enricobuehler
2032c48ffa
Three faults that between them silence a wired DualSense. The trade was committed without asking whether the host can send pad audio at all. Against every released host — no HOST_CAP_PAD_AUDIO — the renderer claimed the interface, took the pad off wire rumble, and then rendered nothing, with `pad_haptics` defaulting on and no UI to turn it off. The capability is now checked before `sink::open`, so nothing is claimed and nothing is traded. Arming was unconditional, so a speaker-only setup took the motors away too. The speaker pair is channels 0/1 and no rumble write can disturb it; only the haptics lane arms now. And the suppression itself was wrong for the case that matters most: a title driving classic rumble and no haptics audio. Suppressing on "a stream is open" assumed the game's rumble rides the haptics mix, which for such a title is false — it renders no haptics audio at all, so the host's -60 dBFS gate emits nothing on 0xD1 and the pad was left with neither. Ownership is now decided by evidence: the coils belong to haptics only while haptics frames are actually arriving, and to wire rumble otherwise. Frames are stamped on arrival rather than after decode, so a decoder hiccup cannot hand the coils back mid-effect, and concealment does not count as evidence. Liveness is dropped at every teardown, because wire indices are recycled and a stale stamp would let a fresh pad inherit the previous occupant's ownership. Arbitrating on evidence rather than on a prediction about the hardware is deliberate, and the module doc now says why. It used to assert that the coils and the rumble motors are the same physical actuators — "a firmware constraint, not a preference". Nothing establishes that: it traces to one reverse-engineered comment in SDL, whose own modern path sets HAPTICS_SELECT alone with amplitude on ucEnableBits3, which reads more like an independent mute than a shared- actuator interlock. The combination that would settle it — rumble with HAPTICS_SELECT cleared — is emitted by no code anywhere, and nothing here writes it either. The evidence rule is correct under either hypothesis. The liveness clock is 1-based so that 0 stays an unambiguous "never stamped": without it a frame arriving in the process's first millisecond read as never-arrived and handed the coils back mid-effect. Its test caught that. Verified: clippy -p punktfunk-client-android --all-targets --locked -D warnings = 0; 15 tests pass. Owed: the desktop twin of the arbiter, and the coil restore — the Android stop write still asserts HAPTICS_SELECT with zero amplitude, where SDL's all-zero stop restores the audio path. From the 2026-08-03 force-feedback sweep (B4, B5; B6 partly).
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