Excellent DVDA2/Vegas tutorial by John Meyer

ken c wrote on 5/13/2006, 9:45 AM

I really enjoyed this tutorial, I didn't know that for best quality, it's best to
do separate audio/video renders in Vegas using DVDA template settings (not default mpg), then combine in DVDA:

http://www.vasst.com/?v=training/VegasFAQnew.htm#DVDA2

superb writing, thanks a lot.

Render QUESTION:
I've already rendered out a few DVDs worth of AVI files directly from vegas last week (but with many more to go, it's taking up too much space...)

I want to re-render them using the guidelines in that FAQ... Will I lose quality if I import those avis back into vegas, then render out (2-pass) into audio and video streams per the FAQ? Or should I go back and re-render from source?

let me know if it matters; I appreciate it!

thanks,

ken

and just checking , are the right render settings:

Save as Type: MainConcept MPEG-2 (*.mpg)
Template: DVD Architect NTSC video stream ?

(plus for best video quality/double render time though, check the
"2-pass encoding option box, right?)

My DVDs will be about 60 mins to 90 mins max long, so an 8k encode
rate should be ok re length

Comments

jrazz wrote on 5/13/2006, 9:55 AM

As for the .avi files- it depends on what type of avi you saved to. If they are lossless- (Gigantic files and of course you would have to select that option) then no, you won't lose any quality.
I don't know what your settings were so I don't know how much of a quality loss there would be for the avi files if you encoded them to mpg2. More than likely, you didn't choose lossless and you will take a hit, but it probably won't be very noticeable (again, speculation b/c I don't know the quality level of the orginal file or the avi encode).

As for the right template- yes DVDA NTSC Video Stream Template and AC3 for audio.

j razz

ken c wrote on 5/14/2006, 6:58 AM

hi - thanks... looks like the 8 minute avi clip is 1.8 gigs; the 8 min video-only mpg w/o sound is 1.2 gigs, so not a large difference using those settings .. which is odd..hmm.
and the 1.2 mpg does look compressed, compared to the source avi, I can see a difference ...

I'll have to try just importing the raw avis into DVDA and then checking the vobs it produces w/8kbit encoding, to see if any differences... appreciate the thoughts..

ken

johnmeyer wrote on 5/14/2006, 10:12 AM

I forgot about writing that, but I think you are correct that I did write it. Don't know how you figured that out.

Render QUESTION: want to re-render them using the guidelines in that FAQ... Will I lose quality if I import those avis back into vegas, then render out (2-pass) into audio and video streams per the FAQ? Or should I go back and re-render from source?

Don't ever re-render from MPEG; always try to go back to the original DV AVI files. You say that the 8 minute AVI clip is 1.8 GB, and this is exactly what I would expect for a DV AVI file. You can certainly use that without losing any quality. However, you say the 8 min video-only mpeg is 1.2 GB. This seems WAY too large. It should be about 10 - 20% of the size of the AVI file, depending on the bitrate you used. Something odd there.

Don't bother to use 2-pass VBR for encodes at average bitrates above 6,500,000 (that's an arbitrary number that I picked as a guideline). I doubt you will see much difference. In fact, for DVDs where the total running time for all the source material is under 75 minutes, you can use 8,000,000 CBR (starting with the DVD Architect NTSC template) and that's all there is to it. You'll get the best possible quality in the shortest possible time.

and just checking , are the right render settings:

Again, the 2-pass is not necessary in all cases, as noted above.

ken c wrote on 5/15/2006, 12:11 PM

hi John, thanks! I'll try rendering w/o 2-pass, and see the resulting file size. Agree a regular mpg should be 10-20% of the avi size, not sure why it's so much larger ... will re-render out w/o 2pass and see what it does, at 8000000cbr..

Update: the 1-pass mpg video stream file is 374megs, which sounds right, from a 1.8gig source.

I'll try again w/2-pass to check this...

ken