Why Can I Only Fit ~75 Min. on DVD?

BT76 wrote on 12/20/2007, 10:14 AM

Can anyone tell me if I am doing something wrong, because the most I have ever been able to fit onto a single layer DVD is around 75 minutes of video.

I am importing the video off of my digital camcorder as AVI files using Vegas 6.0, then editing and rendering in Vegas. I render the video as MPEG-2 in the DVD Architect Studio format and render the audio separately as .WAV file (this ensures no additional rendering is needed in DVD Architect Studio 3.0b).

I understand that perhaps I could lower the bit rate, but the only place where I have seen the option to do that is once I am about to burn the movie to a DVD, under the 'Optimize', 'Fit to Disc' option. However lowering the bit rate at that point never really shrinks the movie enough.

I would really like to be able to fit around 90 minutes onto a single-layer DVD. If there is somewhere (in DVD Architect or Vegas) where I could change the settings to get my files smaller I would love to know where. Thank you!

Comments

bStro wrote on 12/20/2007, 10:55 AM

Your audio is taking up a lot of the room on the disc.

The DVD format allows for two types of audio -- AC3 or WAV. (Well, okay, some will say MPEG audio is acceptable, but that's debatable, and no version of DVDA supports it anyhow.) There are different levels of compression for AC3, but generally speaking it's about 1/10th the size of WAV. So, by using WAV audio, your disc has less space for the video than if you were using AC3 audio.

(Disclaimer: Some version so DVD Architect Studio support AC3 audio, some do not. I'm not sure which is which. Yours minght not.)

Furthermore, to use the Fit to Disc option, you should give DVD Architect an AVI file, not MPEG2. Fit to Disc re-encodes the video at a suitable bitrate, and re-encoding a file that's already been encoded to MPEG2 is inefficient and will probably result in a loss of quality.

Rob

BT76 wrote on 12/20/2007, 11:03 AM

Thanks, Rob. Just for clarification:

You are suggesting that I edit the video the way I wish in Vegas, then render the edited video as an AVI file and bring that into DVD Architect (Studio)? At that point, I can use the Optimize/Fit To Disc option and select an appropriate bit rate that will make the entire video fit onto the disc?

If I understand you correctly, then I suppose DVD Architect will render my AVI file into MPEG-2 between the 'Prepare' and 'Burn' stages?

MPM wrote on 12/20/2007, 4:21 PM

Vegas can render your mpg2 just fine -- DVDA and Vegas use the same encoders but Vegas gives you more control. Using a bit rate calculator is probably the easiest method to find a good setting, then select the correct DVDA template in Vegas, change the field order as (or if) needed, and set the max and average bit rate figures.

That said, Rob's right in that you're throwing away a lot of disc space if you're burning wav files to disc. Most are around a gig, versus somewhere around 300 meg for ac3. If your versions can't encode ac3, visit videohelp.com &/or doom9.org for freeware ac3 encoders.

bStro wrote on 12/20/2007, 9:23 PM

If his version of Vegas Movie Studio won't encode AC3, then his version of DVDA Studio won't accept AC3 either.

Rob

MPM wrote on 12/21/2007, 4:30 PM

"If his version of Vegas Movie Studio won't encode AC3, then his version of DVDA Studio won't accept AC3 either."

OUCH! That's the 1st time I've ever heard of a DVD authoring app not accepting AC3. Not doubting you, Rob, I'm trying hard to phrase this so it doesn't trash Sony too badly... I guess I'll say that given the low cost and free programs out there, I'm really very surprised *that* version ever gets installed.

So if someone had that version that won't import ac3, they'd have to encode their mpg2 so it took up ~4.25 - 4.3 gig, import it with the wav audio into DVDA studio, & render their DVD to hdd regardless final size. Then encode the wav to ac3 using free-ware, use the free version of Muxman to create a DVD without menus, using the Vegas rendered mpg2 and new ac3. Then swap out the VOB files using VobBlanker.

Sounds like a lot of work, but it isn't bad -- I've done the swapping for other reasons and the Muxman and VobBlanker renders each take roughly the same amount of time as copying the DVD files -- I'd guess an average somewhere around 10 minutes or so each. You'd have the ac3 encoding time whether you did it in Vegas or something like Aften, so that wouldn't add anything really except the hassle of using one more tool. The tools (or links to the tools) are available with guides etc at Videohelp.com , [where one can also find info & links to free &/or low cost DVD authoring apps that import ac3 if this work-a-round seems too involved.]

And apologies as needed to BT76 for being I guess naive enough to be caught unawares that any authoring app didn't have ac3 import. The version of Nero I paid $6 for & EMC9 I paid $20 for each include authoring apps that handle ac3 just fine, and they're bundled free-bees, so I just never imagined. Sorry...