NTSC DV vs. Uncompressed

MUTTLEY wrote on 11/15/2003, 1:10 AM
Man I hate ta sound naive about this shtuff but I recently found myself somewhat baffled. By and large I mostly use the presets when importing/exporting etc. Usually if I render something I'm working on to avi to later print to DV or whatnot I export with the standard NTSC DV Template, thinking that that was the best option but just now noticed that under the Custom Template for video format there's also an " Uncompressed " option. Using that the same file ballooned from 615 MB to 4.94 GB. Wow, now I don't care about the file size, got plenty of space, but how much quality is lost saving it as NTSC DV ? Should I just about almost always go uncompressed if I don't want any loss ?

I'm also wondering if somewhere along the line this might have caused another issue I'm noticing. I shoot with an XL1 in Frame Movie Mode, basically 30 frames a second. With Vegas 3 I never had any ill effects when doing slow mo, but now I'm getting some hazing, none of the usual suspect seem to be doing the trick. And it only happens when doing slo mo Wondering where I might be messing up, any suggestions would be most welcome.

Thanks in advance all;

- Ray

ray@undergroundplanet.com
www.undergroundplanet.com

Comments

RBartlett wrote on 11/15/2003, 3:25 AM
Everytime Vegas touches a DV stream within an NLE session, be it a color correction, or anything other than a straight cut, there is a decomp/recomp activity. (in fact slow mo is a case where with smart resampling and supersampling off, that if not making frame adjustments, this is also a direct transfer of duplicates).

All NLEs are like this, Vegas supports passthrough of uncompressed and DV files, but in the case of DV, a quality hit is present everytime the coder is called upon. The compression input blocks don't move, so generally this doesn't create a mess until you do it quite a few tens of times on any given frame (with lots of otherwise "lossless" processing on them.

Should we all convert to uncompressed before we start? Probably not.

Remember that your footage has come in DV. So it isn't likely that you'll escape this cul-de-sac.

If you deal in 3d/CG-compositing or have high end camera/tape formats, then uncompressed is where to stay until you adjust for your final target, be it DVD, DigiBeta, SX, D9, WMV,... The advantage to the NLE is that you don't need a decomp phase. You do need good disc I/O but you probably already have half decent RAM+CPU if you meet the minimum spec for Vegas with DV.

Vegas with its proprietary internal DV codec, and MainConcept's 3rd party DV codec both have a processing advantage over the competition DV codecs. The other NLEs do, in some cases, have MainConcept DV modified into a private codec.

Ultimately there is little benefit in finishing/archiving uncompressed if you've been in DV mode all the way up. You'll have problems firewiring uncompressed out to a camera also.