Continues docs/hdr-pipeline-plan.md. Steps 0/1 + Step 2 (Windows/Android) already
landed in ffae2a3; this is Step 2 (Apple) + Step 3 (all clients). Client-only — no
core/host/ABI change (the 0xCE/next_hdr_meta/color_info surfaces shipped in Step 0).
Step 2 — clients APPLY the host's HDR metadata (each remaps from the wire form: ST.2086
G,B,R order, mastering luminance in 0.0001 cd/m2):
- Apple: connect via punktfunk_connect_ex5 (resurrects the previously-dead HDR pipeline);
nextHdrMeta/colorInfo wrappers + HdrMeta SEI-blob builders; the pump drains nextHdrMeta
-> VideoDecoder.setHdrMeta -> CVBufferSetAttachment of MasteringDisplayColorVolume (24B
BE) + ContentLightLevelInfo (4B BE) on each HDR pixel buffer (correct for the
itur_2100_PQ layer; CAEDRMetadata avoided as ambiguous there).
Step 3 — capability-gate: advertise HDR caps ONLY when the display can present it, so an
SDR display gets a proper BT.709 stream instead of PQ it would mis-tone-map; an HDR
display self-tone-maps from the Step-1/2 mastering metadata.
- Windows: present::display_supports_hdr() (DXGI any IDXGIOutput6 colour space == G2084),
ANDed with the user HDR setting in session.rs; logs the SDR drop.
- Apple: NSScreen.maximumExtendedDynamicRangeColorComponentValue>1 (macOS) /
UIScreen.main.potentialEDRHeadroom>1 (iOS) in SessionModel.
- Android: Settings.displaySupportsHdr (Display.getHdrCapabilities HDR10/HDR10+) passed
through a new hdr_enabled jboolean on nativeConnect; session.rs gates the caps.
Validation: Android native (incl. the jboolean gate) builds + clippy clean via cargo-ndk;
fmt clean. Windows (MSVC), Apple (Swift) and the Kotlin side are CI/on-glass validated —
not compilable on the Linux dev box. Deferred to the RTX box: mid-session Reconfigure
SDR-downgrade on monitor move, and confirming the host emits SDR for an SDR client off an
HDR desktop.
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>
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