Setting start timecode of clips split with split-video

[camjac251]

Similarly to #291 (comment)
It would be cool to be able to force the start timecode of a clip to be baked as the "ffmpeg seek timecode", either through the custom ffmpeg options or maybe a global one like -timecode -tc like how -crf is used in pyscenedetect

[wjs018]

I am not 100% clear on what the feature being requested is. What is your intended usage? Looking at #291 do you want an option to specify a start time for splitting the video and ignoring all the video/scenes prior to that start time?