I'm using Ardour with Blender synced to JACK transport to edit video and audio at the same time. I've noticed that the timecode shown by both programs doesn't quite match at all times.
What is strange - when Blender and Ardour use the same framerate: 24 or 30 FPS - the indication is often off by 4 frames.
When Ardour uses 30 FPS, and Blender uses 24 FPS - the indication is off by only 1 frame.
I recorded two short videos to show this problem:
I also created an issue in Ardour bugtracker - I don't know if Ardour or Blender is causing the TC error.