MIDI velocity normalization in midi2list

[fabianostermann]

Hey there!

I just stumbled over following line from c1/c1s2_symbolic_rep.py, where midi velocity in bytes is normalized to $[0,1]$:

velocity = note.velocity / 128.

Shouldn't it be vel/127.0, because midi velocity is in $[0,127]$, so that 0 maps to 0 and 127 maps to 1.0?

Quick link to the line of code I am referring to:
https://github.com/meinardmueller/libfmp/blob/424127f2cd8317f796ab1591f7c0ec408208e782/libfmp/c1/c1s2_symbolic_rep.py#L70C44-L70C44

Just let me know if I'm thinking wrong or why 128 may be the better choice here! :-)
Anyway, thank you very much for your great work in providing all these reference implementations!!!! 🎉

[meinardmueller]

Dear Fabian,
Good observation. Dividing by 128 indeed yields values between 0 and 127/128. Besides looking more natural than dividing by 127, there is no deeper reason. So, you are right!

• Meinard

[fabianostermann]

Ok, thanks for your clarification :-)
However, when I'm thinking further about it, this minor issue shouldn't yield severe problems when using the /128 version for any experimental data and tasks.
Thx!

[fzalkow]

Thanks for catching this! I fixed it in this commit: 4e8c78d