Hmm, SL would first need to synthesize stereo sound, as should be heard through headphones, very well, it seems. From what I can tell, the technique ends up simulating wearing headphones when you're actually listening through speakers. According to the site, the idea is that the stereo sounds with all the right audio cues (time and volume differences) were recorded, but if you play it back using speakers, the illusion ends up destroyed by the interfering crosstalk. [1]
But I'm pretty sure that some SL sounds (at least, voice - I vaguely recall SL inworld audio stuff being more nuanced?) aren't synthesized with the correct-for-headphones effects. I remember feeling very disoriented in voice meetings because people to my left or right ended up having their voice playing pretty much exclusively in my left or right ear, which isn't correct. I could imagine that, in such situations, real-world crosstalk from loudspeakers actually helps recreate the illusion during playback - perhaps it was a bit of a hack based on having the volume difference be interpreted as attenuation. It does look like implementation is a lot more complicated than it, er, sounds... There's something involving something called a BACCH filter, with "some aspects not published for propriety reasons". [2] So to apply this to SL, there'd need to be: 1) accurate synthesizing of sounds as would be heard next to the ears (i.e. what headphones should play) for both inworld clips and voice, using both time delay and attenuation 2) knowledge of whether the listener is using headphones or speakers 3) implementation of this crosstalk cancellation thing if they're using speakers 3b) permission/licensing to use it from Princeton.... Celi [1] http://www.princeton.edu/3D3A/PureStereo/Pure_Stereose10.html#x21-1000010 [2] http://www.princeton.edu/3D3A/Papers.html On Tue, May 24, 2011 at 1:42 PM, Lee ponzu <lee.po...@gmail.com> wrote: > I saw this cool demo of 3D sound. This is totally different from the SL > Voice technology, and I think it would compliment it perfectly. > > Take a look... > > http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=princeton+3D+sound > > The basic idea is that stereo gives a weak illusion of 3D. You have the > left signal, ls, and the right signal, rs. A filter computes > > rs_new = rs - ls > ls_new = ls - rs > > and then play rs_new and ls_new. (Details left as an exercise...) > > In English---when you record in stereo, you record cross talk between the > mics which is recreated when you play back. This idea removes the cross > talk, and dramatically increases the 3D illusion. It is a simple filter and > works totally at playback time on all sound sources and any stereo > recording. It would be easy to add it to the viewer... > > Just an idea. > ponzu > > > > > _______________________________________________ > Policies and (un)subscribe information available here: > http://wiki.secondlife.com/wiki/OpenSource-Dev > Please read the policies before posting to keep unmoderated posting > privileges >
_______________________________________________ Policies and (un)subscribe information available here: http://wiki.secondlife.com/wiki/OpenSource-Dev Please read the policies before posting to keep unmoderated posting privileges
