Librosa: 24 bit AIFFs imported at 16 bit WAVs does not raise exception

[danmackinlay]

If I import a 24 bit AIFF in librosa, no exception is raised, but it is parsed as (I think?) a 16 bit WAV, resulting in an array of modulated white-ish noise.
This should be either an exception, or correctly load the file.

FWIW, I use subprocess calls to sox and ffmpeg to handle all non-WAVs, since audiorate etc seem to also have problems with non-16-bit non-WAV files, and much of my data is in 24 or 32 bit formats.

[bmcfee]

Since librosa doesn't handle audio decoding directly, I think this is probably an issue in audioread.

Have you tried loading with PySoundFile instead? It will also load into a numpy array, so all of the other librosa functionality ought to work.

[danmackinlay]

Wow, PySoundfile is a find. It does correctly load 24 bit audio. audioread does not.
to quote them:

Each buffer is a buffer or str object containing raw 16-bit little-endian signed integer PCM data. (Currently, these PCM format parameters are not configurable, but this could be added to most of the backends.)

It's a pity they don't throw an exception for non-16 bit audio, but that's not an issue for here.

Of course, libsoundfile doesn't support MP3, and presumably AAC etc for the same reason, so this would still leave a role for audioread. And if you then have a 24-bit MPEG4 audio file, neither library can do it; but once again, implementing universal audio support is not librosa's job.

[bmcfee]

Yup, lack of mp3 support of the main reason we haven't switched over.

If there anything left to do in this thread, or can we close it out?