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No “generation” loss! Eureka!
I know that sounds like a no-brainer in the digital realm, but one thing i had been curious about was if i have exported a QT from my timeline, does it “degrade” the contents at all upon bringing it back in to FCP down the road for additional editing…especially if i export it at the same settings that it is already at. i.e., i have several lovely and pristine VHS clips (ha!) that i’ve just captured, and have done some editing, and now want to save the edited clips on DVDs as QTs for archival and possible further editing in the future. They were captured as DV clips, on a DV timeline, and i exported at those settings. I didn’t honestly know if the files would be compressed again in some way, or more or less just re-“compiled” into a new file…and not degrading the original file at all. (i don’t know if i’m explaining this very well, but some of you might now what i was thinking here).
So, i tried a 10-generation test on a 10 second clip. I would chop it up, then export it at the same settings into one file, import it, drop it on the timeline, chop it up again into a few different cuts, export again at the same settings. etc. Well, after 10 “generations” of doing this, i compared to the “1st generation” clip on the timeline and i saw absolutely no difference. I assume this is because i exported with the same settings each time. Now, if i had exported at a different setting each time (DV50, then 8 bit, then DV, etc.), i’m assuming my results might have been different?
Anyway, that’s just a long fyi for anyone who might have been curious about this issue. A related one coming next…
thanks again!
mh
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3 Replies
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The other thing that would cause generation loss are things like, transitions, filters and effects, if added or changed with each generation.
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Morty
(can i call ya morty?)
My understanding is this:
Which Production Compression codec you use (DV, DV50, DV100, Pro Res)
is kinda dependent on how much compositing your gonna do. IE
dv may look great when simple cuts for 10 iterations, but waht does it start to look like after sending it to motion, then back, then to after effects, then add titles etc etc. People have said it gets ugly
Also there is the issue of color space, 4.2.0., versus 4.2.2. at dv 50
However
So YEAH! thats cool you can “dub” dv down 10 passes and still look good. Comes in handy for versioning and revising. But I would rather do keying off of DV50 or 8 bit UNC, then DV.
To Be Honest, I am considering laying down all my finished projects (anamorphic) to DVCAM rather then BetaSP, as I am starting to see dropouts in some beta stock. So by your tests, It sounds like I could use an existing DVCAM master as a submaster to make a new version, and could do that at least ten times. (rather than recapturing the original master, and the material for revisions everytime i want to change some shots.
cool beans!
“I like video because its so fast!”
Bob Flood
Greer & Associates, Inc. -
If there is no rendering there is no reason for any generation lose.
But this do not happens if you have checked “Recompress all Frames”
In this case only when you work with an Uncompress format there is no lose.
With DV, the first copy you don’t see much degradation, but the second one is noticeable.
If you use some color bars you can see in the screen and in the video-scope the degradation.
Images with gradients will show it really fast.
Cheers,
rafael
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