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Issues with TC at 48.048K


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Hi everyone,

Having some issues that I've never encountered before. Your advice is appreciate!

I'm recording onto a Fostex DV824 as primary and 744t as backup. Shooting 35mm. Post wants sound at 24 ND, 48.048 K. The DV824 doesn't record at 48.048, so I have set it to record at 48K, then pulling it up +.1%.

Here is the issue: Post is saying the TC displayed on slates and the TC being stamped on metadata are totally off, with no consistency. Not a drift. Sometimes is 30 seconds off, sometimes 90. On set, the slates match my decks all day long. I can guarantee the slates and recorders are sync, but I don't know whats being stamped as metadata on the disc.

Keep in mind, they are receiving the DV824 disc and I keep the 744 disc...I will be sending the backup discs tonight for them to check that out for continuity. This is day 3 of the same issue...For today I have made the 744t the master clock and am slaving the DV824 from the 744t, and jamming slates directly from 744T. Im lost on this problem as everything is sync here on set. If the discs from the 744t match up for them, it would seem its a sampling rate issue in the DV824 since I have to pull it up .1%...

Other question is that if I am rolling at 48 K +.1% at a frame rate of 24ND, is that changing the frame rate on transfer?

Appreciate your response...

Michael B. Koff, CAS

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Hi Michael,

At what frame rate are you recording your time code?

You probably already considered this, but with the DV824 (or other Fostex machine) the 0.1% pullup will adjust both sampling rate and time code. Therefore, if what you'd like to end up at is a file @ 48.048 kHz, 24 FPS time code, you'll have to set both sampling rate and time code 0.1% below -- 48 kHz and 23.976 FPS time code. With the 0.1% pull up engaged, you'll end up at your required values.

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Post is saying the TC displayed on slates and the TC being stamped on metadata are totally off, with no consistency.

Doh, 48.048 projects are always headaches at the beginning. You have my sympathies.

I would check the files with a 3rd-party utility like Courtney Goodin's BWF-Widget Pro, and see what it says the headers are stamped at. At the worst, you could manually change the headers as required, then do a test and see if this will work. We occasionally had to do this with 48.048 projects when I was on staff at Technicolor/Hollywood. I seem to recall there was a trick doing this with the DV-40, but Fostex sorted it out with the DV-824. I would also be curious to see if the 744 yields different results, since SD does things a little differently.

Is this a film project? If so, then we know the film is pulled down to 23.976 in playback. In digital, it gets a little more dicey, but it can work. The trick is, not all cameras will run at 24.00fps.

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Noah, thanks for your advice. So if I set the Fostex to 48K 23.976 FPS +.1% I will achieve 30 FPS at 48.048K?

Next question would be what do I set the backup to (SD 744t) since it has 48.048K capability but no pull up/down option (that I know of) and I'm jamming the two recorders. Last, what about slates...keep at 30 or bring down to 23.976 to the rate of decks? Thanks Noah.

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You can set 744t at 24/48048 and 824 at 23.976/48 plus .1% - slates at 24.

Or slates at 30, 744t at 30/48048 and 824 at 29.97/48 plus .1%

Jam slates from 744t

I can't remember if I sent TC or Clock from 744T to 824, but I know 744t was my master. It's been several years since I used this setup.

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Noah, thanks for your advice. So if I set the Fostex to 48K 23.976 FPS +.1% I will achieve 30 FPS at 48.048K?

No problem, and no, 48k 23.976 + 1 will get you *24* FPS at 48.048. (I'm sure that's what you meant). If you want 30/48.048 similarly set the 824 to 29.97/48 and add the 0.1% pullup on the machine which will adjust both upward.

Next question would be what do I set the backup to (SD 744t) since it has 48.048K capability but no pull up/down option (that I know of) and I'm jamming the two recorders.

The 744T has a sampling rate called 408048F. This is what you want. It'll deliver 48.048k files but deliver them with a 48.000k header in the stamp -- which is exactly what the Fostex is doing. Check the files from both with a utility (Wave Agent, Courtney Goodin's, BWF reader etc etc) and you should see the same information in each file's header. This will make the files from either deck interchangeable for post (other than the different track counts offered by the two machines).

Last, what about slates...keep at 30 or bring down to 23.976 to the rate of decks? Thanks Noah.

You mention 30 again and 24 in the previous post, so I'm a little confused. If you want 30 FPS code, set both machines to 29.97 (SD will do this automatically) and your slates to 30. If you're using the newer Denecke slates they have a mode called "Auto Set" where they will set themselves to the frame rate of the incoming code automatically. Otherwise set the slates to 30 FPS. If you want 24 FPS code, do the same but with 23.976 in place of 29.97. Probably needless to say, if you want to end up at 30 FPS code (the usual scenario for 48.048) *DON'T* use 23.976!

Good luck! Hope it works out.

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Still no fix. Biggest issue for post is that the TC stamp in metadata is header of file is 48K, not 48.048K. At this point I may need to be swapping recorders out. Post is super frustrated as am I, as I have recorded 48.048 on one show years ago and there were not issues.

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Give them the 744t mix with the recorder set at 48048, not 48048F.

Let the post sound team use the ISOs from the 824. Perhaps they'll be better equipped to handle it.

At this point it seems like their problem and not yours.

Stick with the settings above and let them figure it out.

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Post is super frustrated as am I, as I have recorded 48.048 on one show years ago and there were not issues.

When you say "post", do you mean the telecine house or the post production company?

Is the telecine house syncing the sound with picture or do they just provide 23.976 video files to the post production company?

What video software is the post production company using?

Mark O.

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I'd be curious if this is real-time HD telecine dailies -- which typically uses a DFT Spirit scanner for picture and a Fostex DVD machine for sound -- or if they're dealing syncing up files.

Seriously, we had to restamp sound files all the time at Complete Post/Technicolor, and it wasn't that big a deal. Once that's done, the equipment will recognize the files and play everything back correctly.

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