FORUMS: list search recent posts

Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.

COW Forums : Avid Media Composer

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Daniel Edelman
Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 4:23:04 am

We're editing and conforming 23.98, then mastering to HDCAM SR 59.94 DF. On the first episode, we did everything in 23.98 then opened the sequence in a 59.94 DF project. Avid added the motion effects properly, but we found that audio clips were randomly slipping and sliding. An engineer at Avid recognized this as a potential bug.

The suggested solution from our engineers is to output through a terranex to create 1080i 59.94 drop frame SR (we do not have access to a Symphony).

We lay the video to tape with temp mix, then make an AAF for pro tools. Mix then does an audio layback the next day.

The big question: will there we any sync/drift issues between the converted 59.94i DF video output, and the 23.98 audio layback?

HP z400 Media Composer 6.5.2 (bug mentioned earlier exists in 6.5.3 and 7.2).


Return to posts index

Jonathan Abrams
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 11:03:28 am

"will there we any sync/drift issues between the converted 59.94i DF video output, and the 23.98 audio layback?"

Are you not doing an digital cut for audio and video when you make your 23.98 master?

If you do not time stretch your 23.98 sequence to make the 59.94 master, your audio will sync up correctly. Export a 23.98 AAF from the original sequence and include a 2-beep. The Pro Tools operator can spot that AAF sequence into a 23.98 session and also display the 59.94 timecode ruler. Next, he can swap primary and secondary timecode rulers, effectively making it a 59.94 session, and perform the layback.

--
Jonathan S. Abrams, CEA, CEV, CBNT
Apple Certified - Technical Coordinator (v10.5) Support Professional (v10.6 and v10.7)
Vice-Chairman, NY section, AES


Return to posts index

Michael Phillips
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 12:49:22 pm

If a true 2:3 cadence is applied to the 23.976 sources, then you get a 59.94 master running at the same duration +/-1 frame due to math and where your last frame falls in the 2:3:2:3 cadence. If you're doing a playout as mentioned, this is done on the fly and is continuous for the entire timeline.

You can open your 23.976 sequence in a 59.94 project and it will have 2:3 added to each clip. but it's cadence will not be continuous from event to event - and I need to check what happens in nests and layers - so while it works, the MPEG encode is not as clean as with a continuous pulldown cadence. Do get around this, you could do a mixdown of the sequence as a new clip, into its timeline and open that in the 59.94 project. Since there are no events, it will be a continuous cadence. It depends on your workflow whether this is a suitable workaround or not.


Michael


Return to posts index


Daniel Frome
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 1:11:00 pm

[Michael Phillips] "ou can open your 23.976 sequence in a 59.94 project and it will have 2:3 added to each clip. but it's cadence will not be continuous from event to event "

Interesting. Do you Michael, by any chance, if there are any decks that receive a 23.98 signal, but can record to tape at 59.94i DF?

Just curious if there is a hardware workaround to creating a 23.98 mixdown, that's all.


Return to posts index

Michael Phillips
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 1:25:52 pm

Good question - off the top of my head, I don't know of any tape decks that do the conversion with pulldown for record - but some do for play out and can create 23.976, 24, 25, and 50i, or 59.94i (Sony decks). But I do not think they can do this on input.

You can always go to a deck at 23.976p and then let it do the 59.95 output as a master to another deck - is this what you mean by 23.98 mixdown workaround? The playback from the deck will insert a continuous 2:3:2:3 once recorded and is the common workflow for production masters (not broadcast masters).

The lower cost JH-3 can play back at different rates, but does not record.



Michael


Return to posts index

Daniel Frome
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 1:44:24 pm

[Michael Phillips] "You can always go to a deck at 23.976p and then let it do the 59.95 output as a master to another deck - is this what you mean by 23.98 mixdown workaround?"

That answers it exactly. So, in theory could you chain two decks together, relegating the first deck to make a 23.98p master, but also output a 59.94i signal into the second deck, thereby also making a broadcast version?


Return to posts index


Michael Phillips
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 2:01:25 pm

I don't think it can be done at the same time, but yet. Record to deck 1 at 23.976, then play back from Deck 1 to Deck 2 with a 2:3 pulldown inserted. The Sony HDW-F500 can record 23.976 and output any of the broadcast standards as needed.

Michael


Return to posts index

Michael Phillips
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 2:03:04 pm

A Blackmagic Teranex may be able to do this in real time as an I/O from MC... Something to try. Can you not get a 59.94 signal from your Avid MC with DX hardware now? Or does Avid still consider that to be Universal Mastering and requires Symphony?

Michael


Return to posts index

Daniel Frome
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 2:17:52 pm

[Michael Phillips] "A Blackmagic Teranex may be able to do this in real time as an I/O from MC... Something to try. Can you not get a 59.94 signal from your Avid MC with DX hardware now? Or does Avid still consider that to be Universal Mastering and requires Symphony?
"


Funny thing, I happen to be in front of a DX MC 5.5 system right now. When I make a 1080p/23.98 project, my settings > video output > cross convert settings do indeed show a 1080i 5994 option that I can enable. So... I guess it is possibe.


Return to posts index


Michael Phillips
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 2:51:00 pm

I thought that it would be with DX, the question may be with third party hardware.

Michael


Return to posts index

Daniel Frome
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 3:05:33 pm

[Michael Phillips] "I thought that it would be with DX, the question may be with third party hardware. "

With my home system with an AJA T-Tap, I don't even have this Settings > Video Output menu item. So, it's definitely not possible within MC's settings. I'll have to check if the AJA control panel enables such an item.


Return to posts index

Daniel Edelman
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 7:21:00 pm

Interesting- I didn't think you could cross convert with Media composer. We do have Nitris DX boxes.
The real questions is, will there be sync issues if we lay off cross-converted video, and Pro Tools lays off audio afterwards.


Return to posts index


Michael Phillips
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 7:40:34 pm

No. If the picture and sound are in sync in the 23.976 project, then there will be no issue going out to 59.94 with pulldown as the audio has stayed 48kHz all the way through the process.

Michael


Return to posts index

Daniel Edelman
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Sep 30, 2013 at 8:48:22 pm

Thank you. I'm being very cautious about the whole thing because we have a very tight turnaround. We lay the video down Thursday night, mix and audio layback is Friday, it's QC'd Friday night, and it airs Saturday night. As you can see, there is zero room for error.

Dell Precision Workstation T5400:
Dual Quad Core Xeon 2.33Ghz
8GB ECC Buffered RAM
nVidia Quadro FX 3700
500GB 7200 RPM System Drive
2TB Internal SATA RAID 0 (2x 7200 RPM Burrered Drives)
Avid MC6


Return to posts index

Clement Hobbs
Re: Edit 23.98, master to SR 59.94i DF. Concerned about mix drifting.
on Oct 30, 2013 at 5:48:04 pm

If you're that tight, then I'd stay at 23.98 for the tape out to Sr which guarantees a copy on tape that is correct.

Once you pass QC (Fri night/Sat AM) simply crossconvert the tape over to 59.94 either in house or at a lab with two decks. Just make sure you check the one hour mark to make sure it's clean. I can't remember if it will automatically be a clean frame or not when running the deck from say a 57:30:00 tape start. You may need to do a separate edit at the one hour mark to make sure you've got a 100% clean solid frame there.

If you only have the one deck, you could crossconvert from your QC'd 23.98 master to 59.94 and ingest back into the Avid (in a 59.94 project), then out from the Avid at 59.94 to a new tape. Long but it works.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]