capullo-audio

The delivery engine of the Capullo Audio Platform. An Android library that decodes whatever a source resolves through ExoPlayer, tees the PCM into a Snapcast FIFO, and broadcasts time-synced audio on the LAN with a bundled web player.

Namespace tech.capullo.audio · Gradle 9.6.1 · Kotlin 2.3.10 · AGP 9.1.0 · Media3 1.9.0.

Where this sits: see Platform shape.

What's in here

Package	Contents
player	FifoAudioBufferSink + FifoRenderersFactory - the ExoPlayer tee → 44100/16/2 FIFO chain
snapcast	SnapserverProcess, SnapclientProcess, SnapcontrolPlugin, JSON-RPC, discovery, NSD
(root)	CapulloAudioEngine - the public facade wiring source → player → snapserver → control plugin
assets/webui	the bundled Snapcast web player (index.html)

Dependencies (dependency direction is one-way)

• api → capullo-audio-contracts (the SPI). The engine speaks only MediaSourceProvider / NowPlaying / PlaybackController - it knows nothing about radio or Telegram, and never depends on a capullo-source-* library: sources are siblings, not a layer underneath.
• implementation → lib-snapcast-android (prebuilt native .so), Media3.
• The FFmpeg decoder (lib-media3-ffmpeg-android) is reflection-loaded by DefaultRenderersFactory when present on the app classpath - not a compile dependency here.

⚠️ Migration notes for consuming apps

1. Artwork moved to the app. The old plugin downloaded artwork from a URL / read an art file itself. The engine's SnapcontrolPlugin now emits NowPlaying.artworkBase64 verbatim - the source/app is responsible for producing base64 artwork (and may set extras["artExtension"]).
2. SnapserverProcess.STREAM_NAME is hardcoded "name=QuantumCast" - parameterize per app before Telecloud consumes the engine.
3. CapulloAudioEngine covers the broadcast core. Still to wire (see its KDoc): prefetch feedback (onQueueAdvanced), snapclient/listen-in mode, and app-owned Service concerns (notifications, watchdog, buffering UI).

Build

./gradlew :capullo-audio:assembleRelease   # library AAR
./gradlew :app:assembleDebug               # harness APK (bundles the snapcast .so)

Requires the Android SDK. Contracts resolves from jitpack by default; for local co-development, check it out beside this repo and settings.gradle.kts substitutes it via a composite build.

License

Copyright 2026 capullo-tech. Licensed under GPLv3 - see LICENSE (integrates GPLv3 Snapcast via lib-snapcast-android; substantially derived from RadioCapullo).