Stats HUD (mirrors the Apple client): the decode thread accumulates FPS, receive
throughput, and capture->client latency (p50/p95, skew-corrected) in Rust
(clients/android/native/src/stats.rs); nativeVideoStats drains a snapshot ~1 Hz
over JNI as a DoubleArray. StreamScreen renders a Compose overlay
(W*H@Hz / fps / Mb/s / latency, + dropped-under-loss), toggled by a Settings
switch (persisted, default on) or a 3-finger tap.
Performance (decode.rs):
- ANativeWindow_setFrameRate(refresh_hz): align display vsync to the stream rate
(no 60-in-120 judder); safe since minSdk 31 >= API 30.
- Raise the decode thread toward URGENT_DISPLAY (best-effort setpriority) so
background work can't preempt it under load.
- Codec low-latency hints KEY_PRIORITY=0 (realtime) + KEY_OPERATING_RATE.
Verified host-side: cargo build/clippy/fmt --workspace (the ungated stats + JNI
accessor). The android-gated decode.rs (NDK) and the Kotlin build only in CI
(android.yml: gradle + cargo-ndk) -- APIs verified against crate sources.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>