RetroArch going all PSP – PSP Version for Next Next release?

RetroArch PSP

This one generated more interest than I had expected. The PSP code in the RetroArch codebase has been dormant for quite some time now, but I never felt like hooking it up until some weeks ago.

Aliaspider did most of the final touches on video/audio after the initial port was up and running. Implemented right now is video, audio, input, RGUI, and most of the features you’d expect from RetroArch. I’ve already been asked about whether or not RetroArch PSP will include shaders or filters, and the answer is ‘no’. PSP’s GPU is fixed function and it has no shader capabilities whatsoever. CPU filters on the other hand would be far too CPU intensive for what is already a pretty weak CPU.

So how is performance with cores? Right now, Gambatte, NXEngine, Doom and some others are running at fullspeed. Aliaspider wrote a custom resampler for Gambatte since even Themaister’s blipper turned out to be too slow for PSP. Nestopia turned out to be surprisingly slow on PSP (about half the framerate of the Raspberry Pi – around 30fps or so) and FBA is also ‘not there’ yet for performance (currently maxing out at 50fps or so for CPS2 games). The latest version of Picodrive seems to be around 50 to 55fps with Sonic 1 – so definitely still a bit slower than the last Picodrive PSP version that was released by notaz back in 2007. It deserves mentioning that most of these cores right now are pretty unoptimized – it is all just generic C code.

Anyway, given that we’re dealing with a very weak CPU here, the need for custom cores arises. My plan is to make libretro versions of NJEMU, gPSP and others so that we can have full-speed CPS1/CPS2/GBA emulation at least on PSP. Aliaspider and me are also looking at ways to improve the current core’s performance. Some of these ideas involve implementing the RETRO_RENDER_HW feature so that we can draw directly to the PSP’s framebuffer and use the raw GPU command buffer through the use of some inlined macros.

So when can you expect a first public release of RetroArch PSP? Not now at least – maybe somewhere in time for 1.0.0.3.  We still believe that with a bit more work, we can release something special on PSP – which is why there will be no release right now. There will be little to no usage of the MediaEngine in cores, so if all goes well you can expect to run RetroArch PSP just fine on your Vita as well.

Remote Joy

Remember this? It was a PRX plugin for homebrew PSPs that allowed you to stream the PSP’s video/audio feed over WiFi to your computer. Well, about a year ago or so we made a very quick-and-dirty initial port to libretro.  The main advantages of this libretro core is that you will be able to use all the advanced functionality of RetroArch, that it is cross-platform and that it embeds libusb into the main core library (the original RemoteJoy was Win32-only).

Right now this core is not yet releasable and there is still some way to go before it can compete with the standalone RemoteJoy Win32 client. Maybe it will be more finished in time for 1.0.0.3.

PPSSPP Libretro core

In case none of the aforementioned two things excited you, maybe this will. We will be looking at making a libretro port of PPSSPP soon. This will be the second non-tech demo libretro GL core after Mupen64. At first it will target Android, iOS, and PC. Xbox 360 support may be considered in the future if I can get my XDK box back – since developing and debugging on a Slim alone is quite painful.

PPSSPP’s GUI will probably be left in (similar to the MAME libretro cores), though it will also be possible to run games headless.