Stream reliability
- Default to the stage-2 presenter (VTDecompressionSession + CAMetalLayer): it detects
and recovers a wedged decoder, where stage-1's AVSampleBufferDisplayLayer freezes hard
on a lost HEVC reference frame with no app-side recovery (confirmed Apple limitation).
Stage 1 is now a DEBUG-only presenter toggle, plus the automatic no-Metal fallback.
- Stage-2 pixel-perfect: render the drawable at the decoded size (shader stays 1:1 =
identity) and let the layer's contentsGravity scale via the system compositor — the
same path stage-1's videoGravity used — instead of scaling in-shader.
- Loss recovery in both pumps is now a persistent awaitingIDR want, retried until an IDR
actually lands, so a keyframe request swallowed by the throttle can't strand a frozen
frame; 100 ms keyframe throttle to match the Android path.
- Fix "Publishing changes from within view updates": defer the HostStore writes out of
the .onChange(of: model.phase) callback.
- Move AVAudioSession setActive/setCategory off the main thread (async on a shared serial
queue) to stop the UI-stall warning.
Controllers
- Rumble: capped-exponential backoff when the gamecontrollerd.haptics XPC breaks (-4811)
so a transient server interruption self-heals instead of cascading; playsHapticsOnly so
a controller engine doesn't join the always-active streaming audio session.
- Host cards: iPad pointer "magnet" hover effect; iPhone press scale + light haptic.
UI / design
- Ship Geist (SIL OFL 1.1) as the app font (bundled OTFs + registration), with the
license surfaced in Acknowledgements.
- Restructure iOS/iPadOS Settings into a category NavigationSplitView; resolution wheel
with custom-resolution entry; 10-bit HDR toggle in Display.
- Industrial host-card redesign (left-aligned, bold, brand monogram tiles).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Adds true HDR (BT.2020 PQ) and 10-bit (HEVC Main10) streaming, negotiated so an
8-bit/SDR client is never sent a stream it can't decode, plus a robust fix for the
capture losing the stream across a secure-desktop transition.
Protocol (punktfunk-core/quic.rs):
- Hello gains `video_caps` (VIDEO_CAP_10BIT / VIDEO_CAP_HDR), Welcome gains `bit_depth`,
both as optional trailing bytes (back-compat). client-rs advertises 10-bit via
PUNKTFUNK_CLIENT_10BIT; the connector advertises 0 for now (in-band detection drives
the native clients). Regenerated punktfunk_core.h.
Windows host:
- 10-bit Main10: host enables it only when the client advertised VIDEO_CAP_10BIT AND
PUNKTFUNK_10BIT is set; threaded through open_video → NVENC (profile Main10,
pixelBitDepthMinus8).
- HDR: when the captured desktop is scRGB FP16 (R16G16B16A16_FLOAT, HDR on), copy it to
an FP16 surface, composite the cursor there, convert scRGB → BT.2020 PQ 10-bit
(R10G10B10A2) via a shader, and encode HEVC Main10 with the BT.2020/PQ colour VUI
(ABGR10 input). Fixes the freeze + cursor-trail that came from feeding FP16 into the
BGRA path. Reacts dynamically to the HDR toggle.
- Capture recovery: rebuild is now a single NON-BLOCKING attempt, throttled to ~4×/s,
repeating the last good frame between attempts (format-tagged last_present). During a
secure-desktop dwell SudoVDA's output is gone; the old blocking 12 s retry starved the
send loop for seconds so the client timed out and disconnected — now the session stays
fed (frozen) until the desktop returns. Also seeds a black frame on recovery.
Apple client (PunktfunkKit):
- Detects HDR in-band from the stream VUI (PQ transfer function), decodes to 10-bit P010,
and presents via an rgba16Float + BT.2020 PQ CAMetalLayer with EDR; SDR path unchanged.
Switches automatically on a mid-session HDR toggle.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The experimental stage-2 presenter (CAMetalLayer + display link) stuttered badly
in fullscreen but ran fine windowed. render() runs on the display-link / MAIN
thread and calls layer.nextDrawable(), which blocks that thread until a drawable
frees. With the layer's own displaySyncEnabled left on (default), present also
waits for the hardware vsync, so the block serializes the main thread to the
display — windowed, the WindowServer's looser compositing hides it; fullscreen's
tighter, more-direct path exposes it as judder. (Apple dev-forum guidance:
displaySync off measurably reduces nextDrawable() blocking.)
- displaySyncEnabled = false (macOS-only): the display link is already the per-
vsync pacing source, so the layer's redundant vsync wait only adds the stall.
- maximumDrawableCount = 3 (explicit): more in-flight headroom before
nextDrawable() has to block on the main thread.
Swift-only (no core/ABI change → no xcframework rebuild). Validated: swift build;
swift test (39 passed, 0 failures).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Opt-in (Settings -> Presenter; `punktfunk.presenter`, default stage-1). Stage-1's
AVSampleBufferDisplayLayer decodes AND presents internally with no per-frame
callback, so neither decode nor present can be stamped or hand-paced. Stage-2
takes explicit control:
- VideoDecoder: VTDecompressionSession, async output callback stamps
decode-completion, session rebuilt on every IDR / format change. Unit-tested
(testVideoDecoderAsyncCallbackDeliversPixels).
- MetalVideoPresenter: CAMetalLayer + CVMetalTextureCache + a runtime-compiled
BT.709 limited-range NV12->RGB shader, present at the next vsync. The
CVMetalTextures + pixel buffer are held until the GPU completes.
- Stage2Pipeline: pump thread -> decoder -> newest-ready 1-slot ring; the hosting
view's display link drains it once per vsync and stamps capture->present
(the display-link target time projected into CLOCK_REALTIME).
- LatencyMeter gains record(ptsNs:atNs:offsetNs:); the HUD shows a capture->present
(glass-to-glass, modulo host render->capture) line, skew-corrected via
clockOffsetNs. Measured live ~11 ms p50 vs ~2.2 ms capture->client.
- StreamView / StreamViewIOS host the CAMetalLayer as a sublayer + a CADisplayLink
(NSView.displayLink on macOS) when stage-2; input capture + HUD unchanged. The
session-active gates switch from `pump != nil` to `connection != nil` so capture
engages without a StreamPump.
Validated: builds macOS/iOS/tvOS; the decode half is unit-tested; the Metal
present is live-validated on glass (correct image + the capture->present number).
Colorspace is BT.709 SDR for now; 10-bit/HDR + a pacing policy are later.
Plan: docs-site/content/docs/apple-stage2-presenter.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler