SMPTE timecode - LTC In

Hi! We have been working for a few months with Touchdesigner on several projects and there is a problem we keep finding in all of our projects doing sync with SMPTE timecode for video sync in several computers. We encounter several jumps of SMPTE when receiving the audio through an audio interface connected to Ableton Live from time to time. We had try different interfaces and also change the cables it seems stable and after a few days when working and editing the main project on Touch it gets unstable the way is receiving the messages in result it gives a lot of jumps in the Sync. The ONLY solution so far it’s to reboot the computer which make the node to start reading the SMPTE in a clear way again otherwise will get this jumps which drive us crazy. I have to say must of the time is stable but there is a 10 percent of time that is unstable and we have to reboot.

In the meantime do you know any alternative to do a SYNC from Ableton LIVE? that could be more solid?.

Thanks a lot.

*BUILD 2018.21150
*WINDOWS

Posible Fix might be creating a new instance of touch getting the SMPTE timecode and streaming the time code to a Touch out/in to the other Touch project. Not the cleanest but at least seems to be working we’ll let you know if this fixed the problem.

Hi,
To be clear, is the same TouchDesigner process running for days on end, or is the toe file being restarted?
-Rob

Hi Rob!

The Toe file which contains the LTC In is driving our main session controlling lights(DMX), projections, OSC messages, Midi etc… we restart this file everyday, we get a quite a lot of SMPTE drop sync after long period of use sometimes is quite random that will not work perfectly. The solution which is currently working is to use a separate instance of touch and stream this data from LTC in thought TouchOut. It seems there is something in the process working with SMPTE that is not getting along with other proceses.

Thanks.

I am running into this same problem. Everything is stable but after a few days LTC starts jumping. It seems like the issue might be with the Audio In not the LTC In. If I toggle the Activate parameter in the Audio In TOP that seems to help. It does come back after a few minutes though. Closing and reopening TouchDesigner fixes it for a few more days.

I will trying moving the Audio In and LTC In CHOPs to a separate toe and see if that helps.

But aren’t you using the LTC In CHOP for input of LTC? I’m a little confused as to how you are using the Audio In CHOP?

thx

Sorry I didn’t explain the signal flow. I am getting a SMPTE feed from Dante Virtual Soundcard. In TouchDesigner I have an Audio In CHOP connected a Select CHOP to get the correct channel and then to the LTC In CHOP.

Okay, I understand the pipeline now. So resetting the Audio In CHOP will clear up the LTC? Wondering if its the LTC acting up or its input, resetting the Audio In CHOP would suggest the latter.

That was exactly my thought. Resetting the Audio In CHOP does seem to fix the problem implying that its the Audio In that has the problem.

I had assumed that the issue was Dante but I added Resolume to the machine for an unrelated reason and noticed that LTC is consistent in Resolume when its jumping in TouchDesigner.

I’m having similar issues with the LTC In CHOP.

The setup I have is:
LTC in XLR → USB Audio Interface → Audio Device In → LTC In → OSC Out
(So basically 3 CHOPs).

I’m getting very weird glitches after 11h to 48h of running the .toe. I would get up to several thousand glitches/inconsistency’s per hour. After closing and restarting the .toe I would get another stable 11-48h.

eg of glitches that happen.
15:34:21:06
15:34:21:07
17:34:21:08
15:34:21:09

I would also see:
24:03:43:11 (should be 00:03:43:11)
15:71:10:21 (don’t even want to guess what’s going on here)

The LTC and TD run at 25FPS. The audio interface and AudioDeviceIn are at 48k.
WIN10 - 2021.13610