[FFmpeg-user] Timecode Burnin with negative start

[betonpfeiler]

Halle Everyone!

I need to make a timecodeburnin to a video and add a 4sek pre-roll. I 
was able to do the burnin, but the timecode needs to be zero at the 
first frame after the pre-roll. Is there any way to start the timecode 
at a negative time and count up? So that the timecode starts at 
"-00:00:04:00". Is that possible?

Thanks!