my load return value is empty

[JunLiangZ]

I installed ffmpeg according to the operation, and modified the path in setup.py, executed the command ./install.sh, and installed:
Processing dependencies for coviar==0.1
Finished processing dependencies for coviar==0.1
but:
from coviar import load
load([input], [gop_index], [frame_index], [representation_type], [accumulate])
The execution result returned is empty