could we get an SPEED IMPROVEMENT in emulators by using SCANLINES?

**xiringu** · June 18th, 2006, 14:09

I'm wondering if any of the emulators (N64, GBA, Amiga, etc) could improve the framerate by using the well known technique of not processing every line.

As many of you already know, if we show only 1 every 2 lines (for example), the image is still ok for most games, and we can get a speed improvement at the same time that we double the vertical size of the screen.

apart from that, I kinda enjoy playing in scanlines mode, because it reminds me the good old coin-op machines back in highschool :P

any idea on this?

is there any reason for this not being used on PSP emulators?

**Cap'n 1time** · June 18th, 2006, 16:10

not really. I believe all scanlines do is make your PC monitor look more like a TV so that cards and emulators that dont support anti aliasing wont appear to have all the jaggies.

I dont think you can just say "dont porcess 20% of the lines".. I believe scanlines are just somthing that appear over the visual layer of the program.

**xiringu** · June 18th, 2006, 16:23

well, I don't know, maybe you're right.

but I guess it depends on the implementation of how the screen is generated

and I understand there's 2 types of scanlines, one being just a filter to change the looks of the screen, but the other is a trick in which you just don't process half of the image, and I mean the later

one clear use I see, is for those cases when framerate drops between 1:1 and scaled image (i experienced that in some emulators, pspUAE for example)

in those cases, scanlines could be a trick to maintain framerate while making the screen just look bigger

**pkmaximum** · June 18th, 2006, 17:10

I believe scan lines are for certain types of outputs on a video game system. Usually on older model t.v. generate scan lines. Now I believe when you see an emulator that has scan lines kawaks for example it just simply meens that it is emulating the t.v. interface for the output. But you can easily just switch it back to normal also by tinkering a bit with the video settings. So the answer to your question, no I don't believe that using scan lines will give it any speed increases at all. As full screen on a game doesn't slow things down iether will adding scan lines. In retrospect its just making the visual image worse for the game play.