How does the surround sound work?
 

I've always encoded my KVCD's audio with dual channel in HeadAC3e. Do I need to set up my DVD in a special way to get the surround sound? Or do I have to have a special function on my surround amplifier? Is the KVCD surround a simulated surround or should I have sound in all speakers? Don't get me wrong, I get sound, but I would really like to get surround sound. :D

Since VCDs only support stereo-sound, your .mp2 file features, as you said, stimulated surround. If you want the sound on all speakers you have to do this on your surround amplifier. Look it up in the manual, most amplifiers can set all stereo sources to surround (I like listening to Metallica's S&M CD that way :twisted: )..

turning it worse:
:(

dvd2avi loose the dolby prologic information of audio tracks,
is extract as a normal ac3 2 channels and
the receiver don't "feel" as dolby prologic.

extract the audio with your ripper....try smartripper.
:wink:

8O Didn't know that!

Not at all !

You can have true surround in stereo-sound. That is the purpose of Dolby Surround encoding (and Dolby Prologic decoding) : to matrix surround channel C+R (center and rear) into the two stereo chanel L+R.

Simulated surround is when you do not have C+R matrixed in the stereo chanel and you "create" a sort of surrounding echo that opens the sound field and tries to give the illusion of a rear channel that does not exist.

So how do I rip and encode the audio to get "real" surround?

You ask to DVD2SVI to extract the AC3 without doing anything on it. And you transform the AC3 track into "dolby surround encoded into stereo" track with headache (see option, you can choose "stereo", "surround", or even "surround2" for better work with a DPL II compatible receiver)

But as told by Jorel, do not do the convert AC3->Stereo directly from DVD2AVI.

8O 8O
So are you saying the AC3 files that are output by DVD2AVi are not 5.1 but only stereo?? 8O

If you are talking to mee Jellygoose, no I didn't said that. Jorel did but I think he is wrong.

What I said is that the downmixing from AC3 to dolby surround must'nt be done with DVD2AVI as it does it very badly.

Well I don't think so either. I do the downmixing with Headache, and it seems to work pretty good. however my receiver gives me jerky sound with the rear speakers when I use Dual Channel as Compression mode... :roll:

i confirm...you loose "details" :!:
dvd2avi extract as a normal ac3 2 channels and
the receiver don't "feel" as dolby prologic.
you have to choose "force to dpl" (manual) in the receiver.

try extract the audio using smartripper!
will be different.

:!:

@jorel
How do I rip the audio with SmartRipper?

EDIT: Do I go to the "Stream Processing" tab, choose "Enable Stream Processing" and the right audio track, choose "Demux to extra file" and then press "Start"?

Do I have to do something to the audio to get it in sync with the video? I mean, the movie on the DVD is NTSC 29,97 fps but 99% FILM so I process the movie with ForceFilm in DVD2AVI. If so, what software do I need?

audioslave my friend,
you wrote:
"Do I go to the "Stream Processing" tab, choose "Enable...
....to extra file" and then press "Start"?"
yes,and you can uncheck the stream that you don't want!
:wink:

"....audio to get it in sync with the video..."
see the "audio delay"(ms) in the log of the ripper.
something like this:
0x80 - AC3 - 6ch / 48kHz / DRC / Delay: -67ms
than set the delay in your audio encoding program to -67ms!
:wink:

"...DVD is NTSC 29,97 fps but 99% FILM so I process the movie with ForceFilm in DVD2AVI."
:?
this i don't know,maybe will need to change the frame rate of the audio!

:wink:

Thank you very much, jorel! :D Just wanted to be sure. So if I rip the audio this way and then encode it with HeadAC3e I should get true surround sound, right?
Well, does anyone else know what to do with the audio? Do I need to change the audio frame rate to get it in sync?

audioslave,
please read my last post again,i edit and put some more details!

you can use HeadAC3he(very,very cool) and adjust this values:
destination format= mp2(of course)
resample= your choice....if your player suport,
use 48k... is better and size change just a little.
downmix type= surround2
bitrate=more bitrate,better quality but more size..your choice!
channel mode=dual channel

will be great!

:)

Thanks again friend! :D What does the "Booster" function do?
And I still need to find out if I need to change the audio framerate... :?:

let booster as default=1

my little big hint:
i choose normalize to 98% cos with 100% sometimes got clicks like
little explodes....and i'm really bored with sound.
when the sound is normalized,the low volume encrease and
the high volume decrease,trying to make a "media" of the audio.
in one movie,we have more "low volumes" than "high volumes",
than normalizing the sound to 100%,can turn it "unreal" and too loud.
i think that the proud volume is the amplifier that give to you,
not the source at 100%...
100% is the last pass to got saturation and distorcions.

i wait that my horrible english don't turn it all more confuse!

:)

"Not at all !

You can have true surround in stereo-sound. That is the purpose of Dolby Surround encoding (and Dolby Prologic decoding) : to matrix surround channel C+R (center and rear) into the two stereo chanel L+R."

Well, that's a matter of definition. The 2 Dolby-Modes Headac3he has built in are "psycho models". If you mix l+r+center+rear into stereo you can't separate them afterwards, but you can give the impression by altering c+r's sound. It may be that Dolby ProLogic amplifiers manage to seperate them, but I wouldn't call that real surround..

ok new_bee my friend
:wink:
i'm with you in this explanations:
"but I wouldn't call that real surround"

little hint:
using dual channel,give the same size as stereo but
dual channel use real 2 individual channels,one for right,another for left.
then,what is in one channel don't "interchange" with other channel.
means...you don't have "leftovers" from other channel,
they are really individual,and one channel don't "corrupt"
(mix in background) with the other channel.
the result is clean.
you can feel it easy encoding mp3 with musics that have
real separations between channels....use the "balance" and
you feel that one channel is really separate from other with dual channels!

hey,this link show big details and tests about quality:
http://rarewares.hydrogenaudio.org/t...sentation.html
seems of topic but is cool,help a lot!
:wink:

ps:
i love music, listen everyday...every time.....all the time.
for me all little detail is important...!

:arrow: ahh,...sorry my bored poor english!
:oops:

Sorry my pal but that is the basis of Dolby Surround encoding : to take 4 indepedant channels and matrix them into the 2 stereo channels. And they are completly dematrixed and restored by the DPL decoder. Go there to see how it's done.
This is real surround because you can have completly different sound on rear channel (for instance music) while other three receive the voices.

It's true surround, and is like this since 25 years.[/b]

Thanks for that link - I've never heard that before. Now I agree with you :D

So does anyone know why my receiver, and also my dad's receiver don't like Dual Channel at all? :roll:
Is there some link, where I can download samples, which are properly made for Dual Channel and Stereo? :?

removing doubts Jell

your receiver don't like dual channel or surround 2 ?
did you try encode using dual channel with "surround(alone)" ?

so the mp2 file will be 2 channels but it will have surround sound within it?
will this work if i have a normal amplifier connected to the front output from the dvd player and another normal amplifier connected to the rear output, or does it need a special surround sound amplifier?
Bilal

i have the same like you Bilal,
one Akai AA-A3s(Japan) and one Polivox AP-800(Brasil)
4 big speakers with piezeletric tweeters (Philips) that don't "hiss"
and some more bla,bla,blas....very cool and clean! :wink:
got good efects.

but for true surround you need a
"real" prologic receiver (amplifier) :!:

:)

will i still get good effects?

yeah,"some" cool effects.
8)

little hint:
remember,don't encode with too loud volume(normalize at 98%)
the volume is for the amplifier(receiver) not for the source.
this will encrease the quality and give less distorctions.
normalize turn the
low :arrow: loud
and
loud :arrow: low...
it means, encrease the low and decrease the high volume
changing the dinamic "impression" of the real sound
and sometimes is dangerous for quality!
listen the cds of "megadeth"...cool musics(i like) but
too loud and "unclear" knocking on the door of "scratch",
in the headphones is better than speakers.
the reason is the high impedance of the headphones that
decrease the volume and turn the sound a bit clear!

hey Bilal,i "talk" too much and it's only my oppinion!

:wink:

thanks jorel for the ideas, this would have probably taken you a while to figure out so thanks for sharing it, and even if you talk to much it's good quality stuff :)

i am trying to encode an ac3 file using head3ache but it's stopping half way and telling me that it can't continue because the ac3 file maybe corrupt, i ripped the sound using smartripper, what's wrong?
thanks
Bilal

try encode this ac3 with BeSweetGUI too.
if don't work,the ac3 is really corrupt.
then extract it again!
:)

does besweet gui have surround as well?
thanks

yes,
in "Hip", check "use mpa decoder"....
use the mouse and see details in the pop up!
:wink:

thanks for the quick reply, are you on here all day long? :lol:

Well, I am :!: This is my virtual home :mrgreen:

-kwag

Nothing special into the amplifier, but you must have a Dolby Prologic Decoder before the amplifier.
In AV amplifier, the decoder is already included, but you if you want you can buy separate decoder and add up to 4 amplifiers, one per channel.

That's the same for DPL2 or DTS.

i didn't have time to try it in the weekend as i went on a ski trip :) but i am encoding ocean's 11 now, already finished the audio using head3ache, i had to run ac3 fixer over it which fixed the head3ache problem, i have dolby prologic in my dvd player so i'll see how it goes when i get back home.
thanks for your help everyone.
Bilal

Bilal, where did you find this ac3 fixer program? I don't know why but I often run into problems with headac3he crapping out on me mid-conversion. I usually find turning off 2-pass fixes it with minimal time difference. Maybe it's because I've always been ripping ac3 from dvd2avi? Maybe I'll try smartripper next time,

i found it in the tools menu in dvdrhelp.com it's called ac3fix here's the exact site for it:
http://www.digital-digest.com/dvd/do....html#ac3utils

i used smartripper and ripped the movie twice but it still gave me errors in ac3 file so this little program is good :wink:

more about audio extracted with dvd2avi and/or smartripper:

http://forum.doom9.org/showthread.php?s=&threadid=58231

no more doubts (i think) !
:wink: