I think IRCAM Spat is doing that quite well. I do not know what algorithm lies behind. Maybe Thibaut Carpentier I sometimes see on this list could tell us something more about that... Ciao simonefontana
On 2/29/12 3:28 PM, "Fons Adriaensen" <f...@linuxaudio.org> wrote: >On Wed, Feb 29, 2012 at 01:15:40PM +0000, Miguel Negrao wrote: > >> I¹ve been a bit disconnected from the ambisonics world. From my past >>reading on this list it is my understanding that there isn¹t an explicit >>formula for decoding coefficients for non-symmetrical setups. Are there >>currently available tools to generate decoding coefficients for >>non-symmetrical setups or an iterative algorithm that I could implement >>on my own ? > > >Two possible methods have been published. > >The first is Franz Zotter's work, using an 'almost regular' virtual >layout based on >t-designs for which a decoder can be designed in closed form. Then the >virtual set >of speakers is mapped onto the real one using VBAP. As far as I know >there is no >'ready to use' toolset for this method. > >The second is the subject of BLaH paper #4, and is based on using a >non-linear >optimisation toolset to find a solution, given the error constraints and >weights >for a set of performance metrics. I developed more or less the same (even >using >the same freely available non-linear library), but wasn't allowed to >publish the >results, so I can confirm this can work rather well. What looks like a >practical >implementation (by B,L & H) of this method is scheduled for presentation >at the >next Linux Audio Conference at CCRMA. > >I don't think either method can be used 'blindly', in the sense that you >just >throw a set of speaker coordinates at it and get a guaranteed result. You >will have to evaluate the results, and you may have to decide on >tradeoffs >and iterate the procedure using modified parameter sets. At this point you >will need some familiarity with the internals in order to be able to >proceed. > >Ciao, > > >-- >FA > >Vor uns liegt ein weites Tal, die Sonne scheint - ein Glitzerstrahl. > >_______________________________________________ >Sursound mailing list >Sursound@music.vt.edu >https://mail.music.vt.edu/mailman/listinfo/sursound > _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
