votes up 3

File format (repr(str1)) not understood. Only 'RIFF' and 'RIFX' supported.

github stars 8546
Exception Class:

Raise code

is_big_endian = False
        fmt = '<I'
    elif str1 == b'RIFX':
        is_big_endian = True
        fmt = '>I'
        # There are also .wav files with "FFIR" or "XFIR" signatures?
        raise ValueError(f"File format {repr(str1)} not understood. Only "
                         "'RIFF' and 'RIFX' supported.")

    # Size of entire file
    file_size = struct.unpack(fmt,[0] + 8

    str2 =
    if str2 != b'WAVE':

Comment explaining raise

There are also .wav files with "FFIR" or "XFIR" signatures?

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Ways to fix

votes up 1 votes down

This happens when a file with the wrong format is used.

Code that reproduces the exception:

from os.path import dirname, join as pjoin
from import wavfile
data_dir = pjoin(dirname(, 'tests', 'data')
wav_fname = pjoin(data_dir, 'fortran-sf8-1x1x7.dat')
samplerate, data =
print(f"number of channels = {data.shape[1]}")

ValueError Traceback (most recent call last)
<ipython-input-16-c418b6b3e727> in <module>()  4 data_dir = pjoin(dirname(, 'tests', 'data')  5 wav_fname = pjoin(data_dir, 'fortran-sf8-1x1x7.dat') ----> 6 samplerate, data =  7 print(f"number of channels = {data.shape[1]}") 
/usr/local/lib/python3.7/dist-packages/scipy/io/ in read(filename, mmap)  648   649 try: --> 650 file_size, is_big_endian = _read_riff_chunk(fid)  651 fmt_chunk_received = False  652 data_chunk_received = False 
/usr/local/lib/python3.7/dist-packages/scipy/io/ in _read_riff_chunk(fid)  519 else:  520 # There are also .wav files with "FFIR" or "XFIR" signatures? --> 521 raise ValueError(f"File format {repr(str1)} not understood. Only "  522 "'RIFF' and 'RIFX' supported.")  523  
ValueError: File format b'8\x00\x00\x00' not understood. Only 'RIFF' and 'RIFX' supported.

Fixed version of the code:

from os.path import dirname, join as pjoin
from import wavfile
data_dir = pjoin(dirname(, 'tests', 'data')
wav_fname = pjoin(data_dir, 'test-44100Hz-2ch-32bit-float-be.wav')
samplerate, data =
print(f"number of channels = {data.shape[1]}")

number of channels = 2

Aug 03, 2022 kellemnegasi answer
kellemnegasi 30.6k

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