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View Full Version : 5.1 to WXYZ and Back


specise_8472
12th January 2004, 11:10
Before you read on - If you have not been keeping up with or follwing the Sticky Thread Stereo to 5.1, READ NOW so as to know what I am talking about.

I have just uploaded a bidule to do 'reverse' engineering of 5.1 music/soundtracks.

ftp://daphy.mine.nu/Ambiophonics/Reverse.rar

What this program does is to decode a 5.1 signal into ambisonic WXYZ format using all the available information in the soundtrack. It even computes a Z (height) channel.
When you feed this WXYZ back through my Ambiophonic 1.5 encoder you will get the original information back plus added sounds. Plus a Center surround channel for DTS matrix decoding. From my tests , the center surround channel sounds like it sould be there - as if mixed by the original sound studio.
There is much more added spacious sounds. Holes in the soundfield have been filled. Plus directional sounds still remain the same.
One of my test peices was the scene 2 from Saving Private Ryan Zone 1 DTS - The storming of the beach at Omaha. It really adds dimension to the sound. And the explosions sound better, the bullets still wizz around with even more direction in them:)

You can re-encode with Emigrator if you want to - but be warned, it will most likely 'KILL' the directional information. IE sounds for certain speakers may not appear or appear in other speakers as will.

A tech note.
Both of the Bidules have choices I J K in them. In testing we (me and kempfand) have found that only I to I and K to K produce these desired results. The others produce interesting sound mixes. Play and see.

I am interested in peoples results. This is uncharted waters. I don't know of any other system like this. But feel free to prove me wrong
:D

BTW the file contains a Bidule to get you started. Take note of the Channel ordering of my plugins (Explained inside).

Sycho
13th January 2004, 00:51
Thank you, been trying to do this for mounths

what are the equations you used?

5.1 > b-form > 7.1 (http://forum.doom9.org/showthread.php?s=&postid=413591#post413591)

specise_8472
13th January 2004, 06:59
Originally posted by sycho
[B]Thank you, been trying to do this for mounths

what are the equations you used?


It is basically the reverse of my Ambiophonic method. The beauty of Ambiophonics is that you convert WXYZ to 5/6.1 for home theatre, but if you then get a ambisonic decoder you can recover the original WXYZ for use on it.
So I's just tried the reverse process on already made commercial 5.1 AC3/DTS, and was very pleased with the result.