N64: Showing VI/second instead of framerate?

[Brunnis]

Hi guys! Is there a way of showing VI/second instead of (or in addition to) framerate when running lr-mupen64-next? When showing the framerate via RetroArch you get the frames per second that the game runs at internally. Many N64 games ran at sub-60 FPS on actual hardware, so this framerate value can be hard to use for determining if a game is emulated at full speed. VI/sec should always be 60 for an NTSC game if it runs fullspeed.

I know you can listen for audio corruption in order to determine if emulation is fullspeed, but something a bit more robust would be nice.

[hhromic]

@Brunnis afaik there is no option for this in the core. But sounds useful indeed.

If such functionality is already in standalone mupen64plus, then maybe is not that hard to bring it to the LR core as an option. In any case the right place to be discussed/requested is in the upstream repository.

[Brunnis]

@hhromic Yep, I’ll put in an issue on Github. Interesting observation: running the same emulator on RetroArch for Windows, with GlideN64 and HLE RSP, RetroArch displays VI/sec and not the game’s internal framerate. Tested Ocarina of Time and it shows 20FPS on Pi 4 and 60 FPS on my laptop. Both appear to run full speed.

[Brunnis]

Had a talk with the mupen64-plus-next dev, m4xw:

"thats because GLES variants use OnColorImageChangeBufferSwap
that only updates it when frames are changed
that has a bit better perf
but also has some side effects
i plan to make it eventually configureable
since some games (like quake) for example wont take inputs while map is loading
and then u cant open RA menu when that happens
if u ever encountered smth like that, its because of this"

I'll probably re-compile the core without this config option enabled to see how the Pi 4 handles it.

[dankcushions]

@Brunnis he actually just added the option: https://github.com/libretro/mupen64plus-libretro-nx/issues/72 (not sure which branch, but i'm sure you'll figure it out)