FA-81443 / MIDI event timing / Member archive

Note-on and note-off pairing into durations: note-offs cross channels · case 03

A note-off on channel 1 ends a still-sounding note of the same pitch on channel 0.

Member previewVariant 3 · 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 1	`[[0, 10, 0, 60, 100], [5, 20, 1, 60, 80]]`	`[[0, 20, 0, 60, 100], [5, 10, 1, 60, 80]]`	Failed

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