4+ hour video-optimize dvd, fit to disc ??????

dukerss wrote on 11/1/2004, 9:46 PM
I recently purchased vegas5 +DVDA and started some video work. I have a problem and not sure the answerl.
I captured about 4 hours and 20 minutes in a file. Rendered as advised (thanks Rob). AC3 first, then MPEG2. From there brought it into DVDA. Well, before I even add a menu w/chapters etc, it says my project is 12.56GB . I thought OK, and click "Fit to Disc" . I get the error mesage "Media file is too big ..."
I thought I could easily put 4 hours or mabye more on a single disc, would just have a lower bit-rate. Even 1/2 of 4 hours would send me over 6GB. What do I need to do to get my 2+ hour file to fit on disc? I realize the video quality would lower as the length goes up.
Thanks, James

P4 1024RAM

Comments

GaryKleiner wrote on 11/1/2004, 10:00 PM
You can get about 2 hours of decent looking video on a 4.7 Gig DVD.
4 hours and 20 minutes?... NOT!

Gary
ScottW wrote on 11/2/2004, 5:16 AM
If you're going to use the "fit to disk" option in DVDA, then don't bother rendering to MPEG-2 first in Vegas. If you do a "fit" with MPEG-2, then DVDA will first decompress the data and then recompress it, which will usually cause a pretty big hit in quality. Start with your original source material (the AVI file) instead. If you start with the AVI, DVDA will have a better chance of correctly determining the final project size.

It is certainly possible to fit 4 hours of video on a 4.7GB DVD, however the bit rate will be so low that you probably won't be at all happy with the quality. My suggestion would be to break it up into two 2 hour chunks or consider DL+R (if you want to be on the bleeding edge and can get over the sticker shock for the media cost).

--Scott
johnmeyer wrote on 11/2/2004, 7:27 AM
I thought I could easily put 4 hours or mabye more on a single disc,

That is incorrect. DVD-R (and DVD+R) can hold a little over an hour of top-quality video (they are roughly half the size of the DVDs used to store Hollywood movies). You can store more by decreasing the encoding bitrate, but as you go much beyond ninety minutes, you will begin to notice a quality degradation compared to your original, especially if your original video is DV quality. By the time you reach two hours, the quality degradation will be quite noticeable. I hesitate to say at what point everyone would find the quality unacceptable, but whatever that point might be, you will be WAY past it by the time you try to put 4+ hours on a single DVD.
Phileas wrote on 11/15/2004, 4:11 AM
Change your resolution to half(if Pal then 352*288), the resulting needed bitrate will be about 1/4. I managed to get 10(3hr 20+) episodes of the simpsons on one SL disc with no apparent quality problems(with space to spare).Secondly play around with different max bitrates( on a short clip) to determine how much you can cut the bit rate(assuming you encode in VBR).
My thinking is this Max Bit Rate= Resolution* Frame rate.
example:
720*576*25=10125kbps
704*576*25=9900kbps
352*288*25=2475kbps
remebering that the combined bitrate for audio&video can't exceed 9800kbps.
Phileas wrote on 11/15/2004, 4:16 AM
Oh and ScottW's right, DVDA2 isn't very good at predicting the final size( what program is when your deadling with MPEG-2) so don't use it. May I also suggest DVD Shrink in addition( this seems to be able to shrink DVDs accurately).
scottshackrock wrote on 11/15/2004, 9:26 AM
and, if you make the bit rate real low on DVDA, (or really, anything besides avg of 8) a lot of dvd players may have trouble reading the dvd. my experience.