Synced AUDIO runs fine then gets OUT OF SYNC

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Carl Jirestedt

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Synced AUDIO runs fine then gets OUT OF SYNC

PostTue Mar 14, 2017 4:20 pm

Ok.
I synced AUDIO (48k) and replaced my in camera 48K audio.
(AUDIO synced using AUTOSYNC and manually syncing slate sound with slate visuals)
Playback is running fine and export is fine. AUDIO is in sync.
Then starts the lag!
Why is it happening and what can I do?
Even the export has AUDIO lag, not just the playback.
If I playback from the same position 2-3 times in a row the audio gets in sync during playback, but if I start from another position it's out of sync again. This seams like a computer lag type of problem but why is the export out of sync too?

Resolve 12.5 Studio/Dongle
25 fps timeline and footage.
Changed timeline resolution from HD to UHD and back in order to edit in realtime and then exporting from UHD settings. Exporting a HD video, audio settings Linear PCM.

Please help
Thanks!
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Simon Rabeder

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  • Location: Vienna, Austria

Re: Synced AUDIO runs fine then gets OUT OF SYNC

PostTue Mar 14, 2017 8:36 pm

I guess you checked the recording sample rate of the audio recorder. Sometimes they have a 4% pullup applied for 23,976 shooting.


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Carl Jirestedt

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Re: Synced AUDIO runs fine then gets OUT OF SYNC

PostWed Mar 15, 2017 2:42 pm

Thanks.
But It cant be the 4% pullup because the lag comes and goes.
Playing from the same start position 3 times fixes the lag. (perhaps RAM issue?)
I found "Playback Proxy mode" and set it to Half resolution and it gets rid of most lag. But how could the lag spill to the export I wonder when to AUDIO is in fact synced?
It sure looks like a bug. Perhaps if the system is overloaded the render could be corrupt. Not all exports have the problem.
Maybe the "render speed" needs top be adjusted?
I don't know about this!
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Simon Rabeder

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Re: Synced AUDIO runs fine then gets OUT OF SYNC

PostSun Mar 19, 2017 11:26 am

try a slower render speed.
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Marc Wielage

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Re: Synced AUDIO runs fine then gets OUT OF SYNC

PostMon Mar 20, 2017 4:49 am

What is the source material and camera type? There are camera phones and drones out there that don't record at a constant speed but instead use a variable framerate.
marc wielage, csi • VP/color & workflow • chroma | hollywood
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Carl Jirestedt

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Re: Synced AUDIO runs fine then gets OUT OF SYNC

PostFri Mar 31, 2017 2:42 pm

Thank you.
I'll try slower render speed. The render speed has always been set to "maximum".

Camera is BMPC4K and sound is coming from timecode devise.

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