Struct SwAudioEncoder 

pub struct SwAudioEncoder { /* private fields */ }

Encodes Audio frames into Packets via a software encoder (see AudioCodec) — the audio sibling of crate::elements::SwEncoder. A Filter: receives via Sink, pushes what it produces into its own (single) src pad.

Unlike SwEncoder (which requires exactly Pixel::YUV420P in and errors on anything else), this resamples whatever it’s fed — building the resampler lazily from the first frame’s own format/channel_layout/rate, same pattern crate::elements::AudioMixer’s own InputBuffer::push uses — to whatever sample_rate/channels SwAudioEncoderOptions asked for, in whichever Sample::F32 layout (packed or planar) the opened codec actually reports (queried via the codec’s own capabilities, not assumed — aac’s native encoder wants planar, but nothing here hardcodes that). This is what lets a crate::elements::TestAudioSource/crate::elements::AudioMixer (both fixed Sample::F32(Packed)) feed this directly with no separate resampler element in between, the same way SwEncoder leaning on a fixed Pixel::YUV420P input still needs a crate::elements::SwScaler in front of it for anything else.

Most audio codecs (aac included) require a fixed number of samples per send_frame call (encoder.frame_size()) — not whatever size happened to arrive. Resampled samples are buffered per-channel (pending) and only handed to the encoder once a full frame_size-sample chunk is ready; a codec that reports frame_size == 0 (accepts any size) skips the buffering and encodes each resampled chunk as-is. Eos flushes both the resampler’s own internal delay line (a few samples of filter latency — see ffmpeg::software::resampling::Context::flush) and whatever’s left in pending (as one final, possibly short, frame — allowed for the last frame only) before flushing the encoder itself.

Implementations

impl SwAudioEncoder

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

Opens the requested audio encoder and configures its output definition.

pub fn parameters(&self) -> Parameters

This encoder’s own codec parameters — what a crate::elements::FileMuxer track needs, same pattern crate::elements::SwEncoder::parameters documents for video.

pub fn time_base(&self) -> Rational

The unit each produced packet’s pts is expressed in.

Trait Implementations

impl Element for SwAudioEncoder

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 SwAudioEncoder

impl Sink for SwAudioEncoder

fn input_contract(&self) -> InputContract

The audio mirror of SwEncoder: decoded samples in, encoded packets out.

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 SwAudioEncoder

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

Returns every output pad owned by this element.