in src/toMidi.ts [257:282]
function constrainFrequency(
onsets: number[][],
frames: number[][],
maxFreq: Optional<number>,
minFreq: Optional<number>,
) {
if (maxFreq) {
const maxFreqIdx = hzToMidi(maxFreq) - MIDI_OFFSET;
for (let i = 0; i < onsets.length; i++) {
onsets[i].fill(0, maxFreqIdx);
}
for (let i = 0; i < frames.length; i++) {
frames[i].fill(0, maxFreqIdx);
}
}
if (minFreq) {
const minFreqIdx = hzToMidi(minFreq) - MIDI_OFFSET;
for (let i = 0; i < onsets.length; i++) {
onsets[i].fill(0, 0, minFreqIdx);
}
for (let i = 0; i < frames.length; i++) {
frames[i].fill(0, 0, minFreqIdx);
}
}
}