Musicreater/bgArrayLib/bpm.py

68 lines
1.7 KiB
Python

import mido
import numpy
'''
bpm
bites per minutes
每分钟的拍数
'''
def mt2gt(mt, tpb_a, bpm_a):
return round(mt / tpb_a / bpm_a * 60)
def get(mid:mido.MidiFile) -> int:
'''传入一个 MidiFile, 返回其音乐的bpm
:param mid : mido.MidFile
mido库识别的midi文件数据
:return bpm : int
'''
# mid = mido.MidiFile(mf)
long = mid.length
tpb = mid.ticks_per_beat
bpm = 20
gotV = 0
for track in mid.tracks:
global_time = 0
for msg in track:
global_time += msg.time
if msg.type == "note_on" and msg.velocity > 0:
gotV = mt2gt(global_time, tpb, bpm)
errorV = numpy.fabs(gotV - long)
last_dic = {bpm: errorV}
if last_dic.get(bpm) > errorV:
last_dic = {bpm: errorV}
bpm += 2
while True:
for track in mid.tracks:
global_time = 0
for msg in track:
global_time += msg.time
if msg.type == "note_on" and msg.velocity > 0:
gotV = mt2gt(global_time, tpb, bpm)
errorV = numpy.fabs(gotV - long)
try:
if last_dic.get(bpm - 2) > errorV:
last_dic = {bpm: errorV}
except TypeError:
pass
bpm += 2
if bpm >= 252:
break
print(list(last_dic.keys())[0])
return list(last_dic.keys())[0]
def compute(mid:mido.MidiFile):
answer = 60000000/mid.ticks_per_beat
print(answer)
return answer
if __name__ == '__main__':
mid = mido.MidiFile(r"C:\Users\lc\Documents\MuseScore3\乐谱\乐谱\Bad style - Time back.mid")
get(mid)
compute(mid)