Measure first.
Plan with confidence.

Multiply duration by the combined average bitrate, convert bits to bytes, label the unit convention, and add evidence-based headroom.

Drop-frame skips selected timecode numbers—not picture frames—to keep fractional-rate timecode close to elapsed clock time.

Record the exact rational rate, drop-frame mode, start timecode, and boundary convention before converting or conforming.

Treat frame count, handles, filename pattern, rate, and colorspace as one delivery record and check gaps before transfer.