SCTE 104
frames
timestamp · Decimal
The frame within the current second for a VITC time code. Its range depends on whether the system is 30 Hz or 25 Hz based video and on whether the frame rate is divided by 1.001, typically 0 to 29 for 30 or 30/1.001 Hz systems and 0 to 24 for 25 Hz systems. The NTSC rates run at 30/1.001 and 60/1.001 frames per second rather than exact integers.
Clause citations
Standards note
Drop-frame is a time code counting convention that skips frame numbers 00 and 01 at most minute boundaries; it does not change this field's per-second range, which is still 0 to 29 at 29.97 Hz.