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  #1  
Old 07-14-2004, 11:54 AM
Lanois WannaB Lanois WannaB is offline
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Default Work Flow for new project

Hello all. I will try to make this brief. I work as the audio director for a small multimedia company who just got a huge project. Most of our projects are corporate video, industrial training and the like. Not the most entertaining stuff but it still needs voice and music.... So far my LE rig PT5.1.1 OS 9.2 has held up fine for the needs of our clients. The video guys send me quicktime from their Avids...I do my post work....shoot it back over....life is good. But with this upcoming project we will be venturing into territory which I have very little experience. Basicly what we will be producing will be a 12-15 minute World War II reenactment on film. With original score and recording. No bombs and artillery but the capture of a German U-Boat. The audio content and aquisition I am not so worried about, it is working with film and the potential problems that it can introduce, frame rate issues,sync, yada yada. I know I won't be able to eliminate all problems but I want to avoid as many pitfalls as I can before I start. So if any of you have any advice or tips to share, I would be more than grateful to hear them. Especially regarding on location audio capturing for film. I have read alot of articles but you can never really know the full scope of things until you talk with people who actually do it. Also, are there any other similar forums that I could post to get some advice? Thanks in advacnce.

BJ Aberle
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  #2  
Old 07-17-2004, 06:36 PM
CCash CCash is offline
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Default Re: Work Flow for new project

You've no doubt come across the typical workflow for this scenario in the articles you've read... but just in case you haven't, I'll offer some basic info:

Typical film sound is recorded on location to a DAT running at 30fps. Film of course is at 24. Both the camera and the DAT deck would be referencing 60Hz (i.e., the frequency of a standard electrical outlet). These are "nice" numbers that play well together. The problem is, the video you work with will be at... video speed (29.97fps - roughly - and 59.94Hz reference).

The conversion of film to video happens during Telecine, where the 24 frames are padded (repeated) to make 30 frames per second. Each frame is broken into 2 repeated fields, while certain fields are repeated 3 times. This is the "3:2 pulldown". From there, it needs to be slowed down .1% to run at 29.97fps, and the video is made. This video .1% difference happened back when color TV was invented... and it's just the rate that the NTSC found satisfied their technical needs.

So you'll need to receive telecined 29.97 video. Easiest these days is to just use a Quicktime movie and work directly in Pro Tools.

The DAT tapes will need to be loaded into a 30fps Pro Tools session (or the Avid guys may do it, in which case you'll end up with an OMF). Then switch Pro Tools to 29.97fps with a .1% Pulldown, to match the slowdown that happened with the video. Pro Tools will run at a slower sample rate of 47952Hz. (Be careful here if you're working with a QT movie imported into the session... with newer PT versions you can set the video and audio rates independently. Otherwise, you'll be slowing down the video too.)

You work at this rate until you're done, and then layback to whatever format, and if the final needs to match film, this usually means taking the pulldown off, bringing you back to 48kHz.

This is the most typical scenario, but there are variations on this. For example, sometimes the DAT tapes are "telecined" (aka Simul-DAT)... i.e. slowed down the .1% before you get them. Then you just load them at 29.97 with No pulldown on and work at normal video speed (48kHz). You may have to then apply a pull-up on the final layback to get back to film speed.

Just be sure of the formats and conventions used when you receive your elements. here are a couple of good links:

http://akwww.digidesign.com/support/docs/FilmSync.pdf
http://www.prosoundweb.com/recording...eo/video.shtml
http://www.prosoundweb.com/recording...eo2/sync.shtml
http://www.trewaudio.com/timecode1.htm
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  #3  
Old 07-17-2004, 06:51 PM
RobMacki RobMacki is offline
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Default Re: Work Flow for new project

Quote:

This is the most typical scenario, but there are variations on this. For example, sometimes the DAT tapes are "telecined" (aka Simul-DAT)... i.e. slowed down the .1% before you get them. Then you just load them at 29.97 with No pulldown on and work at normal video speed (48kHz).
Is this the same as when on, for example, the PD4 you can record @ 30fps / 48.048Hz, then pop it in at play back 48Hz and you get the automatic pull down to 29.97?
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Old 07-18-2004, 01:52 PM
CCash CCash is offline
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Default Re: Work Flow for new project

Rob, I don't want to come off as an expert here, so please get second opinions... but I'd think that yes, it's the same idea - no pulldown required while working. While this may seem like a good solution, I think if the project ultimately has to go back to film speed, it could just be confusing since working with a pulldown has been the normal procedure. Plus, you'd have to now apply a pull-up on the layback. If the project is never going back to film speed, then it seems like a great idea.

If you're transferring into PT digitally, you'd probably want to have a pull-up on, at 30fps, then take the pull-up off and switch to 29.97, but I haven't done this.
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Old 07-18-2004, 02:04 PM
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Chief Technician Chief Technician is offline
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Default Re: Work Flow for new project

Quote:
Is this the same as when on, for example, the PD4 you can record @ 30fps / 48.048Hz, then pop it in at play back 48Hz and you get the automatic pull down to 29.97?
Yes.
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  #6  
Old 07-18-2004, 03:59 PM
proxy proxy is offline
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Default Re: Work Flow for new project

Quote:
...sometimes the DAT tapes are "telecined" (aka Simul-DAT)... i.e. slowed down the .1% before you get them. Then you just load them at 29.97 with No pulldown on and work at normal video speed (48kHz). You may have to then apply a pull-up on the final layback to get back to film speed.
I was about to post something similar, but since this discussion is already going, may I ask for confirmation about a similar variation?

The above quote sounds like what I will be working on, a film project that was edited in the Avid. I will be working on a high-quality 29.97 Quicktime (and a corresponding audio OMF), and when it's done, it will be put back to film. Am I right in thinking I can do the following

- Open the OMF / import the video, working in 29.97/48k
- When done, "Bounce to disk"
- Apply a .1% pitch increase (with a plug-in) to the 2-track file so that it will lock back up with 24fps?

Your experienced advice is much appreciated, and will create a calming effect as I enter into these new waters. I'm studying up a breakneck speed, but a human confirmation would help too.

Thanks,

- proxy
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  #7  
Old 07-21-2004, 11:30 PM
CCash CCash is offline
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Default Re: Work Flow for new project

"Apply a .1% pitch increase "
It's the speed change that's important. The pitch change is just a side effect.

Be careful about just entering numbers in a plug-in. Typing in ".99%" or ".1%" may not work -- read this article and wait for your head to explode:
http://www.seneschal.net/papers/pointohone.htm

I'd feel better about dealing with sample rates than percentages. Just a thought.
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  #8  
Old 07-22-2004, 10:12 AM
Lanois WannaB Lanois WannaB is offline
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Default Re: Work Flow for new project

Thank you for the articles and suggestions. I have been reading all I can about pull up and pull down at break neck speed. As I get into the specifics of the project, I'm sure I will have more technical questions. The destination for this is not back to film. In the past, for this client, we have delivered product on Digibeta. For this project I recieved word that they are contemplating having an HD version delivered on DVD. My next question is, is it possible to do this post work utilizing the 2 current systems that I have. Work rig = Digi 001 PT5.1.1 Home rig = Digi 002R PT6.4. Obviously I would need DV Toolkit for frame reference. If not, taking it to a studio w/ an HD system, although not ideal, is not a problem. Sidenote, I inhereted the system I have at work. I did not make the decision to buy it as the heart of our audio dept. Would Simul-DAT make life any easier for me? When it comes to the musical score, I would like to take Pro-Tools sessions with Quicktime movies (for the conductor) and record directly into Pro-Tools. Will this work? Is there a better way that this is done? Is there a method I should absolutely avoid? i.e. slaving Pro-Tools to video via SMPTE. Thanks for your help!!!!!........more questions to follow.

BJ Aberle
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  #9  
Old 07-22-2004, 11:11 AM
proxy proxy is offline
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Default Re: Work Flow for new project

Quote:
"Apply a .1% pitch increase "
It's the speed change that's important. The pitch change is just a side effect.

Be careful about just entering numbers in a plug-in. Typing in ".99%" or ".1%" may not work -- read this article and wait for your head to explode:
http://www.seneschal.net/papers/pointohone.htm

I'd feel better about dealing with sample rates than percentages. Just a thought.
Thank you so much - my apologies, when I said pitch change, in my head I was really thinking time as well. In fact, more specifically to ProTools, I was picturing the option that is available when you export a file. In the HD system I'm working on, there are sevaral variations or alternate sample rates, etc. for pull-up/down. That was the method I was contemplating.

Thank you for the article (I am heading there to read it now), and thank you for your generous knowledge.

Thanks again,

- proxy

PS - Also, I don't wish to veer this post in a completely separate direction, so I'll start a new topic if need be.
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