FA-78594 / Broadcast timecode arithmetic / Member archive

Non-drop label to wall clock at pulled-down rates: pulldown denominator · case 04

An hour of 29.97 labels maps to exactly one hour of wall clock, 3.6 seconds short.

Member previewVariant 4 · 3 implementations · 9 checks per implementation

Case contract

Rates "23.976", "29.97", "59.94" run at nominal*1000/1001 frames per second while labels count nominal frames per second (non-drop). mode "to_ms": label to elapsed milliseconds, rounded half up. mode "to_tc": milliseconds to the nearest frame (half up), formatted as a non-drop label wrapping at 24 hours.

Why this case matters

Timecode arithmetic errors misplace edits, commercial breaks and captions against the broadcast clock.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: pulldown denominator	`39541875`	`39581417`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.