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View Full Version : MXF to QT ratio 1:1 (as a check)



Toaster
03-03-2008, 07:44 AM
Hey guys -

Has anyone done the math on this yet?

If, for example I have 50 GB (total) in my "Contents" folder, and convert everything to QT (via Log and transfer, of course), what will my total QT GB output be?

Why do I ask: I am getting very very tired of looking for missing files (spanned, incomplete, etc) and trying to determine which, if any, files do not successfully convert to QT. I figure a quick mathematical equation should solve this "test"

For example - 1 GB of all-in MXF Contents data = .87 GB of QT data.

Or any other "checks" that you guys use?

David Saraceno
03-03-2008, 09:56 AM
This may help.

I found a 269.2 MBs mxf file that had no audio.

Imported the file into FCP. It was 269.2 MBs

joelwsmith
03-03-2008, 10:23 AM
David's pretty right on. I did a short film contest over the weekend. My raw footage folder (contents folder and lastclip.txt) was 27.55 GB. My Capture Scratch folder was 25.5 GB. I'm thinking there's .05 GB missing from the capture because of the elimination of XML files and the LastClip.txt file.

Hope this helps.

Toaster
03-06-2008, 06:12 AM
I'm finding a much larger vig / difference. For example (an actual example):

68.25 GB of P2 media
-converts to-
30.98 GB of QT data

Also - I should note this is 720 24P data.

BARRY - any insight?

Barry_Green
03-06-2008, 09:41 AM
Sounds like you shot in 720/24P mode and not 720/24pN mode. If so, that's about the ratio you could expect, as Quicktime is discarding the duplicate frames.

Toaster
03-06-2008, 10:03 AM
Hey Barry - Thanks man!

Yes, 720 24P

Do you know if there is a table that exists that accurately represents these ratios:

1 GB: 1080 24P = x GB QT
1 GB: 720 24P = x GB QT
1 GB 720 24 PN = x GB QT
Etc.

OR - do you know of a tried and true way to confirm that all data has been successfully converted to QT? I seem to regularly get files missing (spanned, incomplete) and go insane trying to reconcile data.

My "check" is doing line-by-line comparisons (e.g., find 00074F MXF ...look for 00074F Quicktime - repeat ad nauseum).

Obviously, this is not an efficient method!!

-K

Barry_Green
03-06-2008, 02:15 PM
I don't use FCP and I certainly don't bother converting my files to Quicktime, but mathematically it should basically be:

1080/24p: 1GB MXF = .8GB QT
1080/anything else: 1GB = 1GB
720/pN: 1GB = 1GB
720/24P: 2.5GB MXF = 1GB QT

Toaster
03-08-2008, 05:04 PM
If you're not converting to QT - what are you doing with your MXF files??? Is there a better way to deal with HD data / info?

Barry_Green
03-08-2008, 06:49 PM
Of course there's a better way -- just edit them right as they are. Every NLE on the market can do that (excepting FCP, of course, and Sony's Vegas). But you can get that same functionality with Vegas or FCP by using Raylight.

So forget the whole "log & transfer" step. Pug the card in, drag the files to the timeline, and edit. A P2 card's fast enough to allow up to six streams of realtime streaming HD, simultaneously.

Imagine when you've been out shooting for a week, offloading cards to an external hard disk, and you've offloaded maybe 8 or 10 hours of footage... when you get back to your edit station, wouldn't it be nice to just plug that hard disk in and edit IMMEDIATELY, without going through that Log & Transfer process? Well, you can.

Download the trial copy of Raylight and give it a try.

Toaster
03-09-2008, 08:26 AM
Actually - that's a nice feature for being able to show clients a cut as well. A sort of VTR-lite!

I'll have to check out Raylight - being an FCP guy :)