video sync?

[subspaceplatform]

I'm getting ready to move my studio and begin the process of doing some upgrades. I want the studio to be able to lock to picture, so I'll be purchasing a black burst generator and a MIDI Timepiece AV to clock the digital devices to video sync (as well as to clock Pro Tools to incoming SMPTE from analog multitracks).

The thing that concerns me is that my console automation system, which I also use as a SMPTE generator for the analog machines (Behringer Cybermix), doesn't support 29.97 fps. Only 24, 25, 30df and 30.

Is it okay to run everything at 30 fps instead of 29.97 while being locked to video? Or should I generate 29.97 SMPTE from the MTP AV for tape striping and just feed that to the automation system which is set for 30 fps? I don't know if that would even work, or if it would cause the automation system to lose sync.

Any thoughts?

[UnlikeKurt]

couldn't you just use 30frames all around, is it that important to use drop frame settings? Sure people say stuff like "as filmmakers we choose to drop frame" but cant ever really tell you why

[subspaceplatform]

That's kinda what I'm thinking.

The thing that concerns me is - if I'm using black burst as my master sync source and running 30 fps SMPTE from it... will it mess with the sync when they take the audio to the dubbing/mix stage (where it will be 29.97 fps)?

Or will the pitch of the audio just lower a tiny bit to compensate? That seems acceptable if it is indeed the case.

[joel hamilton]

I have run mix for picture stuff at 30 without ever getting busted....

what are you locking to for picture? I wind up just streaming via firewire to a DV box, then to a screen. Couldnt you stay fully in the box and skip the behringer thingy altogether, giving you 29.97 compatible action everywhere? Like monitoring through an analog AUX in? I dont know what that behringer thing is, really, so I shouldnt speculate. Just seems like that would be the first thing i would bail out on to be able to stay consistent everywhere else. Unless it is a very crucial part of your workflow...

[subspaceplatform]

I'm looking at an ATI 8500 for Quicktime output to an NTSC video monitor.

The Behringer Cybermix is an insert-based VCA automation system. It is sort of critical part of my workflow for mixing until I get something better.

You make a good point - I could just keep everything in Pro Tools and stay at 29.97 if absolutely necessary.

I don't like mixing in the box, though. Good to know that you've done this at 30 without adverse effects. I'll probably try that first. Do you word clock everything from black burst or not?

[Paul Fury 161]

Just to point out, I own a cybermix, and not to put too fine a point on it, it's not exactly hi-fi nor is it accurate. Don't even use mine any more. I'd mix in the box and make life easy - there aren't any ace analog goodies hiding inside a cybermix. Saying that, i'm gonna strip out all the VCA's from mine and build a few DIY SSL bus compressors - best use for it in my opinion. Never met anybody who got it to work for anything really serious.

Sorry to sound like i'm dissing your gear, not intended that way, just suspect that you'll end up with a lotta stress and grief in pursuit of something that isn't there?

Take it easy - and good luck, keep us posted how you're getting on.

Paul Fury

[joel hamilton]

I'm looking at an ATI 8500 for Quicktime output to an NTSC video monitor.

The Behringer Cybermix is an insert-based VCA automation system. It is sort of critical part of my workflow for mixing until I get something better.

You make a good point - I could just keep everything in Pro Tools and stay at 29.97 if absolutely necessary.

I don't like mixing in the box, though. Good to know that you've done this at 30 without adverse effects. I'll probably try that first. Do you word clock everything from black burst or not?

I wind up just clocking to an aardsync II via wordclock.

[subspaceplatform]

Joel - good to know, thanks!

Paul - Thanks for the input. I'm aware of the accuracy issue with the Cybermix. It seems to be worse with Win95 and higher and much more accurate under Windows 3.1. I've read a lot about repeatibilty issues with the Cybermix but as far as I can tell it repeats my fader moves exactly. Under Win95 and higher the mutes would always move around a little bit, which was really annoying. Not so on Windows 3.1. - it's likely a direct hardware access issue.

As far as sound quality goes, it seems to soften up the sound a bit like all VCAs (an effect that I like, actually). I'm certainly not expecting it to do anything wonderful to the sound - why would I expect any automation system to do that?

I use Pro Tools LE, so mixing in the box is out for two reasons:

1) No trim mode in LE. That's a deal breaker. The Cybermix has online and offline trim capability, even though there is a terrible software bug that drops the signal -10dB when doing online trims. Playback is fine. That's really annoying, so I tend to do offline trims. How the heck do you mix without trim mode? Bus the fader to another fader and raise/lower overall levels from there? I've done it. It's lame.

2) I like to use parallel compression/outboard gear, which gets me into delay compensation issues if I mix in the box. Totally irritating.

I could go on and on actually, but you get the idea... I should also probably mention that I need to mix analog tapes in my studio as well! I need real console automation. The Cybermix will have to do for now. I've been looking at the Mackie Ultramix - wondering if it will work without the fader box attatched...

[jmoose]

I could go on and on actually, but you get the idea... I should also probably mention that I need to mix analog tapes in my studio as well! I need real console automation. The Cybermix will have to do for now. I've been looking at the Mackie Ultramix - wondering if it will work without the fader box attatched...

Yup. It's just a squencer... operates on the same basic principles as the Cybermix. I used to have one. They're not without their own bugs, but it IS a much more stable system then the Bearfooker.

Really through, if you want to replace it you should buy Drumsounds MegaMix system which was MY old system. It was WAY more stable (and I think better sounding) then the Smackie but I wanted the fader pack and needed the ability to patch inserts without crawling behind or under anything...I had a bunch of freelancers coming through my old room so that was a big thing! He never installed it...movers dropped his Amek down a flight of stairs. Sad really.

Anyway...you're probably going to run into problems if you run half your rig at 29.97 and the other half at 30. Years ago I did a transfer from 2" to a DAW and I goofed, the clock was to 29.97 rather then 30. I didn't catch it at first, but a few weeks later when my client brought his DAW back and we tried to get that stuff back to 2" NOTHING would line up.

It would start fine, but by the end of a 4 minute tune things were WAAAAAAY outta' whack. Once I figured out what the problem was I eventually got around it, somehow...but it wasn't "fun" by any stretch.

My advice, commit to either one or the other. If you're serious about doing film & video work you'll most likely have no choice but to run at 29.97 at some point. If the drift is noticeably deal-breaking by the end of a three minute tune, what's it gonna be like by the end of a two hour movie?

[subspaceplatform]

Thanks, J. That makes sense. I'll look into a 29.97 capable automation system. Sounds like the Cybermix system would drift if set for 30 but recieving 29.97 - if it recognizes the code at all.

MegaMix sounds interesting, but the breakout box doesn't have insert patch capability? I can easily see how that would be a problem.

[jmoose]

Thanks, J. That makes sense. I'll look into a 29.97 capable automation system. Sounds like the Cybermix system would drift if set for 30 but recieving 29.97 - if it recognizes the code at all.

MegaMix sounds interesting, but the breakout box doesn't have insert patch capability? I can easily see how that would be a problem.

It does and it doesn't.

Rather then having a seperate 1/4" send & return it has one single TRS jack to handle both. Really, it makes for a cleaner install or you could wire up a breakout box for your inserts pretty easily.

In my case though I was getting a lot of freelancers through and while I certainly don't mind goign behind the console from time to time (I almost never use inserts) a LOT of 'em were griping about that. It was totally a business decision to sell the system and really...it was FAR more stable and better sounding then the Smackie. Not that the Smackie sounded "bad" or was even noticeable but I swear...things sounded a little sweeter with the Megamix in.

Call me crazy.

At the end of the day they were both usable, but I had a far better time using the Megamix. And actually, I got the system from John Noll at Retromedia in Red Bank...he posts here from time to time and might be able to tell you more about it. A search of rec.audio.pro would also pull up more info on those old CAD MegaMix rigs.

~ EDIT ~ Cybermix should see & recognize 29.97 but I have NO idea what would happen. I'd imagine it'll get really wonky.

[pieter]

That's kinda what I'm thinking.

The thing that concerns me is - if I'm using black burst as my master sync source and running 30 fps SMPTE from it... will it mess with the sync when they take the audio to the dubbing/mix stage (where it will be 29.97 fps)?

Or will the pitch of the audio just lower a tiny bit to compensate? That seems acceptable if it is indeed the case.

I'm an Avid editor by day, working at Disney, finishing on average a 22 minute TV episode a week, and our tape outputs have to sync with out of house stages on a daily basis, as do the tapes we receive from our vendors. We work in DF. If I receive a tape in NDF, I send it back. No discussion.

My suggestion would be that under no circumstances should you deliver tapes in 30 if the destination stage is running at 29.97. As someone else said, it can be made to work, but with a lot of aggravation and annoyance. If this is a low budget production with soft delivery dates, maybe it doesn't matter. But if it's a high-strung schedule with margins measurable in hours, sooner or later someone will bring up the subject of why they have to keep accomodating out of spec source material, and suddenly your job is on the line. Nothing is more frustrating on our end than having to accomodate obsolete formats or out-of-spec deliveries from outside vendors.

Also, don't let blackburst confuse you. That's a set-and-forget device. Plug it in, send it to all relevant hardware, and then set up the deck with tapes you're striping and your editing software (ProTools, Avid, Logic, whatever) for the correct frame rate and you're done.

I hope that's helpful. I'm just trying to offer some perspective from the other side; definitely not trying to criticize. Good luck!

[Posterart]

couldn't you just use 30frames all around, is it that important to use drop frame settings? Sure people say stuff like "as filmmakers we choose to drop frame" but cant ever really tell you why

I'm a bit late replying as Pieter and Joel Hamilton have done a nice job already, but I'd like to attempt to clear up the issue of drop frame a bit:
NTSC color video runs at 29.97 fps, .03% slower than the original SMPTE frame rate for B&W video. So, when 1 hour (00:00:00:00-01:00:00:00) of tape time has elapsed, 1 hour 3 minutes and 18 frames of chronological time (clock on the wall) has actually elapsed. Therefore SMPTE created 'drop frame'. While still running at NTSC video speed, 2 frames at the top of each minute excluding every 10th minute are dropped so that tape TC matches chronological time. As Pieter alludes to this is particularly important to broadcasters.
I hope this clears up any misunderstanding regarding filmmakers choosing to drop frames(?) As a sound designer and mixer I get location audio on all different media at all different frame rates, but when it goes out the door, particularly for broadcast, it goes out at 29.97 Drop Frame.