Sycho
28th August 2003, 20:00
I started this tread in hope to have (another) way of upmixing 2-channel audio, if it works it will be simaler to this (http://forum.doom9.org/showthread.php?threadid=29277) but will work better for Dolby Surround
Just so you know, I personaly have not got Eye of Horus guide to work, my comp just kept frezzing
The following was taking from:
http://www.geocities.com/ambinutter/UHJ_and_Ambisonic_equations.html
Dolby MP:
W' = 0.36(S - jD(a /180))
X' = 0.54(S + jD(a /180))
Y' = 1.00D(a /180)
Dave Keating actually suggested constants for X of 0.54 and 0.53; Martin Leese changed these to 0.54 and 0.54 to simply things.
where:
S = Left + Right
D = Left - Right
a = Width control, varying between 0 and 180°
j = 90° phase shift
What Dave Keating suggests in his paper (ref. at end) is to take the outputs from a standard Pro Logic decoder and convert these to B-Format. He makes the point that such a conversion must also cope well with Dolby Surround because when the steering logic of a Pro Logic decoder becomes confused, it falls back to being a Dolby Surround decoder. Here are Dave's equations for this:
W' = 0.250Centre + 0.177S - 0.5jSurround
X' = 0.467Centre + 0.165S + 0.5jSurround
Y' = 0.7D
Is there any way that these equations can be incorperated into EoH's new or even older Ambisonic method, as the other one works best with UHJ encoded material but if these equations can be used instead, it SHOULD provide better results on Dolby Surround encoded content.
Just so you know, I personaly have not got Eye of Horus guide to work, my comp just kept frezzing
The following was taking from:
http://www.geocities.com/ambinutter/UHJ_and_Ambisonic_equations.html
Dolby MP:
W' = 0.36(S - jD(a /180))
X' = 0.54(S + jD(a /180))
Y' = 1.00D(a /180)
Dave Keating actually suggested constants for X of 0.54 and 0.53; Martin Leese changed these to 0.54 and 0.54 to simply things.
where:
S = Left + Right
D = Left - Right
a = Width control, varying between 0 and 180°
j = 90° phase shift
What Dave Keating suggests in his paper (ref. at end) is to take the outputs from a standard Pro Logic decoder and convert these to B-Format. He makes the point that such a conversion must also cope well with Dolby Surround because when the steering logic of a Pro Logic decoder becomes confused, it falls back to being a Dolby Surround decoder. Here are Dave's equations for this:
W' = 0.250Centre + 0.177S - 0.5jSurround
X' = 0.467Centre + 0.165S + 0.5jSurround
Y' = 0.7D
Is there any way that these equations can be incorperated into EoH's new or even older Ambisonic method, as the other one works best with UHJ encoded material but if these equations can be used instead, it SHOULD provide better results on Dolby Surround encoded content.