AssertionError: Minimum of 4 sample datapoints is required

[ZXTube]

I made my ref using generate_reference but for some reason the _ref file it made always had an empty list, so I opened the generate_reference.py file to find out that only .mp3 and .wav files are searched for, while I had .m4a files, so please make some exception to say that.

Sorry I don't know how to make pull requests.

line 56, generate_reference.py:

audio_files = [
        *glob.glob(input_dir+"/*.mp3"),
        *glob.glob(input_dir+"/*.wav")
    ]

if len(audio_files) < 4:
    raise(Exception("Not enough audio files provided, keep in mind that only .mp3 and .wav files are supported"))
else:
    print(len(audio_files), "audio files were found, keep in mind that only .mp3 and .wav files are supported")

Thank you.