Mercurial > hg > adaptinstrspec
diff functions/midiPitch2Shift.m @ 0:b4e26b53072f tip
Initial commit.
| author | Holger Kirchhoff <holger.kirchhoff@eecs.qmul.ac.uk> |
|---|---|
| date | Tue, 04 Dec 2012 13:57:15 +0000 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/functions/midiPitch2Shift.m Tue Dec 04 13:57:15 2012 +0000 @@ -0,0 +1,23 @@ +function shifts = midiPitch2Shift(midiPitches, tuningFreqInHz, binFreqsCQT) +% shifts = midiPitch2Shift(midiPitches, tuningFreqInHz, binFreqsCQT) +% +% converts midi pitch to shift values in constant-Q vector. +% shifts for pitches that below the lowest or above the highest CQT +% frequency are set to a value of -1 + +numMidiPitches = length(midiPitches); +numFreqsCQT = length(binFreqsCQT); + +pitchF0s = midiPitch2Freq(midiPitches, tuningFreqInHz); +outOfBoundsPitches = (pitchF0s < binFreqsCQT(1) | pitchF0s > binFreqsCQT(end)); +if any(outOfBoundsPitches) + warning('F0s of some midi pitches lie outside the constant-Q spectrogram frequency range'); +end + +freqRatios = repmat(binFreqsCQT, 1, numMidiPitches) ./ repmat(pitchF0s', numFreqsCQT, 1); +freqRatios(freqRatios < 1) = 1 ./ freqRatios(freqRatios < 1); + +[dummy shifts] = min(abs(freqRatios), [], 1); +shifts = shifts - 1; % 'no shift' is defined as 0 +shifts(outOfBoundsPitches) = -1; +shifts = shifts'; \ No newline at end of file