Set up your Plex arcade library

1 What you need

• A running Plex Media Server on any machine reachable from your TV (Windows, macOS, Linux, NAS).
• A free folder somewhere on disk to host your arcade collection. Anywhere is fine, you'll add it to Plex as a new library.
• Your own ROMs (you legally own them) and any BIOS files the emulator cores you choose require.
• A few minutes. Once set up, you don't have to touch this again: adding new games is just dropping files into the folder.

2 Create the Plex library

Open Plex Web, go to Settings → Libraries → Add Library:

1. Library type: Other Videos. This is critical: do not use Movies or Shows, or Plex will try to match titles against TheMovieDB and pollute your collection with fake metadata.
2. Name: Arcade (case-insensitive, but exactly that word). The app discovers your arcade content by looking for a library named "Arcade".
3. Add Folders: point it at the directory that will hold your arcade content (e.g. D:\Plex\Arcade, /mnt/storage/arcade, etc.).
4. Advanced → Scanner: leave the default Plex Video Files Scanner.
5. Advanced → uncheck "Use local assets" and disable extra agent fetching if available. There's nothing for Plex to look up online and you'll save scan time.

3 Folder structure overview

Inside your Arcade root, the layout is:

Arcade/
├── cores/                           # libretro emulator binaries
│   ├── nes/
│   │   ├── fceumm-arm64-v8a.mp4
│   │   ├── fceumm-armeabi-v7a.mp4
│   │   └── fceumm-x86_64.mp4
│   ├── snes/
│   │   └── snes9x-arm64-v8a.mp4
│   └── psx/
│       └── pcsx_rearmed-arm64-v8a.mp4
│
├── bios/                            # optional, shared BIOS files
│   ├── SCPH5501.mp4                    # PSX (US)
│   └── SCPH5502.mp4                    # PSX (EU)
│
├── nes/                             # one folder per platform, lowercase
│   ├── Super Mario Bros.mp4
│   ├── Metroid.mp4
│   ├── covers/                       # optional
│   │   └── Super Mario Bros.mp4
│   ├── screenshots/                  # optional
│   │   └── Super Mario Bros.mp4
│   └── gamelists/                    # optional (ES-DE metadata)
│       └── gamelist.mp4
│
├── snes/
│   └── ...
│
└── psx/
    ├── Tomb Raider.mp4                # renamed .chd
    ├── covers/
    └── screenshots/

Three levels matter:

• cores/<platform>/: the emulator binaries. One file per ABI (CPU architecture). Most users only need arm64-v8a.
• bios/: shared BIOS files used across cores. PSX needs them; NES, SNES, Game Boy and most others don't.
• <platform>/ (e.g. nes, snes, psx): your ROMs, one folder per system.

4 Why everything ends in .mp4

Plex was built to scan video, music and photos and ignores files it doesn't recognise. Renaming every file to .mp4 tricks Plex's scanner into indexing them, so the app can list and download them from your server through the normal Plex API. Plex never tries to play the file (the app does that), so the rename is purely cosmetic on disk.

What to rename:

• Emulator cores: fceumm_libretro_android.so → fceumm-arm64-v8a.mp4
• ROMs: Super Mario Bros.nes → Super Mario Bros.mp4
• PSX CHD: Tomb Raider.chd → Tomb Raider.mp4
• BIOS: scph5501.bin → SCPH5501.mp4

5 Get the libretro cores

Emulator cores are the libretro .so binaries published nightly for Android. Drop them under cores/<platform>/ renamed to <core>-<abi>.mp4. Each core is downloaded from:

https://buildbot.libretro.com/nightly/android/latest/<abi>/<core>_libretro_android.so.zip

Unzip, rename the .so to <core>-<abi>.mp4, drop it under cores/<platform>/.

6 Add BIOS files (PSX, NeoGeo...)

A few systems require original BIOS files the emulator cannot supply. Drop them into arcade/bios/ renamed to .mp4 (the base name, no inner extension needed). The app reads them from there and copies them to the system folder the core expects.

Common ones:

• PlayStation (PSX): at minimum one of SCPH5501.bin (US), SCPH5502.bin (EU) or SCPH5500.bin (JP). Drop them as SCPH5501.mp4, SCPH5502.mp4, etc. PCSX-ReARMed picks the region matching the game automatically.
• SNK NeoGeo: rename neogeo.zip to neogeo.mp4.
• Sega CD / Saturn: region-specific BIOS files. Check the core's documentation.
• NES / SNES / Game Boy / Mega Drive: no BIOS needed.

7 Add your ROMs

Drop one ROM per file directly under the platform folder, renamed to .mp4:

arcade/
└── nes/
    ├── Super Mario Bros.mp4              # was .nes
    ├── The Legend of Zelda.mp4           # was .nes
    └── Metroid.mp4                       # was .nes

Some platforms expect a specific archive format:

• PSX: convert disc images to .chd (smaller, indexed) with chdman, then rename to .mp4.
• PSP: .iso or .cso, renamed to .mp4.
• MAME / NeoGeo: rename the .zip romset to .mp4. The romset version must match the core (e.g. mame2003_plus uses 0.78 romsets, mame2010 uses 0.139).

8 Optional: covers, screenshots, gamelists

The browser screen can show a cover, an in-game screenshot, a focus-dwell video preview and rich metadata (year, players, description...) for each ROM. All optional: without them the app just shows the filename.

Covers, screenshots, videos

Drop them in the matching sub-folder, named exactly like the ROM:

arcade/nes/
├── Super Mario Bros.mp4              # the ROM
├── covers/
│   └── Super Mario Bros.mp4          # JPEG / PNG renamed
├── screenshots/
│   └── Super Mario Bros.mp4
└── videos/
    └── Super Mario Bros.mp4          # short gameplay loop

Gamelist metadata (ES-DE format)

Drop the gamelist.xml that ES-DE produced into a gamelists/ folder under each platform, renamed to gamelist.mp4:

arcade/nes/gamelists/gamelist.mp4   # the ES-DE gamelist.xml

The app parses it and uses the entries to enrich the right-hand detail panel: localised title, year, developer, number of players, description.

9 Troubleshooting

The Arcade icon doesn't show up in the rail

• Check that the Plex library is named exactly Arcade (case-insensitive).
• Check that Plex has scanned the library after you added files. Go to Plex Web → Arcade → Scan library files. The app uses Plex's index; if Plex doesn't see your files, the app can't either.
• Force-stop the app once after adding new platforms. The catalogue snapshot is cached in memory.

"Could not download the libretro core"

The app couldn't find a core for that platform matching your device's CPU. Check that cores/<platform>/<core>-arm64-v8a.mp4 exists in your library (or armeabi-v7a for older devices).

"No BIOS files found" in the logs (PSX, etc.)

• Make sure the BIOS file is in arcade/bios/, not in the platform folder.
• Filename must match the canonical core name (e.g. SCPH5501.mp4, SCPH5502.mp4).
• Force-stop the app so the catalogue snapshot is rebuilt.

The game starts but I don't see covers, screenshots or descriptions

• The game's metadata comes from the gamelist.mp4 (renamed gamelist.xml from ES-DE) under arcade/<platform>/gamelists/. Make sure the file is exactly there.
• Covers and screenshots must live in arcade/<platform>/covers/ and arcade/<platform>/screenshots/, named identically to the ROM file (just .mp4 renamed image / video).
• If only some games miss assets, the gamelist <path> entries must match the ROM filename without extension. ES-DE writes those correctly; if you renamed ROMs after scraping, re-scrape.
• Force-stop the app after dropping new metadata. The gamelist is cached locally on first read.

MAME says "ROM not found" or "imperfect video"

MAME romsets are version-specific. mame2003_plus expects MAME 0.78 romsets; mame2010 expects MAME 0.139; modern mame expects the matching current set. Mixing versions is the most common cause of "ROM not found" errors.

Game audio works but video stutters

Many classic games are natively 30 fps (most PSX 3D titles, Crash Bandicoot, Final Fantasy VII...) or 25 fps in PAL. That's the original hardware behaviour, not the emulator. Try a PSX title that was 60 fps natively (Tekken 3, Ridge Racer NTSC, Tony Hawk Pro Skater) to confirm.

10 A note on performance

Emulation runs entirely on your TV device, not on the Plex server. The server only stores and serves the files; the CPU and GPU doing the work are whatever silicon your TV has. So the experience varies a lot between devices.

Rule of thumb with the cores listed here:

• Nvidia Shield TV (2017+) and Chromecast with Google TV 4K: full speed on everything up to and including PSX, PSP and N64. Most games hit their native target frame rate.
• Fire TV Stick 4K Max, Fire TV Cube: 8/16-bit consoles, GBA, Mega Drive, SNES and NES all run at full speed. PSX is fine for 2D games and most 3D titles. PSP is hit-or-miss depending on the title.
• Older Fire TV Stick (2nd / 3rd gen), low-end Android TV boxes: 8-bit and 16-bit consoles work well. PSX, PSP and N64 may stutter or run below full speed.

If a specific game stutters on your hardware, that's the limit of the CPU/GPU emulating the original console, not something the app or your Plex server can fix.