enricobuehlerandClaude Fable 5
e08fd91cd1
The Android port of the Apple client's stage-4 deadline discipline, closing the side-by-side feel gap (both clients 120 Hz; Android released decoded buffers the instant they appeared, with zero vsync awareness — the latch phase inherited every network+decode jitter and bursts queued behind the display). The presenter (async loop only; the sync loop stays the untouched escape hatch behind the Low-latency toggle): - decode/vsync.rs: an AChoreographer thread (dlsym'd like the other above-floor symbols) publishing the panel's vsync grid + frame timelines (postVsyncCallback, API 33; postFrameCallback64 fallback on 31/32) and ticking the decode loop's event channel. Started lazily on the first decoded frame. - decode/presenter.rs: a newest-wins slot (Lowest latency, default) or a 1-3 frame smoothing FIFO with preroll/underflow re-arm (Smoothness) between decode and release; a glass budget of exactly ONE undisplayed release in flight, reopened at the target timeline's DEADLINE (SurfaceFlinger's latch — reopening at present time would halve the sustainable rate) with a 100 ms stale force-open backstop; the release itself via releaseOutputBufferAtTime(expectedPresent) so the latch phase is deterministic. debug.punktfunk.presenter=arrival sysprop restores the legacy path for a rebuild-free on-device A/B. - Metrics: DisplayTracker is now always-on and carries the release stamp, so the display stage splits into pace (decoded→release) + latch (release→displayed); a 1 Hz pf.present logcat line (released/displays/ paced/noBudget/forced/qDry + pace/latch p50/max + measured vsync) makes a HUD-off wireless A/B readable; nativeVideoStats grows to 30 doubles (26=paceP50, 27=latchP50, 28=presents, 29=presenterActive; 0-25 frozen) and the DETAILED HUD prints the split + presents. - Intent parity: present_priority/smooth_buffer — the Apple client's stored values and labels — as globals, profile-overlay fields (round-trip + scope markers), and Settings pickers under Decoding; threaded through nativeStartVideo into the presenter config. Verified: cargo ndk check/clippy clean for arm64 (the two type_complexity warnings are pre-existing audio/mic ones), armv7 via the kit gradle task, host cargo check clean, rustfmt clean, gradle :app/:kit unit tests all pass. On-device before/after on the Nothing Phone 3 still owed. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
punktfunk — Android client (phone & TV)
The native Android app for streaming a punktfunk host to your phone, tablet, or Android TV. A Compose app that finds hosts on your network, pairs with a PIN, and streams at the display's own resolution — with hardware HEVC decode, HDR10, and controller support, built for both touch and the couch (D-pad / gamepad focus navigation).
Features
- Hardware decode — NDK
AMediaCodecHEVC →SurfaceView, including HDR10 (Main10 / BT.2020 PQ), with low-latency tuning and a live stats HUD. - Audio both ways — Opus + AAudio playback with a jitter ring, plus mic uplink to the host.
- Controller support — buttons + axes with rumble and HID feedback (lightbar / adaptive triggers); D-pad / gamepad focus navigation for TV and phone.
- Find hosts automatically — native mDNS discovery; first connect does a one-time SPAKE2 PIN pairing (or TOFU on trusted LANs), then reconnects on a Keystore-wrapped, pinned identity.
- Compose UI — Connect / Settings / Stream screens with Material You theming.
Built for arm64-v8a + armeabi-v7a + x86_64 — the 32-bit armeabi-v7a slice is what keeps the
app installable on the many 32-bit Google TV / Android TV streamers (Walmart onn. 4K, Chromecast with
Google TV, budget Amlogic boxes) that otherwise reject a 64-bit-only build as "not compatible".
Get it
Published to Google Play (Internal Testing) — join the beta via the Discord. Per-device setup and pairing: docs.punktfunk.unom.io/docs/install-client.
How it's built — Rust-heavy
Kotlin can't import the cbindgen C header the way Swift can, so a native bridge is unavoidable. We
write it in Rust and link punktfunk-core directly — so the Android client reuses the Linux
client's orchestration (audio jitter ring, VK keymap inverse, latency/skew math, capture state
machine, trust logic) instead of re-porting it into Kotlin.
| Side | Owns |
|---|---|
Rust (native/ → libpunktfunk_android.so) |
the JNI seam, NativeClient (QUIC control + UDP data plane), AnnexB → AMediaCodec decode (incl. HDR10), Opus + AAudio audio + mic, controller feedback, latency math, trust/pairing, mdns-sd discovery |
Kotlin (app/, kit/) |
Compose UI, SurfaceView lifecycle, input capture, the Wi-Fi MulticastLock + permission UX, Keystore identity |
The single seam is io.unom.punktfunk.kit.NativeBridge ⇄ Java_io_unom_punktfunk_kit_NativeBridge_*.
native/ Rust cdylib (workspace member) — links punktfunk-core directly
src/lib.rs crate doc · JNI_OnLoad · version probes
src/session/ session lifecycle: connect/pair + trust, plane start/stop, input shims
src/decode.rs AnnexB → AMediaCodec HEVC hardware decode → SurfaceView (incl. HDR10)
src/audio.rs · src/mic.rs Opus + AAudio playback / mic uplink
src/feedback.rs · src/stats.rs rumble + HID feedback; live video stats
src/discovery.rs native mdns-sd browse of the host's _punktfunk._udp advert
app/ :app — Compose UI: Connect / Settings / Stream (phone + TV)
kit/ :kit — NativeBridge · native mDNS discovery · Gamepad · Keymap · Keystore identity
Build & run
Prerequisites: Android SDK + NDK r30 (30.0.14904198), platforms;android-37.0,
build-tools;37.0.0, cmake;3.22.1 (builds libopus); JDK 21 (AGP 9.2 runs on JDK 17–21, not
a newer default); Rust with rustup target add aarch64-linux-android armv7-linux-androideabi x86_64-linux-android and
cargo install cargo-ndk. Toolchain is pinned (AGP 9.2 · Gradle 9.4.1 · Kotlin 2.3.21 · Compose BOM
2026.05.01 · compileSdk 37 · minSdk 28).
Android Studio: open clients/android — it uses its bundled JBR 21, and the cargoNdk* task
builds the .so as part of the normal build.
CLI (point Gradle at JDK 21 if your machine default is newer):
export JAVA_HOME="$(/usr/libexec/java_home -v 21)" # or your Temurin 21 path
cd clients/android
./gradlew :app:assembleDebug # cargo-ndk cross-compiles libpunktfunk_android.so first
./gradlew :app:installDebug # onto a running emulator/device
# emulators from env setup: emulator -avd pf_phone | emulator -avd pf_tv
The debug APK lands in app/build/outputs/apk/debug/. Launch it, pick a host, pair, and stream.
Related
- Documentation — quick start, pairing, troubleshooting
- Project README — the host, the other clients, and how it all fits together