Struct SwScaler 

pub struct SwScaler { /* private fields */ }

Converts/resizes decoded video frames — pixel format (e.g. the YUV a decoder produces -> the RGB most inference models expect) and resolution (source resolution -> a model’s fixed input size) in one pass via libswscale. A Filter: receives via Sink, pushes the converted frame on through its own (single) src pad.

Typical placement: right before something with a fixed input contract, e.g. an ONNX object-detection model — not a general-purpose pipeline stage, so most chains won’t need one at all.

Implementations

impl SwScaler

pub fn new( name: impl Into<String>, dst_format: Pixel, dst_width: u32, dst_height: u32, flags: Flags, ) -> Self

dst_format/dst_width/dst_height describe what every output frame will be; the source side is learned automatically from whatever frames actually arrive (see context’s docs), so this doesn’t need decoder parameters up front the way crate::elements::SwDecoder::new does.

Trait Implementations

impl Element for SwScaler

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 SwScaler

impl Sink for SwScaler

fn input_contract(&self) -> InputContract

swscale reads the planes on the CPU, so a device texture is unreachable memory here rather than merely the wrong format.

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

Processes one buffer synchronously on the caller’s thread.

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.

fn ready_consume(&mut self) -> bool

Returns whether calling Self::consume can make progress now.

impl Source for SwScaler

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

Returns every output pad owned by this element.