Also in the Video settings, the 'Display Format' values depend on the 'Screen Ratio' selected, but boot-settings only allows for the first set below:
- with 16:9 (TBL_MENUCONFIG.SCREEN_RATIO=2), the options for TBL_MENUCONFIG.DISPLAY_FORMAT are
Auto - 5
Pillarbox - 1
Zoom - 7
- with 4:3 (TBL_MENUCONFIG.SCREEN_RATIO=1), the options for TBL_MENUCONFIG.DISPLAY_FORMAT are
Auto - 5
Letterbox 16:9 - 0
Letterbox 14:9 - 4
Centre - 3.
Apparently changing 'Screen Ratio' sets 'Display Format' to Auto, the common value of the two sets. Also, if boot-settings forces an invalid combination such as 4:3+Pillarbox, the result is 4:3+Auto. I assume that these are standard values and behaviours, not just on the HD FOX I'm looking at now.
To reflect this without having to know what 'Screen Ratio' is active or whether 'Screen Ratio' has been specified in another boot-settings item, it would be nice to have a boot-settings 'Display Format' that would force both 'Screen Ratio' and 'Display Format', except for Auto, in addition to the plain 'Screen Ratio' option, but that doesn't seem to be possible within the current design.
So, more simply, you can just put all the values in the 'Display Format' menu, annotating the menu text, eg:
Auto, Pillarbox (16:9 only), Zoom (16:9 only), Letterbox 16:9 (4:3 only), Letterbox 14:9 (4:3 only), Centre (4:3 only)
...