Files

T

enricobuehler 8a18e130a2 feat(client): freeze-until-reanchor loss recovery on Android + Apple via shared core gate

After unrecoverable loss the host keeps sending delta frames that reference a
picture the client never received; hardware decoders conceal these as gray/
garbage with a success status. Linux already withheld them and held the last
good frame until a proven clean re-anchor — this brings that behavior to the
Android and Apple clients.

Extract the Linux pump's freeze state machine into a shared `ReanchorGate` in
punktfunk-core (reanchor.rs, 18 tests) exposed over the C ABI (ABI v6, additive —
no wire change) for the Swift clients. Migrate the Linux/Deck pump
(pf-client-core) onto it as the parity proof (no-op refactor). Then wire:

- Android (decode.rs, both sync + async loops): arm on the frame-index gap, a
  pts-keyed flag map carries the wire flags to the output-buffer release, fold
  the gate per drained output, gate.poll replaces the dropped-climb block.
- Apple Stage2Pipeline (default): arm on a gap (new noteFrameIndexGap), withhold
  at the ring-submit seam (CAMetalLayer holds its last drawable), poll
  framesDropped, fold VT decode errors through the no-output streak.
- Apple StreamPump (stage-1): fold at enqueue, withhold via
  kCMSampleAttachmentKey_DoNotDisplay so the layer keeps decoding (reference
  chain intact) but holds the last displayed frame.
- Apple VideoDecoder: thread the AU's wire flags to the async decode callback via
  a retained FrameContext refcon (replaces the receivedNs bit-pattern scalar).

Lifts only on a proven re-anchor (IDR / RFI anchor / 2nd recovery mark) with a
500 ms backstop so a lost re-anchor can never freeze forever. Apple: swift build
clean, 123/123 tests pass (incl. VideoToolboxRoundTripTests). On-glass
loss-injection validation still owed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

2026-07-13 01:22:09 +02:00

benches

fix(core): receive path — replay window covers the loss window, zero-alloc open

2026-07-10 14:55:06 +02:00

src

feat(client): freeze-until-reanchor loss recovery on Android + Apple via shared core gate

2026-07-13 01:22:09 +02:00

tests

perf(core): ref-based FEC encode — packetize shards reference the frame in place

2026-07-10 15:16:07 +02:00

vendor/fec-rs

rename: lumen → punktfunk, everywhere

2026-06-10 13:11:59 +00:00

build.rs

rename: lumen → punktfunk, everywhere

2026-06-10 13:11:59 +00:00

Cargo.toml

feat(transport): Windows DSCP via qWAVE flows — PUNKTFUNK_DSCP now real on the wire there

2026-07-10 15:59:23 +02:00

cbindgen.toml

fix(core,host): make the native data plane survive real Wi-Fi links

2026-07-07 07:35:08 +02:00

README.md

docs: repo-wide housekeeping — sync README & docs with the code as shipped

2026-07-10 09:13:42 +02:00

README.md

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) — the punktfunk/1 data 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 nanors library 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/1 negotiates this one.
Crypto (crypto.rs) — AES-128-GCM session encryption with per-direction nonce salts and sequence-as-AAD; SPAKE2 PIN pairing lives behind the quic feature.
QUIC control plane (quic.rs, client.rs, feature quic) — the Hello/Welcome/Start handshake, cert pinning/TOFU, reverse audio, and the embeddable NativeClient connector. This is the only place tokio/quinn are allowed; the feature is off by default so the core stays runtime-free.
C ABI (abi.rs) — the versioned surface (punktfunk_abi_version(), PunktfunkConfig carrying its own struct_size) that generates include/punktfunk_core.h via 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.

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

README.md Unescape Escape

punktfunk-core

What's in here

Build outputs

Test

Design invariants (do not regress)

Related

README.md