Silly, or not, dv25 finishing question...

[Alon Levi]

Hello there,
I was wondering - I'm before the stage of finishing my dv25 movie, which was edited on xpress pro, on AVID symphony online system.

Now.. I had some problems with capturing some of the clips from the post-house deck, and I do have them on my computer ONLINE - captured from the camera and transfered to xpress pro.

Is there any reason NOT to use the same files in the finished product? Will capturing the DV25 media in the post house has any benefits? regarding the codecs or xpress itself ?

Is there any advantage capturing the dv25 stream to uncompressed right off the deck ?

TIA
Alon

[Glenn Chan]

Is there any advantage capturing the dv25 stream to uncompressed right off the deck ?

I can think of two:
A- Their system may want to work in 720X486 (which is the standard for uncompressed video... i.e. you want to lay off to beta or digibeta), not 720X480. If you work with DV in a 720X486 project, you should move the image down 2 or 4 (not 3) pixels but not resize.

*I'm just guessing here, I have no Avid experience. It may be that their system works fine with DV in a 720X486 project.

B- If you capture via SDI, the deck may apply some sort of chroma interpolation. Chroma interpolation makes "chunky" color appear less bad (see http://www.adamwilt.com/pix-sampling.html ).

In post, you could apply a chroma smoothing filter. If it's G Nicer or other similar intelligent chroma upsampling filter like Magic Bullet Suite, it can be slightly better quality. However, any chroma smoothing/upsampling filter you apply in post may take rendering.

Chroma upsampling is very useful for keying (which you may not want to do in the online) and can be useful for secondary color correction.

If their DV deck doesn't have SDI output, then they may be capturing via analog and you'd suffer generation loss. Capturing via SDI does kind of mean that your footage undergoes DV compression/decompression cycles, which shouldn't be a big issue.

If you're mastering on DVCAM or DVCPRO, then maybe you want to stick with IEEE/firewire transfer throughout because that will give you the best quality.

Now.. I had some problems with capturing some of the clips from the post-house deck, and I do have them on my computer ONLINE - captured from the camera and transfered to xpress pro.

What kinds of problems did you have?

If they're timecode break problems, I'd fix it now by dubbing your tapes with continuous timecode and conforming your project to those tapes.

[Richard Alvarez]

Alon,

I've read your post several times, and I'm a bit confused on your workflow. You say you're - "finishing my dv25 movie, which was edited on xpress pro, on AVID symphony online system."


I'm confused. If I understand you. Your movie was shot in DV25, captured on an AVID symphony suite, and then the files were transfered to your xpress pro, correct?

IF that is the case, then the OMFI files simply move between the systems, there is no generational or quality loss. If' you've been cutting on the PRO system, and take the files back to the symphony, they will be seen just fine.

I don't know why you captured the files originally on the symphony. It's not unusual to FINISH on the symphony, especially for color correction. But I digress.

Did you capture the files on the symphony in 1:1 or in low rez? That might be what you mean? IF you captured in low rez, to keep lots of files small to edit on your pro, (perhaps a laptop?) and you want to go back to the symphony and uprez... Then you will have to recapture the final timeline at full rez on the symphony. Is that what you are talking about?

[Alon Levi]

And actully Glen got it right - I captured to xpress pro mostly via dsr-11 deck, and some thru my camera (there were some matiral the deck I rented transfered with dropouts, and my camera transfered ok).

Now, all my stuff is digitzed as dv25 420 (PAL); and i'm going to scehdule an online session on symphony.

I have some interviews using blue screen that need to be keyed and some standart color correction. so What i asked was - should I recapture my film in the post house deck via SDI, or should I just bring along my OMFI files ?

what are the advantages of recapturing this ? The disadvataged are quite obivous - time (money), and the change that the post-house deck will have similer issues as the dsr-11 with my matiriel....

Thanks

[Glenn Chan]

If they have a DSR-1800 they may not have problems with dropouts since that particular deck has tracking (and SDI output). But they may not have that deck.

For keying, you might want to do that yourself? You can tweak the key in your own time and buy software that's good for dealing with DV keys (i.e. Ultra). Avid may not be that good at keying?? If you do want to pull keys on the Avid, chroma interpolation would be good to have. Capturing via SDI will do it.

2- Have you tried calling them?
I have zero avid symphony experience so there's things I can't tell you (like how Avid handles DV in 720X486 timelines, whether or not the Avid codec applies chroma interpolationg [some DV codecs do]).

Also, what deck they use and whether it captures via SDI or analog/component.

Also, if they have an old symphony they may actually have to capture with compression and can't do uncompressed.

3-

Should I recapture my film in the post house deck via SDI, or should I just bring along my OMFI files ?

Well to be safe I'd do both. If the OMFI doesn't work, you should be able to re-capture off the original tapes (although that would take extra time and may not work for your budget).