fegger
7c04506dde
A headless receiver has no window manager, so a windowed window is meaningless there — the screencast should simply fill the screen. The renderer now goes borderless fullscreen automatically when SDL runs the KMSDRM backend, and --fullscreen forces the same behavior in desktop sessions. The video keeps its aspect ratio via SDL_SetRenderLogicalPresentation(LETTERBOX): a 4:3 desktop on a 16:9 TV renders with black bars instead of a stretched picture, the cursor is hidden, and the clear-before-draw keeps the bars black. Verified live on a 3440x1440 monitor: the --fullscreen receiver window covered the entire display while a 4:3 synthetic feed rendered with pure-black pillarbox bars (Y=0/SAT=0) and a saturated-red center (V=254). meson test 5/5 in both build configurations.
76 lines
2.3 KiB
Markdown
76 lines
2.3 KiB
Markdown
# screen_cast
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A native Linux peer-to-peer screencast application.
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- **Send** your desktop or a window to another Linux machine.
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- **Receive** a stream and render it in a window.
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- Discover receivers on the LAN via **mDNS/Avahi**; negotiate sessions with
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**JSON signaling**; stream **H.264 over RTP/UDP**.
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Built with **C++20**, **Meson**, **PipeWire**, **FFmpeg**, and **SDL3**.
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## Quick start
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Requirements:
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- C++20 compiler with `<format>` (GCC 13+, Clang 18+)
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- Meson >= 0.63, Ninja
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- FFmpeg development packages (`libavcodec`, `libavutil`, `libswscale`)
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- SDL3 development package (`sdl3`)
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- nlohmann JSON (`nlohmann_json`) and Avahi client (`avahi-client`)
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- For the sender only: PipeWire dev (`libpipewire-0.3`) and libportal
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Build and run tests:
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```sh
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meson setup build
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meson compile -C build
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meson test -C build --print-errorlogs
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```
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Stream between two machines:
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```sh
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screencast --receive # machine A: announces itself, opens a window
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screencast --send # machine B: discovers A, negotiates, streams
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```
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See `docs/RUNBOOK.md` for all modes, flags, and validation procedures.
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## Receiver on a small ARM board (e.g. Raspberry Pi Zero 2 W)
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The receiver does not need the sender's PipeWire/portal capture stack. On
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the board, run:
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```sh
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sudo ./scripts/install-receiver.sh
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screencast --receive
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```
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The script installs the dependencies, builds a receiver-only binary
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(`-Dsender=false`), runs the test suite, and installs to `/usr/local/bin`
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(override with `SC_RECEIVER_INSTALL_DIR`). It needs Raspberry Pi OS Trixie
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or newer (GCC 13+ for C++20 `<format>`), builds SDL3 from source when the
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distribution does not package it, and enables `avahi-daemon`. It also
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installs and enables a systemd service so the receiver starts at boot —
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`systemctl status screencast-receiver` to check on it.
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Performance note: decoding is software H.264; on very small boards expect
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smooth playback for modest resolutions and reduced frame rates at high
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resolutions. Hardware decode is planned for Phase 7. On a headless console
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the receiver runs fullscreen automatically with aspect-preserving
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letterboxing.
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## Architecture
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See `docs/ARCHITECTURE.md` for module boundaries and design rules.
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## Roadmap
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Development is split into phases in `docs/PHASES.md`.
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Current phase: **Phase 7 — Resilience and polish**.
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## License
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MIT — see `LICENSE` (to be added). |