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Converting frame rates 552 audio


Rob Lewis

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I currently working on a show with my 552.  Cameras are Sony V1u's shooting 59.94 drop frame. Im recording back up audio on the 552 @ 24b/48k in 30 Non Drop (as the 552 does when no external source is present).  Should I batch convert the files with SD Wave Agent to 29.97 DF then burn to disc or leave them at 30 ND and let the import into Avid do the frame rate conversion??  I am sending to camera via wireless as well.

I doubt these files will ever see the light of day, but i still need to do it right.

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Crew, what I meant to say is 29.97.  I am somewhat confused, because of the dinky cam.  The editor tells me that even though the camera is set at 24P it is written to the HDV tape at 29.97.  Therefore Im assuming the edit is a 29.97 drop frame time line.  The 552 is recording at 30DF because of no external time code source.  Im just asking if converting the files to 29.97 drop frame is gonna mess things up.

Camera set at 24P

Camera set in Drop Frame

Audio Recorded to 552 @ 30 ND

2 Producers shooting 2 different scenes at one time

Take Xanax, Drink Beer, Go to bed!

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Rob,

As far as I know, the 30ND thing only really caused a problem with FCP.  Final Cut would force a .1% slow down on files stamped 30ND when importing into a 29.97 timeline.

That said, check out the 552 firmware released today that should avoid this problem all together:

http://www.sounddevices.com/notes/mixers/552/552-firmware-1-2/

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Crew, what I meant to say is 29.97.  I am somewhat confused, because of the dinky cam.  The editor tells me that even though the camera is set at 24P it is written to the HDV tape at 29.97.  Therefore Im assuming the edit is a 29.97 drop frame time line.  The 552 is recording at 30DF because of no external time code source.  Im just asking if converting the files to 29.97 drop frame is gonna mess things up.

Camera set at 24P

Camera set in Drop Frame

Audio Recorded to 552 @ 30 ND

2 Producers shooting 2 different scenes at one time

Take Xanax, Drink Beer, Go to bed!

I think there's going to be a problem with DF picture & NDF audio syncing but I could be wrong.

Eric

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Pretty sure you are correct Mr. Toline. 

Matt, I did see the issue addressed in the new firmware update, so thanks for the note about that. I do know for a fact they are using avid.  The firmware update poses the question do I need to convert to 29.97 in Wave Agent for FCP.

The fact is there no common timecode source but drifting timecode on the cameras, so we are using the clap sync method or tone bursts when cameras are up to speed. Syncing will be done by the clap or beep, not the timecode. My backup audio still needs to be played back at the right speed in order to sync properly.

Please correct me if I'm wrong!

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I currently working on a show with my 552.  Cameras are Sony V1u's shooting 59.94 drop frame. Im recording back up audio on the 552 @ 24b/48k in 30 Non Drop (as the 552 does when no external source is present).  Should I batch convert the files with SD Wave Agent to 29.97 DF then burn to disc or leave them at 30 ND and let the import into Avid do the frame rate conversion?

I'm not sure this will work. I assume the camera is shooting 29.97DF. Ideally, what you need is a small timecode generator at 29.97DF, jam it to the camera (assuming the camera never turns off), and then feed the generator into the 552.

I'm honestly not sure what would happen if you go into the headers and change the code from NDF to DF. Technically, if there's no pulldown, the files should run at the right speed, so they won't drift, but any slate numbers will be invalid for sure. Manual syncing should work fine.

BTW: I was reminded of "the old days," when I would occasionally drag along a non-TC DAT as a double-secret emergency backup. I loaned this set up to a friend one time, and naturally, we wound up having to use the non-TC DAT (a crappy Sony D7 portable) for the whole session, a film transfer. Amazingly, it synced up just fine and locked for a 7 minute take with zero drift. So no-reference digital recorders can work in a pinch -- they're just not ideal, and syncing is a bitch.

--Marc W.

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A second is a second.  If the file is the correct length when played back it will sync.  The workarounds are just to keep the edit systems from doing "helpful" things to the playback speed.  I think batch changing the FPS flag to 29.97 DF should be fine.  The new firmware will allow you to record generic wav files w/o TC metadata, which is good, although post might like TC for logging purposes if they use your files.    I say try both, see what works w/ the workflow.

Philip Perkins

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  • 1 month later...

sorry to be so late here...

" the camera is set at 24P it is written to the HDV tape at 29.97.  Therefore Im assuming the edit is a 29.97 drop frame time line.  "

one should not ass-u-me...

most camcorders in HDV format do not support SMPTE TC.

29.97 FPS is 29.97FPS, and DF/NDF has nothing to do with that rate (speed). and as long as you match the frame rate (integer or non-integer rates) and there is no pull down (or pull-up) of one media, then they should match (depending onstability issues, of course)

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  • 2 years later...

I just got off the phone with SD Tech Support and asked about the framerate for a 552. I was told that if not receiving timecode, then the 552 doesn't record at any framerate and stamps the file with the time of day. How does this change the way someone is syncing audio to picture?

It seems to me that you could get all of the sync you need with a simple "dumb" slate. Match the audio and video files in post or use PluralEyes.

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Philip is correct. It used to be that the 552 stamped the files even if no external source was present. The 552 doesn't provide a way to set timecode unless it is coming from the timecode input. So even on projects where neither the camera nor audio were running timecode, it was necessary to convert the audio files with Wave Agent to avoid problems when importing to final cut, which would "helpfully" adjust the audio to the project timeline framerate. Sound Devices issued an update long ago and I submit my 552 audio files, unaltered, for a variety of projects and framerates without any issues.

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Philip is correct. It used to be that the 552 stamped the files even if no external source was present. The 552 doesn't provide a way to set timecode unless it is coming from the timecode input. So even on projects where neither the camera nor audio were running timecode, it was necessary to convert the audio files with Wave Agent to avoid problems when importing to final cut, which would "helpfully" adjust the audio to the project timeline framerate. Sound Devices issued an update long ago and I submit my 552 audio files, unaltered, for a variety of projects and framerates without any issues.

This.

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