Struct WlFrame 

pub struct WlFrame<B = Vec<u8>> {
    pub(crate) id: usize,
    pub(crate) buf: B,
    pub(crate) source: Option<Dmabuf>,
    pub(crate) scanout: bool,
    pub(crate) shm: Option<Buffer>,
    pub(crate) frame_id: u16,
    pub(crate) damage: Vec<Rectangle<i32, Physical>>,
    pub(crate) is_animated: bool,
    pub(crate) captured_ns: i64,
}

One captured frame in flight from the calloop (render/readback) to the Wayland encode thread: the slot’s buffer (a readback’s packed rows, or the zero-copy session’s GPU target) plus the per-frame inputs of the encode dispatch (damage, overlay animation); the IDR request travels separately via the controls atomic.

Fields

id: usize

Pool slot id; travels with the buffer so recycle returns it to the right slot.

buf: B

source: Option<Dmabuf>

Zero-copy: a buffer encoded in place of the slot’s own, the host frame the host compositor blitted into or a client’s own buffer (scanout); the slot’s buffer then only holds the place in flight.

scanout: bool

source is a client’s buffer encoded as it stands (scanout_candidate): the encode thread waits out the client’s GPU work on it first, and a session that cannot import it refuses the direct path for the capture rather than failing the session.

shm: Option<Buffer>

Readback: a client’s shm buffer whose rows are encoded in place of the slot’s (scanout_shm), read inside its pool’s mapping on the encode thread; the slot’s buffer then only holds the place in flight.

frame_id: u16

damage: Vec<Rectangle<i32, Physical>>

is_animated: bool

captured_ns: i64

CLOCK_MONOTONIC nanoseconds at which the pixels were in hand.