Set it up how you want to run it.
Copy the command to a text editor.
Find: bwdif=mode=1:parity=-1:deint=0
Check out the documentation.
According to that, you could change it to:
bwdif=mode=0:parity=-1:deint=1
With that it should: keep the frame rate the same, auto detect field order and only deinterlace frames marked as interlaced.
(I tried a run to make sure it would not double the frame rate. It did not. My output was set to PNG, so if you see any -r or -framerate in the command, you may need to correct it.)
