Struct Config 

#[non_exhaustive]
pub struct Config {
    pub width: u32,
    pub height: u32,
    pub framerate: u32,
    pub bitrate: Option<u64>,
    pub gop: u32,
    pub codec: Codec,
    pub kind: Kind,
    pub color: Option<Color>,
}

Encoder configuration. width / height / framerate are the encoded output; input frames must already be at this resolution.

#[non_exhaustive]: build via Config::new and set the optional fields, so future knobs don’t break callers.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

width: u32

height: u32

framerate: u32

bitrate: Option<u64>

Target bitrate in bits per second. None derives a sane default from resolution and framerate (~0.07 bits per pixel per second).

gop: u32

Keyframe interval in frames. Subscribers joining mid-stream wait at most this many frames before they can start decoding.

codec: Codec

Output codec. Defaults to Codec::H264.

kind: Kind

color: Option<Color>

The color space of the input frames, written into the bitstream’s VUI so a decoder doesn’t have to guess. None uses Color::infer, which is both what the crate’s own RGB conversions produce and what a player falls back to, so leaving it unset keeps the pixels and the label in agreement.

Set it only when feeding frames the crate did not convert and whose space you know from elsewhere.

Implementations

impl Config

pub fn new(width: u32, height: u32, framerate: u32) -> Self

A config encoding width x height at framerate, with the default codec, GOP, and bitrate.

pub fn size(&self) -> Size

The encoded resolution.

pub async fn probe(&self) -> Result<VideoConfig, Error>

The catalog rendition an encoder for this config produces.

Resolved by opening a throwaway encoder and encoding one frame, so the profile, level, and constraints are the ones this machine writes into the bitstream rather than a guess. The backend picks all three itself (VideoToolbox asks for High, openh264 leaves it at Baseline, VAAPI writes Main) and its choice depends on the config it opened with, so reading them back is the only way to know.

This is what lets a track be advertised before it carries anything: a subscriber can only discover a track the catalog names, and an on-demand encoder only encodes once a subscriber arrives. Publishing the probed rendition breaks that cycle without publishing a claim that has to be corrected later, since it already says what the first keyframe will say.

Costs an encoder open and a single frame, so call it once per track. Call it before opening the encoder you will actually use, so the two never hold a codec session at once.

Errors

Fails when this machine cannot encode the config at all, which makes it a fail-fast check: better here than on the first frame of a track that is already advertised.

Trait Implementations

impl Clone for Config

fn clone(&self) -> Config

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Config

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.