Python中简单的节拍检测

Question

我正在做一个涉及LED和音频处理的项目。 我试图在Python中获得与Processing的Minim库相同的功能，但没有成功。 Minim的BeatDetect类具有isHat，isSnare等方法，这些方法可以轻松进行处理，因此可以打开相应的LED。

from aubio import source, pitch

def is_hat(frequency):
    lower = 3000
    upper = 5000
    return lower <= frequency <= upper


def is_kick(frequency):
    lower = 20
    upper = 100
    return lower <= frequency <= upper


def is_snare(frequency):
    lower = 300
    upper = 600
    return lower <= frequency <= upper


def read_audio(filename: str):
    downsample = 1
    samplerate = 44100 // downsample

    win_s = 4096 // downsample  # fft size
    hop_s = 512 // downsample  # hop size

    s = source(filename, samplerate, hop_s)
    samplerate = s.samplerate

    tolerance = 0.8

    pitch_o = pitch("yin", win_s, hop_s, samplerate)
    pitch_o.set_unit("midi")
    pitch_o.set_tolerance(tolerance)

    pitches = []
    confidences = []

    # total number of frames read
    total_frames = 0
    while True:
        samples, read = s()
        pitch_s = pitch_o(samples)[0]
        # pitch = int(round(pitch))
        confidence = pitch_o.get_confidence()
        # if confidence < 0.8: pitch = 0.
        print('hat' if is_hat(pitch_s) else '')
        print('kick' if is_kick(pitch_s) else '')
        print('snare' if is_snare(pitch_s) else '')


        #print("%f %f %f" % (total_frames / float(samplerate), pitch_s, confidence))
        print(pitch_s)
        pitches += [pitch_s]
        confidences += [confidence]
        total_frames += read
        if read < hop_s:
            break

    if 0:
        sys.exit(0)


def main():
    read_audio("song.mp3")


if __name__ == '__main__':
    main()

从Minim的BeatDetect的文档（[ http://code.compartmental.net/minim/beatdetect_method_ishat.html][1] ）中可以这样说：

“在频率能量模式下，如果已检测到与踩the的频率范围相对应的拍子，则返回true。已将其调整为与舞蹈/高科技音乐配合使用，可能无法与其他类型的音乐配合使用。模式，这总是返回false。”

我曾尝试研究小军鼓，踢和踩hat的不同频率范围，但是is_kick（）是唯一返回true的频率。 我尝试使用aubio将当前频率与上述范围的频率进行比较，以使其与BeatDetect相同。 我对音频知之甚少，因此将不胜感激。 谢谢。