Definately mentioned and looked at in Wiggins, B. Paterson-Stephens, I., Schillebeeckx, P. (2001) The analysis of multi-channel sound reproduction algorithms using HRTF data. 19th International AES Surround Sound Convention, Germany, p. 111-123.
Wiggins, B. (2004) An Investigation into the Real-time Manipulation and Control of Three-dimensional Sound Fields. PhD thesis, University of Derby, Derby, UK. p. 103 See http://www.brucewiggins.co.uk/ for my look at the you tube implementation which also assumes symmetry...... Cheers Bruce On Wed, 25 May 2016 16:38 Politis Archontis, <archontis.poli...@aalto.fi> wrote: > Hi, > > There has been some discussion before on B-format or HOA to binaural > filters (HRTF-based), which no matter if it goes through a virtual decoder > or with a direct HRTF-to-Bformat approach, two times the number of HOA > channels of filters are needed (so 8 for B-format, 18 for 2nd-order HOA, 32 > for 3rd-order HOA etc. ). > > Playing around a bit I realized that if the HRTFs are made left-right > symmetric, which makes sense to always force for non-individialized ones > (and also for individualized sometimes), then a smaller set of filters is > needed due to this left-right symmetry. For example for B-format binaural > filters, the W, X and Z channel would have exactly the same filters, while > the Y channel would have the same filter with a polarity inversion for one > ear with respect to the other. Hence 4 filters instead of 8. > > Thinking about it, it simply makes sense, as the spherical harmonics are > themselves either symmetric or antisymmetric with respect to the x-z > (median) plane. This is also what makes mirroring of a HOA sound scene from > left to right for example, as easy as inverting certain HOA channels. > > My question to any of the decoder developers on the list is if you have > seen that anywhere analyzed or mentioned in the context of binaural > decoding?? > > Many thanks, > Archontis Politis > > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > https://mail.music.vt.edu/mailman/private/sursound/attachments/20160525/a7b7b617/attachment.html > > > _______________________________________________ > 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. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20160525/f793cacf/attachment.html> _______________________________________________ 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.
