20/2016 06:22 PM, Richard Graham wrote:
>
>> Hi Archontis,
>>
>> I would like to design decoders for 2d and 3d arrays, 1st through
>> 3rd order (at least), both regular and irregular arrays. C code
>> examples would be incredibly helpful as I plan to develop decoders
>> for Pd and Max.
>>
>
> Fons' ambdec is GPL, and it comes with a nice set of example setups.
> It's C++, but the way Fons uses it, it reads pretty much like plain C.
> After all, a dsp loop is a dsp loop...
>
> Most importantly, I’d like to figure out how to calculate these
>> coefficients myself and I am having trouble finding literature on
>> how to do that. I have reached out to a few folks who used their own
>> programs to calculate coefficients. Essentially, I’d like to build
>> my own program in the C programming language.
>>
>
> Aaron Heller has a Matlab/Octave toolkit out that will generate matrices
> for you, and it's completely open. But it relies on quite complex
> functions of the framework... His solutions are used at CCRMA, to
> great effect. Probably your best starting point.
>
> Richard has one but keeps it proprietary, Fons has one but also doesn't
> like to part with it (although he has been very generous about
> generating custom Ambdec setups for people, me included).
>
> For the nitty-gritty, check out the papers from recent Ambisonics
> symposia and the ICSA conferences. Talk to Thomas Musil from Graz for
> the old-school, lovingly hand-optimized matrix approach, or to Zotter et
> al. for the All-Rad approach that works for arbitrary setups but is
> quite complex and kind of brute-forceish. I can dig them up for you if you
> can't find them.
>
> Shortly, I will have access to a 16-channel ring on the horizontal
>> plane and a b-format cube. This system will be modular and
>> configurable into irregular setups, too.
>>
>
> nice! but unless you really need extremely high horizontal resolution for
> research purposes or a truly humongous listening area, a better use for all
> those speakers would be to make a more or less uniform 3D rig.
> gets you a nice dodecahedron for full third-order all around.
>
>
> best,
>
>
> jörn
>
>
>
> --
> Jörn Nettingsmeier
> Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487
>
> Meister für Veranstaltungstechnik (Bühne/Studio)
> Tonmeister VDT
>
> http://stackingdwarves.net
>
> ___
> Sursound mailing list
> Sursound@music.vt.edu
> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here,
> edit account or options, view archives and so on.
>



-- 

As of 1st October 2012, I have retired from the University.

These are my own views and may or may not be shared by the University

Dave Malham
Honorary Fellow, Department of Music
The University of York
York YO10 5DD
UK

'Ambisonics - Component Imaging for Audio'
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Re: [Sursound] Ambisonic Decoder Design Resources

[Bo-Erik Sandholm]

Fons calculated a 2 - 6 - 2 (floor - horisontal - roof) for me that might
be even better
as a 4-6-4 when used for FOA.

It has been verified by listening test that for FOA it is optimal to not
have too many speakers in the horizontal ring. Look at old mails in the
list.

I only have FOA to listen to as I use only tetramic to create material for
listening.

Bo-Erik
On 20 Feb 2016 18:23, "Richard Graham"  wrote:

> Hi Archontis,
>
> I would like to design decoders for 2d and 3d arrays, 1st through 3rd
> order (at least), both regular and irregular arrays. C code examples would
> be incredibly helpful as I plan to develop decoders for Pd and Max.
>
> I have already developed some basic ambisonic externals for Pd (
> http://rickygraham.net/?p=176401730 )
> based on encoding and decoding technical notes from Blue Ripple Sound (
> http://www.blueripplesound.com/decoding <
> http://www.blueripplesound.com/decoding>), which provides coefficients
> for basic array set-ups.
>
> Most importantly, I’d like to figure out how to calculate these
> coefficients myself and I am having trouble finding literature on how to do
> that. I have reached out to a few folks who used their own programs to
> calculate coefficients. Essentially, I’d like to build my own program in
> the C programming language.
>
> Shortly, I will have access to a 16-channel ring on the horizontal plane
> and a b-format cube. This system will be modular and configurable into
> irregular setups, too.
>
> Many thanks,
>
> Ricky
>
> > On Feb 20, 2016, at 12:00 PM, sursound-requ...@music.vt.edu wrote:
> >
> > Hi Richard,
> >
> > there are numerous articles, do you intend to use anything more
> specific? 2D or 3D decoding? regular or irregular setups? Or you are
> looking for the most general case?
> > (when you say in C, do you mean published code examples?)
> > And by low-orders do you mean first-order systems mainly (b-format)?
> Most practical systems at the moment target up to 3rd-order, which are not
> very high orders either, but it makes a difference.
> >
> > Regards,
> > Archontis
>
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Re: [Sursound] Ambisonic Decoder Design Resources

[Jörn Nettingsmeier]

On 02/20/2016 06:22 PM, Richard Graham wrote:

Hi Archontis,

I would like to design decoders for 2d and 3d arrays, 1st through
3rd order (at least), both regular and irregular arrays. C code
examples would be incredibly helpful as I plan to develop decoders
for Pd and Max.


Fons' ambdec is GPL, and it comes with a nice set of example setups.
It's C++, but the way Fons uses it, it reads pretty much like plain C.
After all, a dsp loop is a dsp loop...


Most importantly, I’d like to figure out how to calculate these
coefficients myself and I am having trouble finding literature on
how to do that. I have reached out to a few folks who used their own
programs to calculate coefficients. Essentially, I’d like to build
my own program in the C programming language.


Aaron Heller has a Matlab/Octave toolkit out that will generate matrices
for you, and it's completely open. But it relies on quite complex 
functions of the framework... His solutions are used at CCRMA, to

great effect. Probably your best starting point.

Richard has one but keeps it proprietary, Fons has one but also doesn't
like to part with it (although he has been very generous about
generating custom Ambdec setups for people, me included).

For the nitty-gritty, check out the papers from recent Ambisonics
symposia and the ICSA conferences. Talk to Thomas Musil from Graz for
the old-school, lovingly hand-optimized matrix approach, or to Zotter et
al. for the All-Rad approach that works for arbitrary setups but is
quite complex and kind of brute-forceish. I can dig them up for you if 
you can't find them.



Shortly, I will have access to a 16-channel ring on the horizontal
plane and a b-format cube. This system will be modular and
configurable into irregular setups, too.


nice! but unless you really need extremely high horizontal resolution 
for research purposes or a truly humongous listening area, a better use 
for all those speakers would be to make a more or less uniform 3D rig.

gets you a nice dodecahedron for full third-order all around.


best,


jörn



--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487

Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister VDT

http://stackingdwarves.net

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Re: [Sursound] Ambisonic Decoder Design Resources

[Richard Graham]

Hi Archontis,

I would like to design decoders for 2d and 3d arrays, 1st through 3rd order (at 
least), both regular and irregular arrays. C code examples would be incredibly 
helpful as I plan to develop decoders for Pd and Max.

I have already developed some basic ambisonic externals for Pd 
(http://rickygraham.net/?p=176401730 ) 
based on encoding and decoding technical notes from Blue Ripple Sound 
(http://www.blueripplesound.com/decoding 
), which provides coefficients for 
basic array set-ups. 

Most importantly, I’d like to figure out how to calculate these coefficients 
myself and I am having trouble finding literature on how to do that. I have 
reached out to a few folks who used their own programs to calculate 
coefficients. Essentially, I’d like to build my own program in the C 
programming language. 

Shortly, I will have access to a 16-channel ring on the horizontal plane and a 
b-format cube. This system will be modular and configurable into irregular 
setups, too. 

Many thanks,

Ricky

> On Feb 20, 2016, at 12:00 PM, sursound-requ...@music.vt.edu wrote:
> 
> Hi Richard,
> 
> there are numerous articles, do you intend to use anything more specific? 2D 
> or 3D decoding? regular or irregular setups? Or you are looking for the most 
> general case?
> (when you say in C, do you mean published code examples?)
> And by low-orders do you mean first-order systems mainly (b-format)? Most 
> practical systems at the moment target up to 3rd-order, which are not very 
> high orders either, but it makes a difference.
> 
> Regards,
> Archontis

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Re: [Sursound] Ambisonic Decoder Design Resources

[Politis Archontis]

Hi Richard,

there are numerous articles, do you intend to use anything more specific? 2D or 
3D decoding? regular or irregular setups? Or you are looking for the most 
general case?
(when you say in C, do you mean published code examples?)
And by low-orders do you mean first-order systems mainly (b-format)? Most 
practical systems at the moment target up to 3rd-order, which are not very high 
orders either, but it makes a difference.

Regards,
Archontis


On 20 Feb 2016, at 17:25, Richard Graham 
mailto:ri...@rickygraham.net>> wrote:

Hi all,

Can anyone recommend literature on designing ambisonic decoders (in C)? 
Specifically, articles that speak to the calculation of coefficients for 
low-order decoders.

All the best,

Ricky
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[Sursound] Ambisonic Decoder Design Resources

[Richard Graham]

Hi all,

Can anyone recommend literature on designing ambisonic decoders (in C)? 
Specifically, articles that speak to the calculation of coefficients for 
low-order decoders. 

All the best,

Ricky
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