On a clean link the flat 20% FEC is pure waste: extra wire bytes AND extra
packets. On a packet-rate-bound uplink (the Steam Deck's WiFi tx caps ~22k pps
regardless of bitrate) those extra packets directly cost goodput — measured at
200 Mbps goodput, 20% FEC drove ~10% loss vs ~2.6% at 0% (it saturated the link).
Adaptive FEC closes the loop:
- Client measures the loss FEC is absorbing each ~750 ms window from session stats
(recovered shards / received, + a bump when a frame went unrecoverable) and sends
a periodic `LossReport { loss_ppm }` on the control stream (new message;
`window_loss_ppm` helper, shared + unit-tested). Connector (Apple/Linux/Windows)
and probe both report; suppressed during a speed test so its filler can't skew it.
- Host maps loss → recovery % (`adapt_fec`: ≈ loss×1.4 + 1pt, clamped 1..50) and
applies it live via `Session::set_fec_percent` (the wire is self-describing — each
packet carries its block's data/recovery counts, so the receiver needs no notice).
A clean link decays to ~1%; loss ramps it up and converges.
- `PUNKTFUNK_FEC_PCT`, when set, now PINS FEC static (disables adaptation) so
speed-test / measurement runs keep a fixed, known overhead. Unset ⇒ adaptive,
starting at 10%.
An older host ignores LossReport (unknown control message) and keeps static FEC;
an older client simply never reports and the host holds its start value. Builds +
clippy + fmt + tests green (adapt_fec / window_loss_ppm / loss_report unit tests).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The punktfunk/1 speed test was unusable across every client/host: at the start of
a burst a little data got through, then everything read as dropped (~10 MB total).
Two compounding bugs:
1. Receive side measured throughput from fully-reassembled FLAG_PROBE *access
units* only. The instant loss crossed the 20% FEC budget no AU completed, so the
figure cliffed to 0 / 100% loss even though most bytes still arrived — a binary
cliff, not a graded measurement.
2. Send side blasted each filler AU (up to 256 KB ≈ 200 packets) into the socket
buffer in one unpaced batch, unlike the real video path which paces. On a small
buffer (e.g. the Steam Deck's 416 KB) a single AU overflowed it, so the test
measured self-inflicted buffer overflow instead of the link.
Fixes:
- Host `run_probe_burst` keeps each AU a small (~16 KB) burst and paces by the byte
budget, mirroring `paced_submit`; reports the WIRE packets the kernel accepted and
the ones the send buffer dropped (stat deltas), separating host-side drops from
link loss.
- `ProbeResult` gains `wire_packets_sent` + `send_dropped` (back-compat decode: a
21-byte pre-wire-stats result still decodes, new fields 0).
- Clients (probe + connector) count delivered traffic at the packet level via
`session.stats()` deltas over the burst window, so throughput/loss degrade
gracefully. Connector freezes the delivered figure when the host report lands so
resumed video can't inflate it. New `ProbeOutcome`/`PunktfunkProbeResult` fields:
`host_drop_pct`, `wire_packets_sent`, `send_dropped`.
Validated on loopback (graded 142→1391 Mbps, host_drop/link_loss split correctly,
no cliff) and live against the Deck: clean to ~200 Mbps goodput / 273 Mbps wire at
0% link loss, host send buffer the wall above that (the lever-#1 target).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two bodies of work in one commit (the rename moved files the fixes also touched).
Naming/structure cleanup (pre-launch):
- Host modules m3.rs->punktfunk1.rs, m0.rs->spike.rs; CLI m3-host->punktfunk1-host,
m0->spike; bare `punktfunk-host` now prints help. Types M3Options/M3Source->
Punktfunk1Options/Punktfunk1Source.
- Clients consolidated out of crates/ into clients/: punktfunk-client-rs->
clients/probe (crate punktfunk-probe), client-linux->clients/linux,
client-windows->clients/windows, punktfunk-android->clients/android/native
(crate punktfunk-client-android; kept [lib] name=punktfunk_android so the JNI
contract is unchanged). crates/ now holds only core + host.
- Milestone codes M0-M4 purged from code/CLI/CLAUDE.md/README/docs/docs-site,
kept only in docs/implementation-plan.md. docs/m2-plan.md->
docs/gamestream-host-plan.md. CI/gradle/flatpak paths updated.
Client loss-recovery (video froze and never recovered after a brief drop):
- Export punktfunk_connection_frames_dropped through the C ABI (the core already
tracked it for the client keyframe-recovery loop; it was never reachable from
the ABI clients). Regenerated punktfunk_core.h.
- Apple (StreamPump + Stage2Pipeline) and Android (decode.rs) now poll
frames_dropped and request a keyframe when it climbs -- the same loss-driven
recovery Linux/Windows already had. Under infinite GOP the decoder silently
conceals reference-missing frames, so the decode-error trigger rarely fires.
Apple rumble robustness (worked then went spotty -- DualSense + Xbox):
- Add CHHapticEngine stopped/reset handlers (rebuild on app background / audio
interruption / server reset) and drop the permanent `broken` latch on a
transient drive failure; latch only when the controller truly has no haptics.
- Surface swallowed SDL set_rumble errors on Linux/Windows + diagnostic logging.
Verified: cargo build/clippy/fmt --workspace, C-ABI harness, header drift.
Not runnable on this box (verify in CI): Gitea workflows, gradle/Android,
flatpak, Swift/decky.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler