feat(pyrowave): Apple Metal 4:4:4 + HDR decode, EDR present — self-configured in-band

Phases 4+5 of design/pyrowave-444-hdr.md. The Metal decoder needs NO new ABI:
every frame's sequence header carries chroma (444) and, since the Phase-3
stamps, the PQ/BT.2020 bits — so the decoder self-configures per session.

Decoder: WaveletLayout grows the 4:4:4 block space (chroma runs the full
pyramid like luma — no level-0 skip, no early half-res emit; the Metal
kernels were already chroma-agnostic, only the dispatch structure changes);
the parser accepts chroma_resolution=444, reads the PQ transfer bit, and
lifts the even-dims rule for 444; the plane ring allocates full-res chroma
and r16Unorm for PQ streams; CSC rows switch to depth-10 MSB-packed.

Presenter: planar HDR passthrough reuses pf_frag_planar on an rgba16Float
drawable (itur_2100_PQ + EDR metadata interpret the samples — same split as
pf_frag/pf_frag_hdr), plus a new pf_frag_planar_tm PQ->SDR tone-map (shared
pqToSdr tail refactored out of pf_frag_hdr_tv) for tvOS-without-headroom AND
macOS WINDOWED sessions, whose IOSurface present path (the DCP-panic
mitigation) is BGRA8-only. SessionModel stops stripping the HDR/10-bit/444
caps on the PyroWave opt-in.

New golden: au-dense444 + upstream's own 4:4:4 reference planes (regenerated
via the extended pyrowave_dump_golden); Metal decode matches at 64-67 dB
(420 fixtures re-verify 77-88 dB). Full Apple suite 157 tests green on a
real M-series GPU. Docs updated: the 8-bit-SDR-only wording is gone, the
Windows host is no longer 'on the roadmap', bpp scaling documented.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

clients/apple/Sources/PunktfunkClient/Session/SessionModel.swift

@@ -264,14 +264,11 @@ final class SessionModel: ObservableObject {
             // PyroWave (wired LAN) is a pure opt-in: picking it in the codec setting both
             // advertises the bit and prefers it — the host never auto-selects it, and the
             // picker only offers it when the Metal decode probe passed (simdgroup floor ≈ A13;
-            // every M-series Mac and the ATV 4K gen 3 pass). The codec is 8-bit 4:2:0 SDR
+            // every M-series Mac and the ATV 4K gen 3 pass). The decoder self-configures from
-            // BT.709 by contract, so the opt-in also drops the HDR/10-bit/4:4:4 caps for this
+            // the per-frame sequence header (4:2:0/4:4:4, SDR/PQ — design/pyrowave-444-hdr.md),
-            // session — HDR sessions stay HEVC/AV1 (plan §4.7).
+            // so the session keeps the user's HDR/10-bit/4:4:4 caps exactly like HEVC/AV1.
             if preferredCodec == PunktfunkConnection.codecPyroWave, MetalWaveletDecoder.supported {
                 videoCodecs |= PunktfunkConnection.codecPyroWave
-                videoCaps &= ~(PunktfunkConnection.videoCap10Bit
-                    | PunktfunkConnection.videoCapHDR
-                    | PunktfunkConnection.videoCap444)
             }
             let result = Result { try PunktfunkConnection(
                 host: host.address, port: host.port,

clients/apple/Sources/PunktfunkKit/Video/MetalVideoPresenter.swift

@@ -196,13 +196,11 @@ fragment float4 pf_frag_hdr(VOut in [[stage_in]],
 // display-referred SDR. (When the display IS in an HDR mode — requested per session via
 // AVDisplayManager, see StreamViewIOS — tvOS presents pf_frag_hdr's PQ passthrough instead:
 // in a genuine HDR10 output, PQ passthrough is the correct emission and the TV tone-maps.)
-fragment float4 pf_frag_hdr_tv(VOut in [[stage_in]],
+// The shared PQ→display-referred-SDR tail (see pf_frag_hdr_tv's rationale above): ST 2084
-                               texture2d<float> lumaTex [[texture(0)]],
+// EOTF → 203-nit-anchored scene light → BT.2020→709 primaries → extended-Reinhard rolloff →
-                               texture2d<float> chromaTex [[texture(1)]],
+// BT.709 OETF. Used by the tvOS biplanar tone-map and the planar (PyroWave) tone-map — the
-                               constant CscUniform& csc [[buffer(0)]]) {
+// latter also on macOS windowed sessions, whose IOSurface present path is BGRA8-only.
-    // Y′CbCr → full-range PQ R′G′B′ via the per-frame rows (as pf_frag_hdr).
+static inline float3 pqToSdr(float3 pq) {
-    float3 pq = sampleRgb(lumaTex, chromaTex, in.uv, csc);
-    // ST 2084 EOTF: PQ code value → linear light, 1.0 = 10,000 nits.
     const float m1 = 2610.0/16384.0;
     const float m2 = 78.84375;
     const float c1 = 3424.0/4096.0;
@@ -210,20 +208,49 @@ fragment float4 pf_frag_hdr_tv(VOut in [[stage_in]],
     const float c3 = 18.6875;
     float3 p = pow(pq, 1.0/m2);
     float3 lin = pow(max(p - c1, 0.0) / (c2 - c3 * p), 1.0/m1);
-    // Scene-referred with diffuse white at 1.0 (the same 203-nit anchor the EDR path uses).
     float3 t = lin * (10000.0/203.0);
-    // BT.2020 → BT.709 primaries while still linear; negatives are out-of-gamut, floor them.
     float3 t709 = float3(
         dot(t, float3( 1.6605, -0.5876, -0.0728)),
         dot(t, float3(-0.1246,  1.1329, -0.0083)),
         dot(t, float3(-0.0182, -0.1006,  1.1187)));
     t709 = max(t709, 0.0);
-    // Extended Reinhard: 1.0 stays put, the 1000-nit knee lands at display white, above rolls off.
     const float w = 1000.0/203.0;
     float3 mapped = saturate(t709 * (1.0 + t709 / (w * w)) / (1.0 + t709));
-    // BT.709 OETF — the same encoding the SDR stream arrives in, so both paths present alike.
     float3 e = select(1.099 * pow(mapped, 0.45) - 0.099, 4.5 * mapped, mapped < 0.018);
-    return float4(e, 1.0);
+    return e;
+}
+
+fragment float4 pf_frag_hdr_tv(VOut in [[stage_in]],
+                               texture2d<float> lumaTex [[texture(0)]],
+                               texture2d<float> chromaTex [[texture(1)]],
+                               constant CscUniform& csc [[buffer(0)]]) {
+    // Y′CbCr → full-range PQ R′G′B′ via the per-frame rows (as pf_frag_hdr), then the tail.
+    return float4(pqToSdr(sampleRgb(lumaTex, chromaTex, in.uv, csc)), 1.0);
+}
+
+// PyroWave planar HDR tone-map: three separate R16 planes (P010-style studio codes; the rows
+// fold in depth-10 MSB packing) → PQ R′G′B′ → the shared SDR tail. Used when a PQ pyrowave
+// stream must land on an 8-bit surface: tvOS without HDR headroom, and macOS WINDOWED sessions
+// (the IOSurface present path — the DCP-panic mitigation — is BGRA8). The passthrough planar
+// HDR pipeline reuses pf_frag_planar itself on an rgba16Float drawable (identical math — the
+// layer's itur_2100_PQ colour space + EDR metadata do the interpretation).
+fragment float4 pf_frag_planar_tm(VOut in [[stage_in]],
+                                  texture2d<float> lumaTex [[texture(0)]],
+                                  texture2d<float> cbTex [[texture(1)]],
+                                  texture2d<float> crTex [[texture(2)]],
+                                  constant CscUniform& csc [[buffer(0)]]) {
+    constexpr sampler s(filter::linear, address::clamp_to_edge);
+#ifdef PF_BILINEAR_LUMA
+    float lumaY = lumaTex.sample(s, in.uv).r;
+#else
+    float lumaY = catmullRomLuma(lumaTex, s, in.uv);
+#endif
+    float2 cuv = chromaUV(lumaTex, cbTex, in.uv);
+    float3 yuv = float3(lumaY, cbTex.sample(s, cuv).r, crTex.sample(s, cuv).r);
+    float3 pq = saturate(float3(dot(csc.r0.xyz, yuv) + csc.r0.w,
+                                dot(csc.r1.xyz, yuv) + csc.r1.w,
+                                dot(csc.r2.xyz, yuv) + csc.r2.w));
+    return float4(pqToSdr(pq), 1.0);
 }
 """
 
@@ -287,6 +314,11 @@ public final class MetalVideoPresenter {
     private let pipelineHDRToneMap: MTLRenderPipelineState?
     /// PyroWave's 3-plane SDR path (pf_frag_planar → bgra8) — see `renderPlanar`.
     private let pipelinePlanar: MTLRenderPipelineState
+    /// PyroWave planar HDR passthrough (pf_frag_planar → rgba16Float; the layer's PQ colour
+    /// space + EDR interpret the samples) and the planar PQ→SDR tone-map (pf_frag_planar_tm →
+    /// bgra8; tvOS without headroom + macOS windowed IOSurface presents).
+    private let pipelinePlanarHDR: MTLRenderPipelineState
+    private let pipelinePlanarToneMap: MTLRenderPipelineState
     private var textureCache: CVMetalTextureCache?
 
     /// The PyroWave Metal decoder records on the presenter's device + queue: one device means
@@ -337,6 +369,8 @@ public final class MetalVideoPresenter {
         let pipelineHDR: MTLRenderPipelineState
         let pipelineHDRToneMap: MTLRenderPipelineState?
         let pipelinePlanar: MTLRenderPipelineState
+        let pipelinePlanarHDR: MTLRenderPipelineState
+        let pipelinePlanarToneMap: MTLRenderPipelineState
         do {
             // DEBUG A/B lever: PUNKTFUNK_BILINEAR_LUMA=1 compiles the shader with Catmull-Rom OFF
             // (plain bilinear luma) by prepending a #define ahead of the source. Default (unset) is
@@ -374,8 +408,18 @@ public final class MetalVideoPresenter {
             let planar = MTLRenderPipelineDescriptor()
             planar.vertexFunction = vtx
             planar.fragmentFunction = library.makeFunction(name: "pf_frag_planar")
-            planar.colorAttachments[0].pixelFormat = .bgra8Unorm // PyroWave is 8-bit SDR
+            planar.colorAttachments[0].pixelFormat = .bgra8Unorm
             pipelinePlanar = try device.makeRenderPipelineState(descriptor: planar)
+            let planarHdr = MTLRenderPipelineDescriptor()
+            planarHdr.vertexFunction = vtx
+            planarHdr.fragmentFunction = library.makeFunction(name: "pf_frag_planar")
+            planarHdr.colorAttachments[0].pixelFormat = .rgba16Float // PQ passthrough
+            pipelinePlanarHDR = try device.makeRenderPipelineState(descriptor: planarHdr)
+            let planarTm = MTLRenderPipelineDescriptor()
+            planarTm.vertexFunction = vtx
+            planarTm.fragmentFunction = library.makeFunction(name: "pf_frag_planar_tm")
+            planarTm.colorAttachments[0].pixelFormat = .bgra8Unorm
+            pipelinePlanarToneMap = try device.makeRenderPipelineState(descriptor: planarTm)
         } catch {
             return nil
         }
@@ -416,6 +460,7 @@ public final class MetalVideoPresenter {
         return MetalVideoPresenter(
             device: device, queue: queue, pipelineSDR: pipelineSDR, pipelineHDR: pipelineHDR,
             pipelineHDRToneMap: pipelineHDRToneMap, pipelinePlanar: pipelinePlanar,
+            pipelinePlanarHDR: pipelinePlanarHDR, pipelinePlanarToneMap: pipelinePlanarToneMap,
             textureCache: textureCache, layer: layer)
     }
 
@@ -423,6 +468,8 @@ public final class MetalVideoPresenter {
         device: MTLDevice, queue: MTLCommandQueue, pipelineSDR: MTLRenderPipelineState,
         pipelineHDR: MTLRenderPipelineState, pipelineHDRToneMap: MTLRenderPipelineState?,
         pipelinePlanar: MTLRenderPipelineState,
+        pipelinePlanarHDR: MTLRenderPipelineState,
+        pipelinePlanarToneMap: MTLRenderPipelineState,
         textureCache: CVMetalTextureCache, layer: CAMetalLayer
     ) {
         self.device = device
@@ -431,6 +478,8 @@ public final class MetalVideoPresenter {
         self.pipelineHDR = pipelineHDR
         self.pipelineHDRToneMap = pipelineHDRToneMap
         self.pipelinePlanar = pipelinePlanar
+        self.pipelinePlanarHDR = pipelinePlanarHDR
+        self.pipelinePlanarToneMap = pipelinePlanarToneMap
         self.textureCache = textureCache
         self.layer = layer
     }
@@ -652,7 +701,13 @@ public final class MetalVideoPresenter {
         let surfaceMode = surfacePresentsStaged
         #endif
         stagingLock.unlock()
-        configure(hdr: false)
+        // A PQ (HDR) pyrowave stream drives the same layer/EDR machinery as the biplanar path;
+        // macOS WINDOWED sessions stay on the SDR layer (the IOSurface path tone-maps in-shader).
+        #if os(macOS)
+        configure(hdr: planes.pq && !surfaceMode)
+        #else
+        configure(hdr: planes.pq)
+        #endif
         var csc = planes.csc
         #if os(macOS)
         if surfaceMode != surfacePresentsActive {
@@ -672,9 +727,21 @@ public final class MetalVideoPresenter {
                 planes, targetFromLayout: targetFromLayout, csc: &csc, onPresented: onPresented)
         }
         #endif
+        // PQ passthrough needs the HDR drawable; a PQ frame while the drawable is (still)
+        // 8-bit — tvOS without display headroom, or a not-yet-flipped layer — tone-maps
+        // in-shader instead (the pipeline must match the drawable's pixel format).
+        #if os(tvOS)
+        let planarPassthrough = hdrActive && hdrPassthroughActive
+        #else
+        let planarPassthrough = hdrActive
+        #endif
+        let planarPipeline: MTLRenderPipelineState =
+            planes.pq
+                ? (planarPassthrough ? pipelinePlanarHDR : pipelinePlanarToneMap)
+                : pipelinePlanar
         return encodePresent(
             decodedSize: CGSize(width: planes.width, height: planes.height),
-            targetFromLayout: targetFromLayout, pipeline: pipelinePlanar,
+            targetFromLayout: targetFromLayout, pipeline: planarPipeline,
             presentAtMediaTime: presentAtMediaTime, onPresented: onPresented,
             // The ring textures stay valid by ring depth; retaining them here also pins the
             // slot's set until the sample completes (mirrors the biplanar keep-alive).
@@ -716,7 +783,7 @@ public final class MetalVideoPresenter {
         guard let encoder = commandBuffer.makeRenderCommandEncoder(descriptor: pass) else {
             return false
         }
-        encoder.setRenderPipelineState(pipelinePlanar)
+        encoder.setRenderPipelineState(planes.pq ? pipelinePlanarToneMap : pipelinePlanar)
         encoder.setFragmentTexture(planes.y, index: 0)
         encoder.setFragmentTexture(planes.cb, index: 1)
         encoder.setFragmentTexture(planes.cr, index: 2)

clients/apple/Sources/PunktfunkKit/Video/MetalWaveletDecoder.swift

@@ -47,6 +47,9 @@ struct WaveletLayout {
 
     let width: Int
     let height: Int
+    /// Full-res chroma (4:4:4): chroma components get the full band set including level 0,
+    /// exactly like luma — upstream `init_block_meta` with `Chroma444`.
+    let chroma444: Bool
     let alignedWidth: Int
     let alignedHeight: Int
     /// blockMeta[component][level][band] = (blockOffset32x32, blockStride32x32); -1 offset =
@@ -59,9 +62,10 @@ struct WaveletLayout {
     func levelWidth(_ level: Int) -> Int { (alignedWidth / 2) >> level }
     func levelHeight(_ level: Int) -> Int { (alignedHeight / 2) >> level }
 
-    init(width: Int, height: Int) {
+    init(width: Int, height: Int, chroma444: Bool) {
         self.width = width
         self.height = height
+        self.chroma444 = chroma444
         let align = { (v: Int) in
             max((v + Self.alignment - 1) & ~(Self.alignment - 1), Self.minimumImageSize)
         }
@@ -78,7 +82,7 @@ struct WaveletLayout {
         let ah = alignedHeight
         for level in stride(from: Self.decompositionLevels - 1, through: 0, by: -1) {
             for component in 0..<3 {
-                if level == 0 && component != 0 { continue } // 4:2:0: no top-level chroma
+                if level == 0 && component != 0 && !chroma444 { continue } // 4:2:0: no top-level chroma
                 for band in (level == Self.decompositionLevels - 1 ? 0 : 1)..<4 {
                     let levelW = (aw / 2) >> level
                     let levelH = (ah / 2) >> level
@@ -108,6 +112,9 @@ struct ParsedWaveletFrame {
     var decodedBlocks: Int
     /// VUI bits from the sequence header (BitstreamSequenceHeader).
     var bt2020: Bool
+    /// PQ transfer ⇒ HDR session: 16-bit studio-code planes + EDR present (the host stamps
+    /// this bit iff the session negotiated 10-bit — the depth is coupled to the transfer).
+    var pq: Bool
     var fullRange: Bool
 
     /// The frame's Y′CbCr→RGB signal for the presenter's planar CSC. PyroWave today is always
@@ -203,6 +210,7 @@ enum WaveletBitstream {
         var totalBlocks = 0
         var decodedBlocks = 0
         var bt2020 = false
+        var pq = false
         var fullRange = false
         var sawSOF = false
 
@@ -220,22 +228,28 @@ enum WaveletBitstream {
                     // siting[31].
                     let code = (word1 >> 24) & 0x3
                     guard code == 0 else { return false } // only START_OF_FRAME is defined
-                    let chromaRes = (word1 >> 26) & 1
+                    let chroma444 = (word1 >> 26) & 1 != 0
-                    guard chromaRes == 0 else { return false } // host contract: 4:2:0
                     let w = Int(word0 & 0x3fff) + 1
                     let h = Int((word0 >> 14) & 0x3fff) + 1
-                    guard w >= 2, h >= 2, w % 2 == 0, h % 2 == 0 else { return false }
+                    guard w >= 2, h >= 2, chroma444 || (w % 2 == 0 && h % 2 == 0) else {
+                        return false
+                    }
                     if sawSOF {
                         // One frame, one geometry — a second SOF must agree.
-                        guard layout?.width == w, layout?.height == h else { return false }
+                        guard layout?.width == w, layout?.height == h,
+                              layout?.chroma444 == chroma444
+                        else { return false }
                     } else {
                         sawSOF = true
-                        let l = WaveletLayout(width: w, height: h)
+                        let l = WaveletLayout(width: w, height: h, chroma444: chroma444)
                         layout = l
                         offsets = [UInt32](repeating: .max, count: l.blockCount32)
                         payload.reserveCapacity(64 * 1024 / 4)
                         totalBlocks = Int(word1 & 0xff_ffff)
                         bt2020 = (word1 >> 29) & 1 != 0
+                        // transfer_function bit: PQ ⇒ an HDR session (16-bit studio-code
+                        // planes by the negotiated coupling — design/pyrowave-444-hdr.md).
+                        pq = (word1 >> 28) & 1 != 0
                         fullRange = (word1 >> 30) & 1 == 0 // YCBCR_RANGE_FULL = 0
                     }
                     pos += 8
@@ -280,7 +294,7 @@ enum WaveletBitstream {
             return ParsedWaveletFrame(
                 layout: layout, offsets: offsets, payload: payload,
                 totalBlocks: totalBlocks, decodedBlocks: decodedBlocks,
-                bt2020: bt2020, fullRange: fullRange)
+                bt2020: bt2020, pq: pq, fullRange: fullRange)
         }
     }
 }
@@ -293,6 +307,8 @@ public struct WaveletPlanes: @unchecked Sendable {
     public let cb: MTLTexture
     public let cr: MTLTexture
     public let csc: CscUniform
+    /// PQ (HDR) stream: the presenter picks the HDR/tone-map planar pipeline + EDR config.
+    public let pq: Bool
     public var width: Int { y.width }
     public var height: Int { y.height }
 }
@@ -351,6 +367,8 @@ public final class MetalWaveletDecoder {
 
     private var slots: [Slot] = []
     private var nextSlot = 0
+    /// The ring's plane format facts (from the last SOF): PQ ⇒ 16-bit UNORM planes.
+    private var hdr16 = false
 
     /// The current geometry (from the last SOF that built the resources) — the pump reports
     /// decoded-size changes to the resize overlay from this. PUMP THREAD.
@@ -409,8 +427,9 @@ public final class MetalWaveletDecoder {
                 au: au, chunkAligned: chunkAligned, windowSize: windowSize)
         else { return false }
 
-        if layout?.width != frame.layout.width || layout?.height != frame.layout.height {
+        if layout?.width != frame.layout.width || layout?.height != frame.layout.height
-            guard rebuild(layout: frame.layout) else { return false }
+            || layout?.chroma444 != frame.layout.chroma444 || hdr16 != frame.pq {
+            guard rebuild(layout: frame.layout, hdr16: frame.pq) else { return false }
         }
         guard let layout, !slots.isEmpty else { return false }
 
@@ -450,7 +469,7 @@ public final class MetalWaveletDecoder {
         dequant.setBuffer(slot.payload, offset: 0, index: 1)
         for level in 0..<WaveletLayout.decompositionLevels {
             for component in 0..<3 {
-                if level == 0 && component != 0 { continue } // 4:2:0
+                if level == 0 && component != 0 && !layout.chroma444 { continue } // 4:2:0
                 for band in (level == WaveletLayout.decompositionLevels - 1 ? 0 : 1)..<4 {
                     let meta = layout.blockMeta[component][level][band]
                     let w = layout.levelWidth(level)
@@ -489,15 +508,20 @@ public final class MetalWaveletDecoder {
             let grid = MTLSize(width: (rx + 15) / 16, height: (ry + 15) / 16, depth: 1)
             let group = MTLSize(width: 64, height: 1, depth: 1)
             if inputLevel == 0 {
-                // 4:2:0: the final full-res pass is luma only (chroma finished at level 1).
+                // Final full-res pass: luma only in 4:2:0 (chroma finished at level 1); all
+                // three components in 4:4:4 (chroma runs the full pyramid like luma).
                 idwt.setComputePipelineState(idwtShiftPipeline)
-                idwt.setTexture(coefficients[0][0], index: 0)
+                let components = layout.chroma444 ? 3 : 1
-                idwt.setTexture(slot.y, index: 1)
+                for component in 0..<components {
+                    idwt.setTexture(coefficients[component][0], index: 0)
+                    let out = component == 0 ? slot.y : (component == 1 ? slot.cb : slot.cr)
+                    idwt.setTexture(out, index: 1)
                     idwt.dispatchThreadgroups(grid, threadsPerThreadgroup: group)
+                }
             } else {
                 for component in 0..<3 {
                     idwt.setTexture(coefficients[component][inputLevel], index: 0)
-                    if component != 0 && inputLevel == 1 {
+                    if component != 0 && inputLevel == 1 && !layout.chroma444 {
                         // 4:2:0 chroma emits its final half-res plane one level early.
                         idwt.setComputePipelineState(idwtShiftPipeline)
                         idwt.setTexture(component == 1 ? slot.cb : slot.cr, index: 1)
@@ -513,7 +537,9 @@ public final class MetalWaveletDecoder {
 
         let planes = WaveletPlanes(
             y: slot.y, cb: slot.cb, cr: slot.cr,
-            csc: CscRows.rows(frame.cscSignal, depth: 8, msbPacked: false))
+            csc: CscRows.rows(
+                frame.cscSignal, depth: frame.pq ? 10 : 8, msbPacked: frame.pq),
+            pq: frame.pq)
         cmd.addCompletedHandler { buffer in
             completion(buffer.error == nil ? planes : nil)
         }
@@ -524,9 +550,9 @@ public final class MetalWaveletDecoder {
 
     /// (Re)allocate every size-dependent resource for `layout`'s geometry. Also the mid-stream
     /// resize path: a Reconfigure shows up here as new SOF dims.
-    private func rebuild(layout newLayout: WaveletLayout) -> Bool {
+    private func rebuild(layout newLayout: WaveletLayout, hdr16 newHdr16: Bool) -> Bool {
         waveletLog.info(
-            "pyrowave: building decoder \(newLayout.width)x\(newLayout.height) (aligned \(newLayout.alignedWidth)x\(newLayout.alignedHeight), \(newLayout.blockCount32) blocks)")
+            "pyrowave: building decoder \(newLayout.width)x\(newLayout.height) (aligned \(newLayout.alignedWidth)x\(newLayout.alignedHeight), \(newLayout.blockCount32) blocks, \(newLayout.chroma444 ? "4:4:4" : "4:2:0", privacy: .public)\(newHdr16 ? " HDR16" : "", privacy: .public))")
         var coeff: [[MTLTexture]] = []
         var lls: [[MTLTexture]] = []
         for component in 0..<3 {
@@ -560,19 +586,22 @@ public final class MetalWaveletDecoder {
 
         var newSlots: [Slot] = []
         for i in 0..<Self.ringDepth {
+            let planeFormat: MTLPixelFormat = newHdr16 ? .r16Unorm : .r8Unorm
             let plane = { (w: Int, h: Int, name: String) -> MTLTexture? in
                 let desc = MTLTextureDescriptor.texture2DDescriptor(
-                    pixelFormat: .r8Unorm, width: w, height: h, mipmapped: false)
+                    pixelFormat: planeFormat, width: w, height: h, mipmapped: false)
                 desc.usage = [.shaderRead, .shaderWrite]
                 desc.storageMode = .private
                 let t = self.device.makeTexture(descriptor: desc)
                 t?.label = name
                 return t
             }
+            let cw = newLayout.chroma444 ? newLayout.width : newLayout.width / 2
+            let ch = newLayout.chroma444 ? newLayout.height : newLayout.height / 2
             guard
                 let y = plane(newLayout.width, newLayout.height, "pyrowave Y[\(i)]"),
-                let cb = plane(newLayout.width / 2, newLayout.height / 2, "pyrowave Cb[\(i)]"),
+                let cb = plane(cw, ch, "pyrowave Cb[\(i)]"),
-                let cr = plane(newLayout.width / 2, newLayout.height / 2, "pyrowave Cr[\(i)]"),
+                let cr = plane(cw, ch, "pyrowave Cr[\(i)]"),
                 let offsets = device.makeBuffer(
                     length: max(newLayout.blockCount32 * 4, 4), options: .storageModeShared),
                 let payload = device.makeBuffer(length: 64 * 1024, options: .storageModeShared)
@@ -585,6 +614,7 @@ public final class MetalWaveletDecoder {
         slots = newSlots
         nextSlot = 0
         layout = newLayout
+        hdr16 = newHdr16
         return true
     }
 

clients/apple/Tests/PunktfunkKitTests/PyroWaveDecoderTests.swift

@@ -57,7 +57,7 @@ final class PyroWaveParserTests: XCTestCase {
     func testLayoutMatchesUpstreamBlockSpace() {
         // init_block_meta's walk for 256x144 (aligned 256x160): level extents halve from
         // 128x80; per (comp,level,band) count32 = ceil(ceil(w/8)/4) * ceil(ceil(h/8)/4).
-        let layout = WaveletLayout(width: width, height: height)
+        let layout = WaveletLayout(width: width, height: height, chroma444: false)
         XCTAssertEqual(layout.alignedWidth, 256)
         XCTAssertEqual(layout.alignedHeight, 160)
         XCTAssertEqual(layout.levelWidth(0), 128)
@@ -85,7 +85,7 @@ final class PyroWaveParserTests: XCTestCase {
     }
 
     func testDenseParseFillsOffsetsAndCountsBlocks() throws {
-        let layout = WaveletLayout(width: width, height: height)
+        let layout = WaveletLayout(width: width, height: height, chroma444: false)
         var au = sof(totalBlocks: 4)
         au += packet(blockIndex: 0)
         au += packet(blockIndex: 3)
@@ -273,6 +273,17 @@ final class PyroWaveGoldenTests: XCTestCase {
         try assertMatchesReference(decoded, prefix: "ref-chunked")
     }
 
+    /// 4:4:4: the chroma components run the full pyramid like luma (no level-0 skip, no
+    /// early half-res emit) — the layout + dispatch structure Phase 4 added
+    /// (design/pyrowave-444-hdr.md). The fixture comes from the 4:4:4 host encoder; the
+    /// reference is upstream's own 4:4:4 decode (full-res chroma planes).
+    func testDense444GoldenFrame() throws {
+        try XCTSkipIf(!MetalWaveletDecoder.supported, "no capable Metal device")
+        let au = try fixture("au-dense444")
+        let decoded = try decode(au: au, chunkAligned: false, windowSize: 0)
+        try assertMatchesReference(decoded, prefix: "ref-dense444")
+    }
+
     /// Phase-4 partial delivery: zero a mid-AU window (a lost shard) — the frame must still
     /// decode (blocks > half) and stay recognizably the same picture (holes reconstruct as
     /// localized blur, not garbage).

docs-site/content/docs/pyrowave.md

@@ -36,11 +36,14 @@ Bandwidth. At the codec's ~1.6 bits-per-pixel operating point (4:2:0, 60 fps):
 | 2560×1440 @ 60 | ≈ 355 Mbps |
 | 3840×2160 @ 60 | ≈ 800 Mbps |
 
-120 Hz doubles these. Gigabit Ethernet tops out around 940 Mbps of payload, so 4K60 wants
+120 Hz doubles these, 4:4:4 multiplies them by ~1.6, and an HDR (10-bit) session adds ~15 %.
-2.5GbE (or a lower rate). **Do not run this over Wi-Fi** — that's what HEVC/AV1 are for.
+Gigabit Ethernet tops out around 940 Mbps of payload, so 4K60 wants 2.5GbE (or a lower
+rate). **Do not run this over Wi-Fi** — that's what HEVC/AV1 are for.
 
-Also: PyroWave is **8-bit SDR only**. An HDR session stays on HEVC/AV1 regardless of this
+PyroWave follows the same 4:4:4 and HDR settings as HEVC/AV1: a session negotiates
-setting.
+full-chroma 4:4:4 when your client's 4:4:4 setting is on, and HDR (BT.2020 PQ, carried in
+16-bit planes) when the host's display pipeline is HDR — currently the Windows host only
+(the Linux host's capture path has no HDR source yet, so Linux-hosted sessions are SDR).
 
 ## Turning it on
 
@@ -53,10 +56,10 @@ setting.
      gamepad console, or launch with `PUNKTFUNK_PREFER_PYROWAVE=1`.
    - Apple (Mac, Apple TV 4K, iPad — wired networking strongly recommended): set
      **Settings → Codec → PyroWave (wired LAN)**. The option appears only on devices whose
-     GPU passes the decode probe (Apple Silicon and A13-class or newer); picking it forces
+     GPU passes the decode probe (Apple Silicon and A13-class or newer). The decoder follows
-     the session SDR.
+     the stream: 4:2:0 or 4:4:4, SDR or HDR, per what the session negotiated.
 3. Leave the bitrate on Automatic: a PyroWave session pins itself to the ~1.6 bpp rate for
-   your mode (≈200 Mbps at 1080p60). An explicit bitrate is honored if you set one, but the
+   your mode (≈200 Mbps at 1080p60; ~2.6 bpp for 4:4:4, +15 % for HDR). An explicit bitrate is honored if you set one, but the
    adaptive-bitrate controller stays off either way — this codec has no useful low-rate
    regime, so under sustained loss the right move is switching back to HEVC, not degrading.
    The pin follows the resolution: a mid-stream resize (e.g. Match window) re-pins the rate
@@ -66,7 +69,6 @@ The stats overlay shows `pyrowave` as the decode path when the mode is active.
 
 ## Current limits
 
-- Linux host + Linux client (including docked Deck) and Apple clients (native Metal decode
+- Linux and Windows hosts; Linux clients (including docked Deck) and Apple clients (native
-  on Mac / Apple TV 4K / iPad) today; the Windows host is tracked on the
+  Metal decode on Mac / Apple TV 4K / iPad) today.
-  [roadmap](/docs/roadmap).
+- HDR needs a Windows host (the Linux host's capture path has no HDR source yet).
-- 8-bit SDR, 4:2:0 only.