snes9x aspect ratio bug?

[aspectyl]

After reading nesdev wiki on how PixelAspectRatio works, can someone verify if snes9x has a scaling bug?


snes9x
8:7 DAR ==> 256x224
4:3 DAR ==> 299x224 (*)

wiki
1:1 PAR ==> 256x224
8:7 PAR ==> 292x224 (*)


There's a setting in snes9x.conf:
Stretch:AspectRatioBaseWidth = 256 or 299
(can edit to 292)


DAR = PAR * SAR

DAR = 4/3
SAR = 280/240
PAR = 8/7


Thanks for any help

[tepples]

Yes, it appears Snes9x is a bit wide in its default setting for output scaling.

NTSC picture generators using the TMS9918 dot clock rate include the SMS VDP, TG16 and Genesis VDPs in 256px mode, NES PPU, and S-PPU. If you're scaling the output of one of these to 320x240 square pixels using the Rec. 601 definition of the 4:3 plane, a 256px picture ends up 292.57 pixels wide. The closest multiple of 4 to this is 292. I assume that Snes9x doubles this value when set to 2x for games using interlace or hires.

[aspectyl]

Thanks for the handy explanation. Also found this link which covers a lot of systems
https://pineight.com/mw/index.php?title=Dot_clock_rates

hires = 4:7 PAR. Have to check snes9x Jurassic Park on this.

[LocalH]

Thanks for the handy explanation. Also found this link which covers a lot of systems
https://pineight.com/mw/index.php?title=Dot_clock_rates

hires = 4:7 PAR. Have to check snes9x Jurassic Park on this.

Conveniently, Pin Eight is tepples' site

[aspectyl]

Conveniently, Pin Eight is tepples' site

side-note:
https://atariage.com/forums/topic/18999 ... try2403136

Atari 800 also uses 7.16 MHz / 6:7 ratio NTSC.

Just advertising since it's not in dot clock wiki.

[lidnariq]

(tangent) I was under the impression that the VGA 640x480 and 320x240 modes were "exactly" square, not "sorta" square...? Although it's not like VGA ever was used to directly emit to a TV anyway without using some other kind of reclocking.

[tepples]

https://atariage.com/forums/topic/18999 ... try2403136

Atari 800 also uses 7.16 MHz / 6:7 ratio NTSC.

Just advertising since it's not in dot clock wiki.

Thanks for the citation. If you find more, feel free to sign up on my wiki and add them. You'll need to get confirmed to edit mainspace, which you can do the same way as on NESdev Wiki: PM me here with your username there, confirm e-mail, or make two talk page posts and wait four days.

I was under the impression that the VGA 640x480 and 320x240 modes were "exactly" square, not "sorta" square...? Although it's not like VGA ever was used to directly emit to a TV anyway without using some other kind of reclocking.

In theory, VGA's 480-line modes (mode 12h and mode X) hsync at ~31.5 kHz and vsync at ~60 Hz, the right frequency for 480p EDTV. But the page lists a lot of arcade systems and home computers whose monitors may be configured for an active picture width shorter than the standard 704/13.5 = 52.148 microseconds. Apple IIGS AppleColor RGB monitors, for instance, come set about 11% wide, which accounts for the difference between the 5:6 or 5:12 PAR specified by Apple for super hires modes and the 3:4 or 3:8 PAR seen through the IIGS's composite output. VGA monitors are about 5% wide for the same reason.