I am also running into this issue. It appears that
Input Sizing Preset is a read-only property. If you try to set it using
SetClipProperty() or
SetProperty() it won't work, but if you set it using the GUI and then read it with
GetClipProperty() or
GetProperty() it does return whatever your change in the GUI was.
The README.txt scripting documentation does have this line:
Some properties may be read only - these include intrinsic clip properties like date created or sample rate, and properties that can be disabled in specific application contexts (e.g. custom colorspaces
in an ACES workflow, or output sizing parameters when behavior is set to match timeline)
This is frustrating because, like you, I'd like to set it programatically. More frustrating though is that
SetClipProperty() and
SetProperty() return booleans of
True when trying to set
Input Sizing Preset. If an item is read-only, shouldn't these return
False?
What's even weirder is that, if you set the value in the GUI, then try to set it programatically, it does change. It just always changes to "None" to matter what you pass in.