timeline

Source: timeline.js:17

Video-timeline math for the Music Start marker — the video moment at which music tracks begin playing. Extracted so it's testable in plain Node (test/timeline.test.js). UMD-lite, same as automix.js / track-fade.js.

The renderer keeps mStart() / trackTimeFor() / videoCapForTrack() as thin wrappers that read the DOM + globals and delegate here, so this module never touches either. What lives here is the part that's genuinely easy to get wrong and impossible to test through the DOM: the sign conventions of the video-to-track mapping, and how the marker follows a trim-window change.

All times are in seconds. "Video time" is a position on the video's timeline; "track time" is a position on a track's own timeline.