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Subject: When to use AC-3
Posted by: mhbstevens
Date: 7/25/2004 10:06:42 AM

I produce Widescreen Stereo (not 5.1) DVD'd with Architect so I render video with MainConcept MPEG NTSC Widescreen and render my audio with AC-3 as I find the sound quality is best that way.

My question is should I ALWAYS use AC-3 for all types of projects or is rendering the audio stream along with the mpeg or using some other encoder sometimes beneficial? And if so, why?

Thanks

Subject: RE: When to use AC-3
Reply by: bStro
Date: 7/26/2004 9:15:00 AM

Supposedly, PCM is better quality than AC3, but I wouldn't know the difference. You can try it and see if you like it, and if you do use PCM if you've got the space. (PCM uses more space than AC3.)

FYI, if you're using DVD Architect, PCM and AC3 are your only choices. DVDA will not let you use MPEG audio. Or, rather, if you do, DVDA will re-encode it to whatever you set your DVD project at (again, PCM or AC3).

Rob

Subject: RE: When to use AC-3
Reply by: jltzd
Date: 8/4/2004 3:16:09 PM

PCM is indeed better quality, but at a huge bit cost. If you think that your material warrants it (concert footage), and you have room on the disc, go for it....but don't encode your video too high if you want to keep compatibility up.

Don't use MPEG audio, it sounds like you can't so I suppose no worries there ;)

JL

Subject: RE: When to use AC-3
Reply by: B.Verlik
Date: 8/5/2004 6:15:15 PM

AC3 may be as good or better quality than PCM. You just have to work your butt off to get the right results. Go to www.dolby.com/digita/ and download their 'guidelines' PDF. Then get ready for some serious studying. PCM is on most DVD players, but not all. It takes way more memory than AC3. PCM does sound good and is much simpler to get close to the results you want. AC3 is the norm for all DVD players.

Subject: RE: When to use AC-3
Reply by: Tom Pauncz
Date: 10/6/2004 11:43:48 AM

Hi,
Could you please be a little more specific as to 'which' Guidelines.pdf? A full link would be really helpful. :-)
Thanks,
Tom

Subject: RE: When to use AC-3
Reply by: BJ_M
Date: 10/6/2004 5:03:50 PM

ALL dvd players have to play PCM audio -- or they are not dvd players ..

it is a requirement of the dvd standard ....

2 channel ac3 can not be better quality than uncompressed pcm , how could a very very compressed lossy format be better ?

it (ac3) can about good as and in many cases can be JUST as good as -- but never better than pcm.

it would be like saying that ogg or mp3's are better than the cd's they were made from (exact same idea) .

Subject: RE: When to use AC-3
Reply by: nograde1
Date: 10/25/2004 5:29:47 PM

I'm trying to render a widescreen 5.1 movie in VEGAS 5 and create the DVD in DVD Arch 2. When I render with an AC3 Template in Vegas 5 and open in DVD arch I only have the audio. I've tried to figure this out with the manuals to no avail. What am I missing? Thanks

Subject: RE: When to use AC-3
Reply by: nograde1
Date: 10/25/2004 5:31:22 PM

I'm trying to render a widescreen 5.1 movie in VEGAS 5 and create the DVD in DVD Arch 2. When I render with an AC3 Template in Vegas 5 and open in DVD arch I only have the audio. I've tried to figure this out with the manuals to no avail. What am I missing? Thanks

Subject: RE: When to use AC-3
Reply by: snicholshms
Date: 10/27/2004 8:44:02 PM

You have to render an MPEG2 file (DVDA NTSCWidescreen template) separtely from the audio file. Then render the AC-3 file. Both must be named exactly the same and be of the same length.

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