PPSSPP Feature Request Page

[LunaMoo]

By default PPSSPP scales image to fit the screen without stretching, if it's stretched you either selected that manually yourself or your phone stretches the output automatically to get rid of the black bars, in the latter I dunno, normal phones doesn't do that, if you changed it yourself, the option for that is in display layout editor.

You might also be using skip buffer effects hack, but in this case it will always be stretched as anything else REQUIRES buffers, you can't skip something and still have it, that's the reality. It's a nasty hack left as a speedhack for bottom end devices and nobody should ever be using it on any reasonably modern device, it will additionally cause missing effects, black screens, no post process effects either and nothing of it will ever be fixed as that's what this hack does as a feature.