Pitch Strength Calculation

[akustiker]

libf0/libf0/swipe.py

Line 192 in 0baf532

k = np.multiply(k, np.sqrt(1.0 / erbs_frequencies))

I once had a discussion with @sstrahl about whether this line is correct. Semantically, this solution should be cleaner:

# f_prime / f
q = erbs_frequencies / pitch_candidate
# Apply envelope
k = np.multiply(k, np.sqrt(1.0 / q))

In my tests, I did not see a difference when changing it, most likely because of the normalization step that follows:

libf0/libf0/swipe.py

Line 195 in 0baf532

k = k / np.linalg.norm(k[k > 0])

So, maybe this could be changed with future updates?