Files
punktfunk/clients/session
enricobuehler 2a57ee36f8 feat(client): M4 — the decoder's own verdict reaches the session
This program exists because a field corruption was architecturally
undetectable through FFmpeg: no decode-status read, no corrupt-frame
flag, errors only as scraped log lines, and no recovery-point signal so
intra-refresh healing was invisible. The native decoder has all of those.
M4 is where they stop being internal.

DecodeHealth counts, per session and without allocating per frame, what
the three answers actually are: damaged (the stream arrived incomplete),
refused (the rung would not decode it at all) and driver-failed (the
hardware says it could not decode what arrived), plus the current and
worst concealment run — the figures that separate one bad AU from a
stream that never came back. They ride the stats line additively, so an
FFmpeg session and a healthy native session emit byte-identical output
to today. The status-query capability is reported too: without it a
clean report cannot be told from an unmeasured one, which is the whole
nb_queries=0 lesson.

The headline is local recovery. Until now the pump could only learn that
intra-refresh healing finished from wire flags the host sends; absent
those it froze until the 500 ms backstop forced an IDR. The parsed
recovery-point SEI now feeds the re-anchor gate directly, so a session
lifts on the picture that is actually clean. Wire semantics are
untouched for every client that never calls it.

Detection now asks for recovery instead of erroring — an integrity
warning ticking the error streak would demote the native rung on exactly
the lossy links it exists to diagnose, where an FFmpeg rung conceals
silently and keeps its job.

Review round 12 found that trade had removed the escape hatch entirely.
Concealment returning Ok(None) reset the demotion streak, and worse: the
driver-verdict ledger is only populated when a frame ships, so under
continuous concealment no verdict was ever read and the erroring arm
could not fire at all. A host framing regression of the 0.23.0
slice-wire class — which does not self-heal, and which a keyframe does
not clear — would have frozen indefinitely with no demotion and a clean
integrity line, where before it demoted to FFmpeg-Vulkan and showed a
picture. Now only an answer that proves the rung works clears the
streak: a shipped frame, or a clean no-frame. Concealment neither ticks
nor clears, so a lossy link still cannot demote a healthy rung while a
driver failure interleaved with concealment reaches the threshold again.

Two more honesty defects from the same round. A rung refusing every AU
reported no integrity line at all — the founding failure mode, wearing
the shape of a clean bill of health; refusals are now counted. And
driver-failed could be non-zero on a device that cannot produce driver
verdicts, because a degraded timeline read looked the same as one; the
attribution is now withheld inside the counter rather than at call
sites, so the self-contradictory line is unrepresentable.

Local recovery also no longer trusts any recovery-point SEI: only one
whose target advances past an outstanding wave counts as a new wave, so
an encoder re-announcing the current wave with a decreasing count — legal,
and what x264 intra-refresh does — cannot lift the freeze early onto a
partially stale picture. Frames buffered across an arm are dropped by
decode order for the same reason.

Fault injection is a first-class tool now (PUNKTFUNK_AU_FAULT, inert
unless set, env read once). Its test replays the vendored vectors
through the real planners and asserts a negative the plan assumed away:
truncation and bit flips are PROVABLY invisible to the parser — Annex-B
carries no NALU length, so a cut slice is just a shorter slice and a
flipped payload byte is syntactically perfect. Only dropped AUs are
parser-detectable; the rest need the driver verdict, which is why the
status query matters. The H.265 leg found a second: three of that
vector's faulted AUs are sub-layer non-reference pictures, so dropping
them damages nothing and silence is correct — the test asserts both
verdicts and guards that neither half goes vacuous.

Per-frame decode latency was deliberately NOT built. Polling answers
only 'complete by now', and the pump polls once per AU, so every sample
would quantise up by as much as a frame interval — 8.3 ms at 120 Hz
against decodes of 0.1-2 ms. Sampling faster needs a spin or a second
thread on a decoder that is deliberately not Sync. A blocking per-frame
wait is the field scar that once capped a stream at 51 fps. The honest
sampled stat stands.

Also fixed, pre-existing: the re-anchor gate re-armed on every damaged
AU, so sustained damage permanently zeroed the mark count — meaning the
wire's two-mark rule could never complete on exactly the lossy links it
was written for.

Field note recorded while wiring this: intra_refresh_recovery is set by
exactly one encoder backend (Linux libav-NVENC under
PUNKTFUNK_INTRA_REFRESH). AMF and QSV run a wave with no wire mark, and
AMF emits no recovery-point SEI either, so AMD/Windows intra-refresh
sessions still have no clean recovery point by either route.

Gates: fmt clean; container clippy -D warnings zero across
pf-client-core + pf-presenter + pf-vkdecode + punktfunk-core; tests
69/131/129/354/41 plus 5 fault-detection green; cargo check --workspace
clean.
2026-08-06 04:30:40 +02:00
..

punktfunk-session

The Vulkan session binary: one stream per invocation in an SDL3 window — no UI toolkit, no widgets, terminal stats. The power-user / gamescope stream client, and the stage-2 presenter of the Linux client re-architecture (punktfunk-planning: linux-client-rearchitecture.md).

This binary is deliberately dumb: a renderer the front-ends call INTO — the GTK shell (punktfunk-client), the WinUI shell, and the punktfunk CLI all spawn it through the same brain (pf_client_core::orchestrate), which resolves policy (profiles, settings, wake) and hands the result down, normally as a --resolved-spec file. It reads the shared stores only as the compat fallback for a bare hand-launched invocation.

punktfunk-session --connect host[:port] [--fp HEX] [--launch id] [--fullscreen] [--stats]
punktfunk-session --browse host[:port] [--mgmt PORT] [--fullscreen]

--browse opens the console game library (the Skia coverflow over the animated aurora) instead of connecting: A launches the focused title as a stream in the same window, session end returns to the library, B quits (Gaming Mode returns). Paired hosts only — pairing is the desktop client / Decky plugin's job. PUNKTFUNK_FAKE_LIBRARY=<file.json> feeds canned entries with no host (portrait paths starting with / load from disk).

Reads the same identity / known-hosts / settings stores as the desktop client (punktfunk-client), so enrolling on either side makes the other work; this binary never connects to a host it has no pinned fingerprint for (--fp HEX overrides the store).

Pairing is punktfunk pair <host> — the CLI, which ships alongside this binary in every package and needs no window and no toolkit either. punktfunk-session --pair still works for one release (someone's provisioning script calls it today) but prints a deprecation notice: pairing is a trust ceremony and belongs to the brain, not a renderer.

Stdout is the machine interface: {"ready":true} after the first presented frame, stats: … once per second while the overlay tier isn't Off (always the full detailed text, whatever the OSD shows; --stats forces the overlay on), one {"error"|"ended": …} JSON line on the way out. Logs go to stderr. Exit codes: 0 clean end, 2 connect failed, 3 trust rejected / pairing required, 4 presenter init failed.

In-stream keys match the desktop client: click captures input (Ctrl+Alt+Shift+Q releases), Ctrl+Alt+Shift+D disconnects, F11 toggles fullscreen; the controller escape chord (L1+R1+Start+Select, hold to disconnect) works the same.

The default build carries the Skia console UI (ui feature): the stats OSD and capture hint render in-window. Ctrl+Alt+Shift+S cycles the OSD tier live — Off → Compact (one line: fps · latency · Mb/s) → Normal (mode + end-to-end percentiles) → Detailed (decoder path + per-stage latency equation); any tier but Off also emits the stdout mirror. --no-default-features is the ~5 MB power-user build — same streaming, stats on stdout only, no Skia anywhere in the dependency tree.

Decode follows the Settings preference (auto is vendor-ordered: hardware Vulkan Video → VAAPI → software on Linux, hardware Vulkan Video → D3D11VA → software on Windows, with VAAPI/D3D11VA first on Intel; on H.264 and HEVC the native pf-vkdecode Vulkan decoder is tried immediately before FFmpeg-Vulkan): the Vulkan decoders run on the presenter's own device where the stack supports it (every vendor, zero copy); VAAPI dmabufs import per-plane elsewhere (D3D11VA textures on Windows); software is the universal fallback. 10-bit Main10 and HDR10 are advertised (VIDEO_CAP_10BIT|HDR): P010 decodes through the native, FFmpeg-Vulkan, VAAPI/D3D11VA and software paths alike, and PQ streams present on an HDR10/ST.2084 swapchain when the desktop offers one (KDE HDR, gamescope) or tone-map in-shader to SDR when it doesn't (PUNKTFUNK_TONEMAP_PEAK tunes the rolloff, default ≈1000 nits). The host still gates the upgrade behind its PUNKTFUNK_10BIT policy.

Debug/bisect knobs: PUNKTFUNK_DECODER=native-vulkan|vulkan|vaapi|d3d11va|software, PUNKTFUNK_PRESENT_MODE= mailbox|fifo|immediate|fifo_relaxed (default MAILBOX, FIFO where the surface offers no MAILBOX — AMD on Windows), PUNKTFUNK_VK_DEVICE=<index> (multi-GPU), and PUNKTFUNK_HW_FAULT=import (fault every VAAPI dmabuf import — proves the three-strike demotion to software on healthy hardware).

PUNKTFUNK_AU_FAULT=drop|truncate|flip[:period] deliberately corrupts decoder input on the native Vulkan lane (default period 60 — one AU a second at 60 fps; inert everywhere else, and inert entirely if the value doesn't parse). drop swallows the AU, so the next one references a picture that was never decoded — the bitstream planner catches it immediately. truncate delivers a picture whose slice data stops mid-frame and flip alters one byte deep in the payload: both parse perfectly, so only the driver's per-frame decode-status query can see them, and neither is visible at all on a driver without queryResultStatusSupport or on any FFmpeg lane. Watch the result on the Detailed stats line's integrity: term (damaged = concealment the planner caught, refused = AUs the decoder rejected outright, driver-failed = the hardware's own verdict, run = consecutive frames with no picture, worst run = the longest such stretch of the session — the once-a-second run sample misses the bad moment almost every time — and no driver status = this device cannot answer the driver question at all). A session that lands on any other lane says so in the log rather than faulting silently.

Note that PUNKTFUNK_AU_DUMP records the AU as it arrived from the HOST, while the fault injector runs later, at the native decoder's own entry. On a faulted run the dump is therefore the clean bitstream — reconstruct the damaged bytes from the spec if you need them (the injector is pure and deterministic).