Manim关于声音的操作。

1. 添加声音

添加声音，调用Scene.add_sound函数。

# This method is used to add a sound to the animation.
add_sound(sound_file, time_offset=0, gain=None, **kwargs) # gain (float) – Amplification of the sound.

2. 查看音频多长

查看音频多长，配合Manim动画等待时间，了解到有多种库可以对音频进行操作，我最后用的是mutagen。

（1）mutagen

Overview — mutagen

# Mutagen is a Python module to handle audio metadata.
pip install mutagen

# example
from mutagen.wave import WAVE
from mutagen.mp3 import MP3

audio = WAVE('test.wav')
duration = audio.info.length

卸载mutagen，pip uninstall mutagen：

 D:\workspace\manim> pip uninstall mutagen
Found existing installation: mutagen 1.45.1
Uninstalling mutagen-1.45.1:
  Would remove:
    c:\anaconda3\lib\site-packages\mutagen-1.45.1.dist-info\*
    c:\anaconda3\lib\site-packages\mutagen\*
    c:\anaconda3\scripts\mid3cp.exe
    c:\anaconda3\scripts\mid3iconv.exe
    c:\anaconda3\scripts\mid3v2.exe
    c:\anaconda3\scripts\moggsplit.exe
    c:\anaconda3\scripts\mutagen-inspect.exe
    c:\anaconda3\scripts\mutagen-pony.exe
    c:\anaconda3\share\man\man1\mid3cp.1
    c:\anaconda3\share\man\man1\mid3iconv.1
    c:\anaconda3\share\man\man1\mid3v2.1
    c:\anaconda3\share\man\man1\moggsplit.1
    c:\anaconda3\share\man\man1\mutagen-inspect.1
    c:\anaconda3\share\man\man1\mutagen-pony.1
Proceed (y/n)? y
  Successfully uninstalled mutagen-1.45.1

（2）scipy.io

from scipy.io import wavfile

sample_rate, data = wavfile.read('test.wav')
duration = len(data) / sample_rate          # returns duration in floats

我自己用pyttsx3生成几个声音，长度不同，然而，用上述方法得到的结果却是一样，采样率为22050，长度为26.75。

（3）pydub

pydub · PyPI

from pydub import AudioSegment
song = AudioSegment.from_mp3("test.mp3")

参考资料：

[1] How to get the duration of audio in Python? - GeeksforGeeks