feat(clients): HDR Steps 2-3 — apply mastering metadata + display capability-gate

Continues docs/hdr-pipeline-plan.md. Steps 0/1 + Step 2 (Windows/Android) already
landed in 3526517; 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>
This commit is contained in:
2026-06-21 09:46:58 +00:00
parent 3526517eb1
commit 551012bb43
12 changed files with 193 additions and 27 deletions
@@ -5,6 +5,12 @@ import Foundation
import PunktfunkKit
import SwiftUI
#if canImport(AppKit)
import AppKit
#elseif canImport(UIKit)
import UIKit
#endif
/// Pump-thread-side frame counters; a 1 Hz main-actor timer drains them into @Published
/// values. NSLock instead of an actor the writer is the (non-async) pump thread.
final class FrameMeter: @unchecked Sendable {
@@ -93,6 +99,7 @@ final class SessionModel: ObservableObject {
compositor: PunktfunkConnection.Compositor = .auto,
gamepad: PunktfunkConnection.GamepadType = .auto,
bitrateKbps: UInt32 = 0,
hdrEnabled: Bool = true,
launchID: String? = nil,
allowTofu: Bool = false,
autoTrust: Bool = false) {
@@ -101,17 +108,36 @@ final class SessionModel: ObservableObject {
activeHost = host
errorMessage = nil
let pin = host.pinnedSHA256
// Capability gate (main-actor screen APIs): only advertise HDR when this display can
// actually present it, so the host sends a proper SDR stream to an SDR display rather than
// BT.2020 PQ the panel would mis-tone-map. The display self-tone-maps HDR from the mastering
// metadata we apply (Step 2) when it IS HDR.
let displayHDR: Bool = {
#if os(macOS)
return (NSScreen.main?.maximumExtendedDynamicRangeColorComponentValue ?? 1.0) > 1.0
#else
return UIScreen.main.potentialEDRHeadroom > 1.0
#endif
}()
let hdrCapable = hdrEnabled && displayHDR
Task.detached(priority: .userInitiated) {
// PunktfunkConnection.init blocks on the QUIC handshake keep it off the main
// actor. The persistent identity is presented on every connect so a paired
// host recognizes this Mac (nil = anonymous, fine for hosts without
// --require-pairing; Keychain/generation failure must not block connecting).
let identity = (try? ClientIdentityStore.shared.load())?.identity
// Advertise 10-bit + HDR10 when enabled: the host upgrades to a BT.2020 PQ Main10 stream
// only for actual HDR content (its own gate); the VideoToolbox/Metal present path is
// HDR-capable (P010 + itur_2100_PQ + EDR). 0 keeps the 8-bit BT.709 SDR stream.
let videoCaps: UInt8 = hdrCapable
? (PunktfunkConnection.videoCap10Bit | PunktfunkConnection.videoCapHDR)
: 0
let result = Result { try PunktfunkConnection(
host: host.address, port: host.port,
width: width, height: height, refreshHz: hz,
pinSHA256: pin, identity: identity, compositor: compositor,
gamepad: gamepad, bitrateKbps: bitrateKbps, launchID: launchID) }
gamepad: gamepad, bitrateKbps: bitrateKbps, videoCaps: videoCaps,
launchID: launchID) }
await MainActor.run { [weak self] in
guard let self else { return }
// The user may have abandoned this attempt (window closed, another host
@@ -532,6 +532,11 @@ public final class PunktfunkConnection {
}
}
/// Video-capability bit: the client can decode a 10-bit (Main10) HEVC stream.
public static let videoCap10Bit: UInt8 = UInt8(PUNKTFUNK_VIDEO_CAP_10BIT)
/// Video-capability bit: the client can present BT.2020 PQ HDR10 (implies 10-bit).
public static let videoCapHDR: UInt8 = UInt8(PUNKTFUNK_VIDEO_CAP_HDR)
/// Static HDR mastering metadata (SMPTE ST.2086 + content light level) the host sent for an HDR
/// session. Mirrors the wire/ABI `PunktfunkHdrMeta`; primaries are in ST.2086 **G, B, R** order,
/// 1/50000 units; mastering luminance in 0.0001 cd/m²; MaxCLL/MaxFALL in nits.
@@ -128,6 +128,11 @@ public final class Stage2Pipeline {
lastFramesDropped = dropped
recovery.request()
}
// Drain any HDR mastering-metadata update (0xCE) and hand it to the decoder, which
// attaches it to subsequent HDR frames. Non-blocking; only HDR sessions emit these.
if connection.isHDR, let meta = try? connection.nextHdrMeta(timeoutMs: 0) {
decoder.setHdrMeta(meta)
}
guard let au = try connection.nextAU(timeoutMs: 100) else { continue }
onFrame?(au)
if let f = AnnexB.formatDescription(fromIDR: au.data) {
@@ -49,6 +49,12 @@ public final class VideoDecoder: @unchecked Sendable {
/// pump can re-gate on the next IDR.
private let onDecodeError: @Sendable (OSStatus) -> Void
/// Latest source HDR mastering metadata (from `PunktfunkConnection.nextHdrMeta`), attached to
/// each decoded HDR pixel buffer so the compositor tone-maps from the real grade. Guarded by its
/// own lock written by the pump thread, read on the VT decode callback.
private let metaLock = NSLock()
private var hdrMeta: PunktfunkConnection.HdrMeta?
public init(
onDecoded: @escaping @Sendable (ReadyFrame) -> Void,
onDecodeError: @escaping @Sendable (OSStatus) -> Void = { _ in }
@@ -59,6 +65,14 @@ public final class VideoDecoder: @unchecked Sendable {
deinit { teardown() }
/// Set the source HDR mastering metadata (drained from `PunktfunkConnection.nextHdrMeta`). It's
/// attached to subsequent decoded HDR pixel buffers. Thread-safe; cheap to call on each update.
public func setHdrMeta(_ meta: PunktfunkConnection.HdrMeta) {
metaLock.lock()
hdrMeta = meta
metaLock.unlock()
}
/// Submit one AU for asynchronous decode, (re)creating the session if `format` changed. The
/// caller resolves `format` from the IDR exactly as stage-1 does (`AnnexB.formatDescription`).
/// Returns false if the session couldn't be created or the frame couldn't be submitted.
@@ -185,6 +199,22 @@ public final class VideoDecoder: @unchecked Sendable {
let isHDR =
CVPixelBufferGetPixelFormatType(imageBuffer)
== kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange
// Attach the source's mastering display + content light level (ST.2086 / CEA-861.3) so the
// compositor tone-maps from the real grade rather than inferring from the PQ colourspace
// alone. The SEI byte payloads map 1:1 to these CVImageBuffer attachment keys.
if isHDR {
metaLock.lock()
let meta = hdrMeta
metaLock.unlock()
if let meta {
CVBufferSetAttachment(
imageBuffer, kCVImageBufferMasteringDisplayColorVolumeKey,
meta.masteringDisplayColorVolume() as CFData, .shouldPropagate)
CVBufferSetAttachment(
imageBuffer, kCVImageBufferContentLightLevelInfoKey,
meta.contentLightLevelInfo() as CFData, .shouldPropagate)
}
}
onDecoded(
ReadyFrame(ptsNs: ptsNs, decodedNs: decodedNs, pixelBuffer: imageBuffer, isHDR: isHDR))
}