{"id":128,"date":"2013-08-07T14:01:05","date_gmt":"2013-08-07T14:01:05","guid":{"rendered":"http:\/\/libretro.wordpress.com\/?p=128"},"modified":"2015-10-18T04:03:24","modified_gmt":"2015-10-18T04:03:24","slug":"retroarch-android-0-9-9-4","status":"publish","type":"post","link":"https:\/\/www.libretro.com\/index.php\/retroarch-android-0-9-9-4\/","title":{"rendered":"RetroArch Android 0.9.9.4"},"content":{"rendered":"

By Squarepusher –<\/strong><\/p>\n

Despite this being a point release, a couple of very important changes have been made regarding the Android port, which made me compelled to make this blog post so that I can explain some of the things that have changed.<\/p>\n

New cores added
\n<\/strong><\/p>\n

People always love this part \u2013 especially the Xperia Play guys who are ever struggling to hold onto ever-decreasing internal storage on their outdated devices \":)\" .<\/p>\n

First up is a new core\u00a0 \u2013 Picodrive<\/strong><\/em>. This has been closed-source for a fair while because notaz didn\u2019t like guys like certain guys profiting from it through iPhone ports with donation buttons. With libretro and RetroArch now out, there s justifiable reason to open source it again since the payware\/donationware guys are going to be on the run from now on.<\/p>\n

Picodrive is a Sega Genesis\/Sega CD\/Sega 32X emulator<\/em> especially optimized for ARM processors. It is the fastest Mega Drive emulator in existence for ARM-based devices like Android and iOS. Best of all, it comes with a 32X core which should run most games at fullspeed even on a weak ARM Cortex A8 CPU. There is only one game that has somewhat higher system requirements (Virtua Fighter 32X). An iPad Mini\/2 runs this game at 56~57fps \u2013 about two FPS shy of fullspeed \u2013 your mileage may vary on how it performs on [insert your device]. It runs fullspeed on the Nvidia Shield though.<\/p>\n

What else is new? A Stella<\/strong><\/em> core \u2013 this is an Atari 2600 emulator<\/em>. We already bundled this for the iOS port but I guess we neglected to add it to the Android port up until now. Anyway, here it is.<\/p>\n

Anything else besides? SNES9x mainline<\/strong><\/em> \u2013 ie. not the Next speedhacked version. Use this if you have a beefy device and think you can get away with a non-speedhacked version of SNES9x. It runs at fullspeed with all games on the Nvidia Shield \u2013 your mileage may vary on how it performs on your device. This version of SNES9x is more accurate than SNES9x Next- but is also a lot slower.<\/p>\n

We also threw in the Desmume<\/strong><\/em> core \u2013 Nintendo DS emulator \u2013 with meancoot\u2019s ARM JIT backend. It runs pretty much the same as the iOS port \u2013 no, it\u2019s not going to be giving that payware closed-source emu Drastic any run for its money and it\u2019s just thrown in for the \u2018ah what the heck\u2019 factor \u2013 its main usefulness as a libretro core is on the PC \u2013 but seeing how fast ARM hardware is catching up with even laptop Core processors, perhaps it will only take another year or two until ARM devices are at the level of a Core i5 \u2013 so we will keep it on life-support until then.<\/p>\n

I felt it was also time to throw in Mednafen PSX –<\/strong> an alternative PlayStation1 emulator<\/em>. Users of the PC version will know this emulator \u2013 it\u2019s one of the most accurate open-source PS1 emus around right now. It\u2019s always been deemed as totally unsuitable for ARM devices since it has such high system requirements \u2013 however, the Nvidia Shield is showing that there is reason for optimism. On Shield it hovers right now between 35 and 40fps with occasional spikes to 44fps. Give it some time with stuff like ARM Cortex A57 coming out and who knows if this will be able to run at fullspeed. So \u2013 it\u2019s included by default from now in anticipation of that.<\/p>\n

For practical purposes \u2013 it is recommended you keep using PCSX ReARMed<\/strong><\/em>. Don\u2019t complain to me that this core runs too slow.<\/p>\n

There is one other core which has been added \u2013 Instancing Viewer<\/strong><\/em>. This is another GL tech demo that is meant to show off instancing being done in GL. Load it up with any PNG image file and it should be rendered on a bunch of cubes \u2013 you can look at them from a firstperson perspective. You can increase the cube amount by going to RGUI->Core Options and increasing cube size. Note that the cube sizes are to the power of two \u2013 so 8 is 2 ^\u00a0 meaing 256 cubes. There is no practical gameplay purpose to this right now \u2013 it\u2019s just a Libretro GL tech demo. It might become something more useful later on.<\/p>\n

No more static syncing by default<\/strong>We now enable the threaded video option by default. There have been a couple of improvements to it in that it now applies adaptive jittering which should make the jittering less apparent.This option should lead to audio crackle-less gameplay on most devices. Of course, there is still the option to use static syncing and we certainly recommend its use if you know what you are doing and can set the \u2018refresh rate\u2019 in the RetroArch app to exactly match that of your display source\u2019s refreshrate. This option just turned out to be too difficult to setup for most users and because any refresh rate mismatch in RetroArch leads to audio\/video sync being incorrect, this would manifest itself in audio crackles and lead to a broken user experience.On a platform like iOS, this is simply no issue. On Android unfortunately it is. Therefore, we are playing it safe here. Upon starting up RetroArch Android for the first time, it will ask you whether you want to use threaded video or whether you want to \u2018synchronize by refreshrate\u2019. By choosing the latter option you get the old way of how things worked.<\/p>\n

NOTE: Static syncing should work fine on nearly all libretro cores. However, there has been one annoying exception, and that is PCSX ReARMed. Certain games (like Chrono Cross, FInal Fantasy VII, Crash Bandicoot 1, and lots more) use variable refresh rates instead of running at a fixed refresh rate. This seems to play havoc with RetroArch Android\u2019s way of doing static syncing right now (it is not a problem on iOS however). Enabling threaded video solves all these problems overnight, so we recommend that if you have your \u2018forced refreshrate\u2019 set up right, that you set \u2018threaded video\u2019 off for the PS1 fighter games like the Tekken games, Tobal games, Street Fighter games and others \u2013 ie. games that are guaranteed to run at 60Hz. For everything else, turn on threaded video for now.<\/p>\n

Appeal to low-latency audio in Android 4.1 and up<\/strong><\/p>\n

There have been changes to the OpenSL audio driver to target the new low audio-latency capabilities of Android 4.1 and up. This should lead to much better results where the audio isn\u2019t as hopelessly behind the video like it was in previous releases (which really wasn\u2019t our fault but more due to us having to deal with the awful state of Android\u2019s audio capabilities prior to 4.1 and up).<\/p>\n

We are aware that people with sub-Android 4.0 devices (and even 4.0 itself) will likely get regressions because their Android version can\u2019t possibly deal with low-latency audio buffer sizes. Unfortunately, there\u2019s no getting around the fact that Android was really fundamentally broken on many different levels up to maybe 4.1 and 4.2. Things certainly have been improving a lot since then, and it makes no sense for us to keep appealing to the lowest common denominator when those phones\/tablets are all going to be replaced in the near foreseeable future anyway (and they should). There\u2019s also no point trying to upgrade most of these outdated devices (like the Xperia Play) to the latest Android version because the system requirements of newer versions of Android won\u2019t allow for it. RAM requirements for instance have gone through the roof since Android 4.0 and up, and so it cuts off all older devices with only 512MB of RAM (and even less).<\/p>\n

If the demand is high enough on these old outdated devices, we might introduce back a \u2018high-latency audio\u2019 option. For this release, we are trying to cater to the crowd that bought devices this year and one year ago. We believe that is the right strategy here.<\/p>\n

NVidia Shield support<\/strong><\/p>\n

So we received an Nvidia Shield from Nvidia (two in fact \u2013 one for me, the other for Themaister) and we are certainly walking away with a higher overall impression of Android now. There are still problems, but they seem at least surmountable now.\u00a0 John Carmack in a recent QuakeCon talk has spoken about some of these issues, but really, it doesn\u2019t take a rocket scientist to fire up adb and look at Logcat and see the pages and pages of garbage collector stalls passing by to sense there is something architecturally very wrong going on with this OS from a high-performance games machine perspective. How Google is ever going to fix this and bring it at parity with iOS on most devices is frankly Google\u2019s problem.<\/p>\n