Struct D3d11Download 

pub struct D3d11Download { /* private fields */ }

Available on Windows and crate feature d3d11 only.

Downloads GPU-resident Pixel::D3D11 BGRA video frames (e.g. from crate::elements::D3d11VideoCompositor) to CPU-resident Pixel::BGRA frames — the mirror of crate::elements::D3d11Upload. Needed because this crate’s video encoder (crate::elements::SwEncoder) is software-only and has no zero-copy GPU input path; chain a crate::elements::Scaler after this to convert to whatever pixel format an encoder actually needs.

Unlike D3d11Upload (a plain ID3D11Device::CreateTexture2D call, safe to issue from any thread), reading a texture back to the CPU needs ID3D11DeviceContext::CopySubresourceRegion/Map/Unmap — context-level calls, not device-level ones. context must be the exact same Arc<Mutex<ID3D11DeviceContext>> every other context-touching D3D11 consumer in this pipeline shares (e.g. render_common::D3d11GpuContext::context()) — see that type’s own docs on why a lone per-element context handle isn’t enough to prevent two unrelated bind/draw/copy sequences from interleaving on the one underlying immediate context.

Implementations

impl D3d11Download

pub fn new( name: impl Into<String>, device: &ID3D11Device, context: Arc<Mutex<ID3D11DeviceContext>>, width: u32, height: u32, ) -> Result<Self, D3d11DownloadError>

device must be the same ID3D11Device, and context the same shared context, every other D3D11 element in this pipeline uses — see this type’s own docs on why. width/height are fixed for this element’s lifetime; every frame consume receives must match exactly.

Trait Implementations

impl Element for D3d11Download

fn name(&self) -> Arc<str>

Returns a cheap clone (refcount bump, not a deep copy) of this element’s name — crate::bus::BusEvent stores names as Arc<str> for exactly this reason: a hot path like crate::queue::Queue posting BusEvent::Dropped once per overflowed buffer shouldn’t pay for a fresh heap allocation every time it wants to report which element it is.

fn element_type(&self) -> ElementType

See ElementType.

fn pp_log(&self) -> &PpLog

This element’s identity for crate::bus::Bus::post — same id/name as Element::name, just already wrapped as the crate::pp_log::PpLog its pp_info!/pp_warn!/pp_error! macros need. A stored private field, not built fresh per call, for the same reason name() returns a cheap Arc<str> clone instead of a fresh String — see its own docs.

fn pp_log_mut(&mut self) -> &mut PpLog

Mutable access to the same field Element::pp_log reads — used by crate::pipeline::ChainBuilder to stamp the owning crate::pipeline::Pipeline’s id onto every element that passes through it, via element_pp_log. Not meant to be called from anywhere else.

fn graph_id(&self) -> Option<ElementId>

A pre-reserved graph identity for elements that expose dynamic attachment handles. Most elements receive an ID from ChainBuilder and keep the default None implementation.

impl Send for D3d11Download

impl Sink for D3d11Download

fn consume(&mut self, buf: MediaBuffer) -> Result<()>

fn control(&mut self, msg: ControlMsg) -> Result<()>

Reacts to a ControlMsg (pause/resume/stop) and, for anything with a downstream of its own, forwards it on — same shape as consume, just a separate channel from MediaBuffer so it can reach every element (not just ones that already know how to interpret a data buffer) and, at a crate::queue::Queue, jump ahead of whatever data is backed up instead of waiting behind it. No default: every Sink has to consciously decide what this means for it, rather than silently dropping it.

impl Source for D3d11Download

fn src_pads(&mut self) -> &mut [SrcPad]