M4 Android stage 1 (audio). An audio thread pulls Opus packets from the connector
(next_audio), decodes to interleaved f32 stereo, and feeds AAudio via its realtime
data callback through a jitter ring ported from the Linux client (prime ~3 quanta,
drop-oldest cap, re-prime on drain). All in Rust on native threads — symmetric with
the video decode path.
- crates/punktfunk-android: audio.rs (Opus decode + jitter ring + AAudio callback);
SessionHandle gains an audio slot; nativeStartAudio/nativeStopAudio JNI; Drop stops it.
Android-only deps: opus 0.3 (libopus via cmake, static) + ndk "audio" (AAudio) — pure
C/NDK, no libc++_shared to bundle.
- clients/android: NativeBridge start/stop audio, called in the SurfaceView lifecycle.
- kit/build.gradle.kts: cargo-ndk env for the libopus cmake build (NDK root, Ninja,
LIBOPUS_STATIC/NO_PKG) + --platform 31 (libaaudio is API 26+).
Verified live (emulator -> gamescope host on the LAN box): AAudio opened 48k/stereo/f32;
a 440 Hz tone played into the host capture sink reached the client decoded -- opus ~200/s,
pcm_frames climbing in lockstep, peak=0.089 (real content, not silence), with video
streaming concurrently. Some underruns under emulator jitter (verify on hardware).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
M4 Android stage 1 (video). Pull HEVC access units from the connector and render
them to the SurfaceView entirely in Rust (NDK AMediaCodec → ANativeWindow) — no
per-frame JNI, honoring the native-thread hot-path invariant.
- crates/punktfunk-android: decode.rs (one-in/one-out AMediaCodec loop; in-band
VPS/SPS/PPS so no out-of-band csd; dims from NativeClient::mode). SessionHandle
now holds an Arc<NativeClient> + the decode thread; nativeStartVideo/nativeStopVideo.
- clients/android: connect screen (host/port) + full-screen SurfaceView stream
screen — surfaceCreated -> nativeStartVideo, leaving -> stop + close.
Verified live (Android emulator -> m3-host on the LAN box, ABI v2): QUIC handshake,
8-round clock-skew sync, HEVC decoder configured at 1280x720, and the data plane
delivered + fed all 299 access units (the punktfunk/1 NAT hole-punch worked through
the emulator's SLIRP). Real-pixel render is pending a non-synthetic source:
`m3-host --source synthetic` emits dummy transport payloads (not HEVC), so the
decoder correctly produces nothing; `--source virtual` (a compositor on the host)
is needed to verify decode-to-screen.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Rust-heavy client model (like punktfunk-client-linux): a new cdylib crate
crates/punktfunk-android links punktfunk-core and exposes the JNI seam;
Kotlin (clients/android) owns only the Android-framework surface. Kotlin can't
import the C header the way Swift can, so the bridge is written in Rust to reuse
the Linux client's orchestration rather than re-port it.
- crates/punktfunk-android: JNI bridge — abiVersion/coreVersion native-link
proof + session connect/close handle; plane pumps stubbed for M4 stage 1.
- clients/android: Gradle project — :app (Compose) + :kit (Android library with
a cargo-ndk Exec task -> jniLibs). AGP 9.2 / Gradle 9.4.1 / Kotlin 2.3.21 /
Compose BOM 2026.05.01 / compileSdk 37 / targetSdk 36 / minSdk 31, shipping
arm64-v8a + x86_64. Phone + TV (leanback) installable. README rewritten.
- .gitea/workflows/android.yml: CI mirroring apple.yml on a Linux runner.
- punktfunk-core: switch rcgen to the ring backend so the whole quic tree is
aws-lc-free (smaller client .so, cmake-free cross-compile; a win for all targets).
Validated on this box: :app:assembleDebug -> APK with both ABIs; emulator
first-light renders the bridge linked (core ABI v2) with logcat confirmation;
clippy -D warnings + cargo fmt clean; core tests green on the ring backend.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler