AC3 center channel in all speakers, why?

[Musitektus]

I'm having trouble with multichannel playback on Divx files I've encoded. The Center channel is played back through all 6 speakers (well 5, not LFE of course).

I've checked the AC3 file to be sure that each channel is properly separated into FL, C, FR, SL, SR and LFE -- everything is perfectly fine. Even when I play the AC3 by itself through PowerDVD or other programs each separate channel plays properly through each separate speaker.

However, when the Divx video is played back, the Center channel is played through all the other speakers as well. Is this a setting I need to change in AC3filter?

Does anyone know what's going on?


Musitektus

edit: As far as I know, everything is correctly set up in AC3filter: the output is set for 5.1, the matrix has values for the correct channel output, etc.

[Musitektus]

Has anyone else ever experienced this problem?


edit: If anyone thinks it's important to know, I have a Voyetra Turtle Beach sound card and a typical THX sound setup.

[KpeX]

1. What happens when you play the un-muxed AC3 using AC3 filter ?

2. What are you using to mux the video + AC3 ?

3. What container are you using? If AVI, have you tried alternate container formats such as OGM or MKV?

[Musitektus]

Sorry, I haven't responded in so long. I've been too busy.

[1. What happens when you play the un-muxed AC3 using AC3 filter ?]

The same exact thing happens, but not when I play the un-muxed AC3 in PowerDVD.

[2. What are you using to mux the video + AC3 ?]

Unfortunately, Nandub -- because that's what came with Gordian Knot. I haven't looked at AC3mux or VirtualDubMod yet.

[3. What container are you using? If AVI, have you tried alternate container formats such as OGM or MKV?]

I'd prefer not to switch container formats just yet. I've just started to figure out AVIs, and I want to master one format before I try switching to another.

[sekxx]

try "odio decoda" (another AC3 DSF)(just copy/paste it to a google search)
and see if it work.


On the container subject, IMHO avi is not the container to use with new A/V codecs, i don't think your trouble came from avi but using adavanced feature like 5.1 vbr muxing with video, subtitle, chapter, streaming...
will be much more easier for you to do with OGM/MKV than with avi.

[Musitektus]

Thanks, I'll check out "odio decoda." However, I would still like to know how to get AC3filter to do it correctly.

I know it has to be something I have wrong with AC3filter, since the AC3 plays correctly whenever AC3filter is NOT being used.

I've read that OGG/OGM is a good alternative, so I will definitely check it out in the future. Later, I will probably try more advanced features like "5.1 vbr muxing with video, subtitle, chapter, streaming...," but I really need to master one concept before moving on to another.

edit: One thing I just realised about the AC3 playback with AC3filter is that the Center channel is actually NOT playing through the center speaker at all. The center channel is ONLY played through the speakers that should not (FL, FR, SR, SL). Does that make sense? ...it doesn't to me.
???
confused,
Musitektus

[Valex]

@Musitektus
Filter version/OS/SoundCard?

Test with http://ac3filter.sourceforge.net/download/ac3test.zip - is it the same thing?
Try to switch between WaveOut and DirectSound renderers.
Send me the registry key [HKEY_CURRENT_USER\Software\AC3Filter]

[nuked]

ok I know we have the expert working on the issue now... but I just thought I'd ask the really obvious... is the speaker configuration in AC3filter set to 3/x, like 3/2+SW or something like that not 2/2 or something with no center channel? Quadro mode will does exactly what you are saying.

[Musitektus]

@Valex

[edit: I sent my AC3filter registry key to your e-mail]

I'm using AC3filter v0.61b, Windows XP Pro, Voyetra Turtle Beach soundcard

When I played the AC3 test file I had the same problem. Except, I found another problem that I did not notice at first... the left and right surround channels are extremely quiet. They were nearly impossible to hear without putting my ear against the speakers.

The output levels show everything correctly, but the sound is still wrong.

I tried switching between WaveOut and DirectSound renderers, but it does not play differently.

@nuked
My output is set to '3/2+LFE 5.1 channel'. At first I thought that perhaps it was in quadro mode and not telling me or letting me change it. But this this doesn't seem to be the case. Thanks though.

Musitektus

[GBX]

i recommend updating to ac3filter v0.70b

[Musitektus]

I've been taking AC3filter v0.70b for a test drive, and I have to say: Good job, Valex! You've made quite a few very sweet improvements since v0.61b. Very nice!

However, the problems I've been having are still exactly the same. After a bunch of fiddling around with different settings, I'm beginning to believe that the problem is actually a conflict with the Cyberlink Audio decoder (that PowerDVD uses).

AC3filter shows everything to be correct, but the channel placement is still not right, so I started to look at ways to figure out where the conflict is:

First, I played the AC3test.vob file in PowerDVD -- and it sounds perfect. Then I played it in Media Player Classic (using AC3filter), and it was wrong. So then I selected "Prefer other decoder" under the System tab in AC3filter, and tried it again.

This time the surround channels were playing at the correct volume, but they were coming out of both rear AND FRONT channels. This sounds to me like it was playing as STEREO sound through a 6-channel setup.

This then made me decide to check Cyberlink settings in Media Player Classic (under Play =>Filters =>Cyberlink Audio Decoder). A small dialog box called "Properties" comes up and gives me 2 options for Audio Mode:
DOLBY SURROUND and Stereo (the other options are greyed out)

I shouldn't want either of these, right? DOLBY SURROUND is only for stereo audio that has had the other channels downmixed into it to be extracted on playback. What I need is Dolby Digital AC-3. Somehow I need to convince Cyberlink that I'm not using a stereo audio source. This must be why it always sounds (even when I supposedly am only using AC3filter exclusively) like the center channel is coming out of every speaker -- because it's playing it in stereo -- sort of.

So, it seems like Cyberlink is overriding some of the settings in AC3filter even when I'm only using AC3filter, but how and why?

Is anyone else using the same hardware and/or software that I'm using?

AC3filter v0.70b, Windows XP Pro, Voyetra Turtle Beach soundcard, 5.1 speaker output, Cyberlink PowerDVD Version 4.0C.11

[Musitektus]

I suppose the next logical step would be to uninstall Cyberlink and then try playback using AC3filter. That way there cannot be any conflict (I think).

If possible, I'd really prefer not to do do this though, as PowerDVD is the only thing that DOES play multichannel audio correctly on my computer... grrr.

Musitektus

[melvinvc]

I am using WinMe and Win98SE, and I had exactly the same problem.
The solution I found was: using Graphedit and regdrop I unregistered the PowerDVD directshow control and everything went right. Try that option to not uninstall this application.

[Musitektus]

I'm so excited... someone else has my problem... and even better has been able to fix it themselves...

Right now I'm trying to learn how to use GraphEdit. It's a little confusing, but I'm determined to fix this problem. Also, I'm trying to figure out RegDrop. It looks rediculously simple, but right now I know very little about registry settings and other things like that.:( Also I want to be sure that I am able to get my computer back to where it was if I need to.

I used to be good with computers... then Windows came into existence. Now I'm just a know-nothing front-end user.

Thanks for your info, melvinvc... I hope it works.

[added 9-01-03: haven't had much time to work on this... hopefully soon.]

[Ben Kenobi]

@Musitektus
I have the same issue as your. My specs are: Win2k SP2, Ac3Filter 0.70, PowerDVD 3.0 and Creative 4400 4.1. I have Central input stream played on all 4 satellites LOUD; if i change the matrix to play central channel on surround speakers, then i would listen to all speakers playing Central MUCH MUCH softer.

@melvinvc
After fixing PowerDVD dshow controls, i will be able to play DVD with multichannel option in PowerDVD?

[Valex]

Look at ControlPanel->Sounds&Multimedia->Audio->SoundPlayback->Advaneced. Is it 5 channels set there?