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Drifting Sync in MC 5.0.3
OS 10.6.3
MC 5.0.3We’re shooting a film on 35MM 3 perf. The lab is transferring dailies and we’re cutting in a 1080p/23.976 project using MC 5.0.3. The production audio is being recorded on set at 48/30NDF. We importing the audio and syncing dailies in the Avid.
I’ve tested importing the audio a variety of ways but the audio always drifts my 2-3 frames on long takes.
I know this is an age old question so any feedback is helpful.
Thanks.
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11 Replies
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I assume that film on set was rolling at 24.000fps. When it gets transferred it is slowed down .1%. The audio, at 48kHz on set is in sync with 24.000fps picture. When you work in a 1080p/23.976 project, the picture is still running slower, thus your drift against audio that is still at 48kHz.
The sound should be recorded at 48.048 on set knowing you will be posting 24.000 picture at 23.976.
To fix sync, you can use a free application like Wave Agent from Sound Devices (download) and set the sample rate to 47.952 for your clips. Then import – it will be in sync. Make sure your audio import settings is set to deal with the +/- .1%. Timecode may vary by the number of sample from midnight…
Get your sound guys to record at 48.048 as soon as you can. Or work in a 1080p/24.000 project type.
Michael
Michael Phillips
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Thanks Michael. You’re advice help me get the ball rolling at having production have our sound recordist change to 48.084.
One more quick question. Can you confim the correct import setting in MC for the clips to play correctly? I’m assuming the only box I need checked in the “Import Setting” tab is “Sample rate convert source sample rate to project sample rate”
Thanks again.
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You also want to check the one that says: “do not convert sources with pull-up and down rates. Speed and duration will change from source.”
Michael
Michael Phillips
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Got it. Does that also go from clips converted to 47952?
j. -
Correct. It only deals with the .1% variants of 48kHz. So 48.048kHz and 47.952kHz.
Michael
Michael Phillips
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Michael,
Thanks again for all the help. One last quick question. I’ve found a few clips from one day of shooting that were recorded at 30NDF/44100. What’s the correct conversion (if there is one) in Wave Agent to maintain sync in the Avid?
j. -
Convert to 48kHz first via a roundtrip in Media Composer. Change it to 47.952 in Wave Agent then import with the settings discussed. Should be fine.
Michael
Michael Phillips
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Hi Michael,
So this is the thread that won’t go away. Our mixer is now recording at 48.048/30NDF.
We’re importing those files into our 23.98/1080p MC 5.0.3 project for syncing. On the “import settings” tap we have “sample rate convert source sample rate to project sample rate” and “Do not convert sources with pull-up and down rates speed and duration will change from source” both checked. All per the previous threads. However, on longer clips sync is still drifting by 2-3 frames.
Any thoughts as to why?
Once again. Many thanks.
j. -
Try uchecking the second box for “Do not convert sources with pull-up and down rates speed and duration will change from source” and see what happens. At the very least, the same imported file imported with either setting should show a different in duration when lined up in the timeline.
Michael
Michael Phillips
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I’ve tried that and it does shift the duration by 2 seconds but sync is still drifting.
We’re all a little stumped.
j.
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