AC3 Question at DVinfo.net

Eric Ruff · October 2nd, 2007, 07:16 PM

I've been working on a short video clip and the last couple of days has found me in a bind. The clip is a title with exploding letters. With each letter explosion I have a wave file that is in sync in a 5.1 layout. It's 1 wave file for each letter of a 2 row title. If the letter is on the right top row, the the right front speaker has the explosion. If it's a bottom row left letter then the rear left speaker has it and so on. When I play back the clip in the preview, everything is perfect, I get sound from the RF, center, LF, RR, and LR speakers when I'm supposed to. Then when I render it to an AC3 file I lose the center speaker and that sound goes to both front speakers. Leaving a decent hole in my soundstage. I checked all my surround sound settings, the surround panner, properties, AC3 config and I can't figure out what is wrong.

Any suggestions? Thanks!

Sorry for my first post being a question.... lol

Oh yeah, I'm using Vegas 7.0e.

Emre Safak · October 2nd, 2007, 07:38 PM

Can you post your VEG file?

Seth Bloombaum · October 2nd, 2007, 08:17 PM

Did you go into the "custom" dialog when rendering, and spec the 5.1 template? For some reason, the 5.1 template is not available until you go into the "custom" dialog.

Eric Ruff · October 2nd, 2007, 09:00 PM

Quote:

Originally Posted by Seth Bloombaum

Did you go into the "custom" dialog when rendering, and spec the 5.1 template? For some reason, the 5.1 template is not available until you go into the "custom" dialog.

Yeah, I'm using the 5.1 template... unfortunately I'm getting a 4.1 file... no center channel.

Eric Ruff · October 2nd, 2007, 09:02 PM

Quote:

Originally Posted by Emre Safak

Can you post your VEG file?

Sure.

http://rapidshare.com/files/59888644/Untitled.veg.html

Emre Safak · October 6th, 2007, 08:04 PM

I finally had a chance to inspect your VEG file. It looks okay, so the problem is either in rendering, or playback. Tracks 2 and 8 have information in the center channel so it should not be silent.

How are you playing your AC3 files? Do you have a software "surround mode" enabled, like "SRS CircleSurround" or "Dolby Pro Logic II"?

Eric Ruff · October 6th, 2007, 11:02 PM

Quote:

Originally Posted by Emre Safak

I finally had a chance to inspect your VEG file. It looks okay, so the problem is either in rendering, or playback. Tracks 2 and 8 have information in the center channel so it should not be silent.

How are you playing your AC3 files? Do you have a software "surround mode" enabled, like "SRS CircleSurround" or "Dolby Pro Logic II"?

No, everything is hardware... I have an Audigy 2 soundcard with a Creative 5.1 system. I just noticed that if I play the .ac3 file in Cyberlink PowerDVD 7.2 I lose the center channel, if I play it in Nero ShowTime 4.1 it plays fine. I'm using Sony DVDArchitect 4.0b to make the DVD and it also loses the center channel. I never had this problem before, it just happened one day and it hasn't fixed itself...!

So the problem probably isn't Vegas... I'll keep working on it. Thanks for the help!

Emre Safak · October 7th, 2007, 11:52 AM

That explains it! Go into PowerDVD's audio settings and see what has happened. The AC3 decoder might be doing something funky. Nero has its own AC3 decoder. PowerDVD uses Cyberlink's.

Martyn Biesheuvel · September 11th, 2010, 08:01 AM

vegas 7 & DVDA 4 and 5
after rendering, my theatre center speaker plays zilch!
other dvds are fine, other front and rear speakers i pan to using surround panner per track, in Vegas video, work fine, not the centre speaker

vegas preview window plays center 'sound' [though i have2 speakers attached to my editing pc] but after rendering DVDA plays nothing in preview and in my theatre sound system.... nothing

all other panned sound to speakers are ok.

any ideas??

yours sincerely,

Martyn Biesheuvel.

October 2nd, 2007, 07:16 PM	#1
Eric Ruff Tourist Join Date: Sep 2007 Location: KINGSLAND, GEORGIA Posts: 4	AC3 Question I've been working on a short video clip and the last couple of days has found me in a bind. The clip is a title with exploding letters. With each letter explosion I have a wave file that is in sync in a 5.1 layout. It's 1 wave file for each letter of a 2 row title. If the letter is on the right top row, the the right front speaker has the explosion. If it's a bottom row left letter then the rear left speaker has it and so on. When I play back the clip in the preview, everything is perfect, I get sound from the RF, center, LF, RR, and LR speakers when I'm supposed to. Then when I render it to an AC3 file I lose the center speaker and that sound goes to both front speakers. Leaving a decent hole in my soundstage. I checked all my surround sound settings, the surround panner, properties, AC3 config and I can't figure out what is wrong. Any suggestions? Thanks! Sorry for my first post being a question.... lol Oh yeah, I'm using Vegas 7.0e.

September 11th, 2010, 08:01 AM	#9
Martyn Biesheuvel Tourist Join Date: May 2005 Posts: 4	i'm losing center speaker after rendering as well! vegas 7 & DVDA 4 and 5 after rendering, my theatre center speaker plays zilch! other dvds are fine, other front and rear speakers i pan to using surround panner per track, in Vegas video, work fine, not the centre speaker vegas preview window plays center 'sound' [though i have2 speakers attached to my editing pc] but after rendering DVDA plays nothing in preview and in my theatre sound system.... nothing all other panned sound to speakers are ok. any ideas?? yours sincerely, Martyn Biesheuvel.

October 2nd, 2007, 07:38 PM	#2
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	Can you post your VEG file?

October 2nd, 2007, 08:17 PM	#3
Seth Bloombaum Inner Circle Join Date: Sep 2003 Location: Portland, Oregon Posts: 3,420	Did you go into the "custom" dialog when rendering, and spec the 5.1 template? For some reason, the 5.1 template is not available until you go into the "custom" dialog.

October 6th, 2007, 08:04 PM	#6
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	I finally had a chance to inspect your VEG file. It looks okay, so the problem is either in rendering, or playback. Tracks 2 and 8 have information in the center channel so it should not be silent. How are you playing your AC3 files? Do you have a software "surround mode" enabled, like "SRS CircleSurround" or "Dolby Pro Logic II"?

October 7th, 2007, 11:52 AM	#8
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	That explains it! Go into PowerDVD's audio settings and see what has happened. The AC3 decoder might be doing something funky. Nero has its own AC3 decoder. PowerDVD uses Cyberlink's.