Files
punktfunk/clients/probe
enricobuehler 449a67ce8d feat(protocol): per-AU host-timing plane (0xCF) — split host+network latency (stats phase 2)
The unified-stats equation's host+network stage was one opaque number
because the wire carried nothing but pts_ns. Now the host reports its own
share per frame: when the client's Hello sets VIDEO_CAP_HOST_TIMING (0x08),
the send thread emits a 13-byte 0xCF datagram — [tag][pts_ns u64][host_us
u32] — right after the AU's last packet leaves the socket, so host_us =
capture→fully-sent (capture read/convert, encode, FEC+seal, paced send)
against the same anchor the wire pts carries. Clients correlate by pts_ns
and derive network = (received + clock_offset − pts) − host_us; the two
terms tile per frame by construction.

Back-compat is free in all four combinations: old clients ignore unknown
datagram tags, old hosts ignore unknown cap bits (client keeps the combined
stage). The hardened data-plane format is untouched — this rides the
established QUIC side-plane pattern (0xC8…0xCE). NativeClient ORs the bit
in unconditionally and exposes next_host_timing(); the C ABI gains
PunktfunkHostTiming + punktfunk_connection_next_host_timing (additive).
The synthetic host emits 0xCF too, so pure-loopback protocol tests cover
the plane.

The probe reports the split (host_p50/p95_us · net_p50/p95_us) and is our
direct analogue of Sunshine's "host processing latency" — ours additionally
includes the paced send.

Validated on loopback (synthetic host + probe, debug build): 240/240 AUs
matched, host_p50 6.5 ms + net_p50 6.4 ms ≈ capture→received p50 13.0 ms.
Core suite + new 0xCF roundtrip/truncation test green; host+core+probe
clippy clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-03 21:22:12 +00:00
..

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)