Andamp

Winamp 2.8 on your Android phone. Pixel for pixel.

Andamp renders the classic Winamp interface (player, equalizer and playlist) from real Winamp skin files: the actual sprite sheets from .wsz skins, drawn at integer scale with nearest-neighbor filtering.

Status

Andamp is in internal testing on Google Play. CHANGELOG.md lists what each release changed.

Each release also carries an APK for installing without Google Play. It is signed with a different key than a Play install, so the two do not update each other. A second, small APK beside it, andamp-autoamp, is Autoamp: the app that brings the Android Auto screen described below. It works beside an Andamp from either place.

What works:

• Local files, folders and the phone's music library, plus internet radio streams, through a Media3/ExoPlayer backend that keeps playing in the background with a media notification.
• The whole interface: transport, seekbar, volume and balance, the marquee, a working 10-band equalizer with the factory presets, playlist editing, shade mode, and the built-in spectrum analyzer and oscilloscope.
• A translucent window (Android 9+), so the windows float over your wallpaper, or Double Size (the D in the clutter bar) to fill the screen with the player instead.
• DSP effects in Preferences, extendable with .lua plug-ins.
• A visualizer window running AVS and Milkdrop presets.
• A floating player that stays on top of other apps (Android 11+), and a home-screen widget.
• Android Auto: its own player with the playlist to pick from. With Autoamp beside it, Andamp also puts its skinned main window on the car's screen. Android Auto shows an app with a screen of its own in a car only when the phone records Google Play as its installer.
• A browser for the Winamp Skin Museum.
• Jellyfin, Plex and Subsonic servers, through music sources that install as separate apps beside the player. See docs/source-packs.md.

Build

You need JDK 17 and an Android SDK with NDK 28.2.13676358 and CMake 3.22.1, which build the two native visualizer modules.

git clone https://github.com/mattijsf/andamp.git
cd andamp
echo "sdk.dir=$HOME/Library/Android/sdk" > local.properties   # or wherever yours lives
git submodule update --init --recursive                       # the visualizer engines build from source
./gradlew installDebug

Min SDK is 26. It turns with the phone, and remembers one window arrangement for upright and one for sideways.

Skins

Three skins ship with the app: AndAmp Dark (the default), Light and Spot. To load another, tap the menu button in the top-left corner of the titlebar and pick Skins > Load skin... for any classic .wsz file, or Skins > << Get more skins! >> to browse the Winamp Skin Museum. Loaded skins are kept and listed under Skins. Modern .wal skins are not supported.

Project layout

Everything draws in a 275 pixel wide virtual space, like real Winamp, scaled by a whole number. With Double Size on, the finished picture is then drawn a little smaller, so it is exactly as large as the screen takes: as wide as a phone's. Sprite coordinates come from webamp's skinSprites.ts.

core/model       Track, Transport, BackendState, Capabilities
core/playback    the PlaybackBackend contract and its test fixtures
core/player      the PlayerFacade the UI talks to, and the queue that mixes sources
core/dsp         the audio-effect graph: compiler and engine
core/plugin      .lua effect plug-ins: loader, sandbox, UI binding
core/network     network state, for radio and the server sources
core/packapi     the AIDL contract a music source in its own APK speaks
core/remotewindow  the AIDL an app uses to borrow the player's main window
backend/media3   playback through ExoPlayer
backend/pack     the client side of a music source
pack/common      the source side of that contract
visualizer/      AVS, and Milkdrop through projectM
androidauto/     the app Android Auto talks to, which lends the car's screen to the player
app/
  skin/          .wsz loader, sprite tables, bitmap font, PLEDIT/VISCOLOR/REGION parsers
  state/         render state and the ViewModel
  ui/            the canvas layer, widgets, and the windows
  widget/        the home-screen widget

The UI never touches a backend directly. A new playback backend implements PlaybackBackend and passes PlaybackBackendContractTest.

Translating

Andamp's text is in string resources: English, with translations into Dutch, French, German and Simplified Chinese. Adding a language or correcting one needs no Kotlin, only a copy of the XML files. docs/translating.md says how.

Contributing

After cloning:

brew install lefthook   # or your package manager's equivalent
lefthook install

The pre-push hook runs ./gradlew gate (formatting, detekt, unit tests, golden screenshot comparisons). The commit-msg hook checks that a feat:, fix: or change: commit touches something that ships, because those subjects become the release notes.

./gradlew gate                        # everything the push hook runs
./gradlew test                        # unit tests
./gradlew verifyRoborazziDebug        # unit tests plus golden screenshot comparison
./gradlew recordRoborazziDebug        # re-record goldens (review the diff first)
./gradlew spotlessApply               # format
./gradlew detekt                      # static analysis

Rules:

1. Sprite coordinates come from webamp, not from eyeballing. A golden test that fails is not fixed by re-recording it without understanding the change.
2. Every bug fix comes with a regression test. New features ship with tests in the same PR.
3. Odd behavior is often authentic Winamp behavior. Check webamp before changing it.
4. Formatting and analysis are enforced by tooling. Adjust detekt.yml with a comment if needed; no baselines, no bare suppressions.

The full engineering notes are in ENGINEERING.md.

Credits

Webamp by Jordan Eldredge, whose reverse-engineered sprite maps made pixel accuracy possible. Playlist text is rendered with Liberation Sans (SIL OFL, license in docs/). Milkdrop presets run on projectM; AVS is rebuilt in Kotlin from vis_avs. And Nullsoft, for the greatest media player interface ever made.

Full third-party attribution: NOTICE.md.

License

Copyright (C) 2026 Mattix (Mattijs Fuijkschot).

Andamp is free software under the GNU General Public License, version 3 or later. See LICENSE.

The source SDK is Apache-2.0. The modules a music source is written against (core/model, core/playback, core/network, core/packapi and pack/common, published as nl.mattix.andamp:model, playback, network, source-api and source-common) are licensed under the Apache License 2.0, so a source may carry any license.

Plug-ins, presets and skins are yours. As an additional permission under section 7 of the GPL, you may create and distribute effect plug-ins (.lua), visualizer presets (.milk, .avs) and skins (.wsz) under any terms you choose. This covers files loaded through those formats, not modified versions of Andamp itself.

The tip jar uses Google Play's library. As an additional permission under section 7 of the GPL, you may combine Andamp with the Google Play Billing Library (com.android.billingclient) and the Google Play services libraries it depends on, and distribute the combination, although those libraries are not under the GPL. The GPL keeps applying to all of Andamp's own code. The APK on the releases page is built without that library (-Pandamp.store=none), and its support page opens the website instead.

The bundled skins are artwork. AndAmp Dark, Light and Spot (the .wsz files in skin/dist/ and the art inside them) are licensed under CC BY 4.0. The Python build in skin/ that draws them is GPL like the rest of the code.

The name is not part of the license. "Andamp" and its icon identify this project. A fork gets everything the GPL gives it, under a name and icon of its own.