FA-81432 / MIDI event timing / Member archive

Note-on and note-off pairing into durations: velocity-zero note-on opens a new note · case 02

Running-status style note-offs (note-on with velocity 0) never end notes; every note lasts to the end of the track.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input time-ordered events [tick, kind, channel, note, velocity] with kind on or off. A note-on with velocity 0 acts as a note-off. Each off ends the earliest still-open note with the same channel and note (FIFO); unmatched offs are ignored. Notes still open at the end end at the last event tick. Return [start, end, channel, note, on-velocity] sorted by start, note, channel, end.

Why this case matters

MIDI sequencers, file readers and synth drivers depend on exact event ordering and tick/time arithmetic.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
oracle 2	`[[0, 9, 2, 60, 100], [4, 9, 2, 60, 90], [8, 9, 2, 60, 0], [9, 9, 2, 60, 0]]`	`[[0, 8, 2, 60, 100], [4, 9, 2, 60, 90]]`	Failed

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