Someone asked in a ticket how to work with LTC timecode so I collected a bunch of timecode resources together, which I'm now posting here in case it's helpful to anyone else in future.

Using Incoming LTC/MTC

Isadora can only accept Midi Timecode (MTC) at the moment, but you could use the Pythoner actor and some online Python Libraries to create a system to convert incoming LTC to MTC, or use Pythoner and an online library to output LTC

Alternatively, you could use the free, Mac-only application Lockstep to convert incoming LTC to MTC so that Isadora can use it.

1. Download Lockstep: https://figure53.github.io/studio/
2. Start your LTC source
3. In Lockstep, select your LTC input and MTC Output
4. In Isadora, go to Communications > MIDI Setup then select "Lockstep" for one of the input ports
5. In Isadora, the MTC Reader actor should then be outputting timecode.

Downloads

• Here are the timecode User Actors I have on my main computer: https://www.dropbox.com/scl/fo/otkgwe1ur6wqadak1zz0q/APpJvU-nPyiFg0_g199WbpQ?rlkey=cs1l8ym3pkea3a6dpi5nkfo4l&st=x2q3rblv&dl=0
• There are some timecode-related User Actors on the TroikaTronix Add-Ons Page which you may find helpful:
  • https://troikatronix.com/add-ons/dx-timecode-tools/
  • https://troikatronix.com/add-ons/percentage-to-timecode-user-actor-example-file/
  • https://troikatronix.com/add-ons/srt-subtitle-player/
  • https://troikatronix.com/add-ons/timertool/

Tips

• There's timecode info in the Isadora 3 Release Notes if you use Cmd/Ctrl+F to search for the heading "New Feature: MIDI Timecode Support". 
  • This includes handy tips like shortcuts for typing timecode values:
    • When entering MTC values commas (,) or semicolons (;) can be used as placeholders for "00" (just like AfterEffects!):
      
      • 30;0 = 00:00:30:00 
      • ,1,30, = 00:01:30:00 
      • 1,1,30,0 = 01:01:30:00 
      • 30;15 = 00:00:30:15 
      • 2,45,7 = 00:02:45:07 
      • 2,,0 = 00:02:00:00 
      • 2;;15 = 00:02:00:15
    • Add a forward slash to specify framerate: 
      • 30,0/3 = 00:00:30:00/30
      • 45,0/6 = 00:00:45:00/60
• This forum thread is useful: https://community.troikatronix.com/topic/6399/answered-using-a-list-of-timecodes-to-trigger-events-in-this-case-lights-through-midi
• You can put "MTC" or "Timecode" into the actor search at the top left of the program to see a list of the actors that have "MTC" or "Timecode" in their name.
  • 
• You can learn more about an MTC/timecode actor (or any actor) by right-clicking it and selecting the top option, "Show Actor Help in Browser", from the resulting menu.
  • 
• By default, Movie Player actors use percentages, but you can switch a Movie Player actor to timecode by right-clicking it and selecting "Use Timecode" from the resulting menu.
  • 
• The Control Panel has a Timecode control that can either be connected to inputs to set specific timecodes, or connected to outputs and used to monitor incoming timecode.
  • Gif: https://jmp.sh/WGNqTNsJ
  • 
• Isadora's timecode values can have either a specific timecode rate (e.g., 01:02:03:04/24 = 24 fps, 01:02:03:04/29.97 = 29.97 fps,) or can have a special timecode rate that means "use the default timecode rate for the current show." This special default rate will be displayed as DEF (e.g., 01:02:03:04/DEF) to clearly indicate the use of the default rate. This default rate can be set at the bottom right of the main application window. To the left of the popup menu where you can set the default timecode rate for your Isadora file, there's a timecode display that will show what Isadora is receiving in terms of MTC. 
  • Gif: https://jmp.sh/r9jC1JBF
  • 
• Word of advice, NEVER use a Timecode Comparator actor set to 'eq' (equals), always use "ge" (greater than or equal to) or 'le' (less than or equal to). 
  • For triggering something from timecode that is counting down, use 'le' (less than or equal to).  
  • 'ge' will trigger as soon as a value is equal to or greater than the timecode value you're looking for, and will therefore do what you want it to. 
  • Values generally move too fast or in such small increments that the exact match to trigger on 'eq' is not going to happen.
  • 

Best wishes,

Woland