29.97 NDF LTC recognized as 30fps – time drift issue

[deffuy]

Hello,

I’m using TimeCore with an LTC source at 29.97 non-drop frame.
However, TimeCore seems to recognize it as 30 fps, and over time the displayed time drifts compared to the audio playback.

For example:
   •   At 5:16.22 (audio), TimeCore shows 5:15.25
   •   The longer the playback, the bigger the drift

This only happens with 29.97 NDF. With 30 fps, everything stays in sync.

Questions:
   1.   Is there a way to force TimeCore to correctly interpret 29.97 NDF LTC?
   2.   Or is this a known issue / limitation?

Any advice would be greatly appreciated.

Thanks!

[François Lonnee]

Hi, and thank you for your question!

The TimeCore's functionality in 29.97fps is limited to drop frame only, I'm afraid. So, like you discovered, using 29.97 NDF as input will give you the significant drift.

To work around this, perhaps you can switch things around and have the TimeCore be the timecode source?
We can discuss in detail how that could work in your setup, if needed / wanted.

Kindest regards,

[deffuy]

Hi,

Sorry for the extremely late reply.

Would it be possible to add a feature that compensates for 29.97 NDF by applying a 1001/1000 speed correction and outputs 30 fps timecode?

This would be very useful for systems like Pangolin BEYOND that do not support 29.97 NDF.

Kind regards,

[Jorge Solano]

Hello,

Thank you for the suggestion, and no worries about the late reply 

At the moment, TimeCore does not have a setting to compensate a 29.97 NDF LTC input with a 1001/1000 speed correction and output corrected 30 fps timecode.

So currently the best workarounds are to use 30 fps throughout the system, use 29.97 drop-frame instead of 29.97 NDF, or let TimeCore be the master and output 30 fps. If the 29.97 NDF LTC source must stay the master, then an external converter/resampler that specifically supports this conversion would be needed.

I agree this could be useful, especially for systems like Pangolin BEYOND that do not support 29.97 NDF. I will add it as a feature request for our development backlog, but unfortunately I cannot promise if or when it will be implemented.

Hope this helps!