Dated engineering entries and release notes from the developers building Meridian, the open-source PlayStation 5 emulator for Windows PC. Track improvements in Vulkan 1.3 translation, DualSense controller haptics, shader pipeline caching, audio latency, and Windows installer updates.
Showing all 15 entries
Fig. L1Every entry documents real progress in the Windows emulator: graphics fixes, controller updates, and compatibility changes.Changelog
October 20263 entries
LOG-042Method
A portrait cover strip for the Windows launcher
The landing now shows the library as large portrait covers, each flagged with a clear status. The words are Stable for a full playthrough, Beta for playable builds with noted issues, and Test for early evaluation.
The Windows launcher holds 400+ titles, and most of what’s shown runs stable. Install the Windows app to browse and boot the rest. We never publish fake 4K60 badges — only honest statuses.
Topic: Compatibility Standards
LOG-041Graphics
Vulkan swapchain presentation on HDR Windows displays
On displays with Windows Auto HDR or native HDR enabled, the first frame presented by some titles was clamped to an overly dark color gamut. The issue occurred when the Vulkan swapchain was created before the title finalized its backbuffer presentation format.
We deferred swapchain allocation until the title’s first present call, fixing dark image clipping. Titles render in SDR with accurate color mapping. The fix is merged on main and ships in build 0.9.5.
Topic: Vulkan 1.3 Swapchain
LOG-040Release
Meridian 0.9.4 released for Windows
Build 0.9.4 introduces driver-keyed pipeline caching, custom DualSense controller profiles with adaptive trigger curves, and a rewritten WASAPI audio resampler.
The Windows launcher library also passed 400 titles, with most now rated Stable on modern NVIDIA RTX and AMD Radeon graphics cards. Full release notes and setup instructions are available on the builds page.
Topic: Official Release
September 20265 entries
LOG-039Method
Distinguishing cold vs warm shader pipeline caches
First runs of any 3D title compile shaders on the fly, creating momentary frame stutter. Subsequent runs load precompiled pipelines directly from SSD. We now explicitly document cold vs warm cache states in performance reports so users know that initial stutter resolves after shaders are cached.
Topic: Shader Caching
LOG-038Windows
Isolating local save folders from OneDrive sync
When user Documents folders are synced by OneDrive, cloud background synchronization occasionally locks save files during gameplay, causing write errors. Meridian now writes all game save data directly to %LOCALAPPDATA%\Meridian\saves\<title id>, ensuring fast, exclusive file access with zero sync conflicts.
Local Save Path · Windows 10 / 11Isolated
save %LOCALAPPDATA%\Meridian\saves\<title id>\save_00.dat [exclusive lock ok]
Topic: Windows File System
LOG-037Release
Meridian 0.9.3 released
Introduced seamless HID controller hot-plugging, thread priority synchronization with Windows high-performance scheduling, and Returnal reaching Beta on high-end configurations.
Topic: Official Release
LOG-036Audio
Fixing audio pops on 44.1 kHz USB gaming headsets
Some USB gaming headsets only accept a 44.1 kHz sample rate. Games produce 48 kHz streams, and our previous audio mixer sized buffers around game requests rather than output device periods. The new WASAPI resampler operates directly on device period sizes, eliminating buffer starvation.
Topic: WASAPI Audio
LOG-035Hardware
Why 32 GB RAM is recommended for PS5 PC emulation
The console uses a unified 16 GB memory pool shared between CPU and GPU. On a gaming PC, system RAM and video memory are separate. When a title streams assets, buffers frequently exist simultaneously in system memory and GPU VRAM. 32 GB of system RAM provides smooth paging during level transitions.
Topic: PC Memory Architecture
August 20264 entries
LOG-034Release
Meridian 0.9.2 released
Integrated hardware video decoding through Windows Media Foundation for intro cinematics and cutscenes. Demon’s Souls character creation menu reached interactive status.
Topic: Official Release
LOG-033Input
DualSense touchpad and Xbox controller emulation
Titles frequently map inventory screens and menu shortcuts to the DualSense touchpad. For controllers without a physical touchpad (such as Xbox gamepads), Meridian binds the View/Back button to a touchpad click, with customizable stick gestures for touchpad swiping.
Topic: Controller Subsystem
LOG-032Method
Defining the Beta bar
To keep compatibility ratings honest, we defined Beta as requiring ten continuous minutes of interactive play from a cold start, rather than merely loading the first 3D frame. This guarantees that titles tagged Beta offer real gameplay loops.
Topic: Standards
LOG-031Method
Distinguishing title screen demo loops from playable gameplay
Some titles run automated non-interactive demo reels when left idle on the title screen. We clarified our testing procedures so automated demo reels stay in Test, reserving Beta strictly for player-controlled sessions.
Topic: Verification
July 20263 entries
LOG-030Release
Meridian 0.9.1 released
Resolved Windows 11 thread priority throttling that occurred when game windows lost foreground focus, and added automatic validation for pipeline cache files.
Topic: Official Release
LOG-029Graphics
Initial Vulkan 1.3 pipeline caching
Implemented our first persistent on-disk pipeline cache for translated SPIR-V shaders, substantially reducing frame stutter on subsequent launches of tested titles.
Topic: Vulkan Translation
LOG-028Release
Meridian 0.9.0 public preview launch
The first public release of Meridian, the open-source PlayStation 5 emulator for Windows PC. Features the core x86-64 loader, Win32 kernel services, and initial Vulkan 1.3 GPU translator.
