2cc1310752
The 1080p DMA-BUF pipeline crashed the user's entire Hyprland session tonight. Root cause identified: hyprwm/Hyprland PR #15167 (fixed 2026-06-18, first shipped v0.56.0) -- CGLRenderbuffer's destructor unconditionally dereferences m_framebuffer, which is left null when createEGLImage() fails to import the DMA-BUF. This machine runs v0.55.4, a week before the fix. The crash happens inside Hyprland's own Screenshare::CScreenshareFrame::copyDmabuf(), confirmed against the coredump; it is not a breadcast, GStreamer, or PipeWire bug, and it is not resolution-dependent (upstream's own reports span unrelated triggers -- touchpad gestures, tab switching, a Discord stream -- not capture geometry), so 1080p vs 720p was never the actual variable. choose_capture_backend() now reads the running compositor's version over its own IPC socket and only uses the DMA-BUF path on Hyprland >= 0.56.0 (or non-Hyprland sessions, unaffected by this bug). Below that, or if the version can't be determined, it falls back to the plain system-memory/wl_shm pipeline -- slower and still subject to xdg-desktop-portal-hyprland's separate "Out of buffers" stall bug (also confirmed via journalctl, and also not fixed in the installed xdpw 1.3.12), but that failure mode is a stall, not a compositor-wide abort. That stall used to be silent forever: xdpw stops requesting frames after 10 failed retries and never signals PipeWire, so GStreamer's own bus reports nothing -- no error, no EOS -- and the frame pump just blocks. pull_encoded_frame now bails after 10s of a Playing pipeline producing nothing, converting an indefinite silent freeze into a real, reported session failure (still correctly distinguishing a genuine stall from ordinary EOS/teardown, so a normal stop() doesn't trip it). VideoParams is no longer a hand-synced constant: build_video_pipeline_for_streaming now returns the geometry/frame-rate it actually chose alongside the pipeline, and both breadcastd::cast_mirror and cast_stream_test thread that straight into the OFFER instead of a separately-maintained default. Keeping two copies in sync by hand is exactly how the resolution mismatch bug happened earlier tonight; returning the real value makes that class of bug unrepresentable rather than just fixed once. Verified without touching the real compositor: cargo build --workspace --examples, clippy, and both new unit tests (version parsing, the 0.55.4/0.56.0 backend-selection boundary) are clean. The watchdog's firing path and the DMA-BUF path post-Hyprland-update are not yet validated against real hardware -- deliberately, given what the last live test cost. Recommended order: update Hyprland (pacman -Syu hyprland xdg-desktop-portal-hyprland gets 0.56.1 + xdpw 1.4.1, which also picks up upstream fixes for the exact copy-fence and SHM-handling bugs hit tonight) and confirm `hyprctl version` reports >= 0.56.0 before testing DMA-BUF again. Without updating, this commit still helps: the wl_shm path is selected automatically and the stall is now bounded instead of indefinite. |
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| .forgejo/workflows | ||
| breadcast | ||
| breadcast-caststream-sys | ||
| breadcast-core | ||
| breadcastd | ||
| ci | ||
| contrib | ||
| graphify-out | ||
| vendor/rust_cast-0.21.0 | ||
| .gitignore | ||
| AGENTS.md | ||
| bakery.toml | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CONTRIBUTING.md | ||
| EVENTS.md | ||
| LICENSE | ||
| README.md | ||
breadcast
Cast your screen to a Chromecast, Google TV, or DLNA renderer on the LAN. Two binaries:
breadcastd— background daemon. Discovers Cast (mDNS) and DLNA/UPnP (SSDP) devices, owns the portal screen-capture / encode pipeline, and runs the live session: Cast Streaming (vendored openscreen) or DLNA/AVTransport. One active session at a time.breadcast— GTK4 Layer Shell popup. Thin IPC client ofbreadcastd: pick a device, start or stop a cast. Closing the popup does not interrupt an active session.
This is a bakery product. It is not shipped on the BOS ISO and is not part of the default desktop — install it yourself if you want it.
Install
bakery install breadcast
That puts breadcast and breadcastd on $PATH (usually ~/.local/bin),
installs contrib/breadcastd.service as a systemd user unit, enables it,
and starts the daemon. bakery doctor breadcast checks the system
packages listed in bakery.toml first.
Requirements
- A Wayland compositor with Layer Shell and
xdg-desktop-portalScreenCast (Hyprland is the primary target) - GTK 4.12+ and
gtk4-layer-shell - GStreamer plus
gst-plugin-pipewire,gst-plugins-bad,gst-plugin-va(vah264enc), andgst-plugin-hlssink3 jsoncppandopenssl(runtime deps of the vendored Cast Streaming code)
From source you also need a Rust toolchain (edition 2021).
Build from source
git clone https://git.breadway.dev/Breadway/breadcast
cd breadcast
cargo build --release
Binaries land at target/release/breadcast and target/release/breadcastd.
cp target/release/breadcast target/release/breadcastd ~/.local/bin/
cp contrib/breadcastd.service ~/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now breadcastd
Usage
Start the daemon (or let the systemd unit handle it):
breadcastd
Open the device picker:
breadcast
Running breadcast again while it is open closes it (toggle). Click a
device to start mirroring — the portal picker asks which screen to share.
Stop mirroring ends the session. Status is Idle or Casting.
Discovery examples (optional, for debugging the LAN):
cargo run -p breadcast-core --example discover
cargo run -p breadcast-core --example dlna_discover
Hyprland keybind
On stock Hyprland, add the contents of contrib/hyprland.conf to your
hyprland.conf if you want Super+C and the frosted-glass blur:
layerrule = blur, breadcast
layerrule = ignorezero, breadcast
bind = $mainMod, C, exec, breadcast
BOS does not ship this app or a default keybind for it. Add one yourself if you install breadcast on a BOS machine.
bread event integration
breadcastd works the same with or without breadd. When breadd is
running, it publishes bread.cast.* and honors bread.command.cast.*.
See EVENTS.md for the bus contract. bread is not a bakery
dependency.
Theming
breadcast inherits its colour palette from bread-theme.