Adding support for 960i (2*480i) in the scandoubler or another way to display an interlaced source using the scandoubler

[mathieulh]

A few games output 480i (for example, Sonic 2 multiplayer mode) which the scandoubler does not support, this means that when outputing to a VGA monitor you will see no image as it attempts to output a 15khz signal whenever the game outputs at 480i.

The scandoubler could, at no additional cost, double the interlaced signal to 960i to allow an image to be displayed.

If this is not an option for whatever reason, would it be possible to force the scaler for interlace resolutions only? or use it on a per game basis? (I assume bob deinterlace can't be implemented for the scandoubler?)

[sorgelig]

Scaler supports basic de-interlacing, therefore you can use vga_scaler=1 mode.

[mathieulh]

I am well aware of that, but the scaler introduces additional input lag (though I don't know by how much) and doesn't have proper scaling when either the AR doesn't match or the vertical resolution is too low (such as running at 480p)

If deinterlace isn't possible while running the scandoubler, can't we at least have it double the lines/resolution for an interlaced source? (we aren't talking about deinterlace for 480i to 480p, but rather doubling 480i to 960i), this would allow to at least use the monitor's own interlace output (or deinterlace feature), this would be a whole lot better than no picture at all at 480i (monitors do not like 15khz signals).