Thanks for the info....

Since AC3 is much more compressed, does that mean that the audio will noticeably less quality? I guess my question is, when would you want to render to something other than AC3?

Regards,

TomG

If you're in the NTSC world and you want to make a compliant DVD, you have little choice. For some rather odd reason most of the world that are in PAL format can use the audio straight from MPEG-2 if what others have said is correct. Haven't checked myself since I don't live in PAL land. The specs for NTSC don't allow it which is the reason it gets converted.

There is no real quality issue, not one you can relly do anything about. Regardless what DVD Authoring application you use they should/ will convert to a acceptable NTSC DVD format. The difference is DVD-A tells you it will while msny of the other applications simply do it. There are hacks to force things, but that's beyond the topic and there is no reason to in the first place.

Thanks for the insight... I'm just glad that's not one more "option" I need to consider. Don't know much about the PAL world. I guess my only real concern is that I am a little disappointed about some of the music rendering associated with my video in DVDA. I've tried both SurroundSound and regular stereo. In fact, the SS didn't sound as good but that's a different story....

Appreciate the info...

TomG

I disagree with some of the posts on this subject. MPEG Audio Layer II which is what you get when you render audio and video at the same time is much worse than AC-3. MPEG Audio Layer II is old technology, the sound quality isn't even comparable. Ok, maybe on an old TV you won't hear the difference, but still...

And the absolute worst thing you can do from an audio point of view, is render to MPEG Audio Layer II and then let DVD Architect rerender it to AC-3. Recompressing badly compressed audio makes it really bad.

But I guess it all comes down to what your reference of good is.

For an easy way to render to different formats at once, try Batchrender Pro.

"I have read on several occasions where it is suggested that, in preparation for using DVDA, you render the video only to MPEG2 to prepare it for DVDA and then render the audio in AC3 in the same folder. I always render the MPEG2 file audio and video together. Is there a reason for rendering separately?"

Yeah - short answer: That's the only way you can import it into many authoring apps...

Why? As BillyBoy pointed out, that's specs... As a practical matter, commercial DVD's have more then one audio track, multi-lingual etc... Setting the authoring app to handle separate streams is probably simpler then an either/or approach. And FWIW, many an authoring app shares a good bit of code licensed from the original developers, so even those that don't allow more then one track of audio might inherit this behavior.

"MPEG Audio Layer II which is what you get when you render audio and video at the same time is much worse than AC-3. MPEG Audio Layer II is old technology, the sound quality isn't even comparable. Ok, maybe on an old TV you won't hear the difference, but still..."

An anology if I might: Bake 2 identical cakes, but for one use old and rancid flour - which will taste better? If you've got good audio going in, shouldn't be a huge difference between a higher bitrate mpg audio and AC3. AC3 is cool, don't get me wrong, but it's purpose is usually to encode multi channel, perhaps add enhancements to the sound along the way, store the audio in a smaller file, and make someone holding the patent a nice bit of change.

Yeah, AC3 often sounds better, but is this because of the underlying audio it preserved, or because of the added enhancements from the software or hardware decoding it, like bass enhancement or True Surround or whatever? Strip the wav files out of an AC3, and most often they don't sound much different then the mpg.

That said, mpg is older, and lacks some of the technology of AC3 - mp3 pro, AACPlus, MPEG-4 High Efficiency AAC are changing that.

I'd just like to point out that the MPEG audio we're talking about is nowhere near the quality of MP3 (MPEG 1 Layer III). MP2 is no good. Maybe it's just me :-)

Point of clarification...I tried AC3 audio once as a seperate render and once only. Not that AC3 itself can't be superior, rather that DVD-A in the one attempt I made to use it totally, completely, unforginingly and uttterly trashed the file it turned me against doing it again. Like everyone else I'm only human and this being such a bad experience, I haven't bothered to try again. Your mileage may vary, however I've noticed other threads pretty much confirming my experience. What happened or why, I haven't bothered to look into. So I went back to letting DVD-A do it and the quality was good.

1. I was satisifed with the quality DVD-A did when it converted it automatically. So I needing to do a seperate render for the video and another for the audio a royal pain in the butt.

2. I haven't yet made a DVD where the music was the main focus, the music was background and background is where it should stay. If I ever make a DVD where the music is the focus, perhaps I'll try again.

3. Yes, I admit it, I'm a VIDEO fanantic. I think nothing of spending days fiddling with the V I D E O, after all I'm going to WATCH the video. Even a minor imperfection bugs me even though those not video nuts probably won't even notice the trival things I do. Like I said before a music background BELONGS in the background, I never obsess over it. Of course audio fanantics will endlessly fiddle and whine about the quality of the audio more or less ignoring the imperfections in the video BECAUSE they are audio fanantics. <wink>

4. Why do an extra step? If DVD-A can do it for me and the results and good, then so be it. Since I'm getting to be a 'old man' my range of hearing has dropped off especially at the higher frequencies, so little point in trying to fix what I'll never hear anyway. If you're over 40, you're in the same boat probably.

5. The orignial question really didn't address quaility, rather WHY do it. I offered why I don't.

I was just wondering if "batchrender pro" is based on BatchRenderGUI.js?