HydrogenAudio

Digital Audio/Video => Movie/Multichannel audio => Topic started by: logi on 2004-05-02 18:22:31

Title: prologic2 maker
Post by: logi on 2004-05-02 18:22:31
Hi everyone I'm a new user  .

I have ac3 file and wondering if there is a way to convert him to stereo with prologic2 information .
now I know that if I convert to regular stereo then I will get just stereo effect from my 6 speackers.
BUT if I convert to "special stereo" then I will be able to get somting like ac3 5.1 sound.

(Correct me if I'm wrong)

so I want to know how to convert to "special stereo"?

Thanks in advance. 
Title: prologic2 maker
Post by: sven_Bent on 2004-05-02 18:24:38
use azid v1.9 form www.doom9.org

it supports plain stereos but altso dolby prologic and dolby prologic2 downmixing
Title: prologic2 maker
Post by: 21_already on 2004-05-02 18:33:21
Remember, once you have a stereo soundtrack coded in prologic 2 you'll need to have the proper decoder to correctly upmix it back to 5 channels, so if you're thinking about playing it back on say a DVD player, you'll need somewhere along the way a DPLII capable DVDplayer/amplifier/T.V. The older ones only do DPL1 so be careful
Title: prologic2 maker
Post by: Latexxx on 2004-05-02 18:54:37
Quote
The older ones only do DPL1 so be careful

DPL II is backwards compatible (IMHO).
Title: prologic2 maker
Post by: logi on 2004-05-02 19:37:08
Thanks alot guys !

Say is this normal that regular stereo and dpl2 are at the exact same size??? why???

Is there a way to make sure that I have dpl2 file instead of play it in my amplifier?  (like avinfo for movies)

And one last question:
I converted the ac3 to dpl2 and it came out as wav file so if i encode the wav to mp3 the dpl2 information will be still preserved right?
Title: prologic2 maker
Post by: magic75 on 2004-05-03 16:35:49
Quote
Say is this normal that regular stereo and dpl2 are at the exact same size??? why???

Yes I think it is. I am really not an expert in this area, but as far as I have understood it DPL actually works in the anaolgue domain using some phase shift tricks I really don't know how the work. So in the digital domain, you sample the analogue DPL signal just as you would with a normal stereo signal, and no extra bits are needed since the DPL info is stored in these phase shifts, or whatever they are.... Now someone who really knows this can explain it a bit better, please...

However, sliding over to your last question, this would only be 100% valid if you keep the signal uncompressed. If you want to compress to MP3 you can not be 100% sure that all DPL info is preserved due to the fact that the encoding algorithms are developed to remove info that we humans can't hear anyway. Problem is that these algorithms are not really designed to maintain these phase tricks by DPL. However, it does seems to work pretty good anyway, as I have heard/read in this forum. Do a search on maybe MP3 and surround and I think you will find some info....
Title: prologic2 maker
Post by: logi on 2004-05-05 20:44:53
Thank U good explanation !
I'll search a little