AC3 - I might be onto something!!!

[Gondo]

We all know of the problems we've been having with DivX and DVD's with AC3 sound. We cannot get true 5.1 to work. Well I was playing with a friends system and figured a things out. Please read and post your comments and elaborate.

My bud just bought a new set of Creative Labs Mega Works 550 5.1 speakers with 3 analog inputs. He is using 6ch analog sound onboard an Asus A7V600 board. I couldn't believe the crap Asus is using for onboard sound compared to the better NForce and Gigabyte onboard sound I've used before. So I was trying my DivX's with AC3 and they didn't work. I couldn't get true 5.1 with TCMP or WinDVD. I tried a DVD using WinDVD and nothing. Crap for sound again. When I checked teh AC3 filter properties in TCMP the 6 input bars were not working properly, and the 6 putputs wern't working good. When I'd get the surround going, I'd unlock the bri and crank the surround up to 20db but that would thrw everything off. Every AC3 setting I touched frigged the whole sound. I'd have to lock BRI the LFR, Center, and surround to get it to sound normal. But I don't like that cause then the rears are too low. TCMP and AC3 Filter usually works like a charm on my system. Oh well, I played with it for a few hours then got to thinking. Here's how that went.

I tried ripping Twister DVD to the hard drive. I extracted the AC3 form it using DVD2AVI. I played the AC3 and it worked. I pleyed a .VOB from the hard drive and it worked. Oh my god did it work, and it was loud and the rears were roaring and I was blown away. All discrete 5.1 channels. Then I used WinDVD to open a VOB file directly off the DVD, and again it worked. But when I tried to play the DVD as a whole, with menu in WinDVD the rears didn't work. It sounded almost as if the rears were comming out combined with the fronts.

Here's my conclusion. If you try to play a DVD off the disc WinDVD treats it as a DVD and outputs it through your sound card. If you play a VOB or any seperate file, WinDVD treats it as a media file, and uses windows filters and codecs to play it and therefore you get AC3 Filter kicking in and decoding the ac3. Playing the DVD from disc goes to your hardware which is not capable of AC3 in my case because it's onboard. You need a 5.1 sound card such as a Sound Blaster. The problem with playing the VOB directly in WinDVD is that if the first audio channel isn't English 5.1 you may get French or whatever...you don't have the freedom to choose your audio stream.

questions and conclusions for thought:

1) Now is it possible to get WinDVD to play a DVD using ac3 codecs for the sound, instead of directing the audio through your hardware for decoding? I assume this is part of the problem cause the DVD doesn't work in true 5.1, but the .VOB off the hard drive or DVD works. WinDVD plays the sound from the DVD, but the decoding is screwed and I can pick out the surround mixed into the front speakers. I have trained guitar ears and can pick this out The decoding only works with the VOB file when ac3 filter is used to properly decode it. If we can bypass WinDVD sending the info through your sound or something it might work.

2) The AC3 filter settings in TCMP work like crap. You adjust the settings and it freaks out the input and output channel level bars. You can't get good 5.1 going if you try. How come it works for the .VOB but not a DIVx in TCMP or WinDVD?

3) Will using a 5.1 SOundBlaster Audigy or equuivalent card really work 100% of the time? Will deleting all .ac3 cedecs in windows force all .ac3 streams to direct through the sound card and work 100% of the time?

4) If we really do have an issue with the AC3 streams not being handle and directed properly, this could be our problem. We need to exclusively get the ac3 stream to direct to a good ac3 codec.

5) Is there a better DVD player and DivX player than can handle this stuff better. Is PowerDVD better for this than WinDVD. Is BSPlayer, DivX Player, etc... better than TCMP?

6) How much blasting am I going to get for this long post and for questioning the quality of TCMP.

The problem we have is not with actually playing the .ac3 file, it's with properly decoding the .ac3 file to give you good discrete 6 channels. Let me tell you the twister .vob file was sweet with loud surrounds, I've never gotten it that good before in my life. Why doesn't it work directly from the DVD using the DVD Menu, etc... I think we can realate this to DivX and figure something out.

Well now you people are free to clarify, ponder, and correct anything I've just written. Should be an interesting post.

Thanks

[GeneralLeoFF]

Your right about how WinDVD concidering a directly played VOB file as a media file rather then a DVD. In WinDVD DVD and Media mode use 2 difrent playback methods.

the player acctualy has internal decoders embeded in the player for DVD playback and does not use the external DirectShow filters to play a DVD. The external decoders are there for stuff like Windows Media Player and other DirectShow players.

As a result when you play a DVD as normal with WinDVD it is forced to use these internal decoders rather then the defualt DirectShow decoders. This almost never plays the AC3 correct.

WinDVD media playback mode uses DirectShow so directly playing the VOB is playing the AC3 with whatever your current defualt AC3 codec is.

You should download GraphEdit and open up a VOB and check out how the graph looks. You may also want to check out Zoom Player as with it's custom media and DVD playback you can create infinate combanations of crazy ass codec setups. it'll let you tell your system what codec to use for AC3 even if played on a DVD like normal (insert disc and press play). It bypasses the DirectShoe merrit system and alows you to force yer system into playing ONLY with the codecs you tell it to as sometimes DirectShow can be dumb about it

[GeneralLeoFF]

oh yea forgot.... It depends how you look at things weather or not PowerDVD is better then WinDVD. the WinDVD directshow codecs are more stable and less problimatic for external players then PowerDVD but PowerDVD has better sound. WinDVD is still 5.1 but PowerDVD is now 7.1.

P.S. With Zoom Player you can use the more stable WinDVD codec for Video and use the PowerDVD codec for audio like I do

[Gondo]

Thanks

Thanks. I knew I was right about WinDVD handling the different files differently. I'm going to try that zoom player and see how much control I can get.

If we relate this to DivX with AC3 wouldn't it make sense that The Core is not properly handling our files and screwing up the whole process of using the proper direct show filtering, etc.... It's possible that zoom would also handle our DivX properly.

Well I'm off to do some more testing. At least this stuff is easier then when I first started DivX back in 1999 and these forums didn't exist. Nicky's pages were just getting started.

[GeneralLeoFF]

If WinDVD used DirectShow for DVD playback you would have all sorts of problems. The player is designed with features dependent on it;s own decoders. Usigng DirectShow would probly result in tons of conflicts if you have multiple DVD decoders installed.

You wouldent want WinDVD to be trying to use the defualt DirectShow DVD decoder becose it possably could be a PowerDVD or nVDVD decoder and thertes no way in hell InterVideo is going to allow it;splayer to use 3rd party decoders like that and they would largley be incompatable with the players features.

Theres also the risk of them being damaged or moded in some way so it was safer to use internal decoders.

And yes Zoom Player is outstanding with DivX and AC3 to

[Gondo]

Finally It works!!!!

Well I used Zoom, Iset it up for WInDVD as Video Decoder, and AC3 filter for audio. It worked like a charm. DVDs and DivXs worked like a charm in full bloated ac3 sound jsut like the movie theatre

After all these years and reading over 500 posts realating to stuff like "I can't get my .ac3 to work" "I can't get spdif out" "The Core and AC3 problems" blah blah blah..... Zoom player actually works like a charm.

It's wierd though that The Core doesn't work properly with .ac3 filter. I hate to give up the Core but if Zoom is better then I guess there's no second guessing it. You've got me convinced, Zoom is the superior player. There are so many features and options that it'll take little getting used to, but it's great. Thanks General.

[GeneralLeoFF]

No problem yo. Zoom Player is great