Opening a wave file in Python: unknown format: 49. What's going wrong?

python format wave
Lewistrick picture Lewistrick · Jun 25, 2013 · Viewed 14.8k times · Source

I try to open a wave file with the wave module, but I keep getting the same error whatever I try. The line with the error is the following:

wav = wave.open(f)

This is the error message:

Traceback (most recent call last):
  File "annotate.py", line 47, in <module>
    play(file)
  File "annotate.py", line 33, in play
    wav = wave.open(f)
  File "C:\Program Files (x86)\Python\lib\wave.py", line 498, in open
    return Wave_read(f)
  File "C:\Program Files (x86)\Python\lib\wave.py", line 163, in __init__
    self.initfp(f)
  File "C:\Program Files (x86)\Python\lib\wave.py", line 143, in initfp
    self._read_fmt_chunk(chunk)
  File "C:\Program Files (x86)\Python\lib\wave.py", line 269, in _read_fmt_chunk
    raise Error('unknown format: %r' % (wFormatTag,))
wave.Error: unknown format: 49

String f is a path to a .WAV file and it works when played in any of my media players.

I have of course imported the wave module. I tried f both as a relative and an absolute path. I tried replacing "WAV" by "wav".

What is the error caused by?

Answer

Leonardo Andrade picture Leonardo Andrade · Nov 24, 2014

Python's wave module works with a specific type of WAV: PCM (WAVE_FORMAT_PCM: 0x0001).

In your case, you're using a WAV of type WAVE_FORMAT_GSM610 [0x0031 = hex(49)].

You can use a program like Audacity or some lib for converting codecs to change the type of the WAV file.

You can see a list of WAV types here: https://www.videolan.org/developers/vlc/doc/doxygen/html/vlc__codecs_8h.html

Python's wave module source code: https://github.com/python/cpython/blob/master/Lib/wave.py

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