cannot convert with ffmpeg

[ROBERT-MCDOWELL]

here is the log:
whisper_init_state: kv cross size = 147.46 MB
whisper_init_state: compute buffer (conv) = 25.61 MB
whisper_init_state: compute buffer (encode) = 170.28 MB
whisper_init_state: compute buffer (cross) = 7.85 MB
whisper_init_state: compute buffer (decode) = 98.32 MB
Converting video to audio.
Couldn't get video.
module 'ffmpeg' has no attribute 'input'
Couldn't convert video to audio.
'NoneType' object has no attribute 'output'
Video converted to audio.
Captioning audio.
Couldn't transcribe audio.
temporary_audio.wav
Traceback (most recent call last):
File "/usr/local/bin/gptsubtitler", line 8, in
sys.exit(main())
^^^^^^
File "/usr/local/lib64/python3.12/site-packages/gptsubtitler/cli.py", line 26, in main
Transcriber.transcribe(
File "/usr/local/lib64/python3.12/site-packages/gptsubtitler/transcriber.py", line 128, in transcribe
srt_content = Transcriber.generate_srt_file(transcript, supress_output=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib64/python3.12/site-packages/gptsubtitler/transcriber.py", line 156, in generate_srt_file
for count, line in enumerate(transcript):
^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not iterable

any idea? thanks