Convert Dolby Pro Logic to 5.1

DataMeister wrote on 9/19/2003, 6:29 PM
Does anyone know of a way to decode the prologic surround sound from a stereo stream so that the separate channels could be used as a base when creating the rest of a 5.1 surround project. Or do you basicly just have to start over from scratch?

And if that is the case then what is the standard procedure for taking a stereo reccording and simulating 5.1 surround? Are there any quick tips, or web sites, or good books on this subject?

JBJones

Comments

DataMeister wrote on 9/21/2003, 9:59 PM
Just wondering if this got lost over the weekend.

JBJones
AudioIvan wrote on 9/22/2003, 2:17 AM
jbjones, if you want to do 5.1 from prologic or 2 channel audio there are 3 or 4 ways.
1.Import stereo wav in Adobe Audition,Multitrack layout,wiev Multichannel Encoder,on the right side there is track options,I choose surround panner,stereo source,adjust sub channel level to 50,center channel 100,track level 100.Export options:Export as 6 individual mono wave files.After that import just the LFE in Sound Forge & apply resonant filter @ 65 Hz,Resonance 2.0,Wet/Dry 100%,Apply filter settings & export as 48000,32 Bit mono.The LFE now is set all I need now is surround "effect".
Import the LeftSurround & RightSurround in Sound Forge apply "AnalogX Vocal Remover" & export them again to the same dir where I have the other files.Now I have 6 mono wave files ready for encoding AC3,DTS.
THIS METHOD IS FOR MUSIC ONLY

2.http://forum.doom9.org/showthread.php?s=805e17d8be4d5cfec926040afee83a39&threadid=60137
THIS IS THE BEST WAY !!!

3.http://www.freewebs.com/kpex/ac3guide.htm
GOOD & EASY

4.Almost the same like 3. but encoding with SoftEncode(batch options)
by Eye of Horus
MUCH BETTER SOUND QUALITY DUE TO COMERCIAL AC3 Encoder Inclided

To transcode your Dolby ProLogic Use BeSweet,hope this helps.
AudioIvan
DataMeister wrote on 9/23/2003, 2:18 AM
After doing a little research I found the information on Dolby's web site which gives a really good idea of how surround information is encoded into two channels and then back into 4 channels for the Pro Logic surround sound.

It's quite ingenious in fact. But its seems like it would probably be really simple (for a programer) to create a DirectX plugin that could perform all of these calculations and just spit out a 4 channel Pro Logic or perhaps even a 5 channel Pro Logic II mix.

Any programers out there want to tackle this?
Dolby Surround Pro Logic II decoder Principles of Operation

JBJones