Files
punktfunk/clients/android/native/Cargo.toml
T
enricobuehler b5f91d50bb feat(android): tier-A pad audio — the 0xD1 plane on the pad's USB endpoint (WP9)
The Android twin of `pf-client-core`'s pad_audio: drain the host's per-pad
DualSense streams, Opus-decode haptics (kind 0) and speaker (kind 1), interleave
into the pad's own 4-channel layout, and render on the pad itself.

Every other client hands that stream to the platform's audio graph. Android
cannot: AOSP's UsbAlsaManager denylists the DualSense's output by VID/PID, so
the kernel enumerates the pad's playback node and the framework discards it —
`hasOutput: false`, nothing for setPreferredDevice to target, /dev/snd closed by
SELinux, and UsbRequest rejects non-bulk/interrupt endpoints. So this drives the
pad's isochronous endpoint directly via uac-host on the descriptor Java owns.

That is measured, not assumed. On a Nothing Phone (3): the claim succeeds
unprivileged, the gamepad and the pad's microphone both keep working, and the
underrun-free floor is 4 ms — holding under eight-core load with the SoC in
severe thermal throttling. The renderer runs at 6 ms, one step of headroom,
because the same measurement found transient events that are not depth-dependent.

Structured to the crate's own convention: the mixer and PLC are ungated so they
compile and unit-test in the host workspace (8 tests), while everything touching
an Android-only dependency is cfg'd to android. Two details worth review:

- The kinds arrive on different cadences (5 ms vs 10 ms), so each has its own
  write cursor and both shift together on overflow — a haptics-only session
  renders with a silent speaker pair instead of stalling on a kind that will
  never arrive, and the two can never skew.
- An unrecognised kind is dropped rather than folded into the coil pair. A
  `min(1)` clamp would have rendered a future kind straight into the actuators.

Lifecycle mirrors MicCapture: dropping the handle joins the thread, and
nativeStopPadAudio returns only once it has, so Kotlin may close the
UsbDeviceConnection as soon as it returns and not before.

usbfs-iso/uac-host enter as git dependencies pinned by revision — a transport
under a real-time deadline should move when we choose. They become version
dependencies once published to crates.io.
2026-08-02 23:39:25 +02:00

78 lines
5.1 KiB
TOML

[package]
name = "punktfunk-client-android"
description = "punktfunk Android client — JNI bridge ('nativecore') over punktfunk-core (Rust-heavy client model)"
version.workspace = true
edition.workspace = true
rust-version.workspace = true
license.workspace = true
authors.workspace = true
repository.workspace = true
[lib]
# `libpunktfunk_android.so` — loaded by Kotlin via `System.loadLibrary("punktfunk_android")`.
name = "punktfunk_android"
crate-type = ["cdylib"]
[dependencies]
# The whole protocol/transport/FEC/crypto + the embeddable NativeClient connector. `quic` pulls
# the punktfunk/1 control plane (now ring-only — no aws-lc, see punktfunk-core/Cargo.toml).
punktfunk-core = { path = "../../../crates/punktfunk-core", features = ["quic"] }
jni = "0.21"
log = "0.4"
# LAN host discovery: browse the host's `_punktfunk._udp` mDNS advert — the SAME crate + service the
# Linux/Windows clients use (`crates/pf-client-core/src/discovery.rs`), replacing Android's per-OEM
# `NsdManager` system daemon with one tested browse path. Pure Rust (socket2/if-addrs/mio), so it
# cross-compiles to the Android targets AND builds on the host (the JNI seam links into
# `cargo build --workspace`). Kotlin keeps only the Wi-Fi `MulticastLock` + permission UX.
mdns-sd = "0.20"
# Android-only deps. Gated so `cargo build --workspace` on the Linux/macOS dev boxes + CI still
# compiles this crate (as a host cdylib) — the Android-framework glue (logging, AMediaCodec + AAudio
# via `ndk`, the Opus codec) is only pulled in for the real `*-linux-android` targets.
[target.'cfg(target_os = "android")'.dependencies]
android_logger = "0.14"
# Feature bridge, no code here: punktfunk-core logs through `tracing`, but this client only
# installs `android_logger` (a `log` backend). Core transport warnings (e.g. "UDP socket buffer
# capped well below target") reach logcat only via tracing's "log" feature, which forwards events
# as `log` records when no tracing subscriber is set (always, here). Today that feature happens to
# be enabled transitively — quinn's default `log` feature unifies `tracing/log` onto the whole
# graph — but nothing about this client's logging should hinge on a QUIC crate's default feature
# set, so declare it explicitly.
tracing = { version = "0.1", default-features = false, features = ["std", "log"] }
# NDK bindings. "media" = AMediaCodec/ANativeWindow (video); "audio" = AAudio (audio playback).
# Pure-Rust FFI to libmediandk/libnativewindow/libaaudio — no C++/libc++_shared to bundle. Decode +
# audio run entirely in Rust on native threads (the "no async on the hot path" invariant).
# api-level-28 matches the app's minSdk floor (Android 9). AAudio (26), AMediaCodec (21) and
# ANativeWindow_setBuffersDataSpace (28) are all ≤28; every call above the floor —
# ANativeWindow_setFrameRate (30), …WithChangeStrategy (31), AMediaCodec_setOnFrameRenderedCallback
# (33), the ADPF hints — is dlsym-resolved at runtime (decode::try_set_frame_rate,
# decode::install_render_callback, adpf), never linked, so the .so still loads on API 28+.
ndk = { version = "0.9", features = ["media", "audio", "nativewindow", "api-level-28"] }
# Raw FFI *types* for the one AMediaCodec entry point the `ndk` wrapper lacks:
# `AMediaCodec_setOnFrameRenderedCallback` — the per-frame render-timestamp callback behind the
# HUD's `display` stage (see decode::DisplayTracker). The symbol is API 33 ("Available since
# Android T"), ABOVE the minSdk-28 floor, so it is dlsym-resolved at runtime
# (decode::install_render_callback), NEVER hard-linked: 0.9.0 hard-linked it and
# `System.loadLibrary` failed on every pre-Android-13 device. Only ndk-sys's pointer/typedef
# types are referenced, which creates no import. Reaching it needs the codec's raw pointer, which
# is why the workspace pins `ndk` to the vendored copy whose only patch makes `MediaCodec::as_ptr`
# public (vendor/ndk, wired in the root Cargo.toml).
ndk-sys = { version = "0.6", features = ["media"] }
# setpriority/gettid to raise the decode thread toward URGENT_DISPLAY (see decode::boost_thread_priority).
libc = "0.2"
# Opus decode for the host→client audio plane (0xC9: 48 kHz stereo, 5 ms frames). Same crate the
# host + Linux client use. audiopus_sys vendors libopus (pure C) and builds it static via cmake —
# the cargo-ndk build sets LIBOPUS_STATIC=1/LIBOPUS_NO_PKG=1 so it links the bundled lib, not the host's.
opus = "0.3"
# Tier-A pad audio (WP9). Android's audio framework denylists the DualSense's output by VID/PID,
# so the pad's isochronous endpoint is driven directly on the fd `UsbDeviceConnection` hands over.
# Our own crates, developed openly because the hole they fill — isochronous USB in Rust — is an
# ecosystem-wide one: https://github.com/unom-io/usbfs-iso
# Pinned by revision rather than floating: this is a transport under a real-time deadline and it
# should move when we choose to. Becomes a plain version dependency once the crates are published.
uac-host = { git = "https://github.com/unom-io/usbfs-iso", rev = "fb01ea69c59e3bf08b3918f53a159287b5187ed2" }
usbfs-iso = { git = "https://github.com/unom-io/usbfs-iso", rev = "fb01ea69c59e3bf08b3918f53a159287b5187ed2" }
[lints]
workspace = true