Thanks a lot Bruce for the pointers, I will check your work! Regards, Archontis
On 25 May 2016, at 19:42, Bruce Wiggins <bruce.wigg...@gmail.com<mailto:bruce.wigg...@gmail.com>> wrote: 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<mailto: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<mailto: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/e9cb0744/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.
