On 01/27/2016 01:56 PM, Jörn Nettingsmeier wrote:
On 01/26/2016 11:05 PM, Politis Archontis wrote:
Hi Jorn,
yes that is correct. I think however that the virtual loudspeaker
stage is unnecessary. It is equivalent if you expand the left and
right HRTFs into spherical harmonics and multiply their coefficients
(in the frequency domain) directly with the coefficients of the sound
scene (which in the 1st-order case is the B-format recording). This
is simpler and more elegant I think. Taking the IFFT of each
coefficient of the HRTFs, you end up with an FIR filter that maps the
respective HOA signal to its binaural output, hence as you said it's
always 2*(HOA channels) no matter what. Arbitrary rotations can be
done on the HOA signals before the HOA-to-binaural filters, so
head-tracking is perfectly possible.
Wow. That sounds intriguing, thanks! I'll try to wrap my head around the
SH expression of an HRTF set in the coming months, hopefully with the
help of Rozenn Nicol's book.
Sorry to revive such an old thread, but the AES monograph on binaural
technology has arrived, and I've begun to study it. Definitely a great
resource, recommended:
http://www.aes.org/publications/monographs/
Archontis, I'm still trying to understand how to express a set of HRTFS
as a SH series.
If I understand correctly, all HRTFS for a given ear can be expressed as
a function on the sphere, but it would be frequency dependent. So we'd
need an extra degree of freedom there, how does that tie in with
Ambisonics? One HRTF "balloon" per frequency bin?
Also, how do you express the inter-aural time delay conveniently (which,
as I've learned from Rozenn Nicol, depends not only on direction, but
also on frequency)?
Are there papers out there that describe this in detail?
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.
