enricobuehler
1099c94ca3
Caught on glass during the WP2 baseline, on the first stream the metric ever measured: judder=0 mode=0 cadN=0 disorder=119, every second, on a perfectly healthy 118 fps stream with the panel period correctly learned at 8.33 ms. Every single present was scoring as disordered. The cause was the vendor quirk decode/display.rs already documents — Android's render callback can deliver a garbage far-future system_nano on a session's first frames. The rule "hold the later instant so one reordered delivery cannot corrupt the following spacings" then latched onto that stamp permanently: every real timestamp afterwards was behind it, so nothing was ever scored again for the rest of the session. The rule was right for what it was written for and wrong past a bound. A step backwards of a few refreshes IS a reordered delivery and the later instant should win; a step backwards of an hour is a bogus stamp and the run must re-anchor onto the new sample. One bad sample now costs one sample. Both implementations get the bound and the regression test, since the two must agree; the Swift port would otherwise have shipped the same latch-up. Also makes the statistic self-diagnosing, which is what turned a puzzling result into a five-minute diagnosis: summary() returning None was indistinguishable from a window of perfectly smooth zeros in a log line, so "no cadence is being scored at all" looked exactly like "no judder". The pf.present line now carries the raw sample/stall/disorder counts and the period the run is quantising against, whatever the evidence bar. Gates: punktfunk-core 190 tests green (22 in phase, incl. the new a_garbage_far_future_stamp_does_not_wedge_the_run); swift test --filter PresentIntervalsTests 11/11 green; fmt clean; on-glass re-run against .173 now reports judder 8-36permille with cadN ~119/s.
punktfunk — Apple client (macOS · iOS · iPadOS · tvOS)
The native Apple app for streaming a punktfunk host to your Mac, iPhone, iPad, or Apple TV. A SwiftUI app that finds hosts on your network, pairs with a PIN, and streams at your display's own resolution and refresh rate — with VideoToolbox hardware decode and full controller support.
All the networking and protocol work — QUIC control plane, UDP data plane, GF(2¹⁶) FEC, AES-GCM,
Opus audio, cert pinning — lives in the shared Rust punktfunk-core (statically linked as
PunktfunkCore.xcframework). This package is the Swift shell: decode, present, input, and UI.
Features
- Hardware decode — VideoToolbox H.264/HEVC (plus AV1 on devices with an AV1 hardware
decoder — M3-class Macs, A17 Pro-class iPhones), with a low-latency stage-2 presenter
(
VTDecompressionSession→CAMetalLayer, presented off aCADisplayLink, ~11 ms p50) as the default and anAVSampleBufferDisplayLayerfallback. - HDR & 4:4:4 — PQ passthrough with a correct reference-white anchor, mid-session SDR↔HDR reconfiguration, and hardware-probed 4:4:4 support.
- Your display's native mode — the host builds a virtual output at exactly your WxH@Hz; mid-stream resize renegotiates without reconnecting.
- Audio both ways — Opus playback (CoreAudio, no bundled libopus) with a jitter ring, plus mic uplink; speaker/mic selectable in Settings.
- Full controller support — one selected controller forwarded as pad 0, including DualSense feedback (rumble → CoreHaptics, lightbar, player LEDs, adaptive triggers) and touchpad/motion. The virtual pad type auto-resolves from your physical controller.
- Mouse & keyboard —
GCMouse/GCKeyboardcapture with click-to-capture and a ⌃⌥⇧Q release (the cross-client Ctrl+Alt+Shift+Q; ⌘⎋ still works as the macOS/iPad toggle), plus iPad pointer lock and touch input. - Find hosts automatically — mDNS discovery (
NWBrowserover_punktfunk._udp); first connect does a one-time SPAKE2 PIN pairing (or TOFU on trusted LANs), then reconnects on a pinned, Keychain-stored identity. - Tune the stream — a fps / Mb·s / latency HUD (skew-corrected across machines), a bitrate control, a per-host network speed test with a recommended bitrate, and a host-compositor picker.
Runs from one shared codebase across macOS, iOS, iPadOS, and tvOS.
Get it
Install from the App Store / TestFlight, or build from source below. Per-device install steps and the pairing walkthrough: docs.punktfunk.unom.io/docs/install-client.
Build / run / test (on a Mac)
Requires Xcode 26.5 / Swift 6.3. First build the Rust core into an xcframework, then build the app:
rustup target add aarch64-apple-darwin x86_64-apple-darwin
bash scripts/build-xcframework.sh # → clients/apple/PunktfunkCore.xcframework
# BUILD_IOS=1 also builds the iOS slices (add the ios rustup targets)
# BUILD_TVOS=1 also builds tvOS (tier-3 targets, built from source — see below)
cd clients/apple
open Punktfunk.xcodeproj # the real app: ⌘R builds + runs Punktfunk.app
swift run PunktfunkClient # or the unbundled dev shell (CLI)
swift build && swift test # unit + loopback/remote tests (self-skip w/o a host)
tvOS slices are tier-3 Rust targets, built from source:
rustup toolchain install nightly && rustup component add rust-src --toolchain nightly.
Test against a host
# full loopback proof — builds punktfunk-host (synthetic source, runs on macOS) and streams
# byte-verified frames into the Swift client, incl. the PIN pairing ceremony:
bash test-loopback.sh
# against a real Linux host on the LAN (see the repo README "Running on this box"):
PUNKTFUNK_REMOTE_HOST=<box-ip> swift test --filter RemoteFirstLightTests # headless
PUNKTFUNK_AUTOCONNECT=<box-ip> PUNKTFUNK_MODE=1280x720x60 swift run PunktfunkClient # on glass
Project layout
PunktfunkKit(library) — the reusable pieces:PunktfunkConnection— the wrapper over the C ABI (thread-safeclose(), per-plane locks, pinning + TOFU).AnnexB/StreamView/VideoDecoder/MetalVideoPresenter— format handling, the stage-1 (AVSampleBufferDisplayLayer) and stage-2 (VTDecompressionSession→CAMetalLayer) presenters.InputCapture—GCMouse/GCKeyboard→ host VK/mouse, with fractional-delta accumulation.GamepadManager/GamepadCapture/GamepadFeedback/DualSenseTriggerEffect— controller discovery + selection, capture (buttons/axes/touchpad/motion), and host-feedback rendering.HostDiscovery—NWBrowserover_punktfunk._udp.
PunktfunkClient(the app) — hosts grid with an On this network section, add-host sheet, the two trust flows (TOFU prompt + SPAKE2PairSheet), the stream view with the HUD, a tabbed Settings pane (General / Display / Audio / Controllers / Advanced), and the network speed test. A Scene-level Stream menu carries the cross-client shortcut set: Release Mouse (⌃⌥⇧Q), Disconnect (⌃⌥⇧D) and the HUD toggle (⌃⌥⇧S) — the same Ctrl+Alt+Shift combos the Windows and Linux clients reserve, also shown on a 6-second banner at stream start. On iOS/iPadOS and macOS a connected controller swaps the whole home for the gamepad UI (Home/Gamepad*,Settings/GamepadSettingsView): a console-style host carousel (A connect · Y library · X settings), a controller-navigable settings screen, an add-host flow with an on-screen controller keyboard (no touch required anywhere), and the coverflow library browser — all driven by the sharedGamepadMenuInputpoller +GamepadCarousel/GamepadMenuListfocus machinery, with dual-channel haptics (device Taptic + controllerMenuHaptics), over an animated "aurora" backdrop (GamepadScreenBackground— TimelineView-driven drifting color blobs; deliberately pure SwiftUI, since a .metal library only reliably bundles in one of the two build systems these sources compile under). macOS presents the settings/add-host screens as sheets (nofullScreenCoverthere);PUNKTFUNK_FORCE_GAMEPAD_UI=1forces the mode without a physical pad (dev/screenshots).- Tests (
swift test) — Annex-B units, a real-codec VideoToolbox round trip, DualSense trigger-effect and gamepad-wire conversions, loopback integration against real local hosts, and the remote first-light test.
Notes for contributors
- Xcode project (
Punktfunk.xcodeproj) wraps the same sources as theswift runshell (a synchronized folder — no duplication). The macOS target is App-Sandboxed (needsnetwork.server— the raw-UDP plane and quinn bothbind()); iOS/tvOS use the shared entitlements file (keepapp-sandboxout of it). Verify withcodesign -d --entitlements :- <built .app>. - Decode flow: the host opens every stream with an IDR carrying VPS/SPS/PPS in-band, and recovery keyframes re-send them — refresh the format description on every IDR; there is no out-of-band extradata, ever.
- ABI threading: one video pump thread per connection, one optional audio drain thread, and one
optional feedback drain thread (rumble + HID-output).
send()is enqueue-only and safe alongside all of them. The wrapper's per-plane locks makeclose()safe from anywhere. - DualSense motion scale (
GamepadWire) is derived from hid-playstation's math, not yet live-verified — if gyro/accel feel wrong in a game, correct sign/scale there andevtestthe host's virtual pad. - App Store screenshots are automated —
tools/screenshots.sh allrenders the real UI at the required pixel sizes via a DEBUG-only shot mode; theappleCI workflow captures the iOS sizes on every main push. See the script header for details. The script'sSCENESarray is the listing set, in listing order; override it (SCENES="06-gamepad-home 10-edithost" tools/screenshots.sh ios) to capture any of the other scenes inShotScenes.all. Mock data — hosts, adverts, profiles — is seeded inShotMockso a capture is byte-for-byte deterministic and never browses the real LAN (a stranger's hostname reached the live listing that way once). - Deeper design notes live in the internal planning repo (punktfunk-planning:
apple-stage2-presenter.md).
Related
- Documentation — quick start, pairing, troubleshooting
- Project README — the host, the other clients, and how it all fits together