Add a property to show the active vf filters

Expected behavior of the wanted feature

The ideal use case:

• run mpv with --hwdec=auto
• insert any active vf filter (mpv will enable auto-copy)
• remove all filters (mpv will switch to auto)

I tried to find a property to make a simple auto-profile/script to make it come true. But the reliable property seems not be exist.
vf is just a simple string. Even though invalid values were set, check vf will return True.

Is it possible to add a property to show the active vf filters (like vo-passes can allow checking the active shader)?

Alternative behavior of the wanted feature

Or other better methods?

Log File

N/A

Sample Files

N/A

Start with the issue's --hwdec=auto scenario and trace how the existing vf property reports configured filters versus the active state. Compare the desired behavior with the vo-passes example; done means a reliable property or agreed alternative distinguishes no active filters from filters that are merely configured.