Audio LTC interpretation faulty

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LucaLuca

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Audio LTC interpretation faulty

PostTue Oct 08, 2019 1:04 pm

Hi,

we are using three Tentacles to sync two panasonic cameras (GH4 / GH5) and one Zoom F8 recorder. The timecode on the cameras is being recorded on the audio track. We had some difficulties with our workflow, as sync never worked properly, until we found that Audio LTC readout in Davinci is not working accurate. The same video files work in Pomfort Silverstack as expected, so the audio timecode track is recorded properly.

LTC.png
LTC.png (676.31 KiB) Viewed 1607 times


Testfiles
I'm not allowed to post links. If you provide me an email, i could send you the testclips.

Thank you
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Jim Simon

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Re: Audio LTC interpretation faulty

PostTue Oct 08, 2019 3:42 pm

What frame rate?
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Gary Hango

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Re: Audio LTC interpretation faulty

PostTue Oct 08, 2019 9:02 pm

Any chance you could test this on a Resolve v15.3.1 system? It seems there have been more than just a few reports of anomaly’s in v16+ audio system.
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LucaLuca

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Re: Audio LTC interpretation faulty

PostWed Oct 09, 2019 3:31 am

Jim Simon wrote:What frame rate?

25fps

Gary Hango wrote:Any chance you could test this on a Resolve v15.3.1 system? It seems there have been more than just a few reports of anomaly’s in v16+ audio system.


Ill try that later!
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LucaLuca

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Re: Audio LTC interpretation faulty

PostWed Oct 09, 2019 8:37 am

Gary Hango wrote:Any chance you could test this on a Resolve v15.3.1 system? It seems there have been more than just a few reports of anomaly’s in v16+ audio system.


Same behaviour in 15.3.1.
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neilpho

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Re: Audio LTC interpretation faulty

PostMon Nov 11, 2019 8:55 pm

Search for the thread: Update Timecode from Audio LTC is Inaccurate

(I can't post URLs)
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2fanatyk2

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Re: Audio LTC interpretation faulty

PostWed Nov 13, 2019 11:58 am

Hi,

Using similar setup, had same problems, root cause explained below.

The problem is not exactly with Resolve, but with GH5. If you take a close look at audio in your GH5/4 file, you'll see that audio in GH5 is not being recorded for first 7-11 frames (dependent on resolution & settings). Because of this, resolve reads first timecode that appears and saves it as file timecode - not taking into account that delay. Luckily for particular setting this delay is repeatable, so for me simply offsetting audio recorder file by particular no of frames solved the issue.

Not exactly issue with resolve, but rather GH5 implementation.

However, it can be easily done way better in resolve, so that this issue is corrected. Tentacle sync software checks for timecode approx. 3 seconds into the video, so that it ignores issues with first frames. I've already requested this fix in one of "Feature requests" topics. You could also add your voice to one of those topics - the more this point is mentioned, the higher likelihood BM will actually do something around it, as from programming point of view the fix should be crazy simple.

BR,
Adam
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Steven Williams

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Re: Audio LTC interpretation faulty

PostMon Mar 02, 2020 2:01 pm

PLease fix this!!!

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