yet another ac3 question for the forum

[apost1]

Ive looked through a few posts here concerning ac3 sound and saw some how tos and stuff. I'm a little confused on the whole ac3 thing right now. I have heard that one can make svcds with surround sound if they have a divx file with ac3.

Can someone tell me please if this is feasible to do? will the sound file be to big for cdrs so that it would actually only be feasible to burn on a dvdr? Can someone tell me if the better sound would be worth the trouble or does it really make that much of a difference compared to regular mpeg2 sound. Also, might there be any compatability issues with certain DVD players?

Im not really looking for real specific answers for these questions. What I really want someone to do is just give me a brief overview of what can be done with ac3 sound source for svcds and an explanation of advantages and drawbacks (e.g. limitations) brought forth by using ac3 to make surround sound.

[Rickster]

Hey,
Your dilmena is not a new issue, but one I can't directly address. I'll leave the issue of trying to get an .ac3 audio file from MPEG-4 (DIVX) video to someone more in the know than I. What I can comment on is the benefits and drawbacks of burning your own .ac3 files with video on DVD. First, time. I use Acid Pro 4.0 from Sonic Foundry to mix multi-channel audio in Dolby Digital 5.1 surround and burn onto DVD, and let me tell you, you need alot of patience to do this. First, you need all the .wav files from your original song (drums, vocals, lead guitar, backup guitar, bass, etc.) that you assign to different busses in the program. The busses correspond to different audio channels in the 5.1 surround environment (center, left front, right front, left surround, right surround, and LFE). You can either position an individual .wav file (say lead guitar) in a static position in its buss's "envelope" or attach keyframes in your project timeline to make the sound move around from one channel to another on its own. Sound tedious? It is, because you have to make sure that your freq cutoffs and filters are set correctly, and you have to ensure your bass management selections are correct for proper LFE usage with your subwoofer. It take alot of time, but it's worth it in the end.
Second, price. The Acid Pro 4.0 program--last time I checked, anyway--is about 400 bucks. And that doesn't include the Dolby Digital 5.1 encoder plug-in, which is another 279 bucks. But with this significant outlay, you can actually score your video (the program lets you import .avi files) and encode the audio to .ac3 (you can either save the project to Dolby Digital 5.1 or DTS, depending on your settings). What I do is save the audio to .ac3 and encode the .avi file to MPEG2 with TMPEGenc, import both files into DVDLab and burn. I did a compilation DVD this way with a client's music videos that I shot and edited, and he couldn't be happier.
Now, if you want to use BeSweet for .ac3 work, go ahead, but I don't know the program (I think it will convert to .ac3 but not let you mix your own, and I think that's half the fun!). For me, mixing and encoding with Acid Pro was money well spent.
Okay, on to some of your specific questions. You're trying to burn MPEG2 video onto CD (650mb, or thereabouts). An .ac3 file will take less disc space than a .wav file, but whether you can fit the whole video on an SVCD will depend on the length of your video. And then there is the compatability issue: as far as I know, there's not alot of DVD players that support SVCD (check the compatability chart to the left). If I was you, I'd skip the SVCD issue completely, spend about 250 bucks and get a decent DVD-R drive for your computer, and start burning DVD's. That's where the action's at!