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View Full Version : PT & Analog lockup with video ref and 30ND? Possible? How?


Disco_Doctor
10-21-1999, 06:57 PM
So, the "best" way to do an analog transfer into Pro Tools from 2" is to reference the machine and Pro Tools to video...we don't wanna use no stinking timecode as the clock reference anymore. Ok, so....

If the 2" reels have 30ND timecode, and I reference the 2" machines and Pro Tools to video, everything is going to get pulled down, right? How do I get around that?

Stream of thought:

Is there a way to reference Pro Tools to video via the USD, pull up the clock (maybe in the session setup window), send word to the Lynx from the USD, and have everything playing at the right pitch - while referenced to video using 30ND timecode? That doesn't sound right at all...

Or...let's say I have two 2" machines locked up with 30ND. Could I stripe new 29.97 timecode on a blank track on one of the 2" reels, reference the 2" machines and Pro Tools to video and use the 29.97 timecode for transferring to and from Pro Tools but still have the machines locked to each other with the 30ND timecode? Hmmm...I'm thinking I could do that with one 2", but not two...

What about a box that outputs a +.1% VSO'd video reference? Anything like that out there...?

I feel like the solution is on the tip of my brain but it's not quite crossing the threshold into reality...any ideas?

Am I making this too complicated? (That wouldn't surprise me...)

(Poof! - Disco Dr.'s head explodes)

http://www.digidesign.com/ubb/images/icons/smile.gif

Rail Jon Rogut
10-21-1999, 10:41 PM
Don't forget the option of printing a stripe to a track in Pro Tools (as audio) -- then feed that into a Lynx module as a code only master and have the 2" chase it with another Lynx module. I normally lock the SMPTE region to prevent it being accidently moved when using this method.

Rail

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Recording Engineer

Kasper
10-21-1999, 10:43 PM
How about-

Ref. the 2" to black-29.97

Ref. ProTools to black-29.97

Record into PT at pull-dn.

Disengage pull-dn on play back from PT.Back to orig Pitch.

Maybe?

You could also feed black from a black and white camera into PT as your vid sync. This would pull-up PT and it should lock it to 30 fps. Make sure the camera is stable.

kasper

Disco_Doctor
10-21-1999, 11:10 PM
Let me describe a hypothetical here...

Mixing session - two 2" machines locked up. 30ND on the reels. Some tracks will be transferred into Pro Tools, edited, effects added, etc...then Pro Tools will roll along with the 2" machines for the mix. So there can't be any pull up/pull down - all machines would need to be online simultaneously.

Pro Tools can't be the code master because the SSL can't machine control Pro Tools (right?).

How would you do it?

Thanks!

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[This message has been edited by Disco_Doctor (edited 10-21-99).]

Kasper
10-21-1999, 11:39 PM
OK

Do you normally drive the 2" with code from a video machine?

If yes-

Stripe 30 fps code on a video tape.
Have the 2" machines chase to code from the video deck.
Lock PT and the 2"s to black.
Record on line at pull-up and 30 fps in PT.
Don't come out of pull-up on playback from PT.

You may be able to do this without pulling up PT, but since I work in post with film/vid rates I always think of 30 fps as a pull-up.

Also, have you got an open track on each of the 2"s ??
You could restripe code at 29.97 on the open tracks. If this does not work you would still have the old 30 fps code to fall back on.

kasper

Rail Jon Rogut
10-21-1999, 11:49 PM
DiscoD

Is this a 9k?

Rail

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Recording Engineer

Steve MacMillan
10-22-1999, 02:04 AM
As Rail suggested the best way to xfer to and from ProTools to analog striped at 30ND is to make ProTools a code only master (you need an extra Lynx). If you have a USD you don't need to print the code on a ProTools track you can generate on the fly.

With an SSL that insists on being the master forcing ProTools to chase, I would cheat and run ProTools at 29.97ND ref to video and then ref the analog as well, which would pull down the analog to 29.97. For music this will often be just fine, you are only running one tenth percent slow which works out to about 2.4 cents of pitch change. Many analog machines running wild can vari by that much. Just be careful to compensate when overdubbing keys or auto tuning. You might have a hard time convincing some people to do it. You can always sync to LTC only.

sm

Earjam
10-23-1999, 02:14 PM
I'm pretty new to PT. I've only had it for a few months. I've been trying to keep up with you guys because I do alot of 2" PT lock up.
I stripe smpte and let PT chase the 2".
Apparentely this is a cheesy way to handle it.
My question is, Is the 256Superclock the real deal or do I need an external clock to improve the sound quality. And I guess I need a Lynx or somethimg to drive the 2" with.
How much difference will I see?

Disco_Doctor
10-24-1999, 02:25 PM
DiscoD Is this a 9k?

Well, it's likely that it would be. I heard whisperings of the 9K not needing to be the timecode master...is that why you're asking? Does it work? Can a 9K just chase code?

Thanks

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Rail Jon Rogut
10-26-1999, 12:05 AM
Hi DiscoD

Well, I haven't tested it yet... but my thought was with the 9k and their enhanced support for Sony 9-pin with their new v4 software, you may be able to set up Pro Tools as the tape deck via 9-pin control and then attempt to use the Pro Tools transport and see what happens.

SSL told me that with their v4 software, controlling the transport from the machine should work better than it did with previous software revisions.

Regards.

Rail

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Recording Engineer

10-26-1999, 03:34 AM
Earjam,
These guys are a bit wrapped up and passed over you.
I am in the same boat as you. You do get apparently a better sound getting the 2" to chase PT as opposed to the other way round.
As for this video option, sounds like a nightmare, I don't know any session that would truck with a 2 cent "watch out for tuning" vairisped method regardless of quality improvement!

29.97 ??
30ND ?? (what the f is that?)
Over here (UK) 25 fps is the EBU rock n roll standard.

Q, Guys!
How do you start a session with this "video lock" with out having to "pull down" and monkey about with all these wierd (nightmare for 3rd party midi programmers) timecode standards?

Just when I thought I had it all figured out!

Jules

http://www.digidesign.com/ubb/images/icons/grin.gif

Rail Jon Rogut
10-26-1999, 10:09 AM
Julian

If you prestripe all your reels with video referenced SMPTE, and always resolve the 2" to video - then you won't have to worry about any pull down/pitch problems, and you'll be guaranteed that the speed of your 2" is always constant between sessions/locations regardless of the 2" machine used. Playing the 2" unresolved, will have the opposite effect though - you will have a pitch change, so it is important to always resolve to video.

The downside to this method of working for music production, is that you can't vari-pitch the 2" while it is resolved to the video.

As for why it's better - if you have Pro Tools as the master transport, it has a solid stable clock source, if you resolve Pro Tools to an external LTC stream via a device such as the USD, it is phase locking the Word Clock to the incoming LTC and therefore the word clock is constantly changing as it follows the incoming LTC.

BTW even though you use 25 fps code, the frequency of the LTC stream may vary (unless your generator has a very stable clock source) -- so it's always a good idea to reference your SMPTE generator to a stable, repeatable clock source such as video.

Regards.

Rail

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Recording Engineer

Steve MacMillan
10-26-1999, 10:39 AM
Julian,

I wouldn't be so quick to dismiss a pull down cheat as a bad idea. If all you have is a video slave driver and a SMPTE reader, then there is no other way to do it. Listen for yourself and tell me what sounds better ProTools referenced to black burst or ProTools chasing SMPTE only. Then tell me if you can hear the pull down (maybe, but soooo slight). When you want to overdub a piano you run on internal or offline on your tape machines.

A far better idea is to always ref your machines to video with 29.97 drop or non-drop code. You insure that your machines run at a constant rate no matter how off speed it was to begin with (when you striped code).

But when you are working in a situation where ProTools cannot be the master and you inherit 30ND code, well...

Rail,

Provided your analog machine is running on speed and you are using 29.97 code, there should be no pull up if you are not referenced to video. The whole idea of 29.97 code is so the speed of the machine doesn't change (except to stabilize) when you resolve to video.

A cool trick for mixing from ProTools on a SSL with G automation, is to stripe a reel of analog tape with 29.97 code. Video reference the analog and ProTools, and let the SSL control the analog and ProTools chase. Kinda takes the fun out of random access.


sm


[This message has been edited by Steve MacMillan (edited 10-26-99).]

10-26-1999, 11:29 AM
Is getting the 2" to chase PT OK?

With a Lynx and 25fps time code?

My need for it is to "suck up" into PT. A one time deal (2 x passes max with 2 x Apogee AD8000's).

I am a magnet for tuning problems, especialy on long seious projects! I print a 440 tone now, but something usualy comes to get me, like one string on a bass!

Usualy here in the UK music scene you have to face a fireing squad for useing anything but 25 fps.

I think this thread is a bit too advanced for me!

[This message has been edited by Julian Standen (edited 10-26-99).]

Rail Jon Rogut
10-26-1999, 04:31 PM
Hi Steve

When I wrote you will have a pitch change... I should have written you may have a pitch change. You are correct, if the speed of the machine on which you originally striped the SMPTE was running at the correct speed, and all other machines you use run at the same speed, then there shouldn't be a speed change.

Thanks and hope all's well.

Best regards.

Rail

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Recording Engineer

Disco_Doctor
10-26-1999, 05:44 PM
Much thanks to Steve and Rail for their comments on this subject...I know I can always count on you guys for some creative ideas and advice when I toss out these gruesome sync questions! Kasper, thanks for your suggestion too.

http://www.digidesign.com/ubb/images/icons/smile.gif

PS - If any equipment manufacturers/designers out there read this forum - a "pulled up" 30 frame video black box sure would be a cool thing. There's a real need for it.

alfred
10-27-1999, 06:38 AM
you can lock up anything provided all clock must be the same, as far as i know EBU standard is 25 frame on PAL video, so why go for 30ND or 29.97 NTSC.

1] Do you have house sync or black burst clock generator. Make this your master clock.

2] Do you have USD, VSD or SSD?

OK I work with VSD received house clock to be send to trigger pt 888 256 clock to play in time. Opcode Studio 4 to receive or stripe smpte [LTC]from 2" tape.

Stripe 25f to 2" MASTER to trigger opcode studio 4 to move pt. use pt post control to control 2" and VTR via syncronizer.
That's all.

hope this can help.

always remember a ship has only one captain.

who is master. you for sure.

Rail Jon Rogut
10-27-1999, 11:11 AM
Alfred,

The Studio 4 does not accept external clock or video - so if you generate SMPTE from it, it will not be synchronous with your word clock/video ref. and you're asking for trouble.

Rail

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Recording Engineer

Roof Bros
12-04-1999, 05:52 PM
Q? I've got a quite elementary question.
I want to have my PT III rig lock to a 2" with 30ND. Is a S.S.D. all I need?

Is it a better scenario to have the 2" chase PT? If that is the case, can I print 30ND into PT and have the 2" follow that?

Any advice would be welcome

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Josh Roberts

Greg Malcangi
12-05-1999, 07:02 AM
Julian Wrote: "Over here (UK) 25 fps is the EBU rock n roll standard... Usualy here in the UK music scene you have to face a fireing squad for useing anything but 25 fps."

This isn't entirely true, it depends on what part of the music scene you are into in the UK.

Film of course is 24fps, but is usually transfered to video for editing. However the frame rate obviously needs to be altered to a supported video frame rate. It's much smoother to convert between 29.97 and 24fps than between 25 and 24. For this reason even UK studios that are involved in film score production have to deal with different time-codes and pull up/down issues.

Greg