Files
punktfunk/clients/probe
enricobuehler d4467a44e2 feat(core): mid-stream clock re-sync — live offset survives wall-clock steps and drift
Networking-audit deferred plan §2. The host↔client offset was measured once
at connect; an NTP step or slow drift silently corrupted the clock-based
jump-to-live signal, the ABR one-way-delay signal, and every latency stat —
4a3b1ae2's disarm backstop stopped the IDR storm but lost the detector for
the session. Now the client re-estimates mid-stream and recovers it.

- quic: ClockResync — the connect-time 8-round probe/echo estimate as a
  select!-driven state machine (rounds matched by echoed t1, stale batches
  ignored), plus accept_resync (batch min-RTT ≤ max(2 ms, 1.5× connect RTT)
  so a congested window can never bias the offset). No wire change: the
  host has always answered ClockProbe at any time on the control stream.
- client: the offset lives in an Arc<AtomicI64> seeded at connect; the
  control task re-probes every 60 s and immediately after the pump's FIRST
  no-op clock flush (the "clock stepped under me" signal, sent on the next
  report tick). On apply: store, reset stale_frames/noop_clock_flushes,
  re-arm the clock detector if a step had disarmed it. The disarm heuristic
  stays as the final backstop. Public NativeClient::clock_offset_ns keeps
  the connect-time value (ABI untouched); new clock_offset_now_ns() /
  clock_offset_shared() expose the live value.
- consumers migrated to the live offset: pf-client-core session stats, the
  pf-presenter e2e stamp, Windows session/render, Android feeder/drain/
  DisplayTracker (the tracker holds the shared handle, not the client, so
  the leaked render-callback refcount can't pin the session).
- probe: --clock-resync runs a second full handshake mid-connection and
  asserts a sane, consistent estimate. Live against the local canary host:
  offsets 8646/2139 ns, disagreement 6 µs, 8/8 rounds — OK.

Unit tests cover the round collection, stale-echo rejection, batch restart,
min-RTT selection, and the acceptance guard. cargo ndk check green.
Remaining manual validation: `sudo date -s "+2 sec"` on a live streaming
client → expect one no-op flush, a re-sync, re-armed detector, no IDR pulse.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-10 15:45:12 +02:00
..

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._udp hosts 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=1 advertise the 10-bit / 4:4:4 client caps (for testing a host's PUNKTFUNK_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.

  • 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)