Struct SwVideoCompositor 

pub struct SwVideoCompositor { /* private fields */ }

Composites the latest frames from any number of independent input pipelines into one fixed-rate opaque BGRA video stream.

Like crate::elements::AudioMixer, this is a SourceElement, not a conventional one-input filter: upstream pipelines terminate at the sinks returned by SwVideoCompositorHandle::add_source, while this element’s own pipeline drives output on its independent clock. Input frame PTS values therefore do not become output PTS; output advances by one tick in SwVideoCompositor::time_base for every composed frame.

Implementations

impl SwVideoCompositor

pub fn new( name: impl Into<String>, options: VideoCompositorOptions, ) -> Result<(Self, SwVideoCompositorHandle), SwVideoCompositorError>

Creates a compositor and a weak runtime handle for registering inputs.

pub fn format(&self) -> Pixel

Returns the fixed output pixel format, ffmpeg::format::Pixel::BGRA.

pub fn width(&self) -> u32

Returns the fixed output width in pixels.

pub fn height(&self) -> u32

Returns the fixed output height in pixels.

pub fn frame_rate(&self) -> Rational

The output frame rate, which is what construction was given unless SwVideoCompositorHandle::set_frame_rate has changed it since.

pub fn time_base(&self) -> Rational

The reciprocal of Self::frame_rate, used as output PTS units — and so a value that moves with it.

Trait Implementations

impl Element for SwVideoCompositor

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.

fn attach_context(&mut self, _context: &Arc<Context>)

Hands this element the pipeline it is being wired into, at the moment and for the reason Element::pp_log_mut hands it the pipeline’s identity: the clock, the playback clock and the bus are the pipeline’s to give, not the caller’s to choose.

impl Send for SwVideoCompositor

impl Source for SwVideoCompositor

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

Returns every output pad owned by this element.

impl SourceElement for SwVideoCompositor

fn is_live(&self) -> bool

Whether this source produces data from a live, externally advancing input rather than from a finite or application-controlled timeline.

fn is_seekable(&self) -> bool

Whether this source can reposition its own input timeline through Self::seek.

fn run(&mut self, control: &ControlReceiver, bus: &Bus) -> Result<()>

Drives this source until Eos (normal completion), crate::pipeline::Pipeline::finish, or Stop (see ControlMsg::Stop) — call crate::control::drain_control once per loop iteration to make control responsive between blocking reads.

fn seek(&mut self, _target: Duration) -> Result<Duration>

Repositions this source to target, an absolute position from the start of the media (e.g. av_seek_frame for crate::elements::FileDemuxer). Called by crate::control::drain_control as part of handling ControlMsg::Seek, before that message is forwarded to the source’s own pads — so whatever’s read next comes from the new position by the time downstream elements receive the new timeline announcement. Buffered and stateful old-timeline data is discarded by the preceding ControlMsg::Flush.

fn on_control(&mut self, _msg: &ControlMsg)

Reacts to one control message before it is forwarded to this source’s own pads — the same ordering Self::seek gets, and for the same reason: whatever this source holds must already reflect the message by the time downstream elements see it.