cargo tree -p punktfunk-client-session finds no ffmpeg. The host still does, which is the whole point: pf-encode keeps libavcodec unconditionally and no host workflow, packaging script or licence file was touched. Deleted: crates/pf-ffvk, video_vulkan.rs, video_vaapi.rs, video_libav.rs, the libavcodec half of video_d3d11.rs, the av_log machinery, ffmpeg::codec::Id as the decoder's vocabulary (the quic CODEC_* wire constants now serve, which is why the evidence table was keyed on them), DecodedImage::VkFrame and ::Dmabuf, the presenter's AVVkFrame lane, and the ffmpeg-fallback feature with everything behind it. DrmFrameGuard collapses from an enum to a newtype, which removes an unsafe impl Send. Roughly 25,000 lines. Then the CI, packaging, licensing and docs work the plan's §6 lists: the Windows workflows lose FFMPEG_DIR, PF_FFVK_VULKAN_INCLUDE and their PATH prepend; the MSIX loses its DLL wildcard; the client .deb stops emitting libav sonames on its own because depends come from dpkg-shlibdeps; arch, flatpak and nix drop the dependency; and the README's "FFmpeg 7 or 8" contract narrows to the host. Three defects reached users' machines in the first cut, and none was in the deletion itself. All three desktop Settings UIs offer vulkan, vaapi and d3d11va as stored decoder values, so those strings sit in shipped settings files today. Refusing them by name — which is the correct rule for a stale pin — would have bricked every upgraded client whose owner ever touched that dropdown. They now migrate onto the native rung for the same hardware family, at decoder construction AND at each dialog's lookup, because a legacy value that matches no preset displays as "Automatic" and silently rewrites the user's preference on the next save. M9's evidence filter was deleted on the argument that with no libavcodec twin below, barring an unproven rung removes hardware decode rather than moving down one rung. That is true on Windows and false on Linux for Intel and every unknown vendor id, where prefer_vulkan_first is false and the order is native-vaapi → native-vk: a rung that has decoded nothing anywhere sitting above one that is 250/250 on three drivers. Every Intel Linux desktop would have moved from libavcodec VAAPI, shipping for years, onto pf-vaadec by default — and a rung that constructs and then produces wrong pixels leaves only by the error-streak demotion, which this codebase already documents as not tripping on the B580's strobing. The filter is restored as a narrow, pure, testable rule: an unproven rung yields to a proven one, and to nothing else. Windows deliberately passes no rung below, because that vendor family is the one with a measured wrong-pixel report against Vulkan decode, and trading no evidence for evidence of corruption is the wrong direction. And the notices still said FFmpeg was bundled. The root file is what both desktop clients include_str! and what the MSIX ships, three lines under the new card saying no FFmpeg is bundled; Apple's Acknowledgements said it too, on iOS, tvOS and macOS. The generator now emits four per-client files scoped by transitive closure — 0 FFmpeg mentions in each, verified — while the root file keeps it for the host. That also ends the standing false attribution of ffmpeg-next, GTK4, windows-rs and the NVENC SDK to an iPhone. Windows has no reachable box, so it was compiled instead: a cross clippy at -D warnings on x86_64 and aarch64-pc-windows-msvc with the C toolchain stubbed so build scripts run without linking. That gate immediately caught an include_str! path one directory too deep, which nothing else could have. Gates: container clippy -D warnings, 160 tests, workspace check, both Windows targets clean, client ffmpeg count 0 and host 2. The four decode crates are untouched, so the hardware rungs' 250/250 stands. ⚠ Owed and unrun: no GPU has executed any of this milestone. M8's on-glass software check, M7's D3D11 and VAAPI AV1 hardware legs, and M9's field bake all still want hardware, and the bake window and criteria remain the user's.
punktfunk-core
The shared protocol core — the one place where punktfunk's transport, forward error correction, and crypto live. It's linked into the host and every native client, so there's exactly one implementation of the wire format everywhere.
Written in Rust with no async on the per-frame path (native threads only). It exposes both a normal Rust API and a stable, versioned C ABI, so the Swift and Kotlin clients — and any C embedder — link the same code as the Rust ones.
What's in here
- Transport & session (
session.rs,transport/,packet.rs) — thepunktfunk/1data plane over raw UDP: packetization, reassembly (with attacker-bounded limits), pacing, and socket tuning. - FEC (
fec/) — the wall-breaker. Two codes:- GF(2⁸) classic Reed–Solomon with the Cauchy generator matrix — byte-identical to the
nanorslibrary Moonlight uses, so our parity is decodable by a stock Moonlight client. - GF(2¹⁶) Leopard-RS (SIMD, O(n log n)) — up to 65535 shards/block, which removes the ~1 Gbps
FEC ceiling.
punktfunk/1negotiates this one.
- GF(2⁸) classic Reed–Solomon with the Cauchy generator matrix — byte-identical to the
- Crypto (
crypto.rs) — AES-128-GCM session encryption with per-direction nonce salts and sequence-as-AAD; SPAKE2 PIN pairing lives behind thequicfeature. - QUIC control plane (
quic.rs,client.rs, featurequic) — the Hello/Welcome/Start handshake, cert pinning/TOFU, reverse audio, and the embeddableNativeClientconnector. This is the only placetokio/quinnare allowed; the feature is off by default so the core stays runtime-free. - C ABI (
abi.rs) — the versioned surface (punktfunk_abi_version(),PunktfunkConfigcarrying its ownstruct_size) that generatesinclude/punktfunk_core.hvia cbindgen at build time.
Build outputs
The crate builds three ways at once (crate-type = ["lib", "cdylib", "staticlib"]):
| Output | Used by |
|---|---|
lib (rlib) |
the host, probe, and tools link it as a normal Rust crate |
cdylib (.so/.dylib) |
the Swift / Kotlin clients via the C ABI |
staticlib (.a) |
the C test harness and static embedding |
Test
cargo test -p punktfunk-core # unit + proptest + loopback
cargo run -p loss-harness # FEC loss-resilience sweep (no network needed)
bash crates/punktfunk-core/tests/c/run.sh # standalone C-ABI link + round-trip proof
Design invariants (do not regress)
- One core, linked everywhere — protocol/FEC/crypto live only here, behind the stable C ABI.
- No async on the hot path — the per-frame pipeline is native threads only;
quic(tokio/quinn) is control-plane only, feature-gated, off by default. - Security hardening stays intact — the reassembler bounds attacker-controlled fields before
allocating; AES-GCM keeps per-direction nonce salts + seq-as-AAD; the ABI checks
struct_size. Regression tests exist — keep them green.
Related
punktfunk-host— the streaming host built on this core- Clients — the apps that link this core over the C ABI (or directly, in Rust)
- punktfunk-planning:
implementation-plan.md(internal planning repo) — why GF(2¹⁶) FEC, the latency budget, and the architecture thesis