Improves the commint 4682cf65 (2024-08-19) allowing also the capture
filter to be specified both before and after the vcap (if only one
used), eg. `-F flip -t testcard -F mirror`.
`-s` parameter now sets audio only to following video capture, just like
`-F` (capture filter) does.
This allows different setting for different audio connectors for
different video sources, namely for switcher, eg.:
uv -t switcher -s analog -t decklink:device=1 -s embedded -t \
decklink:device=2
refer to GH-318
