Minamp

A small Plexamp-style music player for Plex, built for the Samsung Galaxy Mini (GT-S5570: Android 2.2/2.3, 240×320 ldpi screen, 600 MHz ARMv6, 384 MB RAM). Runs on any Android 2.2+ phone.

Install

1. On the phone: Settings → Applications → Unknown sources (tick it).
2. Copy Minamp.apk to the SD card (USB cable, or download it in the browser) and open it with a file manager, or from a computer: adb install Minamp.apk.
3. The app can live on the SD card (Settings → Applications → Manage → Minamp → Move to SD card), which helps with the Mini's tiny internal storage.

Sign in

Open Minamp → Sign in with Plex. It shows a 4-character code; on any other device go to plex.tv/link and type it in. Minamp then lists your servers (owned and shared) and music libraries.

Connect to a server address is the manual fallback: an IP/hostname plus an optional X-Plex-Token.

Streaming from anywhere

After sign-in Minamp knows every address Plex advertises for your server and picks the best working one, re-checking whenever the phone switches network:

Order	Connection	When it's used
1	Home network, HTTPS (*.plex.direct)	On your Wi-Fi
2	Home network, plain HTTP	Same, if your router blocks plex.direct DNS (rebind protection)
3	Remote, HTTPS	Away, if Remote Access is set up on the server
4	Plex Relay	Away, when the server isn't reachable directly (bandwidth-capped; Minamp caps itself at 192 kbps)

For the best remote experience enable Settings → Remote Access on your Plex Media Server. Without it, Relay still works.

Android 2.x can't do modern TLS, so Minamp bundles its own TLS 1.2/1.3 stack (Bouncy Castle, renamed to com.minamp.bc so it doesn't clash with the old copy inside Android) and verifies certificates against Mozilla's root store (from certifi). A tiny loopback proxy feeds the phone's media player, so HTTPS streams and relay work the same as local ones. If the phone's clock has been reset to before 2024 the certificate date check is skipped rather than failing.

Playback and quality

• MP3, AAC (M4A) and Ogg Vorbis play directly. FLAC, ALAC etc. are transcoded to MP3 by the server (Android 2.2/2.3 can't decode FLAC).
• Menu → Settings: separate quality for home Wi-Fi (default Original) and for away/mobile data (default 192 kbps MP3); 320/256/192/128/96 kbps available.
• Seeking in a transcoded track restarts the transcode at the new position.
• If a stream fails, Minamp re-picks the connection and resumes; if it fails again it downloads the whole track first and plays from the SD card. "Download tracks before playing" forces that mode (useful on flaky mobile data).
• Plays are reported to Plex (Now Playing in the Plex dashboard, play counts, resume position).

Features

• Home: Library radio, Loved radio (rated 4★+ / loved), Time-travel radio (pick a decade), Random album, Recently added and Recently played shelves.
• Artists / Albums (5 sort orders) / Playlists tabs with paging and fast scroll; Search.
• Artist page with Play all and Artist radio; album and playlist pages with Play/Shuffle.
• Long-press anything: Play next, Add to queue, Go to album/artist, Love.
• Now Playing: big art on a backdrop coloured from the cover, seek bar, shuffle, repeat (queue/track), love, sleep timer (15–90 min or end of track), where it's streaming from.
• Up Next queue: jump, play next, remove, clear; the queue and position survive restarts.
• Wired headset button: 1 click play/pause, 2 next, 3 previous; Bluetooth media keys; pauses for calls and when headphones are unplugged.

Building (no Android SDK needed)

tools/setup_toolchain.sh      # once: fetches aapt2, the API 8 android.jar, builds dx, renames Bouncy Castle
./build.sh                    # -> build/Minamp.apk

build.sh runs aapt2 (resources), javac (Java 8 bytecode checked against the API 8 android.jar), dx (dex 035) and tools/signapk.py, which writes the v1 signature in the classic Android SignApk format and aligns the APK. (Modern jarsigner output does not install on Android 4.2 and older: it names digests SHA-1-Digest and labels the PKCS#7 signer algorithm in a way old JarUtils can't read, so the phone treats the APK as unsigned.) The debug key in signing/ (password minamp123) is what this APK is signed with, so rebuilt APKs install over it.

Tests (desktop JVM, no device):

• test/PlexTest.java + test/mock_plex.py: PIN sign-in, server discovery, connection picking/fallback, TLS with a wildcard plex.direct-style certificate (ECDSA leaf, RSA root), untrusted-root rejection, browsing, search, artwork, and the stream proxy (Range requests over TLS, de-chunking transcodes, aborting).
• test/QueueTest.java: shuffle/unshuffle, repeat modes, play next, remove, move, clear.

Limits

• No gapless playback (Android 2.2/2.3 have no API for it).
• Notification has no playback buttons (pre-Android 3 can't); tap it to open Now Playing.
• Downloads for offline listening aren't implemented.