Normalization by default

[stefan-balke]

Hey,

currently there is a default normalization when using fluidsynth:
https://github.com/craffel/pretty-midi/blob/master/pretty_midi/pretty_midi.py#L940

Could we make this optional? This way different MIDI velocities are ignored...

Fluidsynth is producing 16-bit integer values...this normalization scales it such that the values lie in [-1, 1]. I would rather say we divide the fluidsynth output by 2^16 plus making the normalization optional.

What do folks think?

[craffel]

The normalization is a lazy way of addressing the fact that we may be summing together the synthesis of many instruments, so the output of the PrettyMIDI.fluidsynth method (before normalization) is [-len(self.instruments)*2^15, len(self.instruments)*2^15 - 1]. I am fine with making the normalization disable-able via a keyword argument but I would still advocate for hard-normalizing to [-1, 1] when normalization is enabled.

[yawjalik]

Hello there, is this issue still up for grabs?

[craffel]

Yep!