Struct Policy 

#[non_exhaustive]
pub struct Policy {
    pub headroom: f64,
    pub max: u64,
    pub min: u64,
    pub hysteresis: f64,
    pub ramp: f64,
}

How a bandwidth estimate maps onto the bitrate a sender should produce at.

Build one with Policy::new and override what you need. The defaults are tuned for a live contribution encoder on a cellular uplink: give back bandwidth immediately when the pipe closes, take it back slowly when it opens, and don’t twitch at every jitter in the estimate.

#[non_exhaustive]: construct via Policy::new and set fields, so new knobs stay additive.

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.

headroom: f64

Fraction of the estimate to target, reserving room for the other tracks sharing this connection (audio) and for transport overhead. Defaults to 0.9. Must be greater than 0; values above 1.0 target more than the link is estimated to carry and are clamped away.

max: u64

Upper bound in bits per second, normally the bitrate the caller asked for. The estimate can only ever take the target down from here: an optimistic estimate is not a reason to send more than was configured.

min: u64

Lower bound in bits per second. Below some rate the picture isn’t worth sending, so the target holds here and the transport’s priority queue sheds the excess instead. Defaults to a tenth of max.

hysteresis: f64

Ignore moves smaller than this fraction of the current target, so a jittering estimate doesn’t reconfigure the encoder every 100ms. Defaults to 0.05 (5%).

ramp: f64

How fast the target may climb back, as a fraction of the current target per second. Defaults to 0.25 (25%/s, so ~3s from the floor back to a 2x higher rate). Drops ignore this and apply at once: overshooting a closing uplink costs a stalled picture, while undershooting an opening one costs only a few seconds of lower quality.

Implementations

impl Policy

pub fn new(max: u64) -> Self

A policy targeting at most max bits per second, with the documented defaults for every other knob.

Trait Implementations

impl Clone for Policy

fn clone(&self) -> Policy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Policy

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

Formats the value using the given formatter.