enricobuehlerandClaude Opus 5
166c93c079
Three defects in the 0.23.0 timeline presenter, all found while root-causing the field report that turned out to be the slice wire. None of them is that bug; all three are real, and the first is the one that would still bite once it is fixed. The panel-period learner could only ever narrow. It is seeded from the display mode Kotlin asked for — and `preferredDisplayModeId` is a REQUEST the system may refuse (Smooth Display off, battery saver, thermal, an OEM governor). Ask for 120 Hz on a panel that stays at 60 and the presenter pins an 8.33 ms grid on a 16.67 ms display with no way back, for the rest of the session: it then aims at instants that never arrive and releases faster than the panel scans. The learner moves both ways now, and lives in `punktfunk_core::phase::PanelGrid` where it is host-testable and where the iOS and desktop presenters can share it. The asymmetry is kept and made explicit — narrowing is immediate (a finer real grid is always safe to subdivide onto, and it is the per-uid down-rate case the seed most often gets wrong), widening needs eight consecutive agreeing observations and then takes the narrowest of them, because one wide sample is a missed callback and eight in a row is a display that really did slow down. The glass budget was a prediction with nothing underneath it. `OnFrameRendered` already reports what actually reached glass, but the budget never consulted it, so a wrong grid could hand SurfaceFlinger frames indefinitely: BufferQueue fills, MediaCodec runs out of output buffers, the decoder stalls, and the no-output backstop starts begging for keyframes. Releases are now counted against their confirms and the presenter holds back past six outstanding — loose on purpose, since the callbacks are allowed to arrive batched and a held frame in the newest-wins slot is a dropped one. It self-clears when the confirms catch up, and writes the ledger off after the same 100 ms the stale reopen uses, so a platform that stops confirming can never wedge the stream. `qWait` and `unconfirmed` join the 1 Hz pf.present line, which is what would have made this visible from a log. The adaptive latch margin widened on `paced_drops` — the newest-wins store's own policy evictions, which happen whenever the stream out-runs the panel and say nothing about SurfaceFlinger's latch lead. On a healthy device that walked the margin to its 2.5 ms ceiling and re-imposed the display latency the P2e sweep had just measured away. It now widens on the measured latch exceeding one panel period plus the live margin, which is what a missed vsync actually looks like. Also corrects two doc comments that named `display.refreshRate` as the panel_hz source; it has been the mode table since the A024 down-rate fix. Gates: 278 punktfunk-core lib tests (7 new PanelGrid cases incl. the refused-mode regression), clippy -D warnings and fmt clean, cargo ndk check green on arm64 and armv7. Android clippy reports the same 4 warnings as the base commit and no new ones. NOT yet confirmed on glass. Co-Authored-By: Claude Opus 5 (1M context) <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