last updated 24 Dec 2005

DI - Preparation

Preparing for the Digital Intermediate process

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There's a bit of work to be done before you embark upon finishing your film
via a Digital Intermediate.
How well you prepare and how careful and precise you are
will decide how much time you get in the end
for more creative things like grading.
Rather than spending time just matching the offline edit.

I've written this page as if I were addressing a production house that is about to embark upon a DI project. The tone and content is as if I'm saying this to a bunch of ADs or Asst Editors. If that's not you, don't take offence. Just pass this link on to them

Also, this is page is incomplete. I'm still working on it so please come back and check. But do return, it won't be long.


Gathering the stuff

First and foremost, get everyone concerned to look at the edit. Everyone who is likely to ask for changes and modifications, that is.

After all and sundry are happy, then consider the edit "locked". So no more changes. If you're realistic, then hope there are none, but be prepared for some. That's the way it is.

So with your edit locked, proceed to break down the film into "reels". Theatrical presentation requires film to be broken into 2000 feet rolls of film called "reels" Each such reel runs about 22 mins. So if your film is one long 2-3 hour sequence, break it down 22 min sequences. A 3 hour film usually has 8 or nine such sequences. Call these sequences by their reel numbers like "Reel 1", "Reel 2" and so on.

Take care to ensure that a scene is completed at the end of each reel. You may find that some reels run into 20 mins or less, while others reach 22 mins. But 22 mins is really sacrosanct.







This breaking the film into reels of 200 feet is an editorial process. There may be a bit of trimming and joining needed to make things flow just right.


So, with these final reeled sequences, proceed to make an EDL of each sequence. Make one layer at a time. If you're on an Avid Film Composer, you need to make the EDL as "PAL Film 1" and select "Method 1" if and when asked. Make sure transitions and clip names are included and nothing else. And include black edits and optimize EDL. This is a 25 fps EDL.

If your film was edited in FCP (Final Cut Pro) ensure the track V1 is selected and make an EDL of just that track. Your original sequence has to have had the setting DV-PAL 24@25 else the EDL won't be right. Make sure transitions and clip names are included and nothing else.

Whether FCP or Avid, you need to make an EDL for each reel separately. The DI house will also treat the film as reels.




I usually make my DI clients give m just these sequences placed in a separate bin and I make my own EDLs using my own "magic formula"


In versions of FCP before version 4.5 it was not possible to make a true 25 fps EDL without resorting to some workarounds. But since version 4 is no longer common I won't go into that. If you happen to have version 4, do upgrade to 4.5. It's free.

Cut lists

From each of the reels of your film, make a cut list. Ensure the cut list does not show feet and frames, but frames instead. Most DI folks are too young to make sense of the "feet+frames" measure. Besides no grading or conforming machine can work in this measure.

Go over the cut list and check for any missing events. In an Avid you'll be warned about inconsistencies one by one before the cut list is generated. Note down each of these and correct them before handing over the cut list.Don't bother trying to avoid this check. The DI guys will come right back and make you find those shots. Even if its a Saturday night and you're partying with your girlfriend thinking you've made the cut lists and your job is done, you still need to find each and every last shot or the DI doesn't get done. So make that check.

The cut list may or may not be used directly in the DI process, but it helps the DI people identify material that isn't there. I've found that with a cut list I've had to call up the original editor or the post coordinater far less often.





Here too, I make my DI clients give my just these sequences placed in a separate bin and I make my own cut lists using my own "magic formula"

Reference transfers

For the DI conform boys (or girls) to do a final check they need to see your final offline edit as a picture. On a tape or in some other form. So they can compare it with their own "Digital negative" and make sure you and they are working on the same film.

This tape transfer has to be at 25 fps. But you've edited at 24 fps in Avid/FCP. And film runs at 24 fps. Right? Then why 25 fps tape?

Precisely. Tape as in Betacam, DV, DVCAM, DigiBeta, etc all run at 25 fps. An Avid/FCP, when transfering to tape "normally" take a 24 fps timeline and "convert" it to 25 fps. How? By adding one frame each second. this keeps the time constant but introduces these "adjustment frames" once every second. So this picture cannot be used as a comparison for the DI conform process.

Because in a 24 fps transfer, the number of frames on the tape is not equal to the number of frames in the original film.

Transferring to tape at 25 fps ensures that each and every frame in the timeline is copied out. No more, no less.

Avid lets you make a 25 fps transfer via Digital Cut. Its called Video Rate 100%+. FCP doesn't let you make a 25 fps transfer directly. But you can check with the DI folks if a 24 fps Quicktime movie is OK. If it is, you just need to export your final sequences as Quicktime movie self contained and copy these onto a hard disk. Incidentally on most new G5s this takes less than 5 mins per 22 min reel. Cool ! I always urge my DI clients who've edited on FCP to give me a Quicktime transfer instead of a tape transfer.

Also, if the DI house is using a Nucoda Data Conform or Nucoda Film Cutter to check their scanned EDL, you can even give them a .jpeg sequence instead of a tape transfer. Making a .jpeg sequence in FCP is easy and possible within FCP itself. On an Avid Media Composer, (only newer versions after 8.0) too you can make a .jpeg sequence by exporting to Quicktime first and then makeing a .jpeg sequence from there.

But if you have to make a 25 fps tape transfer, the only choice is to export the sequence as a self-contained Quicktime and then use CinemaTools to conform these reels into 25 fps. Just like that! And use these to transfer to tape.

On these tape transfers ensure you put a slate at the head of each reel, and a 1 frame "pop" at the head and tail of each reel.

Finally, from your final sequence, measure the length of each sequence from FFOA to LFOA. (First Frame of Action, Last Frame of Action). Check this in number of frames, not hrs mins, secs fr. And make up a list of these reel durations and hand them over to the DI people on a paper.






The alert reader would have no doubt surmised that if there was some kind of a 24 fps tape machine, one could make a 24 fps tape transfer and that would also work. Right?

Right. Now go and find a 24 fps tape machine.

What about HD you say. Yeah right, HD has 24 fps tape format. So go ahead and use HD for making reference transfers to tape.

Giving it out

All this stuff needs to be labelled correctly and unambiguously, dated conspicuously and sent. Use CDs for the EDLs, sequences, cut lists, whatever. Even e-mail, memory stick, or mobile phone memory will do as the files are quite small.

Tape transfers also need to be labelled correctly and unambiguously, and dated conspicuously. And if you're really paranoid, make a copy of all this and keep it safely till the courier reaches the DI studio.






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