feresaria/docs/screen-sharing.md

Screen sharing and recording

Share a monitor, workspace, or window from a Wayland-compatible recording or conferencing app, or save a video using the panel's Recording control. The installation guide covers the portal and PipeWire dependencies.

Record from the panel

1. Click the Recording item in the panel, or open Controls → Recording in Morph.
2. Choose a display and an audio source: Off, System sound, Microphone, or Both. Audio is off by default; the other choices use your default output or input device from audio settings.
3. Click Record to capture the whole display. For part of it, turn on Select a region, click Select region, then drag a rectangle inside the chosen display. Press Escape to cancel selection.
4. Click the stop square to finish.

The recorder saves WebM files with VP8 video and, when selected, Opus audio under Ferese in your XDG Videos folder, then shows the path in a notification. Region recordings cover a rectangle within one display; they cannot span displays. If recording fails, a notification reports the error and any unfinished .webm.part file.

Start sharing

Select a Wayland screen-sharing source in your application. In Ferese's picker, choose a display, workspace, or window and click Share. Nothing is selected initially. Apps requesting multiple sources can select up to eight.

A shared display includes everything visible on it, including notifications. Window sharing captures only the selected app's content and subsurfaces, even if the window is covered or on another workspace. It excludes separate popups and compositor decorations. Window streams preserve backing pixel density across the captured surface tree when it exceeds the display scale. For example, a 2× application buffer stays at 2× in the stream on a 1.75× display, avoiding a fractional downsample before the recording app scales it. The video size follows window resizes and backing buffer density changes; closing the window ends sharing. At fractional scales, clients can round the two backing dimensions separately. Capture preserves those pixel dimensions rather than adding a row or column by applying the larger axis density to both axes, which would soften text.

A shared workspace stays attached to its identity when you switch elsewhere. It includes that workspace's windows, their popups and decorations, and the wallpaper. It excludes desktop layers (including panels and notifications), overview, and windows protected by capture rules. Authentication windows are protected by default. Scrolling shares the workspace viewport, not the entire offscreen canvas. Capture does not activate the workspace, move focus, or resize hidden applications.

Workspace video fits a 1920 × 1080 bounding box (1080 × 1920 for portrait displays), preserving aspect ratio and avoiding upscaling. This bounds capture buffers even on a desktop using 2× scaling. The canvas is fixed for the session. Changing the source output's scale, transform, geometry, or workspace ownership ends sharing; select the workspace again. Removing the workspace or locking also ends sharing. Window blur and desktop transition effects are omitted from the workspace view.

Workspaces appear when an application requests display sharing. The portal exposes them as restricted views of an existing monitor using the standard MONITOR source type; it does not advertise a new workspace type or create a virtual display. Applications requesting only windows still see only windows. The panel recorder continues to select displays.

The picker follows your shell colors, font, corners, opacity, and blur.

Stop sharing

Click Stop sharing or close the sharing window. For the built-in recorder, use the panel's stop button, which Morph also shows while recording. Sharing also ends when the app closes or Ferese locks. If you disconnect a shared monitor or change its capture size, its stream ends and you need to start sharing again.

Remember permissions

When an app requests saved display permissions, the picker offers Allow without asking, off by default. Approval lasts for the duration requested by the app. The portal manages stored permissions and revocation.

A different app, changed display, or changed cursor option needs approval again. Nested previews and displays without a reliable identity always ask. Window and workspace permissions are not saved. Stopping a stream does not erase a saved permission.

Requirements and limits

Install PipeWire, WirePlumber, xdg-desktop-portal, and xdg-desktop-portal-gtk. The built-in recorder also needs GStreamer's PipeWire, base, and good plugins. Region selection needs slurp; audio recording needs PipeWire-Pulse or PulseAudio and the GStreamer PulseAudio and Opus plugins. With audio set to Off, the recorder does not open an audio device. For distribution package names, see the package lists.

The installer supplies Ferese's portal backend and selects it for screen sharing. Log into a new Ferese session after installation.

Streams negotiate their frame rate with the recording app, with a default of 30 fps and a ceiling of 60 fps. To set a different ceiling, give the portal process FERESE_CAPTURE_MAX_FPS with an integer from 1 to 240. This controls capture independently of the display refresh rate; for workspace capture, set the same ceiling in the compositor environment. It does not make an idle desktop generate frames.

On supported GPUs, Ferese renders directly into DMA-BUF buffers shared with PipeWire and waits for GPU completion before handing them to the recording app. If GPU buffers are unavailable, capture uses shared memory without the portal's intermediate frame copies. Both paths wait for source damage, while a resumed consumer receives an initial image even if the desktop has stayed unchanged. For troubleshooting, FERESE_CAPTURE_FORCE_SHM=1 selects shared memory; large or rapidly changing captures on this path still incur GPU readback costs.

Workspace capture resources

Workspace sources reuse the existing image-copy-capture and PipeWire transport. Each workspace/cursor view has one retained GPU image with independent damage history and render resources. At most one changed workspace is composed per event-loop dispatch, yielding to input and display deadlines between views. Matching consumers reuse its composition and keep separate output buffers. Surface commits invalidate only their owning workspace; layout samples are reused until geometry changes. Consumer demand alone does not invalidate the image.

Hidden applications receive paced frame callbacks only while their content contributes to an active capture. An unchanged source waits for damage. A paused consumer stops capture work without prematurely returning a buffer still owned by the compositor; its retained capture target is released after two idle seconds. Closing the last session releases its view immediately on event-loop cleanup. No workspace capture targets or recurring capture timers exist without sessions.

Persistent capture admission reserves up to 512 MiB of pixel storage across all sessions, accounting conservatively for eight consumer buffers, a composition target, a fallback transfer texture, and stride padding. Matching views can use less than the reservation. This is not a cap on total process RSS, driver bookkeeping, wallpaper storage, or the recording application's encoder. The existing per-image and session-count limits also apply. GPU fences remain asynchronous; slow consumers do not accumulate a queue of rendered frames.

Troubleshooting

• Confirm PipeWire and WirePlumber are running.
• Confirm XDG_CURRENT_DESKTOP includes Ferese.
• Check that FERESE_ENABLE_SCREENCOPY was not set to 0 before session startup.
• Check for portal overrides in ~/.config/xdg-desktop-portal/.

The installed preference is /usr/share/xdg-desktop-portal/ferese-portals.conf. Its ScreenCast entry should select Ferese:

[preferred]
default=gtk;
org.freedesktop.impl.portal.ScreenCast=ferese;

xdg-desktop-portal-ferese --sources lists displays on the current WAYLAND_DISPLAY without starting a stream. Nested previews do not replace the host desktop's portal environment. See Development for isolated sharing tests.