[FFmpeg-user] Why is it possible to set a timecode with 24:00:00:00 and beyond?

[Christoph Gerstbauer]

FFmpeg allows me to set a timecode of 24:00:00:00 and beyond.

e.g "-timecode 24:00:00:00"

When I make an MXF D10 for example, the value of 24:00:00:00 is still in 
the file.
Most but not all programs ignore this and display 00:00:00:00 correctly.

Here are some sample extractions of the timecode offset value in 
different mxf d10 files generated by ffmpeg:

PAL 25fps:

-timecode 12:34:56:11  -> in file: 11477b hex -> 1132411 dec

-timecode 10:00:00:00 -> in file: 0dbba0 hex -> 900000 dec

-timecode 20:00:00:00 -> in file: 1b7740 hex -> 1800000 dec

-timecode 23:59:59:24 -> in file: 20f57f hex -> 2159999 dec

-timecode 24:00:00:00 -> in file: 20f580 hex -> 2160000 dec -> 24h

-timecode 24:00:00:01 -> in file: 20f581 hex -> 2160001 dec

-timecode 25:00:00:00 -> in file: 225510 hex -> 2250000 dec -> 25h


NTSC 30fps

-timecode 23:59:59;29 -> in file: 2782df hex -> 2589407 dec

-timecode 24:00:00;00 -> in file: 2782e0 hex -> 2589408 dec


Why is this possible to set a timecode after 23:59:59:XX?
Is there a usecase?

Best Regards
Christoph Gerstbauer