python 音频文件计算语速

计算音频文件的语速可以通过以下步骤实现：

1. 导入必要的库

import wave
import contextlib
import numpy as np

2. 打开音频文件并获取采样率和帧数

with wave.open('audio.wav', 'rb') as wf:
    frames = wf.getnframes()
    rate = wf.getframerate()
    duration = frames / float(rate)

3. 读取音频数据并计算音频的语速

with contextlib.closing(wave.open('audio.wav','r')) as f:
    frames = f.getnframes()
    rate = f.getframerate()
    duration = frames / float(rate)
    buffer = f.readframes(frames)
    audio_data = np.frombuffer(buffer, dtype=np.int16)
    speech_rate = len(np.where(audio_data > 200)[0]) / duration

其中，`np.where(audio_data > 200)[0]` 表示音频数据中所有大于 200 的采样点的位置，`len(np.where(audio_data > 200)[0])` 表示这些采样点的数量，除以音频长度 `duration` 就得到了语速。

完整代码如下：

import wave
import contextlib
import numpy as np

with wave.open('audio.wav', 'rb') as wf:
    frames = wf.getnframes()
    rate = wf.getframerate()
    duration = frames / float(rate)

with contextlib.closing(wave.open('audio.wav','r')) as f:
    frames = f.getnframes()
    rate = f.getframerate()
    duration = frames / float(rate)
    buffer = f.readframes(frames)
    audio_data = np.frombuffer(buffer, dtype=np.int16)
    speech_rate = len(np.where(audio_data > 200)[0]) / duration

print("语速为：{:.2f} 字/分钟".format(speech_rate))