IOError：[Errno 2]没有这样的文件或目录：'./audio.wav'

Question

我正在尝试运行一个将audio.mp3转换为audio.wav的程序

os.system("echo 'y' | ffmpeg -i " + DOWNLOAD_LOCATION + "audio.mp3 ./audio.wav 2>/dev/null")
    with sr.AudioFile('./audio.wav') as source:
        audio = r.record(source)

但是我总是遇到相同的错误

Traceback (most recent call last):
  File "run.py", line 151, in <module>
    res = runCap()
  File "run.py", line 119, in runCap
    with sr.AudioFile('./audio.wav') as source:
  File "/usr/local/lib/python2.7/dist-packages/speech_recognition/__init__.py", line 203, in __enter__
    self.audio_reader = wave.open(self.filename_or_fileobject, "rb")
  File "/usr/lib/python2.7/wave.py", line 511, in open
    return Wave_read(f)
  File "/usr/lib/python2.7/wave.py", line 160, in __init__
    f = __builtin__.open(f, 'rb')
IOError: [Errno 2] No such file or directory: './audio.wav'

非常感谢您的帮助