rename: lumen → punktfunk, everywhere
ci / rust (push) Has been cancelled

Full project rename, decided 2026-06-10:
- Crates/binaries: punktfunk-core / punktfunk-host / punktfunk-client-rs.
- C ABI: punktfunk_* symbols, Punktfunk* types, include/punktfunk_core.h,
  PUNKTFUNK_FEATURE_QUIC guard (header regenerated; cbindgen renames updated, incl.
  PUNKTFUNK_BTN_*/PUNKTFUNK_AXIS_* wire constants).
- Protocol: punktfunk/1 — control-plane magic LMN1 → PKF1, nonce salt lmn1 → pkf1.
  WIRE BREAK: clients must be rebuilt from this revision.
- Env knobs: PUNKTFUNK_VIDEO_SOURCE / PUNKTFUNK_COMPOSITOR / PUNKTFUNK_ZEROCOPY / ….
- Host config dir: ~/.config/punktfunk (the box's dir was migrated in place — the
  persistent identity is unchanged, pinned fingerprints stay valid).
- Swift package: PunktfunkKit + PunktfunkCore.xcframework + PunktfunkConnection
  (Sources/PunktfunkClient app + tests renamed with it); build-xcframework.sh updated.
- scripts/: 60-punktfunk.rules, punktfunk-host.service; OpenAPI doc regenerated.

Also: scripts/headless/run-headless-kde.sh — full headless Plasma bringup. Root cause of
"desktop but no apps/settings" over the stream: plasmashell launched without
XDG_MENU_PREFIX=plasma-, so the launcher resolved a nonexistent applications.menu and
rendered an empty menu. The script sets the complete KDE session env (menu prefix,
KDE_FULL_SESSION, session version) and rebuilds ksycoca before starting plasmashell.

Gate: 97/97 tests, clippy -D warnings (both feature sets), fmt, C-ABI harness PASS,
zero lumen references left outside .git.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-06-10 13:11:59 +00:00
parent b8b23c8fb2
commit bfd64ce871
119 changed files with 1245 additions and 1185 deletions
+963
View File
@@ -0,0 +1,963 @@
//! Live capture: xdg ScreenCast portal (`ashpd`) → PipeWire (`pipewire`), CPU-copy path.
//!
//! Two dedicated threads, because both stacks are tied to their thread:
//! * **portal thread** drives the async ashpd handshake on a multi-thread tokio runtime
//! (control plane — never the per-frame path), then parks on a pending future so the
//! `proxy` + its zbus connection stay alive (the cast is torn down when that connection
//! drops; ashpd's `Session` has no `Drop`);
//! * **pipewire thread** owns the (`!Send`) MainLoop/Stream and pumps frames.
//!
//! The portal hands the PipeWire remote fd + node id to the pipewire thread; decoded BGRx
//! frames leave the pipewire thread over a bounded channel. The authoritative frame size
//! comes from the negotiated PipeWire format, not the portal's size hint.
//!
//! Cleanup note (M0): the two threads are detached and torn down at process exit. A
//! graceful stop (pipewire `channel` quit + Session close) belongs with the M2 session
//! lifecycle.
use super::{CapturedFrame, Capturer, FramePayload, PixelFormat};
use anyhow::{anyhow, Context, Result};
use std::os::fd::OwnedFd;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::mpsc::{sync_channel, Receiver, RecvTimeoutError, TryRecvError};
use std::sync::Arc;
use std::thread;
use std::time::Duration;
/// Live monitor capturer backed by the portal + PipeWire threads. Kept alive (reused) across
/// streams — [`set_active`](Capturer::set_active) gates the per-frame de-pad copy so it costs
/// almost nothing between streams while the screencast session stays up (instant reconnect,
/// and no second session to conflict with).
pub struct PortalCapturer {
frames: Receiver<CapturedFrame>,
active: Arc<AtomicBool>,
/// Owns the virtual output (if this capturer was built from one) — dropped when the capturer
/// is, releasing the compositor-side output via the keepalive's own `Drop`. `None` for the
/// portal source (its session ends with the portal thread's zbus connection).
_keepalive: Option<Box<dyn Send>>,
}
impl PortalCapturer {
/// `anchored` drives ScreenCast off a RemoteDesktop session (KWin/GNOME) so it inherits the
/// RemoteDesktop grant and never raises a separate ScreenCast dialog; `false` uses a plain
/// ScreenCast session (wlroots, which has no RemoteDesktop portal).
pub fn open(anchored: bool) -> Result<PortalCapturer> {
// Portal handshake (async) on its own thread; hands back the PW fd + node id.
let (setup_tx, setup_rx) = std::sync::mpsc::channel::<Result<(OwnedFd, u32), String>>();
thread::Builder::new()
.name("punktfunk-portal".into())
.spawn(move || {
if anchored {
portal_thread_remote_desktop(setup_tx)
} else {
portal_thread(setup_tx)
}
})
.context("spawn portal thread")?;
let (fd, node_id) = match setup_rx.recv_timeout(Duration::from_secs(20)) {
Ok(Ok(v)) => v,
Ok(Err(e)) => return Err(anyhow!("ScreenCast portal setup failed: {e}")),
Err(_) => return Err(anyhow!("timed out waiting for the ScreenCast portal")),
};
tracing::info!(
node_id,
"ScreenCast portal session started; connecting PipeWire"
);
let (frames, active) = spawn_pipewire(Some(fd), node_id, None)?;
Ok(PortalCapturer {
frames,
active,
_keepalive: None,
})
}
/// Build a capturer from an already-created virtual output ([`crate::vdisplay::VirtualOutput`]):
/// connect PipeWire to its node (`remote_fd` selects portal-remote vs. default-daemon) and
/// take ownership of its keepalive so the output lives exactly as long as this capturer. This
/// is how the client's requested resolution becomes the captured resolution without scaling.
pub fn from_virtual_output(vout: crate::vdisplay::VirtualOutput) -> Result<PortalCapturer> {
tracing::info!(
node_id = vout.node_id,
"connecting PipeWire to virtual output"
);
let (frames, active) = spawn_pipewire(vout.remote_fd, vout.node_id, vout.preferred_mode)?;
Ok(PortalCapturer {
frames,
active,
_keepalive: Some(vout.keepalive),
})
}
}
/// Spawn the PipeWire consumer thread for `node_id` (fd `Some` = portal remote, `None` =
/// default daemon) and return the frame channel + the activation flag it gates on.
/// `preferred` seeds the format negotiation's default size/framerate — for Mutter virtual
/// monitors this is what actually sizes the monitor.
fn spawn_pipewire(
fd: Option<OwnedFd>,
node_id: u32,
preferred: Option<(u32, u32, u32)>,
) -> Result<(Receiver<CapturedFrame>, Arc<AtomicBool>)> {
// Frames flow from the pipewire thread over a small bounded channel.
let (frame_tx, frame_rx) = sync_channel::<CapturedFrame>(8);
let active = Arc::new(AtomicBool::new(false));
let active_cb = active.clone();
let zerocopy = crate::zerocopy::enabled();
thread::Builder::new()
.name("punktfunk-pipewire".into())
.spawn(move || {
if let Err(e) =
pipewire::pipewire_thread(fd, node_id, frame_tx, active_cb, zerocopy, preferred)
{
tracing::error!(error = %format!("{e:#}"), "pipewire capture thread failed");
}
})
.context("spawn pipewire thread")?;
Ok((frame_rx, active))
}
impl Capturer for PortalCapturer {
fn next_frame(&mut self) -> Result<CapturedFrame> {
// First frame can lag behind format negotiation; later frames arrive at ~fps.
match self.frames.recv_timeout(Duration::from_secs(10)) {
Ok(frame) => Ok(frame),
Err(RecvTimeoutError::Timeout) => Err(anyhow!("no PipeWire frame within 10s")),
Err(RecvTimeoutError::Disconnected) => Err(anyhow!("PipeWire capture thread ended")),
}
}
fn try_latest(&mut self) -> Result<Option<CapturedFrame>> {
// Drain to the newest queued frame without blocking; `None` means the compositor
// hasn't produced a new frame since last call (static/idle desktop).
let mut latest = None;
loop {
match self.frames.try_recv() {
Ok(frame) => latest = Some(frame),
Err(TryRecvError::Empty) => break,
Err(TryRecvError::Disconnected) => {
return Err(anyhow!("PipeWire capture thread ended"))
}
}
}
Ok(latest)
}
fn set_active(&self, active: bool) {
self.active.store(active, Ordering::Relaxed);
}
}
/// The portal handshake: connect ScreenCast, select a single monitor, start, open the
/// PipeWire remote, hand the fd + node id back, then keep the session alive.
fn portal_thread(setup_tx: std::sync::mpsc::Sender<Result<(OwnedFd, u32), String>>) {
use ashpd::desktop::screencast::{CursorMode, Screencast, SelectSourcesOptions, SourceType};
use ashpd::desktop::PersistMode;
use ashpd::enumflags2::BitFlags;
// Multi-thread runtime: the zbus connection's background reader must be pumped
// continuously across the create_session → select_sources → start handshake, or the
// portal reports "Invalid session". (A current-thread runtime starves it.)
let rt = match tokio::runtime::Builder::new_multi_thread()
.worker_threads(2)
.enable_all()
.build()
{
Ok(rt) => rt,
Err(e) => {
let _ = setup_tx.send(Err(format!("build tokio runtime: {e}")));
return;
}
};
let err_tx = setup_tx.clone();
rt.block_on(async move {
let result: Result<()> = async {
let proxy = Screencast::new()
.await
.context("connect ScreenCast portal")?;
let session = proxy
.create_session(Default::default())
.await
.context("create_session")?;
proxy
.select_sources(
&session,
SelectSourcesOptions::default()
.set_cursor_mode(CursorMode::Embedded)
// Only MONITOR is offered by the wlroots backend
// (AvailableSourceTypes=1); requesting unsupported types
// invalidates the session.
.set_sources(BitFlags::from_flag(SourceType::Monitor))
.set_multiple(false)
.set_persist_mode(PersistMode::DoNot),
)
.await
.context("select_sources")?
.response()
.context("select_sources rejected (unsupported source type / cursor mode?)")?;
let streams = proxy
.start(&session, None, Default::default())
.await
.context("start cast")?
.response()
.context("start response (chooser cancelled? portal misconfigured?)")?;
let stream = streams
.streams()
.first()
.context("portal returned no streams")?
.clone();
let node_id = stream.pipe_wire_node_id();
let fd = proxy
.open_pipe_wire_remote(&session, Default::default())
.await
.context("open_pipe_wire_remote")?;
setup_tx
.send(Ok((fd, node_id)))
.map_err(|_| anyhow!("capturer dropped before setup completed"))?;
// Keep `proxy` + `session` (and the underlying zbus connection) alive for the
// capture; the cast is torn down when the connection drops (ashpd's `Session`
// has no `Drop`), which here happens at process exit.
let _keep_alive = (&proxy, &session);
std::future::pending::<()>().await;
Ok(())
}
.await;
if let Err(e) = result {
let _ = err_tx.send(Err(format!("{e:#}")));
}
});
}
/// Combined RemoteDesktop+ScreenCast portal setup (KWin/GNOME). ScreenCast sources are selected
/// on a session created via RemoteDesktop, so a single RemoteDesktop `start` grant —
/// pre-authorized headlessly via the `kde-authorized` permission, exactly like the libei input
/// path — also covers screen capture, with no separate ScreenCast dialog (which has no such
/// bypass). Yields the same PipeWire fd + node id as the standalone path; the consumer is
/// identical.
fn portal_thread_remote_desktop(setup_tx: std::sync::mpsc::Sender<Result<(OwnedFd, u32), String>>) {
use ashpd::desktop::remote_desktop::{DeviceType, RemoteDesktop, SelectDevicesOptions};
use ashpd::desktop::screencast::{CursorMode, Screencast, SelectSourcesOptions, SourceType};
use ashpd::desktop::PersistMode;
use ashpd::enumflags2::BitFlags;
let rt = match tokio::runtime::Builder::new_multi_thread()
.worker_threads(2)
.enable_all()
.build()
{
Ok(rt) => rt,
Err(e) => {
let _ = setup_tx.send(Err(format!("build tokio runtime: {e}")));
return;
}
};
let err_tx = setup_tx.clone();
rt.block_on(async move {
let result: Result<()> = async {
let remote = RemoteDesktop::new()
.await
.context("connect RemoteDesktop portal")?;
let screencast = Screencast::new()
.await
.context("connect ScreenCast portal")?;
let session = remote
.create_session(Default::default())
.await
.context("create RemoteDesktop session")?;
// RemoteDesktop requires a device selection; we never connect_to_eis on this session
// (input injection runs its own), but selecting devices is what makes `start` the
// RemoteDesktop grant the kde-authorized bypass covers.
remote
.select_devices(
&session,
SelectDevicesOptions::default()
.set_devices(DeviceType::Keyboard | DeviceType::Pointer)
.set_persist_mode(PersistMode::DoNot),
)
.await
.context("select_devices")?
.response()
.context("select_devices rejected")?;
screencast
.select_sources(
&session,
SelectSourcesOptions::default()
.set_cursor_mode(CursorMode::Embedded)
.set_sources(BitFlags::from_flag(SourceType::Monitor))
.set_multiple(false)
.set_persist_mode(PersistMode::DoNot),
)
.await
.context("select_sources")?
.response()
.context("select_sources rejected (unsupported source type?)")?;
let streams = remote
.start(&session, None, Default::default())
.await
.context("start RemoteDesktop+ScreenCast")?
.response()
.context("start response (grant not pre-authorized / headless dialog?)")?;
let stream = streams
.streams()
.first()
.context("portal returned no screencast streams")?
.clone();
let node_id = stream.pipe_wire_node_id();
let fd = screencast
.open_pipe_wire_remote(&session, Default::default())
.await
.context("open_pipe_wire_remote")?;
setup_tx
.send(Ok((fd, node_id)))
.map_err(|_| anyhow!("capturer dropped before setup completed"))?;
// Keep the proxies + session (and their zbus connection) alive for the capture.
let _keep_alive = (&remote, &screencast, &session);
std::future::pending::<()>().await;
Ok(())
}
.await;
if let Err(e) = result {
let _ = err_tx.send(Err(format!("{e:#}")));
}
});
}
mod pipewire {
//! The PipeWire consumer, confined to its own thread (the PW types are `!Send`).
use super::{CapturedFrame, FramePayload, PixelFormat};
use anyhow::{Context, Result};
use pipewire as pw;
use pw::{properties::properties, spa};
use std::os::fd::OwnedFd;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::mpsc::SyncSender;
use std::sync::Arc;
use std::time::{SystemTime, UNIX_EPOCH};
use spa::param::video::{VideoFormat, VideoInfoRaw};
use spa::pod::Pod;
/// Map a negotiated SPA video format to a layout the encoder can consume. Returns
/// `None` for formats we don't handle (the frame is then skipped).
fn map_format(f: VideoFormat) -> Option<PixelFormat> {
Some(match f {
VideoFormat::BGRx => PixelFormat::Bgrx,
VideoFormat::RGBx => PixelFormat::Rgbx,
VideoFormat::BGRA => PixelFormat::Bgra,
VideoFormat::RGBA => PixelFormat::Rgba,
VideoFormat::RGB => PixelFormat::Rgb,
VideoFormat::BGR => PixelFormat::Bgr,
_ => return None,
})
}
struct UserData {
info: VideoInfoRaw,
/// Negotiated layout (`None` until param_changed, or if unsupported).
format: Option<PixelFormat>,
/// Negotiated DRM format modifier (for dmabuf import); 0 = LINEAR.
modifier: u64,
tx: SyncSender<CapturedFrame>,
/// When false (no active stream), skip the de-pad copy — the buffer is just released.
active: Arc<AtomicBool>,
/// Present when zero-copy is enabled: imports a dmabuf → CUDA device buffer.
importer: Option<crate::zerocopy::EglImporter>,
}
/// Log a frame-drop reason once per process (the process callback runs per frame; a stuck
/// pipeline must say why without flooding).
fn warn_once(msg: &'static str) {
use std::sync::Mutex;
static SEEN: Mutex<Vec<&'static str>> = Mutex::new(Vec::new());
let mut seen = SEEN.lock().unwrap();
if !seen.contains(&msg) {
seen.push(msg);
tracing::warn!("{msg}");
}
}
/// A read-only mmap of a dmabuf fd, unmapped on drop. Used when MAP_BUFFERS didn't map the
/// buffer (producers don't always flag dmabufs mappable, e.g. gamescope's Vulkan exports).
struct DmabufMap {
ptr: *mut std::ffi::c_void,
len: usize,
}
impl DmabufMap {
fn new(fd: i32, len: usize) -> Option<DmabufMap> {
let ptr = unsafe {
libc::mmap(
std::ptr::null_mut(),
len,
libc::PROT_READ,
libc::MAP_SHARED,
fd,
0,
)
};
(ptr != libc::MAP_FAILED).then_some(DmabufMap { ptr, len })
}
}
impl Drop for DmabufMap {
fn drop(&mut self) {
unsafe {
libc::munmap(self.ptr, self.len);
}
}
}
fn serialize_pod(obj: pw::spa::pod::Object) -> Result<Vec<u8>> {
Ok(pw::spa::pod::serialize::PodSerializer::serialize(
std::io::Cursor::new(Vec::new()),
&pw::spa::pod::Value::Object(obj),
)
.context("serialize pod")?
.0
.into_inner())
}
/// Build a BGRx dmabuf `EnumFormat` pod advertising the EGL-importable `modifiers` as a
/// mandatory enum Choice; the compositor fixates to one of them that it can allocate, which
/// we read back in `param_changed`.
fn build_dmabuf_format(
modifiers: &[u64],
preferred: Option<(u32, u32, u32)>,
) -> Result<Vec<u8>> {
let (dw, dh, dhz) = preferred.unwrap_or((1920, 1080, 60));
use pw::spa::param::format::{FormatProperties, MediaSubtype, MediaType};
let mut obj = pw::spa::pod::object!(
pw::spa::utils::SpaTypes::ObjectParamFormat,
pw::spa::param::ParamType::EnumFormat,
pw::spa::pod::property!(FormatProperties::MediaType, Id, MediaType::Video),
pw::spa::pod::property!(FormatProperties::MediaSubtype, Id, MediaSubtype::Raw),
pw::spa::pod::property!(FormatProperties::VideoFormat, Id, VideoFormat::BGRx),
pw::spa::pod::property!(
FormatProperties::VideoSize,
Choice,
Range,
Rectangle,
pw::spa::utils::Rectangle {
width: dw,
height: dh
},
pw::spa::utils::Rectangle {
width: 1,
height: 1
},
pw::spa::utils::Rectangle {
width: 8192,
height: 8192
}
),
pw::spa::pod::property!(
FormatProperties::VideoFramerate,
Choice,
Range,
Fraction,
pw::spa::utils::Fraction { num: dhz, denom: 1 },
pw::spa::utils::Fraction { num: 0, denom: 1 },
pw::spa::utils::Fraction { num: 240, denom: 1 }
),
);
obj.properties.push(pw::spa::pod::Property {
key: pw::spa::sys::SPA_FORMAT_VIDEO_modifier,
flags: pw::spa::pod::PropertyFlags::MANDATORY,
value: pw::spa::pod::Value::Choice(pw::spa::pod::ChoiceValue::Long(
pw::spa::utils::Choice(
pw::spa::utils::ChoiceFlags::empty(),
pw::spa::utils::ChoiceEnum::Enum {
default: modifiers[0] as i64,
alternatives: modifiers.iter().map(|&m| m as i64).collect(),
},
),
)),
});
serialize_pod(obj)
}
/// The default (shm/CPU-path) format offer: raw video in any encoder-mappable layout, any
/// size, any framerate (0/1 = variable allowed — gamescope fixates exactly that).
fn build_default_format_obj(preferred: Option<(u32, u32, u32)>) -> pw::spa::pod::Object {
let (dw, dh, dhz) = preferred.unwrap_or((1920, 1080, 60));
pw::spa::pod::object!(
pw::spa::utils::SpaTypes::ObjectParamFormat,
pw::spa::param::ParamType::EnumFormat,
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::MediaType,
Id,
pw::spa::param::format::MediaType::Video
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::MediaSubtype,
Id,
pw::spa::param::format::MediaSubtype::Raw
),
// Offer the layouts the encoder can map to an NVENC input format. wlroots
// commonly fixates packed RGB (3 bpp); other compositors offer 4 bpp. Only
// these are requested, so negotiation fails loudly rather than handing us a
// format we'd misinterpret.
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::VideoFormat,
Choice,
Enum,
Id,
VideoFormat::RGB,
VideoFormat::RGB,
VideoFormat::BGR,
VideoFormat::RGBx,
VideoFormat::BGRx,
VideoFormat::RGBA,
VideoFormat::BGRA,
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::VideoSize,
Choice,
Range,
Rectangle,
pw::spa::utils::Rectangle {
width: dw,
height: dh
},
pw::spa::utils::Rectangle {
width: 1,
height: 1
},
pw::spa::utils::Rectangle {
width: 8192,
height: 8192
}
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::VideoFramerate,
Choice,
Range,
Fraction,
pw::spa::utils::Fraction { num: dhz, denom: 1 },
pw::spa::utils::Fraction { num: 0, denom: 1 },
pw::spa::utils::Fraction { num: 240, denom: 1 }
),
)
}
/// Build a Buffers param for the CPU path accepting anything mappable: MemPtr, MemFd, and
/// DmaBuf. The DmaBuf bit matters for producers like gamescope whose format intersection
/// lands on their modifier-bearing (LINEAR) pod: they then offer *only* DmaBuf buffers, and
/// without this bit the buffer-type intersection is empty and the link silently stalls in
/// "negotiating". A LINEAR dmabuf is mmap-able by MAP_BUFFERS, so the CPU de-pad copy works.
fn build_mappable_buffers() -> Result<Vec<u8>> {
serialize_pod(pw::spa::pod::Object {
type_: pw::spa::utils::SpaTypes::ObjectParamBuffers.as_raw(),
id: pw::spa::param::ParamType::Buffers.as_raw(),
properties: vec![pw::spa::pod::Property {
key: pw::spa::sys::SPA_PARAM_BUFFERS_dataType,
flags: pw::spa::pod::PropertyFlags::empty(),
value: pw::spa::pod::Value::Int(
(1i32 << pw::spa::sys::SPA_DATA_MemPtr)
| (1i32 << pw::spa::sys::SPA_DATA_MemFd)
| (1i32 << pw::spa::sys::SPA_DATA_DmaBuf),
),
}],
})
}
/// Build a Buffers param requesting dmabuf-only buffers.
fn build_dmabuf_buffers() -> Result<Vec<u8>> {
serialize_pod(pw::spa::pod::Object {
type_: pw::spa::utils::SpaTypes::ObjectParamBuffers.as_raw(),
id: pw::spa::param::ParamType::Buffers.as_raw(),
properties: vec![pw::spa::pod::Property {
key: pw::spa::sys::SPA_PARAM_BUFFERS_dataType,
flags: pw::spa::pod::PropertyFlags::empty(),
value: pw::spa::pod::Value::Int(1i32 << pw::spa::sys::SPA_DATA_DmaBuf),
}],
})
}
pub fn pipewire_thread(
fd: Option<OwnedFd>,
node_id: u32,
tx: SyncSender<CapturedFrame>,
active: Arc<AtomicBool>,
zerocopy: bool,
preferred: Option<(u32, u32, u32)>,
) -> Result<()> {
crate::pwinit::ensure_init();
let mainloop = pw::main_loop::MainLoopRc::new(None).context("pw MainLoop")?;
let context = pw::context::ContextRc::new(&mainloop, None).context("pw Context")?;
// A portal source hands us an fd to a (sandboxed) PipeWire remote; the KWin
// virtual-output source has no fd — its node lives on the user's default daemon.
let core = match fd {
Some(fd) => context
.connect_fd_rc(fd, None)
.context("pw connect_fd (portal remote)")?,
None => context
.connect_rc(None)
.context("pw connect (default daemon)")?,
};
// Build the EGL→CUDA importer up front; if it fails, log and fall back to the CPU path
// (we simply won't request dmabuf below).
let importer = if zerocopy {
match crate::zerocopy::EglImporter::new() {
Ok(i) => Some(i),
Err(e) => {
tracing::warn!(error = %format!("{e:#}"), "zero-copy import unavailable — using CPU path");
None
}
}
} else {
None
};
// Modifiers our import stack handles for BGRx: the EGL-importable (tiled) set, plus
// LINEAR (0) — NVIDIA's EGL won't list it, but LINEAR dmabufs (gamescope's only offer)
// import via CUDA external memory instead. Tiled stays first so allocators that can do
// both (KWin) prefer it. If none, we can't negotiate dmabuf → shm path.
let mut modifiers = importer
.as_ref()
.map(|i| i.supported_modifiers(crate::zerocopy::drm_fourcc(PixelFormat::Bgrx).unwrap()))
.unwrap_or_default();
if importer.is_some() && !modifiers.contains(&0) {
modifiers.push(0); // DRM_FORMAT_MOD_LINEAR
}
let want_dmabuf = importer.is_some() && !modifiers.is_empty();
if zerocopy && !want_dmabuf {
tracing::warn!("zero-copy: no EGL-importable dmabuf modifiers — using CPU path");
} else if want_dmabuf {
tracing::info!(
count = modifiers.len(),
sample = ?&modifiers[..modifiers.len().min(6)],
"zero-copy: advertising EGL-importable dmabuf modifiers"
);
}
let data = UserData {
info: VideoInfoRaw::default(),
format: None,
modifier: 0,
tx,
active,
importer,
};
let stream = pw::stream::StreamBox::new(
&core,
"punktfunk-screencast",
properties! {
*pw::keys::MEDIA_TYPE => "Video",
*pw::keys::MEDIA_CATEGORY => "Capture",
*pw::keys::MEDIA_ROLE => "Screen",
// Never let the session manager re-target this stream to a different node when
// its target goes away: an orphaned stream auto-linked to a fresh Video/Source
// wedges that node — and a stuck link head-blocks the PipeWire daemon's shared
// work queue, stalling ALL new link negotiation system-wide.
"node.dont-reconnect" => "true",
},
)
.context("pw Stream")?;
let _listener = stream
.add_local_listener_with_user_data(data)
.state_changed(|_stream, _ud, old, new| {
tracing::info!(?old, ?new, "pipewire stream state");
})
.param_changed(|_stream, ud, id, param| {
let Some(param) = param else { return };
if id != pw::spa::param::ParamType::Format.as_raw() {
return;
}
let Ok((media_type, media_subtype)) =
pw::spa::param::format_utils::parse_format(param)
else {
return;
};
if media_type != pw::spa::param::format::MediaType::Video
|| media_subtype != pw::spa::param::format::MediaSubtype::Raw
{
return;
}
if ud.info.parse(param).is_ok() {
let sz = ud.info.size();
ud.format = map_format(ud.info.format());
ud.modifier = ud.info.modifier();
tracing::info!(
width = sz.width,
height = sz.height,
spa_format = ?ud.info.format(),
mapped = ?ud.format,
modifier = ud.modifier,
"pipewire format negotiated"
);
if ud.format.is_none() {
tracing::error!(
spa_format = ?ud.info.format(),
"negotiated a pixel format the encoder cannot consume — frames will be skipped"
);
}
}
})
.process(|stream, ud| {
// PipeWire dispatches this from a C trampoline with no catch_unwind; a
// panic crossing that FFI boundary would abort the whole host. Contain it.
let outcome = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
let Some(mut buffer) = stream.dequeue_buffer() else {
return;
};
// No active stream: release the buffer without the (expensive at 5K) de-pad.
if !ud.active.load(Ordering::Relaxed) {
return;
}
let datas = buffer.datas_mut();
if datas.is_empty() {
return;
}
let sz = ud.info.size();
let (w, h) = (sz.width as usize, sz.height as usize);
if w == 0 || h == 0 {
return; // format not negotiated yet
}
// Zero-copy path: if the buffer is a dmabuf and we have an importer, import it
// into a CUDA device buffer (no CPU touch) and deliver that. Otherwise fall
// through to the shm de-pad copy below.
let mut gpu_import_broken = false;
if let (Some(importer), Some(fmt)) = (ud.importer.as_mut(), ud.format) {
if datas[0].type_() == pw::spa::buffer::DataType::DmaBuf {
let plane = crate::zerocopy::DmabufPlane {
fd: datas[0].fd(),
offset: datas[0].chunk().offset(),
stride: datas[0].chunk().stride().max(0) as u32,
};
// Tiled modifier → EGL/GL de-tile import; LINEAR (0/unset, e.g.
// gamescope) → direct CUDA external-memory import (NVIDIA EGL can't
// sample LINEAR).
let modifier = (ud.modifier != 0).then_some(ud.modifier);
if let Some(fourcc) = crate::zerocopy::drm_fourcc(fmt) {
let imported = if modifier.is_some() {
importer.import(&plane, w as u32, h as u32, fourcc, modifier)
} else {
importer.import_linear(&plane, w as u32, h as u32)
};
match imported {
Ok(devbuf) => {
static ONCE: std::sync::atomic::AtomicBool =
std::sync::atomic::AtomicBool::new(true);
if ONCE.swap(false, Ordering::Relaxed) {
tracing::info!(w, h, modifier = ud.modifier,
"zero-copy: dmabuf imported to CUDA (no CPU copy)");
}
let pts_ns = SystemTime::now()
.duration_since(UNIX_EPOCH)
.map(|d| d.as_nanos() as u64)
.unwrap_or(0);
let _ = ud.tx.try_send(CapturedFrame {
width: w as u32,
height: h as u32,
pts_ns,
format: fmt,
payload: FramePayload::Cuda(devbuf),
});
return;
}
Err(e) => {
// GPU import unavailable for this buffer kind (e.g. the
// driver rejects LINEAR external-memory import). Disable
// the importer and fall through to the CPU mmap path —
// degraded, not dead.
tracing::warn!(error = %format!("{e:#}"),
"dmabuf GPU import failed — falling back to the CPU copy path");
gpu_import_broken = true;
}
}
} else {
return; // format has no DRM fourcc mapping — skip the frame
}
}
}
if gpu_import_broken {
ud.importer = None;
}
let d = &mut datas[0];
// CPU path may also receive LINEAR dmabufs (gamescope offers only those once its
// modifier-bearing format pod wins); capture the fd before `data()` borrows `d`.
let dmabuf_fd =
(d.type_() == pw::spa::buffer::DataType::DmaBuf).then(|| d.fd());
let (size, offset, stride) = {
let c = d.chunk();
(
c.size() as usize,
c.offset() as usize,
c.stride().max(0) as usize,
)
};
let Some(fmt) = ud.format else { return }; // unsupported/not negotiated
let bpp = fmt.bytes_per_pixel();
let row = w * bpp;
let stride = if stride == 0 { row } else { stride };
if stride < row {
warn_once("chunk stride < row — frames dropped");
return;
}
let needed = stride * (h - 1) + row;
// dmabuf chunks commonly report size 0; fall back to the computed span.
let size = if size == 0 { needed } else { size };
// MAP_BUFFERS only maps buffers flagged mappable; Vulkan-exported dmabufs
// (gamescope) usually aren't, so mmap the fd ourselves for the de-pad read.
let _mapping; // keeps a manual mmap alive for the copy below
let buf: &[u8] = if let Some(data) = d.data() {
data
} else if let Some(fd) = dmabuf_fd.filter(|&fd| fd > 0) {
match DmabufMap::new(fd, offset + needed) {
Some(m) => {
_mapping = m;
unsafe {
std::slice::from_raw_parts(_mapping.ptr as *const u8, _mapping.len)
}
}
None => {
warn_once("mmap(dmabuf) failed — frames dropped");
return;
}
}
} else {
warn_once("buffer has no mappable data — frames dropped");
return;
};
// Need stride*(h-1)+row valid bytes within [offset, offset+size).
if offset > buf.len() {
return;
}
let avail = buf.len() - offset;
if needed > avail || needed > size {
warn_once("buffer smaller than frame span — frames dropped");
return;
}
let region = &buf[offset..offset + size.min(avail)];
// De-pad into a tightly-packed buffer (chunk stride may exceed w*bpp).
let mut tight = vec![0u8; row * h];
for y in 0..h {
tight[y * row..y * row + row]
.copy_from_slice(&region[y * stride..y * stride + row]);
}
let pts_ns = SystemTime::now()
.duration_since(UNIX_EPOCH)
.map(|d| d.as_nanos() as u64)
.unwrap_or(0);
let frame = CapturedFrame {
width: w as u32,
height: h as u32,
pts_ns,
format: fmt,
payload: FramePayload::Cpu(tight),
};
// Drop if the encoder is behind — never block the pipewire loop.
let _ = ud.tx.try_send(frame);
}));
if outcome.is_err() {
tracing::error!("panic in pipewire process callback — frame dropped");
}
})
.register()
.context("register stream listener")?;
// Debug knob: offer a single fixed format (PUNKTFUNK_PW_FIXED_POD="WxH") to bisect
// negotiation failures against a producer's exact EnumFormat (e.g. gamescope).
let fixed_pod: Option<(u32, u32)> = std::env::var("PUNKTFUNK_PW_FIXED_POD")
.ok()
.and_then(|v| v.split_once('x').map(|(w, h)| (w.parse(), h.parse())))
.and_then(|(w, h)| Some((w.ok()?, h.ok()?)));
// Request raw video in any encoder-mappable layout, any size/framerate.
let obj = if let Some((fw, fh)) = fixed_pod {
tracing::info!(fw, fh, "PW DEBUG: offering fixed BGRx pod");
pw::spa::pod::object!(
pw::spa::utils::SpaTypes::ObjectParamFormat,
pw::spa::param::ParamType::EnumFormat,
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::MediaType,
Id,
pw::spa::param::format::MediaType::Video
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::MediaSubtype,
Id,
pw::spa::param::format::MediaSubtype::Raw
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::VideoFormat,
Id,
VideoFormat::BGRx
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::VideoSize,
Rectangle,
pw::spa::utils::Rectangle {
width: fw,
height: fh
}
),
pw::spa::pod::property!(
pw::spa::param::format::FormatProperties::VideoFramerate,
Fraction,
pw::spa::utils::Fraction { num: 0, denom: 1 }
),
)
} else {
build_default_format_obj(preferred)
};
// When zero-copy is on, offer ONLY a BGRx dmabuf format with our EGL-importable modifiers
// (offering shm too makes the compositor pick shm). The modifier list is advertised with
// DONT_FIXATE so the compositor's allocator chooses one; we re-emit the fixated format in
// `param_changed` (the two-step DMA-BUF handshake). Otherwise offer the multi-format shm
// pod and let MAP_BUFFERS map it.
let shm_values = serialize_pod(obj)?;
let (dmabuf_values, buffers_values) = if want_dmabuf {
(
Some(build_dmabuf_format(&modifiers, preferred)?),
Some(build_dmabuf_buffers()?),
)
} else {
// CPU path still accepts mappable dmabufs (gamescope offers only those once its
// modifier-bearing format pod wins the intersection).
(None, Some(build_mappable_buffers()?))
};
let mut byte_slices: Vec<&[u8]> = Vec::new();
match &dmabuf_values {
Some(d) => byte_slices.push(d),
None => byte_slices.push(&shm_values),
}
if let Some(b) = &buffers_values {
byte_slices.push(b);
}
let mut params: Vec<&Pod> = byte_slices
.iter()
.map(|&b| Pod::from_bytes(b).context("pod from bytes"))
.collect::<Result<_>>()?;
stream
.connect(
spa::utils::Direction::Input,
Some(node_id),
pw::stream::StreamFlags::AUTOCONNECT | pw::stream::StreamFlags::MAP_BUFFERS,
&mut params,
)
.context("pw stream connect")?;
// Blocks this thread, pumping frame callbacks until process exit.
mainloop.run();
Ok(())
}
}