feat(linux/vulkan-encode): default-on native NV12 capture + RGB true-extent

Flip both zero-copy levers from opt-in to default:

- The capture negotiation now PREFERS gamescope's producer-side NV12 pod by
  default (PUNKTFUNK_PIPEWIRE_NV12=0 restores the packed-RGB negotiation).
  Codec-aware gating rides a new OutputFormat::nv12_native ->
  ZeroCopyPolicy::native_nv12_session edge resolved by the host facade from
  the session plan (pf_encode::linux_native_nv12_ok): only H265/AV1 sessions
  whose backend can open the raw Vulkan Video encoder ever see the NV12 pod
  -- an H264/Moonlight session (libav VAAPI, which would misread the
  two-plane buffer) keeps today's BGRx negotiation, as do the
  GameStream-resolve and portal-mirror paths, PyroWave, and NVENC prefs.
- RGB-direct's unaligned modes default to the true-extent direct import
  (PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT=0 restores the padded-copy staging).
  Guarded-tested on Van Gogh with the kernel journal watched: clean, and at
  5.38 ms p50 the fastest 1080p encode path measured on that hardware. The
  EFC only exists on Mesa >= 26, where the codedExtent-driven session_init
  padding is guaranteed (verified back to Mesa 24.2).

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

crates/pf-capture/src/lib.rs

@@ -259,6 +259,12 @@ pub struct ZeroCopyPolicy {
     /// passthrough (like the VAAPI backend) instead of the EGL→CUDA import whose payloads only
     /// NVENC can consume. Per-session (the codec is negotiated), unlike `backend_is_vaapi`.
     pub pyrowave_session: bool,
+    /// THIS session's encoder can ingest a producer-native NV12 capture (the Linux raw Vulkan
+    /// Video backend on an H265/AV1 session — resolved by the host facade via
+    /// `pf_encode::linux_native_nv12_ok`). Gates whether the negotiation PREFERS gamescope's
+    /// producer-side NV12 pod: libav VAAPI (H264's backend) would misread the two-plane buffer,
+    /// so H264/GameStream/PyroWave sessions must never see NV12 frames.
+    pub native_nv12_session: bool,
     /// The PyroWave encoder's Vulkan-importable dmabuf modifiers for the capture's packed-RGB fourcc,
     /// resolved when the session encodes PyroWave (the passthrough advertises them so Mutter+NVIDIA,
     /// which allocates tiled-only, still negotiates zero-copy). Empty otherwise.

crates/pf-capture/src/linux/mod.rs

@@ -2086,22 +2086,26 @@ mod pipewire {
         // PyroWave session (the wavelet encoder's own Vulkan device, any vendor) → hand the raw
         // dmabuf straight to the encoder.
         let vaapi_passthrough = zerocopy && !force_shm && importer.is_none() && raw_passthrough;
-        // Bring-up gate for producer-side NV12. Gamescope offers a one-fd LINEAR NV12 image when
-        // the consumer asks for it; keep this opt-in until the live Vulkan import path is proven.
-        // Raw passthrough is required because CUDA/PyroWave expect packed RGB, and 4:4:4/HDR must
-        // not be silently subsampled/downconverted.
-        let prefer_native_nv12 = std::env::var("PUNKTFUNK_PIPEWIRE_NV12").as_deref() == Ok("1")
+        // Producer-side NV12 (default-on; PUNKTFUNK_PIPEWIRE_NV12=0 escapes): gamescope offers a
+        // one-fd LINEAR NV12 image when the consumer asks — its compositor pass does the RGB→YUV,
+        // and the Vulkan Video encoder imports the buffer as its encode source directly (no host
+        // CSC at all). `native_nv12_session` restricts this to sessions whose encoder can ingest
+        // it (Linux vulkan-encode H265/AV1 — never H264/libav-VAAPI, GameStream-resolve, or
+        // PyroWave, whose Vulkan compute CSC ingests packed RGB only). Raw passthrough is
+        // required because the CUDA importer expects packed RGB, and 4:4:4/HDR must not be
+        // silently subsampled/downconverted. Non-NV12 compositors (KWin/GNOME) simply match the
+        // packed-RGB fallback pod.
+        let prefer_native_nv12 = std::env::var("PUNKTFUNK_PIPEWIRE_NV12").as_deref() != Ok("0")
+            && policy.native_nv12_session
             && backend_is_vaapi
             && vaapi_passthrough
-            // PyroWave rides the same raw passthrough but its Vulkan compute CSC ingests packed
-            // RGB only — native NV12 would feed it an unreadable two-plane image.
             && !policy.pyrowave_session
             && !want_444
             && !want_hdr;
         if prefer_native_nv12 {
             tracing::info!(
-                "PUNKTFUNK_PIPEWIRE_NV12=1: preferring gamescope producer-side NV12 LINEAR \
-                 DMA-BUF (no host RGB CSC)"
+                "zero-copy: preferring gamescope producer-side NV12 LINEAR DMA-BUF (no host \
+                 RGB CSC; PUNKTFUNK_PIPEWIRE_NV12=0 restores the packed-RGB negotiation)"
             );
         }
         // Modifiers our import stack handles for BGRx: the EGL-importable (tiled) set, plus LINEAR

crates/pf-encode/src/enc/linux/vulkan_video.rs

@@ -84,13 +84,14 @@ fn rgb_request() -> Option<bool> {
     }
 }
 
-/// `PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT=1` (bring-up): at unaligned modes, replace RGB-direct's
-/// padded-copy staging with a direct import carrying the TRUE-SIZE source `codedExtent` — RADV
-/// derives nonzero VCN firmware padding from it, so the EFC is told the source lacks the
-/// alignment rows (see [`RgbDirect::true_extent`]). Off by default until the EFC front-end is
-/// proven to honor the padding like the YUV fetch path does.
+/// True-extent RGB-direct at unaligned modes (default ON; `PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT=0`
+/// restores the padded-copy staging): direct-import the visible-size capture with the TRUE-SIZE
+/// source `codedExtent` — RADV derives nonzero VCN firmware padding from it, so the EFC is told
+/// the source lacks the alignment rows (see [`RgbDirect::true_extent`]). Guarded-tested on Van
+/// Gogh 2026-07-21 (kernel clean, and the fastest 1080p encode path measured); the EFC only
+/// exists on Mesa ≥ 26, where the `codedExtent`-driven `session_init` is guaranteed.
 fn rgb_true_extent_request() -> bool {
-    std::env::var("PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT").as_deref() == Ok("1")
+    std::env::var("PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT").as_deref() != Ok("0")
 }
 
 /// Live RGB-direct session config: the chroma-siting bits the session was created with
@@ -105,13 +106,13 @@ struct RgbDirect {
     /// with the edge rows/columns duplicated into the padding (transfer-only, no shader) and
     /// encoded from there. Aligned modes keep the true zero-copy import.
     padded: bool,
-    /// `PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT=1` bring-up alternative to `padded` at unaligned
-    /// modes: direct-import the visible-size buffer and pass the TRUE-SIZE source
+    /// The default unaligned-mode source strategy (`PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT=0` falls
+    /// back to `padded`): direct-import the visible-size buffer and pass the TRUE-SIZE source
     /// `codedExtent` — RADV then programs nonzero firmware padding from it (Mesa ≥ 24.2
     /// derives `session_init` padding from `srcPictureResource.codedExtent`; see
     /// [`VulkanVideoEncoder::native_nv12`]), telling the VCN the source lacks the alignment
-    /// rows. The session/SPS/DPB stay app-aligned. Field-proven for YUV fetches; the EFC RGB
-    /// front-end honoring the padding is what this gate exists to prove.
+    /// rows, which the hardware edge-extends internally. The session/SPS/DPB stay app-aligned.
+    /// Guarded-tested on Van Gogh (kernel clean; fastest 1080p path measured).
     true_extent: bool,
 }
 
@@ -696,7 +697,7 @@ impl VulkanVideoEncoder {
                     ) =>
                         "active(true-extent: unaligned mode, direct import with the true-size \
                          source codedExtent — RADV firmware padding covers the alignment rows; \
-                         PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT bring-up)",
+                         PUNKTFUNK_VULKAN_RGB_TRUE_EXTENT=0 restores the padded copy)",
                     (_, _, Some(RgbDirect { padded: false, .. })) => "active",
                     (_, _, Some(RgbDirect { padded: true, .. })) =>
                         "active(padded-copy: mode is not 64x16-aligned — staging blit + edge \

crates/pf-encode/src/lib.rs

@@ -351,8 +351,8 @@ fn open_video_backend(
                     Err(e) if format == PixelFormat::Nv12 => {
                         return Err(e.context(
                             "Vulkan Video open failed on a native-NV12 capture \
-                             (PUNKTFUNK_PIPEWIRE_NV12=1) — no VAAPI fallback exists; unset the \
-                             flag to restore the packed-RGB pipeline",
+                             — no VAAPI fallback exists; set PUNKTFUNK_PIPEWIRE_NV12=0 to \
+                             restore the packed-RGB negotiation",
                         ));
                     }
                     Err(e) => tracing::warn!(
@@ -365,10 +365,10 @@ fn open_video_backend(
             // PUNKTFUNK_VULKAN_ENCODE=0, or a build without the feature).
             if format == PixelFormat::Nv12 {
                 anyhow::bail!(
-                    "native NV12 capture (PUNKTFUNK_PIPEWIRE_NV12=1) requires the Vulkan Video \
-                     encoder (HEVC/AV1 session, --features vulkan-encode, \
-                     PUNKTFUNK_VULKAN_ENCODE not 0) — this session resolved to libav VAAPI; \
-                     unset the flag"
+                    "native NV12 capture requires the Vulkan Video encoder (HEVC/AV1 \
+                     session, --features vulkan-encode, PUNKTFUNK_VULKAN_ENCODE not 0) — this \
+                     session resolved to libav VAAPI; set PUNKTFUNK_PIPEWIRE_NV12=0 to restore \
+                     the packed-RGB negotiation"
                 );
             }
             vaapi::VaapiEncoder::open(
@@ -841,6 +841,33 @@ fn vulkan_encode_enabled() -> bool {
         .unwrap_or(true)
 }
 
+/// Whether THIS session's encoder can ingest a producer-native NV12 capture: only the raw
+/// Vulkan Video backend does (libav VAAPI would misread the two-plane buffer as packed RGB —
+/// [`open_video`] refuses the combination), so the session's codec must be one it encodes and
+/// the backend must be eligible to open. The host facade threads the verdict into the capture
+/// negotiation (`OutputFormat::nv12_native` → `ZeroCopyPolicy::native_nv12_session`), which
+/// then PREFERS gamescope's producer-side NV12 pod (default-on; `PUNKTFUNK_PIPEWIRE_NV12=0`
+/// escapes at the capture gate).
+#[cfg(target_os = "linux")]
+pub fn linux_native_nv12_ok(codec: Codec) -> bool {
+    #[cfg(feature = "vulkan-encode")]
+    {
+        matches!(codec, Codec::H265 | Codec::Av1)
+            && vulkan_encode_enabled()
+            // NVENC/PyroWave prefs never open the Vulkan Video backend; every other pref
+            // (auto/vaapi/amd/intel/vulkan) tries it first on AMD/Intel — see [`open_video`].
+            && !matches!(
+                pf_host_config::config().encoder_pref.as_str(),
+                "nvenc" | "nvidia" | "cuda" | "pyrowave"
+            )
+    }
+    #[cfg(not(feature = "vulkan-encode"))]
+    {
+        let _ = codec;
+        false
+    }
+}
+
 /// Cheap, side-effect-free NVIDIA-presence probe for the `auto` backend selector: the NVIDIA
 /// kernel driver exposes these device nodes, AMD/Intel boxes have neither. Deliberately does NOT
 /// create a CUDA context (that would allocate GPU state on every host that merely *might* be

crates/pf-frame/src/lib.rs

@@ -146,6 +146,12 @@ pub struct OutputFormat {
     /// (never BGRA-passthrough / P010). `false` on every non-PyroWave session and on Linux (the
     /// wavelet encoder ingests dmabufs / CPU RGB there, not a D3D11 texture).
     pub pyrowave: bool,
+    /// THIS session's encoder can ingest a producer-native NV12 capture (Linux raw Vulkan Video
+    /// backend on an H265/AV1 session — see `pf_encode::linux_native_nv12_ok`). The Linux capture
+    /// negotiation only offers gamescope the NV12 pod when this is set: libav VAAPI (the H264
+    /// codec's backend, and the fallback family) would misread the two-plane buffer as packed
+    /// RGB. Always `false` on Windows (the IDD-push capturer owns its own formats).
+    pub nv12_native: bool,
 }
 
 impl OutputFormat {
@@ -163,6 +169,11 @@ impl OutputFormat {
             chroma_444: false,
             // GameStream never negotiates PyroWave (native punktfunk/1 only).
             pyrowave: false,
+            // Conservative: the GameStream + spike paths don't resolve the codec here, and a
+            // Moonlight client may negotiate H264 (whose VAAPI backend can't ingest NV12) — so
+            // they never prefer the producer-native NV12 pod. The punktfunk/1 plane opts in via
+            // `SessionPlan::output_format()`, which knows the codec.
+            nv12_native: false,
         }
     }
 }

crates/punktfunk-host/src/capture.rs

@@ -26,7 +26,10 @@ pub use pf_capture::{dxgi, synthetic_nv12};
 /// capture→encode cycle). Resolved here (the host facade) and threaded in, so the edge stays one-way
 /// (plan §2.4 / §W6).
 #[cfg(target_os = "linux")]
-fn zero_copy_policy(pyrowave_session: bool) -> pf_capture::ZeroCopyPolicy {
+fn zero_copy_policy(
+    pyrowave_session: bool,
+    native_nv12_session: bool,
+) -> pf_capture::ZeroCopyPolicy {
     let backend_is_vaapi = crate::encode::linux_zero_copy_is_vaapi();
     // The raw-dmabuf passthrough serves a PyroWave session on ANY vendor (the wavelet encoder's
     // own Vulkan device imports the dmabuf) — per-session from the negotiated codec, plus the
@@ -56,6 +59,7 @@ fn zero_copy_policy(pyrowave_session: bool) -> pf_capture::ZeroCopyPolicy {
         backend_is_gpu: crate::encode::resolved_backend_is_gpu(),
         pyrowave_session,
         pyrowave_modifiers,
+        native_nv12_session,
     }
 }
 
@@ -70,7 +74,9 @@ pub fn open_portal_monitor(want_hdr: bool) -> Result<Box<dyn Capturer>> {
     let anchored = crate::inject::default_backend() == crate::inject::Backend::Libei;
     // Monitor mirrors never carry the native PyroWave plane (GameStream protocol) — per-session
     // passthrough is virtual-output-only; the global encoder-pref lever still applies inside.
-    pf_capture::open_portal_monitor(anchored, want_hdr, zero_copy_policy(false))
+    // Native NV12 stays off too: the mirror path doesn't resolve the codec here, and the desktop
+    // compositors it mirrors (GNOME/KWin) don't produce NV12 anyway.
+    pf_capture::open_portal_monitor(anchored, want_hdr, zero_copy_policy(false, false))
 }
 
 #[cfg(not(target_os = "linux"))]
@@ -101,7 +107,7 @@ pub fn capture_virtual_output(
         vout.keepalive,
         want.gpu,
         want.chroma_444,
-        zero_copy_policy(want.pyrowave),
+        zero_copy_policy(want.pyrowave, want.nv12_native),
     )
 }
 

crates/punktfunk-host/src/session_plan.rs

@@ -179,6 +179,13 @@ impl SessionPlan {
             // Vulkan device; on Linux the capture facade flips the zero-copy policy to the
             // raw-dmabuf passthrough (see above).
             pyrowave: self.codec == crate::encode::Codec::PyroWave,
+            // Producer-native NV12 (gamescope) is consumable only by the Linux Vulkan Video
+            // backend — resolved HERE from the plan's codec so the capturer never reaches back
+            // into encode (the same one-way edge as `gpu` above).
+            #[cfg(target_os = "linux")]
+            nv12_native: crate::encode::linux_native_nv12_ok(self.codec),
+            #[cfg(not(target_os = "linux"))]
+            nv12_native: false,
         }
     }
 }