How does ffmpeg record -timecode in different file formats?
FFmpeg only supports timecode in a limited set of formats. They are the MOV family (MOV/MP4/3GP..), MXF family, raw DV and Grass Valley GXF.
How the timecode is stored and flagged is specific to the format. MOV stores a DF flag, integer framerate and the timecode as a rate-adjusted integer frame index. MXF does essentially the same.