Onset Detection
https://www.cnblogs.com/lyrichu/p/6848732.html
https://blog.csdn.net/matrix_laboratory/article/details/53709638
https://www.cnblogs.com/meelo/p/7839453.html
librosa：
https://blog.csdn.net/zzc15806/article/details/79603994
这个是钢琴乐谱识别：https://github.com/Zulko/unroll
Unroll is a Python module to ease transcription of piano rolls to sheet music. It transcribes either a MIDI file or a video of a piano roll. It finds the notes, the tempo, roughly separates the hands, and writes the result in a Lilypond file. In particular
https://github.com/salu133445/pypianoroll
