hrydgard / ppsspp

A PSP emulator for Android, Windows, Mac and Linux, written in C++. Want to contribute? Join us on Discord at https://discord.gg/5NJB6dD or just send pull requests / issues. For discussion use the forums at forums.ppsspp.org.
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[Request] Would ASIO/WASAPI Exclusive backend help with input lag on Rhythm games? #12494

Open GamerzHell9137 opened 4 years ago

GamerzHell9137 commented 4 years ago

After seeing how Project Diva Future Tone Arcade runs on PC with the backend there's no way to unsee the input lag difference btw that and WASAPI. Would ASIO help alleviate the input lag on PPSSPP if it was implemented? I literally can't feel any lag with couple of Nvidia settings enabled and using the ASIO on PDArcade (emulated).

EDIT: As i delve deeper into it, ASIO is a hardware based backend meaning that only people with audio interfaces will be able to use it which means that not all would be able to try it out. WASAPI atm has a delay of 30ms, while DirectSound has a 40ms delay. There's one more mode that can be used by most users and that's WASAPI_Exclusive mode. The delay is 10ms vs the WASAPI normal mode (shared mode called which i'm guessing PPSSPP is using rn). Exclusive mode should make the input lag lower.

PepeJulio commented 4 years ago

There's ASIO4ALL, which doesn't need an interface (each interface has it's own ASIO driver) but requires direct connection to the soundcard. If the library got implemented as a backend on the emu, phones would have no problem since they have built-in speakers, but PC users would have to AUX out because ASIO doesn't work with HDMI.

hrydgard commented 4 years ago

ASIO4ALL is equivalent to using WASAPI which PPSSPP already does. Our sources of latency are elsewhere unfortunately (graphics can end up buffering up to two frames, which is huge in a 30fps game).