How to use bsf

Created by: xdwgood

Thanks all！

I can use ffmpeg to add sei information

ffmpeg -i output.h264 -c:v copy -bsf:v h264_metadata=sei_user_data='086f3693-b7b3-4f2c-9653-21492feee5b8+qqqqq' xx.sei.h264

Does anyone know how to implement it in Python? thanks！！！