enricobuehler
73c911cae4
Rumble was level-triggered, unbounded state on a lossy channel: a non-zero level meant "buzz until further notice", healed only by the host re-sending state every 500 ms, and every client guessed when the host had died with its own magic timeout (SDL 1.5 s, Apple 1.6 s, Android up to 60 s). A lost stop, a reordered start, or a dead host could drone the motor for seconds. Make "stuck rumble" inexpressible on the wire. The 0xCA datagram grows a length-tolerant tail — [u8 seq][u16 ttl_ms] — so it self-terminates: the host authorizes a level for at most ttl_ms and renews it (~120 ms) while it holds, letting an abandoned one lapse client-side. seq is a per-pad wrapping reorder gate (reusing GamepadSnapshot::seq_newer) so a reordered stale start can't re-light a stopped motor. Decoders read the first 7 bytes as a plain level and ignore the tail, so no wire-version bump: an old client renders a new host's levels, and a new client falls back to its prior staleness heuristic against an old host (ttl = None). All four generation pairings render correctly. - core: encode_rumble_datagram_v2 / decode_rumble_envelope (datagram.rs); the client demux applies the seq gate then forwards (pad, low, high, Option<ttl>); next_rumble is unchanged (drops ttl), next_rumble_ttl keeps it; ABI adds punktfunk_connection_next_rumble2 + PUNKTFUNK_RUMBLE_NO_TTL, ABI_VERSION 4->5 (WIRE_VERSION unchanged — the tail is backward-compatible). - host (punktfunk1.rs): the flat 500 ms refresh becomes a renewal loop that bumps seq + stamps a fresh TTL on active pads and drains a short post-stop zero burst, then goes quiet. Hatches: PUNKTFUNK_RUMBLE_ENVELOPE=0 (legacy v1 + flat refresh, a bisect switch), PUNKTFUNK_RUMBLE_TTL_MS (clamped [150, 5000]). - renderers honor the TTL as their playback duration/deadline and keep their old heuristic only for a legacy (ttl=None) update: pf-client-core (the Deck haptic keep-alive is now deadline-bounded so it can't sustain a host-stopped rumble), clients/windows (SDL duration), android (JNI packs the lease out-of-band in bit 48 so any u16 ttl is unambiguous; Kotlin createOneShot(ttl)), apple (RumbleRenderer.envelopeDeadline + nextRumble2; sessionStaleSeconds demoted to the legacy fallback). - tests: codec round-trip + tail tolerance + seq-gate reorder (Rust); the probe asserts the v2 tail arrived under PUNKTFUNK_TEST_FEEDBACK; the Apple loopback asserts ttlMs round-trips end to end; RumbleTuning lease-decision cases. The host-side idle-timeout from the previous commit is defense in depth on the game side; this is the guarantee on the client side. Design: punktfunk-planning/design/rumble-envelope-plan.md. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
punktfunk — probe (reference client)
punktfunk-probe is the headless reference client for the punktfunk/1 protocol — a
command-line tool for testing, latency measurement, and validating host behavior. It's not a
streaming app you'd watch on; it connects, exercises a plane, and reports numbers. If you want to
actually stream, use the Linux, Windows,
Apple, or Android clients.
Because it links the same punktfunk-core as every other client, it's also the canonical
example of driving the protocol end to end: QUIC control plane, UDP data plane, and the side planes
(input, audio, rumble) over QUIC datagrams.
What it does
- Receives a real stream, writes a playable elementary stream (
.h265/.h264/.av1— the extension tracks the negotiated codec; the probe advertises all three and the host picks), and reports per-frame capture→received latency percentiles (the host stamps each frame with its capture clock). - Verification mode against a synthetic host — byte-checks deterministic test frames.
- Exercises every plane with scripted test traffic:
--input-test(mouse/keyboard),--mic-test(a 440 Hz Opus tone up to the host mic),--touch-test(a synthetic finger),--rich-input-test(DualSense touchpad + motion, logging the HID-output feedback that comes back). - Trust —
--pin <64-hex>pins the host fingerprint;--pair <PIN>runs the SPAKE2 pairing ceremony and prints the verified fingerprint to pin from then on. Without a pin it trusts on first use. - Discovery —
--discover [secs]browses the LAN for_punktfunk._udphosts and prints each (name, addr:port, pairing requirement, cert fingerprint), then exits. - Negotiation knobs —
--mode WxHxFPS,--remode(mid-stream mode change),--bitrate,--codec auto|h264|hevc|av1(preference; the host resolves),--audio-channels(stereo / 5.1 / 7.1),--compositor,--gamepad,--launch,--speed-test. Env:PUNKTFUNK_CLIENT_10BIT=1/PUNKTFUNK_CLIENT_444=1advertise the 10-bit / 4:4:4 client caps (for testing a host'sPUNKTFUNK_10BIT/PUNKTFUNK_444).
Usage
# stream 720p120 from a host, save the video, and print latency percentiles:
cargo run -p punktfunk-probe -- --mode 1280x720x120 --connect HOST:PORT --out /tmp/a.h265
# list hosts on the LAN:
cargo run -p punktfunk-probe -- --discover
# pair with a host that requires it (read the PIN off the host), then stream:
cargo run -p punktfunk-probe -- --connect HOST:PORT --pair 1234
cargo run -p punktfunk-probe -- --connect HOST:PORT --pin <64-hex> --input-test
Full flag reference is in the module doc-comment at the top of src/main.rs.
Related
- Project README — the host, the streaming clients, and the protocol
punktfunk-host punktfunk1-host— the persistent native-protocol listener to probe against (see the "Running on this box" section of the repo README /CLAUDE.md)