detected video in carrier.mp3

i think ffprobe is detecting a single image (album art) as video in my carrier.mp3, causing this line in process:

if 'video' in carrier_type:

to be true. i ran ffprobe with debug loglevel and got this output:

Duration: 00:05:53.31, start: 0.000000, bitrate: 256 kb/s
Stream #0:0, 50, 1/14112000: Audio: mp3, 44100 Hz, stereo, fltp, 256 kb/s
Stream #0:1, 1, 1/90000: Video: mjpeg (Baseline), 1 reference frame, yuvj420p(pc, bt470bg/unknown/unknown, center), 1280x720 [SAR 1:1 DAR 16:9], 0/1, 90k tbr, 90k
tbn (attached pic)
Metadata:
comment : Other
audio
video

i tried this:
ffprobe -v error -select_streams v:0 -count_frames -show_entries stream=nb_read_frames -print_format csv=p=0 carrier.mp3
and it returned 1

i get this error when i run stammer:

File "C:\Users\thoma\source\stammer\stammer.py", line 61, in make_frames
frames = np.zeros((num_frames, frame_length * 2), dtype=input_audio.dtype)
ValueError: negative dimensions are not allowed

after removing the album art and running again:
ffprobe -loglevel error -show_entries stream=codec_type -of csv=p=0 carrier.mp3
returns only 'audio' and stammer works fine.

maybe stammer can use the file extension rather than ffprobe to determine the file type?